Pathology

Clinical focus: Documentation of wounds and injuries is a clinical, communication and medico-legal skill. A good record allows another clinician to understand what happened, reproduce your examination, continue treatment and assess evidence without guessing. Record observations separately from history and opinion, use precise measurements, preserve originals and state limitations honestly. Learning objectives Write a contemporaneous, objective, complete wound record using a reproducible structure. Describe location, size, shape, orientation, margins, tissue, contamination, function and neurovascular findings precisely. Use body diagrams, photographs, imaging and specimen logs safely and lawfully. Distinguish fact, patient report, interpretation and expert opinion. Document consent, refusals, safeguarding, chain of custody, treatment and follow-up. 1. The principles of defensible documentation Principle Meaning in practice Contemporaneous Record as soon as possible; include date/time and who was present. If delayed, state when and why. Accurate Measure and describe what is seen or reliably reported; do not guess depth, age, weapon or intent. Complete Include relevant positive and negative findings, treatment, consent, investigations, referrals and follow-up. Objective Use neutral language and separate the patient’s account from examination findings and interpretation. Legible/secure Use approved forms, secure electronic records, clear units and controlled access. Transparent Correct errors with a dated, signed amendment; never erase, backdate or silently overwrite. Reproducible Another clinician should be able to locate the injury, repeat measurements and understand change over time. 2. The four-layer note History: what the patient or witness says, ideally in quotation marks for key phrases. Label the source and avoid leading questions. Examination: your observed findings, measurements, vital signs, function and relevant normal findings. Interpretation: clinical reasoning, differential diagnosis and limitations, clearly identified as opinion. Plan: treatment, investigations, consultation, safeguarding, evidence handling, discharge advice and follow-up. Example: History: “I was cut by a knife during an argument.” Examination: “2.5-cm linear wound, left volar forearm, 4 cm proximal to wrist crease; brisk venous ooze; reduced sensation in ulnar distribution; radial pulse palpable.” Interpretation: “Possible sharp-force injury with suspected ulnar-nerve involvement; urgent hand review.” 3. Patient and encounter identifiers Full name, date of birth/age, hospital number, sex/gender as relevant, address/contact and emergency contact according to policy. Date, exact time and place of examination; referral source; arrival mode; accompanying persons. Examiner name, designation, registration/department, chaperone and interpreter details. Consent for examination, photographs, specimens, record release and police/safeguarding referral; document refusals and capacity assessment. Allergies, medicines (especially anticoagulants), immunisation/tetanus status, pregnancy possibility and relevant comorbidity. 4. History documentation Mechanism and timeline Record the patient’s account using their words, then clarify only what affects care: date/time, location, object or surface, direction, force, number of impacts, bleeding, loss of consciousness, first aid, washing/changes of clothing, contamination, animal/human bite, chemical/electrical exposure and symptoms since injury. Symptoms and function Document pain score and character, bleeding, swelling, numbness, weakness, reduced range of motion, foreign-body sensation, fever, breathing/swallowing difficulty, urinary/bowel symptoms and mental-health distress. Reliability and limitations Record the source, interpreter use, language, memory gaps, intoxication, sedation, cognitive impairment or contradictory information neutrally. Do not label a patient “unreliable” because their trauma memory is fragmented; state the specific limitation. 5. Wound-description template Field What to record Example Number/label Number wounds and use the same labels in text, diagram and photograph. “Injury 1” and “Injury 2.” Site/side Region, side and fixed anatomical landmarks; record body position. “Right lateral thigh, 8 cm above the knee joint line.” Size Length × width × visible depth in mm/cm; state whether wound is open or measured after approximation. “3.0 × 0.8 cm; depth not probed due to possible tendon injury.” Shape/orientation Linear, curved, stellate, irregular, patterned; transverse/oblique/longitudinal. “Curved, oblique, long axis inferomedial.” Margins/ends Sharp/blunt, abraded, contused, everted/inverted, tissue bridges, tails or angles. “Irregular contused margins with tissue bridges.” Base/depth Skin/subcutis/fat/fascia/muscle/tendon/nerve/vessel/bone visible; foreign material. “Subcutaneous fat visible; no exposed tendon; foreign body not seen.” Colour/associated change Redness, bruising, swelling, blister, eschar, discharge, necrosis; measure surrounding erythema. “2-cm surrounding ecchymosis; no pus or cellulitis.” Bleeding Active arterial/venous/oozing, haemostasis method and response. “Oozing stopped after 5 minutes direct pressure.” Pain/function Tenderness, movement, strength, sensation, pulses and capillary refill. “Finger extension limited by pain; sensation and radial pulse intact.” Photograph/diagram File/figure number, scale, orientation and consent. “Photo 1A overall, 1B close-up with scale.” 6. Documenting specific injuries Abrasions Record superficial versus deep abrasion, site, dimensions, direction/pattern, crust, embedded debris and tenderness. Describe road rash or patterned impressions without claiming a unique surface unless compared by a qualified forensic examiner. Contusions and haematomas Measure maximum dimensions, site, shape, colour and swelling. State that bruise colour cannot reliably establish exact age. Record anticoagulants, bleeding disorders, skin tone, platelet abnormalities and alternative causes where clinically relevant. Lacerations Record irregular/contused margins, tissue bridges, depth, contamination, devitalised tissue and underlying structure function. Do not call every irregular wound “blunt force” without considering surgical wounds, animal bites and other causes. Sharp, puncture and firearm wounds Number entry/exit wounds, record dimensions, shape, margins, soot/stippling/foreign material where relevant and possible trajectory only as a cautious interpretation. Do not probe a deep wound or infer a specific weapon from a single wound. Burns Record agent if known, depth, total body surface area method, location, circumferential involvement, airway signs, ocular injury, pain/sensation and associated trauma. Photograph with consent and preserve clothing/evidence according to protocol. Bites Record human/animal source if known, site, dimensions, tooth/pressure pattern, bruising, puncture, tissue loss, contamination, neurovascular/tendon/joint function, tetanus and rabies risk. The appearance alone rarely identifies an individual. 7. Neurovascular and functional documentation Write the actual findings, not “NVI” alone. Include time and comparison side. Vascular: colour, temperature, capillary refill in seconds, pulses (named and graded), Doppler, bleeding and perfusion. Motor: each relevant tendon/nerve action, strength grade, active/passive range and pain limitation. Sensory: light touch/two-point discrimination or named nerve territory; map numbness. Compartment: pain at rest/passive stretch, firmness, swelling, paresthesia and weakness; record serial examinations. Post-intervention: repeat after anaesthetic, reduction, splint, dressing, tourniquet or closure and document who was informed. 8. Body diagrams and injury mapping Use a standard front/back/anatomical diagram. Mark the same injury number as the text and photograph. Include orientation (patient’s right/left, anterior/posterior), measurements, arrows or legend,

Clinical focus: Examination of wounds and injuries must be systematic, gentle and reproducible. Stabilise life threats first, obtain consent, expose enough to identify hidden injury, examine function and neurovascular status, use imaging selectively, and document both positive and relevant negative findings. The examination describes facts; it does not decide guilt, intent or legal responsibility. Learning objectives Perform an ABCDE-informed primary and secondary survey in an injured patient. Examine skin, soft tissue, bones, joints, tendons, nerves, vessels and body cavities according to mechanism. Identify red flags for occult haemorrhage, compartment syndrome, open fracture, tendon/nerve injury, vascular injury and infection. Choose appropriate bedside tests and imaging, including when a normal examination is not reassuring. Use trauma-informed consent, chaperones, safeguarding and forensic documentation principles. 1. Before touching the patient Ensure scene and staff safety; use gloves, eye protection and sharps precautions. Introduce yourself, confirm identity, explain the purpose and likely discomfort, and obtain consent for examination, photographs, chaperone and specimens separately. Provide privacy, warmth and a chaperone according to patient preference and policy. Use a trained interpreter rather than a family member when possible. Look at the mechanism, time, first aid, contamination, anticoagulants, bleeding disorders, diabetes, immunosuppression, pregnancy and tetanus history. Control catastrophic bleeding and perform ABCDE before detailed wound inspection. 