Intravenous fluid therapy. Routine maintenance. NICE guideline.

Routine maintenance

1.4.1If patients need IV fluids for routine maintenance alone, restrict the initial prescription to:

• 25–30 ml/kg/day of water and
  
• approximately 1 mmol/kg/day of potassium[3], sodium and chloride and
• approximately 50–100 g/day of glucose to limit starvation ketosis. (This quantity will not address patients' nutritional needs; see Nutrition support in adults [NICE clinical guideline 32].)
  
  For more information see IV fluid prescription for routine maintenance over a 24-hour period.

1.4.2For patients who are obese, adjust the IV fluid prescription to their ideal body weight. Use lower range volumes per kg (patients rarely need more than a total of 3 litres of fluid per day) and seek expert help if their BMI is more than 40 kg/m2.

1.4.3Consider prescribing less fluid (for example, 20–25 ml/kg/day fluid) for patients who:

• are older or frail
• have renal impairment or cardiac failure
• are malnourished and at risk of refeeding syndrome (see Nutrition support in adults [NICE clinical guideline 32]).

1.4.4When prescribing for routine maintenance alone, consider using 25–30 ml/kg/day sodium chloride 0.18% in 4% glucose with 27 mmol/l potassium[3] on day 1 (there are other regimens to achieve this). Prescribing more than 2.5 litres per day increases the risk of hyponatraemia. These are initial prescriptions and further prescriptions should be guided by monitoring.

1.4.5Consider delivering IV fluids for routine maintenance during daytime hours to promote sleep and wellbeing.