Fluid and Electrolyte Management Principles

Clinical assessment

Assessment of fluid status (history of intake/losses, weight changes, clinical signs of dehydration or overload, vital signs, urine output). Clinical suspicion of specific electrolyte issues based on context and symptoms.

Investigations

• Vital signs monitoring (HR, BP, RR, Temp)
• Fluid balance charting (Intake vs Output)
• Daily weights
• Serum electrolytes (Sodium, Potassium, Chloride, Bicarbonate)
• Renal function tests (Urea, Creatinine)
• Blood glucose
• Consider Arterial Blood Gas (ABG) if acid-base disturbance suspected
• Consider specific electrolytes like Calcium, Magnesium, Phosphate if clinically indicated

Diagnostic criteria

Based on clinical assessment combined with laboratory results compared to normal physiological ranges.

Non-pharmacological management

• Address and treat the underlying cause of the fluid/electrolyte disturbance.
• Careful monitoring of fluid balance (strict intake/output charting).
• Adjust oral intake/diet if possible and appropriate.
• Regular reassessment of clinical fluid status.

Pharmacological treatment

• Objectives: 1. Replace existing deficits and ongoing losses. 2. Correct specific electrolyte imbalances. 3. Provide daily maintenance requirements.
• Replacement Therapy: Fluid choice depends on type of loss. Use isotonic solutions (Ringer's Lactate or Normal Saline 0.9%) for isotonic losses (e.g., diarrhoea, vomiting, haemorrhage, shock resuscitation). Use blood products for significant haemorrhage.
• Maintenance Therapy (Adults): Approx. 2.5-3 litres/24 hours. Typically combine isotonic saline (e.g., 1L NS 0.9% or RL) with glucose solution (e.g., 2L Dextrose 5%). Add Potassium Chloride (KCl) as needed if patient is nil by mouth for >24-48h and renal function adequate.
• Maintenance Therapy (Children): Calculated based on weight: 100 ml/kg for first 10 kg + 50 ml/kg for next 10 kg + 25 ml/kg for each subsequent kg over 24 hours. Use appropriate solutions (e.g., 0.45% NaCl + 5% Dextrose, or RL + 5% Dextrose). Add KCl as needed. Increase for fever (10% per 1°C) or ongoing losses.
• Maintenance Therapy (Neonates): Specific graduated daily volumes starting Day 1: 60 ml/kg/day (Dextrose 10%), increasing to 150 ml/kg/day by Day 4 (using half-normal saline + 5% dextrose). Adjust based on clinical status, feeding, phototherapy etc. Do not exceed 100ml/kg/day IV if sole source unless dehydrated.
• Fluid choice considerations: See UCG Table p.21 for compositions (NS 0.9%, Dextrose 5%, Dextrose 10%, RL, Darrow's). Note preparation instructions for Dextrose 10% and combined solutions.
• Electrolyte Correction: Requires specific protocols based on the imbalance (e.g., slow correction of hyponatremia, careful potassium replacement) - Refer to specific guidelines.
• Follow specific Ugandan treatment algorithms/guidelines.

Monitoring

Closely monitor IV infusion rate and volume administered. Check IV site daily for signs of infection or extravasation (change site every 2-3 days or prn). Monitor vital signs, urine output, mental status, and clinical signs of fluid status (hydration/oedema). Monitor electrolytes as clinically indicated.