2. Primary survey: ABCDE Domain Examination Red flags Airway/cervical spine Talk to the patient, inspect mouth/face/neck, listen for voice change/stridor, palpate gently and protect the spine when indicated. Obstruction, expanding haematoma, hoarseness, dysphagia, neck penetrating injury or facial burns. Breathing Respiratory rate/effort, oxygen saturation, chest expansion, percussion, breath sounds and open wounds. Severe distress, absent breath sounds, tracheal deviation, sucking chest wound, cyanosis or shock. Circulation External bleeding, pulse/skin/mental status, capillary refill, blood pressure, pelvis and long bones; obtain IV/IO access as needed. Uncontrolled haemorrhage, weak/absent pulses, cool clammy skin, altered mental state or disproportionate tachycardia. Disability GCS/AVPU, pupils, glucose, focal neurology, spinal tenderness and limb motor/sensory function. GCS decline, seizure, unequal pupils, focal deficit or new paralysis. Exposure Undress systematically, inspect front/back/perineum and protect from hypothermia. Missed wounds, pressure injury, hidden bleeding or unsafe environment. 3. Secondary survey and SAMPLE history Once immediate threats are treated, repeat vital signs and complete a head-to-toe examination. Use SAMPLE: Symptoms, Allergies, Medicines (including anticoagulants), Past history/pregnancy, Last meal/menstrual period, Events/environment/mechanism. Ask about pain location, severity, movement limitation, numbness, weakness, bleeding, foreign-body sensation and loss of consciousness. Clarify the object or surface, force, direction, distance, protective clothing, chemical/electrical source, animal/human bite and time since injury. Ask what the patient did after injury (washing, pressure, medication, removal of an object) and record it without blame. Assess psychosocial safety, violence, self-harm and safeguarding when the mechanism or history suggests assault, neglect or abuse. 4. Systematic local wound examination Element How to examine and document Site Use anatomical landmarks, side, body region and distance from fixed points; avoid vague terms such as “near the arm.” Number Count and number wounds; examine surrounding skin and hidden surfaces. Size Measure length, width and visible depth in millimetres/centimetres; do not force a probe into a puncture. Shape/orientation Describe linear, curved, stellate, irregular, patterned, transverse/longitudinal and relation to skin tension lines. Margins/base Clean, ragged, abraded, inverted/everted, tissue bridges, devitalised tissue, fat/tendon/bone exposure and foreign material. Colour/appearance Redness, bruising, swelling, blister, eschar, discharge, granulation or necrosis; colour alone cannot date a bruise. Bleeding Active venous/arterial bleeding, oozing, haematoma, pulsatility and haemostasis after pressure. Tenderness/function Pain, sensation, movement, strength, range of motion and function before local anaesthetic when safe. Associated findings Fracture, dislocation, compartment signs, vascular deficit, infection, foreign body or cavity penetration. 5. Neurovascular examination Document before and after manipulation, anaesthesia, splinting or closure. Compare with the uninjured side when appropriate. Vascular: colour, temperature, capillary refill, pulses proximal/distal to injury, Doppler signal, active bleeding and signs of ischaemia. Motor: test each relevant tendon and nerve against resistance; record power and pain limitation separately. Sensory: light touch and two-point discrimination in named nerve territories; map numbness rather than writing “normal sensation.” Compartment: pain out of proportion, pain on passive stretch, tense swelling, paraesthesia, weakness and late pulselessness. Pulses may remain present. Region Useful function checks Hand/wrist Finger flexion/extension, thumb opposition/abduction, wrist movement, radial/ulnar pulses, median/ulnar/radial sensory territories. Forearm/elbow Wrist/finger tendons, pronation/supination, elbow range, pulses and compartment signs. Lower limb Toe/ankle movement, knee/hip function, dorsalis pedis/posterior tibial pulses, peroneal/tibial sensation and compartment signs. Neck Airway/voice/swallowing, neurological exam, expanding haematoma, pulses and penetrating trajectory; avoid blind probing. 6. Regional examination priorities Head and face Inspect scalp, ears, nose, mouth, teeth, eyes, facial symmetry and cranial nerves. Look for skull depression, CSF/blood from ear/nose, malocclusion, orbital injury, dental fracture and facial nerve deficit. Do not press on a suspected open globe; use a rigid shield and urgent ophthalmology. Neck and strangulation Ask about loss of consciousness, voice change, breathing/swallowing difficulty, neck pain, incontinence and neurological symptoms. Inspect petechiae, ligature marks, bruising and swelling, but absence of marks is not reassuring. Consider delayed airway/vascular injury and urgent imaging/ENT/vascular review. Chest and back Inspect all surfaces, palpate ribs/sternum/spine, assess expansion and breath sounds, and look for penetrating wounds. A small wound can conceal pneumothorax, haemothorax, cardiac or great-vessel injury. Abdomen and pelvis Inspect, auscultate as appropriate, palpate gently for tenderness/guarding/rigidity and assess pelvic stability only once. Check flank/perineum, urinary blood, pregnancy possibility and genital injury. Do not repeatedly rock an unstable pelvis. Limbs and joints Inspect alignment, swelling, open wounds and deformity. Palpate bone and compartments, test active/passive movement, tendon function, sensation and distal circulation. Examine the entire limb, not only the obvious wound. Genital/anal examination Use trauma-informed consent, a chaperone, appropriate lighting and a trained examiner. Document injuries, discharge, bleeding and normal findings. Avoid speculum or digital examination when contraindicated or not consented; children require specialist pathways. 7. Bedside tests and imaging Test When useful Limitations Plain radiograph Fracture, dislocation, radiopaque foreign body, gas or chest injury. May miss radiolucent wood/plastic, tendon injury or early occult fracture. Ultrasound/POCUS Free fluid, pneumothorax, vascular flow, tendon, abscess or retained superficial foreign body. Operator dependent; a negative scan does not

Clinical focus: Wounds and injuries range from superficial abrasions to life-threatening haemorrhage, airway injury, open fractures and penetrating trauma. Assess the patient before the wound, control bleeding before irrigation, preserve function and evidence, and use local surgical, tetanus and antibiotic protocols. Learning objectives Define and classify wounds by mechanism, depth, contamination, timing and tissue involvement. Recognise life threats and perform a structured trauma assessment. Describe abrasions, contusions, lacerations, incised, puncture, bite, avulsion, crush, burn and firearm injuries. Apply haemorrhage control, irrigation, debridement, closure, analgesia, tetanus, antibiotic and referral principles. Recognise complications and medico-legal evidence requirements. 1. Definitions and classification A wound is a disruption of tissue continuity caused by mechanical, thermal, chemical, electrical or biological energy. An injury is broader and includes internal damage without a skin break, such as a closed head injury or organ contusion. Classification Categories Why it matters Skin integrity Closed (bruise, haematoma, crush) or open (abrasion, laceration, cut, puncture) Open wounds allow contamination and may need closure/tetanus assessment. Mechanism Blunt, sharp, penetrating, firearm, bite, thermal, chemical, electrical Predicts hidden damage, contamination and specialist needs. Depth Superficial, partial-thickness, full-thickness, tendon/nerve/vessel/bone/cavity involvement Determines functional assessment, imaging and operative referral. Contamination Clean, clean-contaminated, contaminated, dirty/infected Guides irrigation, debridement, closure timing and antibiotic decisions. Time Acute, delayed, chronic or infected Influences closure and infection risk; do not use an arbitrary “golden period” alone. Forensic description Antemortem, perimortem or post-mortem; self-inflicted, accidental or inflicted (only with adequate evidence) Use neutral language; medical findings do not determine intent or guilt. 2. First priority: find life threats Use a structured trauma approach (ABCDE) and treat while assessing. A dramatic skin wound must never distract from airway obstruction, tension pneumothorax, internal haemorrhage, spinal injury or shock. A – Airway with cervical-spine protection: look for facial/neck wounds, swelling, blood, burns, hoarseness, stridor, dysphagia or expanding haematoma. B – Breathing: expose the chest; assess respiratory effort, oxygen saturation, breath sounds and penetrating chest wounds. Seal an open chest wound and treat tension physiology urgently. C – Circulation/haemorrhage: direct pressure, wound packing, tourniquet for life-threatening limb bleeding, two IV/IO lines, blood products and shock management. D – Disability: GCS, pupils, glucose, lateralising signs, spinal pain and limb neurovascular status. E – Exposure/environment: fully inspect for additional injuries, prevent hypothermia and preserve clothing/evidence. Call for help immediately: uncontrolled bleeding, shock, penetrating torso/neck injury, open fracture, tendon/nerve/vessel injury, compartment syndrome, eye injury, genital injury, extensive burns, severe bite or suspected child abuse. 3. Wound types and their forensic/clinical features Type Definition and appearance High-risk concerns Abrasion/graze Superficial epidermal loss from friction, scraping or pressure; may show direction or pattern. Embedded gravel, infection, road rash, ocular involvement; clean thoroughly and document pattern. Contusion/bruise Blunt-force bleeding into tissue with intact skin; may be tender or swollen. Internal injury, anticoagulants, bleeding disorder; colour cannot accurately date a bruise. Haematoma Local collection of blood; may be subcutaneous, intramuscular or internal. Expanding neck/retroperitoneal haematoma, compartment syndrome or shock. Laceration Blunt tearing with irregular/abraded margins and tissue bridges. Deep structure damage, foreign body and vascular bleeding. Incised wound Sharp-edge injury longer on the surface than in depth, usually clean margins. Exsanguination, tendon/nerve/vessel injury and forensic comparison. Stab/puncture Pointed object penetrates; depth may exceed surface length. Hidden chest/abdomen/vascular injury, retained foreign body and tetanus. Avulsion/degloving Skin/tissue partially or completely separated from underlying structures. Ischaemia, contamination, tissue loss and need for reconstructive surgery. Crush Compression damages skin, muscle, vessels and nerves. Compartment syndrome, rhabdomyolysis, hyperkalaemia, renal failure and crush shock. Bite Human or animal puncture, crush or avulsion with saliva/microbial inoculation. Polymicrobial infection, tendon/joint involvement, rabies and tetanus. Burn Thermal, chemical, electrical or radiation tissue injury. Airway injury, shock, circumferential compromise, ocular/chemical damage and sepsis. Firearm/blast Projectile or explosive energy causes entry/exit, cavitation, fragments and burns. Internal bleeding, retained fragments, contamination and multiple casualties. 4. Bleeding control Apply firm direct pressure with gauze or a clean dressing. Do not repeatedly lift the dressing to check; add layers if soaked. Pack deep junctional wounds (groin, axilla, neck where appropriate) with haemostatic gauze if trained; maintain pressure for the recommended time. Apply a commercial tourniquet above a life-threatening limb wound when direct pressure fails or the scene is unsafe. Note application time; do not loosen intermittently. For suspected pelvic or internal bleeding, minimise movement, keep warm, obtain large-bore IV/IO access, activate major haemorrhage protocol and arrange urgent surgery/interventional care. Assess distal pulses, capillary refill, sensation and motor function before and after compression or splinting. 5. Focused wound assessment Question What to assess When and how? Time, mechanism, force, object, contamination, first aid, bite/saliva, chemical/electrical exposure and tetanus status. Where and how deep? Location, length/width/depth, tissue layers, cavities, exposed tendon/bone, foreign bodies and tissue viability. What function is threatened? Active/passive range of motion, tendon integrity, sensation, motor power, pulses, perfusion and compartment signs. What systemic risks exist? Shock, anticoagulants, diabetes, immunosuppression, renal disease, bleeding disorder, pregnancy and allergies. What does imaging show? Radiopaque foreign body, fracture, joint penetration, gas, chest/abdomen injury; ultrasound/CT according to site and stability. 6. Cleaning, irrigation and debridement Obtain haemostasis before irrigation. Use analgesia and local anaesthetic as needed. Irrigate with generous volumes of potable water or sterile saline using a syringe/appropriate pressure; remove visible debris and devitalised tissue while preserving viable structures. Do not blindly probe a deep puncture or force fluid/foreign material deeper. Suspected retained foreign body, tendon/nerve/vessel injury, joint penetration, eye injury or deep cavity wound requires specialist exploration. Clean the surrounding skin and move from least contaminated to most contaminated areas. Remove rings, bracelets and constricting items before swelling develops. Elevate and immobilise when appropriate; avoid hydrogen peroxide or strong antiseptics in deep tissue because they can injure viable cells. After irrigation, re-examine depth, function and haemostasis before deciding closure. 7. Closure and healing decisions Option When considered Limitations Primary closure (suture, staple, adhesive, strip) Clean, viable, adequately irrigated wounds with controlled contamination and low tension. May trap bacteria in dirty, crushed, puncture or bite wounds. Delayed primary closure Contaminated wounds observed after cleaning/debridement when infection is not developing. Requires

Emergency focus: Management of a rape survivor is urgent, comprehensive and survivor-led. Stabilise life-threatening injury first, then offer confidential first-line support, examination, pregnancy/STI/HIV prevention, mental-health care, safeguarding, forensic options and follow-up. Drug doses below are educational adult examples; follow the current Uganda Ministry of Health protocol, product labels and specialist advice for children, pregnancy, renal disease, drug interactions and allergies. Learning objectives Provide safe, trauma-informed first-line support and obtain informed consent. Perform emergency triage, examination, injury care and safeguarding assessment. Offer emergency contraception, HIV PEP, STI prophylaxis, hepatitis B/HPV prevention and tetanus when indicated. Collect forensic evidence without delaying treatment and document findings objectively. Plan mental-health support, safety, follow-up testing and referrals for adults, children and people lacking capacity. 1. The first minutes: safety, dignity and stabilisation Private welcome: move the survivor away from the alleged perpetrator, provide a chaperone/interpreter if wanted, and ask how they prefer to be addressed. ABC and danger: airway/neck injury or strangulation, breathing, circulation/bleeding/shock, head injury, poisoning, severe pain, burns, fractures and altered consciousness. Immediate psychological safety: Listen, Inquire, Validate, Enhance safety and Support (LIVES). Do not demand a detailed narrative before treating a critical injury. Consent: explain each step—treatment, examination, photographs, samples, police contact and record release. Consent is ongoing and may be withdrawn. Safeguarding: assess danger from a partner, weapon access, stalking, children/dependants, trafficking, child abuse and suicide/self-harm. Red flags requiring urgent senior/critical-care input: stridor, voice change or dysphagia after strangulation; respiratory distress; uncontrolled bleeding; shock; reduced consciousness; repeated vomiting or focal neurological signs; suspected intracranial, chest or abdominal injury; severe intoxication/poisoning; suicidal intent; or a child in immediate danger. 2. History and examination Trauma-informed history Start with open questions and record the survivor’s words. Clarify time, location, acts, penetration sites, ejaculation, barrier use, injuries, bleeding, pain, washing/urination/clothing change, food/drink, substances, threats, weapons, loss of consciousness, last menstrual period, contraception, pregnancy possibility, allergies, medicines, HIV/HBV status and relevant medical conditions. Avoid “why” questions, blame, repeated retelling and assumptions about consent. Examination Record vital signs, mental status, pain score, hydration, weight when medication dosing requires it and pregnancy status where relevant. Inspect the whole body and document injuries with site, side, dimensions, shape, colour, tenderness, swelling, discharge, function and associated findings. Assess scalp, face, mouth, neck and neurological status carefully after strangulation or head injury. Delayed airway and vascular complications can occur even with minimal external marks. Examine genital, anal or oral sites only with informed consent and a chaperone; stop when requested. A normal examination does not exclude assault. Offer photographs and forensic specimens separately from treatment. Use the local kit and chain-of-custody procedure; never delay emergency care. 3. Immediate injury care Problem Immediate actions Escalation External bleeding Direct pressure, wound cleaning, haemostasis, tetanus assessment and analgesia. Large/deep wound, shock, suspected vascular injury or uncontrolled bleeding—surgery/trauma team. Head injury GCS, pupils, glucose, cervical-spine precautions and serial observations. Loss of consciousness, seizure, focal signs, anticoagulants or repeated vomiting—urgent imaging/transfer. Strangulation Airway and voice assessment, oxygen as indicated, neurological examination, observe for delayed swelling. Any breathing/voice/swallowing change, neck tenderness, petechiae, syncope or focal deficit—emergency airway/ENT/vascular assessment. Fracture/dislocation Immobilise, analgesia, neurovascular check before/after splinting. Open fracture, neurovascular compromise or compartment syndrome—urgent orthopaedic care. Burn/chemical exposure Remove contaminated clothing, irrigate chemical exposure, analgesia and fluid assessment. Airway, extensive/deep burns, genital/ocular burns or toxic ingestion—burns/poisoning specialist. Abdominal/chest pain Vital signs, pregnancy test where relevant, focused examination, analgesia and imaging. Peritonism, respiratory compromise, internal bleeding or pregnancy complication—urgent surgical/obstetric review. 4. Laboratory and baseline assessment Tests are guided by exposure, symptoms, consent and local protocol. They should not delay time-critical prophylaxis. Urine or serum pregnancy test before teratogenic medicines or when pregnancy is possible; a negative early test does not exclude very recent conception. Baseline HIV test using the national algorithm, with consent and post-test counselling; a baseline negative test does not rule out infection from the current exposure. Hepatitis B surface antigen/antibody when available; do not delay vaccine when indicated. Syphilis, gonorrhoea, chlamydia, trichomonas and other tests according to local capacity; collect diagnostic specimens before empiric therapy when this does not delay care. Full blood count, renal/liver tests, glucose, blood group/cross-match, toxicology or imaging when injury, poisoning, bleeding or treatment risk warrants. 5. HIV post-exposure prophylaxis (PEP) Offer PEP after a substantial exposure when the survivor presents as soon as possible, ideally immediately and within 72 hours. It is generally not recommended after 72 hours for sexual exposure in WHO emergency protocols, but the survivor still needs HIV testing, counselling, prevention and specialist advice. Do not wait for the alleged source’s HIV result when this would delay starting PEP. Example adult regimen used in many programmes Medicine Example dose Duration/notes Tenofovir disoproxil fumarate (TDF) 300 mg orally once daily Part of a three-drug regimen; assess renal disease and HBV. Lamivudine (3TC) or emtricitabine (FTC) 3TC 300 mg once daily or FTC 200 mg once daily Use the locally supplied fixed-dose combination where available. Dolutegravir (DTG) 50 mg orally once daily Check interactions (especially polyvalent cations, rifampicin and enzyme inducers) and current pregnancy guidance. Continue for 28 days unless a specialist changes the plan. If renal function, pregnancy, breastfeeding, hepatitis B, age/weight or drug interactions are complex, contact the HIV clinician urgently. Provide adherence counselling, side-effect advice, condoms where desired, and a safe method for follow-up. PEP is not a substitute for emergency contraception or STI care. 6. Pregnancy prevention Offer emergency contraception (EC) as soon as possible after exposure, with shared decision-making and a pregnancy test when appropriate. It does not interrupt an established pregnancy. Option Example dose/timing Key cautions Levonorgestrel 1.5 mg orally once, as soon as possible and within 120 hours (5 days) Effectiveness decreases with time and may be reduced by enzyme-inducing drugs or higher body weight; follow local guidance. Ulipristal acetate 30 mg orally once, within 120 hours Hormonal contraception may reduce its effect; follow product instructions and specialist advice. Copper intrauterine device Insertion by a trained provider within 5 days where eligible Highly effective; assess pregnancy, infection, uterine injury and consent. Vomiting

Clinical focus: Medical evidence in Sexual and Gender-Based Violence (SGBV) is collected during compassionate clinical care—not as an interrogation. Evidence can support health decisions and legal processes, but no single finding proves or disproves assault, consent or identity. Follow current Ugandan Ministry of Health, police, child-protection and laboratory procedures for kits, reporting and retention. Learning objectives Explain the purpose, limits and consent requirements of medical-forensic evidence. Take a focused, trauma-informed history and conduct a complete, respectful examination. Collect, label, package, store and transfer biological and non-biological evidence correctly. Document injuries and normal findings objectively with diagrams, photographs and measurements. Interpret DNA, semen, blood, toxicology and injury findings without overstating their significance. Protect the survivor’s health, privacy, safety and choices throughout the process. 1. What medical evidence can and cannot answer Medical evidence may help to It generally cannot determine on its own Identify injuries, infection, pregnancy or urgent medical needs. Whether a person is truthful, whether a crime occurred, or who is legally guilty. Document the survivor’s account and the condition of the body at examination. Consent from the absence or presence of injury. Recover biological material or foreign material for validated laboratory testing. The exact time of an assault from a bruise, semen or DNA result alone. Provide an expert opinion about compatibility of findings with a described event. That a “negative” sample excludes assault, especially after delay, washing, condom use or non-penetrative contact. Guide treatment, follow-up, safeguarding and referrals. That detection of a drug proves incapacitation or perpetration without dose, timing and context. Interpretive language: Record “finding present,” “finding absent,” “consistent with,” “compatible with,” and limitations. Avoid “proof,” “definitely,” “rape confirmed,” or “no assault” unless a specific legal authority—not the clinical record—requires such wording. 2. Consent and patient-centred preparation Consent for treatment, forensic examination, photographs, specimen collection, release of records and police contact should be explained separately. Consent must be voluntary, informed, specific and ongoing. A survivor may accept some parts and decline others without losing care. Ensure privacy, a chaperone chosen with the survivor, an interpreter who is not involved in the case, and a safe way to communicate. Explain the purpose of the examination, what it may involve, possible discomfort, storage and possible release of evidence, and alternatives. Ask the survivor to tell you when to pause. Offer breaks, clothing, blankets, water, pain relief and support. For children and adults lacking capacity, follow Ugandan law and safeguarding policy regarding assent, legally authorised permission and mandatory reporting. Document consent, refusals, pauses, who was present, the information provided and any limits. Emergency exception: Life-saving care should not wait for forensic consent. Treat airway injury, bleeding, poisoning, shock, head injury, strangulation or suicide risk immediately, then revisit evidence options when the patient is stable. 3. Before evidence collection: history and contamination control Focused history Use open questions first and record the survivor’s words. Clarify the time, location, acts, sites of contact, use of barrier protection, ejaculation, bleeding, pain, urination, washing, changing clothes, eating/drinking, oral or anal exposure, loss of consciousness, drugs/alcohol, threats, weapons and previous consensual intercourse. Explain that these questions guide medical care and sample selection; they are not a test of credibility. Contamination control Use clean gloves and change them between body areas or specimens. Avoid touching swabs or the inside of containers. Use sterile, individually packaged equipment and a clean examination surface. Keep known reference samples separate. Collect clothing and debris in paper bags when dry; do not seal wet biological material in plastic. Air-dry according to protocol. Do not wash, brush, cut hair or remove foreign material before sampling unless clinically necessary; if the patient already did so, document it without blame. Use a new instrument for each swab/site. Label at collection, not later. 4. General medical assessment Stabilisation: ABC, vital signs, glucose where indicated, mental status, pain, bleeding, pregnancy possibility, head/neck injury and strangulation red flags. Whole-body examination: inspect scalp, face, mouth, neck, torso, limbs, hands, genital and anal areas as indicated by history and consent. Injury description: site, side, anatomical landmark, size, shape, colour, orientation, edge, base, tenderness, swelling, discharge, healing and associated findings. Normal findings: document relevant normal skin, oral, genital or anal findings; a normal examination is common and does not exclude violence. Clinical tests: pregnancy test, HIV/STI tests, urinalysis, imaging, blood count, renal/liver tests and toxicology according to exposure, symptoms and local protocol. 5. Evidence categories Category Examples Collection/interpretation notes Biological Blood, saliva, semen, epithelial cells, hair, urine, vaginal/anal/oral swabs Collect targeted samples promptly; dry/package correctly; DNA presence does not establish timing, consent or identity without comparison and statistics. Non-biological trace Fibres, soil, glass, paint, vegetation, lubricants, condoms, foreign material Use clean instruments and separate packaging; avoid transferring scene material. Clothing and personal items Underwear, sanitary products, bedding, condoms, torn clothing Package each item separately in paper; record who supplied it and whether it was washed. Injury evidence Photographs, diagrams, measurements, imaging, swabs from wounds Describe, do not label an object or weapon without comparative examination. Toxicology Blood, urine, hair or vomitus for alcohol/drugs Timing, specimen type, preservatives and chain of custody are critical; a negative result does not exclude drug-facilitated assault. Digital/contextual Messages, images, location data, call logs Do not seize or alter devices outside authority; preserve metadata through trained investigators. 6. Specimen selection and collection Use the current local sexual-assault evidence kit and laboratory instructions. The following framework helps students understand why each sample is considered; it is not a substitute for the kit’s validated swab sites or time windows. History/examination Potential specimen Important limitation Oral contact or ejaculation Oral swabs, oral rinse where protocol allows Short persistence; eating, drinking and brushing reduce recovery. Vaginal/cervical contact External, vaginal and/or cervical swabs according to protocol Normal flora and consensual intercourse can contribute DNA; interpret with history and reference samples. Anal contact Perianal/anal swabs and injury documentation when indicated Stool contamination and delayed presentation affect yield. Skin, bite or lick Swab before cleaning; photograph injury Touch DNA is easily transferred and may be low quantity. Clothing or bedding Separate

Clinical focus: Sexual and Gender-Based Violence (SGBV) is a health, human-rights and safeguarding emergency. This lesson defines the terms, forms, risk factors, health consequences and survivor-centred clinical principles. It does not replace current Ugandan law, Ministry of Health protocols or specialist sexual-assault and child-protection services. Learning objectives Define gender, gender-based violence, sexual violence, rape, intimate-partner violence, harassment, exploitation and trafficking. Recognise physical, sexual, psychological, reproductive, social, economic, disability-related and technology-facilitated violence. Understand consent, coercion, capacity, power, intersectionality and why myths cause clinical harm. Provide safe first-line support using the WHO LIVES approach and make an immediate safety plan. Identify urgent medical, mental-health, safeguarding, forensic and referral priorities without blaming or retraumatising a survivor. 1. Core definitions Term Definition for clinical teaching Practical implication Sex Biological attributes associated with reproductive anatomy, physiology and chromosomes; sex characteristics vary naturally. Do not assume anatomy, identity or risk from appearance; ask respectfully and privately. Gender Socially constructed roles, behaviours, expressions and expectations associated with being a woman, man, girl, boy or another gender. Gender norms can create power imbalances and barriers to care. Gender identity A person’s internal experience of gender, which may or may not correspond with sex assigned at birth. Use the person’s name and pronouns where safe and appropriate. Sexual orientation Pattern of emotional, romantic or sexual attraction. It is not a cause or justification for violence. Provide non-discriminatory care to all survivors. Gender-based violence (GBV) Harmful acts directed against a person because of gender or acts that disproportionately affect a gender, including physical, sexual, psychological, economic and controlling behaviours. GBV can occur in private or public, during peace or emergencies, and to any gender. Sexual violence Any sexual act, attempt, unwanted sexual comment/advance, or act directed at a person’s sexuality using coercion, regardless of relationship or setting. Medical care is indicated even when there is no visible injury or penetration. Rape A legal term for non-consensual penetration; exact elements and terminology vary by jurisdiction. Use local law for reporting and forms; clinically document the survivor’s account without deciding guilt. Intimate-partner violence (IPV) Physical, sexual, emotional or controlling violence by a current or former intimate partner. Assess immediate danger, stalking, weapons, children and safe communication. Domestic violence Violence or coercive control within a household or family relationship; legal definitions differ. Do not assume that returning home is safe; develop a survivor-led plan. Violence against women and girls Gender-based violence directed against women/girls or disproportionately affecting them, including public and private violence. Women and girls are affected at high rates, but men, boys and gender-diverse people also require care. 2. Consent, coercion and capacity Consent is a voluntary, informed and specific agreement to a particular act. It can be withdrawn at any time, is not transferable to another act, and cannot be inferred from clothing, prior intimacy, marriage, payment or silence. Consent is absent when a person is asleep, unconscious, severely intoxicated, threatened, detained, deceived, under coercive control or unable to understand and communicate a choice. Freely given: no force, threats, intimidation, abuse of authority, economic pressure or fear of retaliation. Informed: the person understands what is proposed and its likely consequences. Specific and ongoing: agreement to one act does not authorise another; consent can stop at any time. Capacity: the ability to understand, weigh and communicate the decision. Capacity can be affected by age, disability, illness, intoxication or trauma. Follow current safeguarding law for children and adults lacking capacity. Coercion: pressure that removes meaningful choice, including threats to children, economic dependence, immigration status, social exclusion or exposure of private images. Clinical rule: “No injury” does not mean “no violence,” and delayed disclosure, fragmented memory, calm affect or continued contact with the perpetrator do not disprove an account. Trauma responses vary widely. 3. Forms of SGBV Form Examples Possible health consequences Physical violence Hitting, kicking, burning, choking/strangulation, weapon injury, confinement Fractures, head injury, internal bleeding, airway injury, chronic pain, disability and death. Sexual violence Rape, attempted rape, unwanted touching, forced sexual acts, sexual humiliation, reproductive coercion STIs/HIV, pregnancy, genital/anal injury, pelvic pain, trauma, depression and PTSD. Psychological/emotional abuse Insults, threats, humiliation, intimidation, isolation, stalking and coercive control Anxiety, depression, sleep problems, self-harm, suicidality and impaired functioning. Economic violence Withholding money, preventing work/school, taking earnings, property destruction Dependence, inability to access food, medicines, transport or safe housing. Neglect and deprivation Withholding food, water, medical care or assistive devices; abandonment Malnutrition, uncontrolled disease, pressure injury, infection and death. Child sexual abuse/exploitation Sexual contact, grooming, exposure, trafficking, online exploitation, transactional abuse Injury, STI/pregnancy, developmental effects, behavioural change and long-term trauma. Harmful practices Female genital mutilation/cutting, forced marriage, child marriage, so-called “honour” violence Acute bleeding, infection, obstetric complications, chronic pain and psychological harm. Technology-facilitated violence Image-based abuse, cyberstalking, threats, doxxing, location tracking and online grooming Fear, isolation, reputational harm, sleep disturbance, self-harm and physical danger. 4. Where and how violence occurs Partner/family: violence may be episodic, escalating or continuous coercive control; separation can increase danger. Community/public: assault by a stranger or acquaintance, school or workplace harassment, transport-related violence. Institutional/custodial: abuse in health facilities, prisons, police custody, refugee settlements, schools or care institutions. Conflict and humanitarian emergencies: displacement, loss of services, armed actors and dependency increase risk. Trafficking and exploitation: recruitment, transport or harbouring through force, deception or abuse of vulnerability for exploitation. Multiple perpetrators or repeated exposure: the survivor may present with cumulative injuries, pregnancy, infection or complex safety needs. 5. Risk and vulnerability are not blame Violence is the responsibility of the perpetrator. Risk factors can guide safety planning but never justify harm. Level Examples Clinical action Individual Young age, disability, pregnancy, illness, substance dependence, prior violence, migration or economic dependence Offer accessible communication, private care, support persons chosen by the survivor and safe referrals. Relationship Controlling partner, threats, weapon access, stalking, recent separation, violence toward children Ask about immediate danger, safe contact, safe place and children; avoid contacting the partner without consent. Community Unsafe transport, school/workplace power imbalance, stigma, displacement, lack of services Map trusted services and transport; protect confidentiality and continuity. Structural

Scope: Definitions and terms used in forensic medicine connect clinical facts to legal questions. The clinician’s first duties remain emergency care, dignity, consent, accurate documentation and preservation of potential evidence. Laws, forms, reporting duties and court procedures vary by country; this teaching guide uses internationally recognised terminology and must be applied with current Ugandan law, institutional policy and senior medico-legal advice. Learning objectives Distinguish forensic medicine, forensic science, legal medicine, clinical forensic medicine and forensic pathology. Use precise terms for evidence, documentation, expert opinion, chain of custody, consent, confidentiality and court processes. Separate cause, mechanism, manner and circumstances of death. Describe injury, wound, biological evidence, toxicology and identification terminology without overstating what a finding proves. Recognise ethical duties: treat first, obtain informed consent, protect privacy, document objectively and preserve evidence. 1. The essential vocabulary Term Working definition Clinical example Forensic Relating to the use of scientific knowledge in law or legal proceedings. Forensic interpretation of a toxicology result. Forensic medicine Application of medical knowledge to questions arising in law, courts, public investigations and human-rights protection. Assessing an injury, documenting assault or certifying death. Legal/medico-legal medicine The interface between health care and law, including duties, rights, standards, liability and evidence. Explaining confidentiality and mandatory reporting. Clinical forensic medicine Forensic assessment of living people, including injury, sexual violence, intoxication, neglect and custody-related harm. Examination and evidence collection for a survivor of sexual violence. Forensic pathology Medical specialty applying pathology to sudden, unexpected, violent, suspicious or unexplained death. Post-mortem examination after a suspected homicide. Forensic science Scientific disciplines used to answer legal questions, including biology, chemistry, toxicology, DNA, anthropology and digital examination. DNA profiling of a biological stain. Medicolegal case A clinical or death-investigation case in which findings may be relevant to legal decision-making. Road-traffic injury, poisoning or an unexplained death. Medical evidence Relevant clinical information, specimen, image, record or expert interpretation presented to help establish facts. An X-ray, wound photograph, laboratory report or expert testimony. 2. Evidence and proof: do not confuse observation with opinion Fact: an objectively observed or reliably recorded event, such as “a 4-cm linear wound is present on the left forearm.” Finding: an observed clinical, laboratory or post-mortem result, such as “blood alcohol concentration is X by a validated method.” Inference: a reasoned interpretation from facts, such as “the pattern is compatible with impact by a blunt object.” Opinion: an expert’s professional conclusion within their competence. It should identify the data, method, limitations and degree of certainty. Direct evidence: evidence that, if accepted, directly addresses a fact (for example an eyewitness account). Circumstantial evidence: indirect evidence from which a fact may be inferred. Medical findings are often circumstantial and should not be presented as absolute proof. Material evidence: evidence relevant to an issue in the case. Exculpatory evidence may support a person’s innocence; inculpatory evidence may support involvement. Corroboration: independent information that supports another piece of evidence. A medical examination should not be used to force a predetermined story. Language discipline: “consistent with” means the finding does not contradict the account; “compatible with” allows several explanations; “highly suggestive of” is stronger but still not necessarily specific; “diagnostic” should be reserved for findings that truly establish a condition. 3. People and roles in a medico-legal process Role Meaning and responsibility Patient/survivor/complainant Person receiving care or reporting harm. Use the person’s preferred, respectful terminology; do not label someone “victim” unless appropriate to the context. Suspect/accused Person alleged to be involved. An examination does not establish guilt or innocence. Clinician/forensic examiner Provides independent clinical care, examination, documentation, evidence collection and opinion within competence. Forensic pathologist Investigates death through scene information, records, autopsy, specimen examination and cause/manner opinion. Police/investigator Secures the scene, investigates circumstances, obtains statements and lawfully transfers exhibits. Prosecutor/defence counsel Legal representatives who present and test evidence; they do not direct the medical finding. Judge/magistrate/jury Assesses admissibility, credibility and weight of evidence under the applicable legal system. Expert witness A person with specialised training who assists the court with technical opinion, not advocacy for a side. Fact witness A witness who reports what they personally saw, heard, did or recorded, without specialised opinion. 4. Consent, capacity, confidentiality and duty of care Consent Informed consent is voluntary agreement after understandable information about purpose, procedures, benefits, risks, alternatives, privacy, evidence storage and the right to decline or stop. Consent for medical treatment, forensic examination, photography, specimen collection and release of records may be separate. Document what was accepted and refused. Capacity: the ability at that time to understand relevant information, appreciate consequences, reason about options and communicate a choice. Capacity is decision-specific and can fluctuate. Assent: a child’s or person with limited legal capacity’s affirmative participation, sought in addition to permission from the legally authorised decision-maker where required. Voluntariness: consent is not valid when obtained through force, threats, deception or undue pressure. A person in custody retains bodily autonomy subject to lawful procedures. Emergency exception: life-saving treatment may proceed without prior consent when the patient lacks capacity and delay risks serious harm, according to law and policy. This does not automatically authorise forensic evidence collection. Confidentiality and privacy Confidentiality protects information obtained in care. Disclose only the minimum necessary, with consent, lawful authority or a recognised safeguarding/serious-risk exception. Explain limits before examination. Use private rooms, chaperones, respectful language, secure records and safe communication. A subpoena or statutory report may require disclosure; seek legal/ethical advice rather than ignoring it. 5. Records, reports and court documents Term Meaning Good practice Contemporaneous note Record made at or near the time of the event. Date/time, author, source of information, objective observations and corrections that remain visible. Medical record Complete clinical account of assessment, treatment, consent, results and follow-up. Never rewrite history to fit a legal theory; distinguish quoted words from clinician interpretation. Forensic report Structured report of history, examination, specimens, results, interpretation and limitations. State who requested it, methods, chain of custody, qualifications and opinion boundaries. Statement/affidavit Written account or sworn declaration according to the applicable procedure. Read carefully, correct errors transparently and sign only

Clinical focus: Interpreting electrolytes is an emergency skill: verify the sample, identify the dominant water/solute problem, assess symptoms and ECG, correct dangerous abnormalities at a safe rate, and always search for the cause. Reference ranges vary by laboratory, age, pregnancy and method. Treat the patient and trend—not an isolated number. Learning objectives Interpret sodium, potassium, chloride, bicarbonate, calcium, magnesium and phosphate in relation to water balance, kidney function and acid–base status. Use serum osmolality, urine osmolality and urine sodium to classify hyponatraemia and hypernatraemia. Recognise ECG and neuromuscular dangers of potassium, calcium and magnesium abnormalities. Calculate corrected sodium, corrected calcium, anion gap, delta gap and effective osmolality. Choose safe emergency priorities, infusion principles, monitoring and escalation for severe electrolyte disorders. 1. First principles and pre-analytical safety Electrolytes are charged particles that determine extracellular tonicity, nerve and muscle excitability, cardiac conduction, fluid distribution, enzyme activity and acid–base balance. A result can be misleading when blood is drawn from an IV line, the sample is haemolysed, prolonged tourniquet time causes stasis, the patient is receiving a concentrated infusion, or the analyzer method differs. Repeat an unexpected critical result from a clean venous sample, but do not delay ECG monitoring and treatment when symptoms or an ECG-toxic result are present. Check glucose, urea/creatinine, albumin, blood gas, phosphate, magnesium, medication list, fluid balance and recent vomiting/diarrhoea or diuretic use. Ask what the patient’s baseline was and how rapidly the abnormality developed. Rate of change often predicts symptoms better than the absolute number. Look at the ECG for potassium, calcium and magnesium toxicity. A normal ECG does not guarantee safety. Common adult reference interval (approximate) Typical range Main role Sodium (Na+) 135–145 mmol/L Extracellular tonicity and water balance. Potassium (K+) 3.5–5.0 mmol/L Resting membrane potential and cardiac conduction. Chloride (Cl−) 98–106 mmol/L Electroneutrality and acid–base balance. Total CO2/bicarbonate 22–29 mmol/L Metabolic component of acid–base status. Total calcium 2.15–2.55 mmol/L (8.5–10.5 mg/dL) Neuromuscular, cardiac and bone function. Magnesium 0.70–1.00 mmol/L (1.7–2.4 mg/dL) ATP reactions, neuromuscular and potassium/calcium handling. Phosphate 0.80–1.50 mmol/L (2.5–4.5 mg/dL) ATP, bone, cell membranes and oxygen delivery. 2. Sodium: water balance and tonicity Serum sodium mainly reflects the ratio of body water to exchangeable sodium and potassium, not total-body sodium alone. Always ask: is the abnormality hypotonic, isotonic or hypertonic, and is the patient hypovolaemic, euvolaemic or hypervolaemic? Hyponatraemia (Na <135 mmol/L) Step Interpretation 1. Confirm and check glucose Exclude sample error and hyperglycaemia-related translocation. Severe symptoms include seizure, coma, severe confusion, vomiting or respiratory arrest. 2. Measure serum osmolality Hypotonic (<275 mOsm/kg) is the common true hyponatraemia; isotonic suggests pseudohyponatraemia; hypertonic suggests glucose or another effective osmole. 3. If hypotonic, measure urine osmolality ≤100 mOsm/kg suggests excess water intake or low solute intake; >100 means antidiuretic hormone (ADH) is active. 4. Measure urine sodium and examine volume status Low urine sodium often supports hypovolaemia (unless diuretics/CKD); higher urine sodium may occur in SIADH, adrenal insufficiency, renal salt loss or diuretic use. Causes: hypovolaemic losses (diarrhoea, vomiting, burns, diuretics), SIADH from pulmonary/CNS disease or drugs, adrenal insufficiency, hypothyroidism, heart failure, cirrhosis, nephrotic syndrome, advanced kidney disease, primary polydipsia and low-solute intake. Severe symptomatic hyponatraemia ABC, seizure precautions, ECG and frequent sodium checks. Stop hypotonic fluids and offending drugs; obtain glucose, serum/urine osmolality and urine sodium, but do not delay rescue therapy. A common adult emergency regimen is 3% hypertonic saline 100 mL IV over 10 minutes, repeated up to two more times if severe symptoms persist (some protocols use 150 mL over 20 minutes). Aim for an initial rise of about 4–6 mmol/L, then stop boluses. Limit correction to generally ≤8 mmol/L in 24 hours in high-risk patients (and not more than about 10–12 mmol/L in 24 hours or 18 mmol/L in 48 hours under local guidance). High-risk patients include alcoholism, malnutrition, liver disease, hypokalaemia and very low sodium. If overcorrection occurs, stop active correction and seek expert help; desmopressin and free water (for example D5W) may be used to re-lower sodium under monitored protocol. Never give routine isotonic saline to presumed SIADH without assessment: it may worsen hyponatraemia. Treat hypovolaemic hyponatraemia with cautious isotonic crystalloid, adrenal insufficiency with steroid replacement, and SIADH with fluid restriction and cause-specific therapy. Hypernatraemia (Na >145 mmol/L) Hypernatraemia is usually water deficit (impaired access/thirst, fever, osmotic diuresis, diabetes insipidus, diarrhoea or burns), less often sodium gain. Assess chronicity, neurological symptoms, volume status, urine volume and urine osmolality. Shock requires isotonic crystalloid first to restore circulation; replace the remaining free-water deficit with oral/enteral water, IV dextrose 5% or hypotonic fluid as appropriate. For chronic or unknown-duration hypernatraemia, lower sodium slowly—often ≤0.5 mmol/L/hour and ≤10–12 mmol/L/day—to reduce cerebral oedema risk. Acute sodium loading may be corrected more rapidly with specialist guidance. Very dilute urine despite hypernatraemia suggests diabetes insipidus; distinguish central from nephrogenic causes and involve endocrinology. Free-water deficit (L) ≈ TBW × [(current Na/desired Na) − 1]. Estimate TBW as about 0.6 × weight (kg) in a young adult male, 0.5 in an adult female, and lower in older adults; reassess frequently because ongoing losses and renal function alter the calculation. 3. Potassium: the immediate cardiac electrolyte Hypokalaemia (K <3.5 mmol/L) Common causes are gastrointestinal loss, loop/thiazide diuretics, renal tubular losses, hyperaldosteronism, insulin or beta-agonist shift, alkalosis and low magnesium. Ask whether the loss is renal or extrarenal and correct magnesium if low. Severity Clinical approach 3.0–3.4 mmol/L Oral potassium replacement and cause treatment if stable; review drugs and repeat level. 2.5–2.9 mmol/L or symptoms Urgent ECG, oral/IV replacement depending on tolerance, renal function and monitoring capacity. <2.5 mmol/L, ECG changes, paralysis or arrhythmia Monitored emergency replacement, usually IV potassium chloride; senior/critical-care input. Typical adult IV replacement is 10 mmol/hour through a peripheral line; higher rates (up to 20 mmol/hour, occasionally more in critical care) require continuous ECG and local protocol. Never give potassium as an IV bolus. Check the level every 2–4 hours during aggressive replacement. Oral potassium is safer when the gut works. Insulin, beta-agonists and bicarbonate may worsen the shift. Hyperkalaemia (usually K ≥5.5

Clinical focus: Interpreting blood sugar tests means integrating the result, sampling conditions, symptoms, HbA1c, ketones, electrolytes and the patient’s illness. A number is not a diagnosis by itself. Use a laboratory method and local reference ranges for diagnosis, and treat immediately when hypoglycaemia or a hyperglycaemic emergency is suspected. Learning objectives Convert and interpret glucose in mg/dL and mmol/L, and recognise pre-analytical errors. Use fasting, random, 2-hour oral glucose tolerance and HbA1c results to classify normal glycaemia, prediabetes and diabetes. Interpret capillary bedside testing, continuous glucose monitoring (CGM), urine/blood ketones and urinary glucose. Recognise hypoglycaemia, diabetic ketoacidosis (DKA), hyperosmolar hyperglycaemic state (HHS), stress hyperglycaemia and euglycaemic DKA. Apply targets safely, identify discordant results and plan repeat testing, escalation and monitoring. 1. Units and the first safety checks Glucose is reported as either mg/dL or mmol/L. The bedside conversion is: mmol/L = mg/dL ÷ 18    and    mg/dL = mmol/L × 18. Result Approximate conversion Immediate interpretation 3.0 mmol/L 54 mg/dL Clinically significant hypoglycaemia threshold. 3.9 mmol/L 70 mg/dL Alert value; treat a symptomatic patient and investigate. 7.0 mmol/L 126 mg/dL Fasting diabetes threshold when confirmed by an appropriate laboratory test. 11.1 mmol/L 200 mg/dL 2-hour OGTT or random-with-symptoms diabetes threshold. 33.3 mmol/L 600 mg/dL Typical HHS-range hyperglycaemia; assess urgently. Before interpreting any value, document whether the sample was fasting (at least 8 hours without calories), pre-meal, 1–2 hours after a meal, random, during an illness, after exercise or after glucose-containing treatment. Check the meter strip expiry, hand contamination, sample volume, device calibration and whether capillary blood is appropriate for a shocked or severely dehydrated patient. Confirm unexpected, critical or discordant bedside results with a venous laboratory sample, but do not delay emergency treatment in a symptomatic patient. 2. What each glucose test actually measures Test Time window Best use Main limitations Fasting plasma glucose (FPG) One point after ≥8-hour fast Diagnosis and follow-up of diabetes/prediabetes Stress, infection, sleep loss and fasting errors alter results; requires confirmation if asymptomatic. Random plasma glucose Any time Symptomatic patients and emergencies Meal timing affects it; ≥200 mg/dL diagnoses diabetes only with classic symptoms or crisis. 75-g OGTT Fasting and 2-hour value after glucose drink Detects impaired glucose tolerance and diabetes when FPG/A1c is equivocal; pregnancy testing Preparation, vomiting, acute illness and incorrect timing invalidate results. HbA1c Approximate weighted mean over 2–3 months (more recent weeks influence it more) Diagnosis and long-term glycaemic monitoring Unreliable with altered red-cell survival, haemoglobin variants, recent transfusion, severe anaemia or advanced kidney disease. Capillary point-of-care glucose Immediate current glucose Rapid treatment decisions and bedside monitoring Perfusion, temperature, haematocrit, contamination and device error can bias values. CGM/interstitial glucose Usually every few minutes with a short physiological lag Trends, variability, nocturnal hypoglycaemia and time-in-range Lag during rapid change; confirm a result that does not fit symptoms or before high-risk treatment. 3. Diagnostic thresholds for non-pregnant adults The following thresholds are widely used for laboratory plasma glucose and a standardised laboratory HbA1c. In a person without unequivocal symptoms or hyperglycaemic crisis, confirm an abnormal result on another day, preferably with the same test. Marked discordance requires repeat testing and investigation rather than averaging values. Category HbA1c Fasting plasma glucose 2-hour 75-g OGTT Random plasma glucose Normal <5.7% (<39 mmol/mol) <100 mg/dL (<5.6 mmol/L) <140 mg/dL (<7.8 mmol/L) No diagnostic random cut-off Prediabetes 5.7–6.4% (39–46 mmol/mol) 100–125 mg/dL (5.6–6.9 mmol/L) 140–199 mg/dL (7.8–11.0 mmol/L) No diagnostic random cut-off Diabetes ≥6.5% (≥48 mmol/mol) ≥126 mg/dL (≥7.0 mmol/L) ≥200 mg/dL (≥11.1 mmol/L) ≥200 mg/dL (≥11.1 mmol/L) with classic symptoms or crisis Do not use a portable point-of-care HbA1c alone to diagnose diabetes unless the method is certified and the local policy explicitly allows it. A patient with polyuria, polydipsia, weight loss, blurred vision, vomiting, abdominal pain, altered mental state or dehydration needs immediate clinical assessment—not an outpatient repeat appointment. 4. HbA1c: interpreting the three-month story Glucose binds non-enzymatically to haemoglobin. HbA1c therefore estimates average glycaemia, but it does not show daily peaks, variability or recent hypoglycaemia. As a rough educational conversion, estimated average glucose (mg/dL) is approximately 28.7 × HbA1c − 46.7; this is not a substitute for a meter or CGM. HbA1c interpretation Clinical meaning Near target but symptomatic lows Possible overtreatment or wide variability; review glucose logs and medication timing rather than intensifying treatment. High A1c with normal clinic glucose Missed post-meal or nocturnal hyperglycaemia, adherence variation, meter error or altered red-cell survival. Rapid fall over weeks May reflect recent treatment or red-cell loss/transfusion; it does not prove stable control. Unreliable A1c Haemolysis, blood loss, transfusion, erythropoietin, haemoglobin variants, pregnancy, advanced CKD and some haemoglobinopathies. Use plasma glucose, fructosamine/glycated albumin or CGM where appropriate. 5. Fasting, post-meal and inpatient targets Targets are individualised by age, pregnancy, comorbidity, hypoglycaemia risk and available resources. For many non-pregnant adults, a common starting outpatient target is pre-meal 80–130 mg/dL (4.4–7.2 mmol/L), peak post-meal below 180 mg/dL (10.0 mmol/L), and HbA1c below 7%; frail adults, older adults and people with recurrent severe hypoglycaemia may need less stringent goals. In most critically ill hospitalised adults, protocols commonly aim for about 140–180 mg/dL (7.8–10.0 mmol/L) and avoid both hypoglycaemia and very tight control. Always apply local protocol. Pregnancy uses tighter, time-specific targets. Common treatment targets are fasting <95 mg/dL (5.3 mmol/L), 1-hour post-meal <140 mg/dL (7.8 mmol/L) or 2-hour <120 mg/dL (6.7 mmol/L); local obstetric guidelines take precedence. 6. Hypoglycaemia Level Glucose Meaning and response Level 1 (alert) <70 to ≥54 mg/dL (3.9 to 3.0 mmol/L) Treat promptly, identify cause and recheck. Level 2 (clinically significant) <54 mg/dL (<3.0 mmol/L) Neuroglycopenia is more likely; urgent treatment and observation. Level 3 (severe) No fixed number Cognitive/physical impairment requiring another person, regardless of the measured value. Immediate treatment (adult educational protocol) If awake and able to swallow: give 15–20 g fast-acting carbohydrate (for example glucose tablets or 150–200 mL ordinary sugary drink), recheck in 15 minutes, and repeat until ≥70 mg/dL (3.9 mmol/L). Follow with a meal or longer-acting carbohydrate if the next meal is not soon. If confused, seizing,

Clinical focus: This single-page guide teaches students to interpret renal function tests in a structured way—from specimen quality and individual analytes to complete AKI/CKD patterns and emergency decisions. Reference intervals vary by laboratory, age, sex, pregnancy and clinical context; use the local laboratory range and the patient’s baseline whenever available. Learning objectives Explain what the kidneys measure and why no single “kidney test” is sufficient. Interpret creatinine, urea/BUN, eGFR, creatinine clearance, cystatin C, electrolytes and acid–base results. Read urinalysis, albumin–creatinine ratio (ACR), protein–creatinine ratio (PCR) and urinary sediment. Recognise and stage acute kidney injury (AKI), distinguish pre-renal, intrinsic and post-renal patterns, and identify chronic kidney disease (CKD). Recognise nephritic, nephrotic, tubular and obstructive patterns, adjust medication risk, and escalate renal emergencies. 1. What renal function means The kidneys maintain internal homeostasis by filtering plasma, selectively reabsorbing and secreting solutes, excreting metabolic waste and drugs, regulating water, sodium, potassium, calcium and phosphate, maintaining acid–base balance, and producing or activating hormones (erythropoietin, renin and calcitriol). Renal tests therefore assess several domains: Domain What to assess Typical tests Filtration How much plasma is filtered per minute Serum creatinine, eGFR, measured creatinine clearance, cystatin C Glomerular barrier Leakage of albumin, other proteins or blood Urine ACR/PCR, dipstick, microscopy Tubular function Concentration, dilution and selective handling of solutes Urine osmolality, specific gravity, urinary sodium, casts, fractional excretions Excretion and homeostasis Waste, potassium, bicarbonate and fluid balance Urea/BUN, K+, Na+, HCO3−, phosphate, calcium, fluid balance Endocrine function Erythropoiesis, blood pressure and bone/mineral regulation Haemoglobin, renin/aldosterone and calcium–phosphate–PTH profile when indicated 2. Before interpreting: verify the clinical and laboratory context Confirm patient identity, sample type, collection time and whether results are comparable with the same laboratory. Find the baseline creatinine and trend over hours to days, not just the latest value. A “normal” creatinine may be dangerous in a patient with very low muscle mass. Record weight, urine output (hourly in an unstable patient), blood pressure, volume status, fever, sepsis, bleeding, vomiting/diarrhoea, heart failure and urinary symptoms. Review drugs and exposures: NSAIDs, ACE inhibitors/ARBs, diuretics, aminoglycosides, vancomycin, amphotericin, tenofovir, chemotherapy, herbal medicines and recent iodinated contrast. Interpret results alongside glucose, liver tests, full blood count, CK, lactate, blood gas and imaging when clinically indicated. Safety rule: Never diagnose AKI or CKD from one isolated creatinine value. Compare with baseline, repeat promptly when the patient is ill, and investigate the cause. 3. Serum filtration markers Serum creatinine Creatinine is generated from muscle creatine and released relatively steadily into blood. It is filtered at the glomerulus and only minimally secreted, so a rising concentration usually indicates reduced filtration. It is a lagging marker: a major fall in GFR can occur before serum creatinine rises, especially during rapidly evolving AKI. Creatinine result Possible explanation Interpretive caution High Reduced GFR, dehydration/pre-renal state, obstruction, rhabdomyolysis, high muscle mass or creatine intake Trimethoprim and cimetidine reduce tubular secretion; assay interference may occur with ketones or bilirubin. Low or “normal” Low muscle mass, malnutrition, amputation, pregnancy or severe liver disease May conceal severe kidney dysfunction; assess eGFR trend, urine findings and clinical state. Rapid rise AKI until proven otherwise Repeat, quantify urine output and search for reversible causes immediately. Estimated glomerular filtration rate (eGFR) eGFR is calculated from creatinine (and sometimes cystatin C) with demographic variables. It is more useful than creatinine alone for stable outpatient CKD, but it is not a directly measured value and is unreliable when kidney function is changing quickly. G category eGFR (mL/min/1.73 m2) Meaning G1 ≥90 Normal or high; CKD only if another marker of kidney damage persists. G2 60–89 Mildly decreased; not CKD without persistent albuminuria, structural disease or another marker. G3a 45–59 Mild-to-moderate decrease. G3b 30–44 Moderate-to-severe decrease; medication review is essential. G4 15–29 Severely decreased; prepare renal replacement planning and specialist care. G5 <15 Kidney failure; assess symptoms and dialysis/transplant needs, not the number alone. When eGFR is less reliable: rapidly changing creatinine (AKI), extremes of muscle mass, amputation, severe malnutrition, oedema or pregnancy, unusual diets, and some medications. Consider a combined creatinine–cystatin C estimate, a measured GFR, or a carefully collected creatinine clearance when a precise value changes management. Do not use an indexed eGFR blindly for drug dosing in a very large or small body size; follow the medicine’s dosing guidance. Creatinine clearance With a timed urine collection, creatinine clearance can be estimated as: CrCl (mL/min) = (urine creatinine × urine flow rate) ÷ plasma creatinine. The collection must be complete and timed accurately. Tubular secretion can make CrCl overestimate true GFR, and a missed urine collection makes the result meaningless. The Cockcroft–Gault equation is used by some drug labels but should not be substituted automatically for the laboratory eGFR. Urea/BUN and the BUN:creatinine relationship Urea is produced by hepatic protein metabolism and is filtered, then variably reabsorbed. It rises with reduced filtration but also with gastrointestinal bleeding, high protein intake, catabolism, fever, corticosteroids or dehydration. Low urea can occur with severe liver dysfunction, low protein intake or overhydration. Pattern Common interpretation Urea rises out of proportion to creatinine Pre-renal hypoperfusion, upper GI bleeding, catabolism or steroids; interpret with volume status, not as proof of dehydration. Creatinine rises with modest urea change Intrinsic renal injury, low protein intake or reduced hepatic urea production may contribute. Both high Reduced filtration is likely; determine acute versus chronic and identify the cause. The traditional BUN:creatinine ratio is unit- and assay-dependent and is supportive only. It must never override urine findings, haemodynamics or the creatinine trend. Cystatin C Cystatin C is produced by nucleated cells, filtered freely and less dependent on muscle mass than creatinine. It may improve GFR estimation in frailty or unusual body composition. Inflammation, thyroid disease, corticosteroids and some other conditions can alter cystatin C; it is not a perfect AKI marker. A combined creatinine–cystatin C eGFR can improve confidence when values are discordant. 4. Urine tests: the kidney’s “microscope” Dipstick and physical examination Finding What it suggests Important limitations Specific gravity Urine concentration; persistently fixed around 1.010 may indicate poor concentrating ability