Guidelines and recommendations for the use of Intravenous fluid therapy within Critical Care. For use on all patients including post-operative.

Important points to consider:

• Fluid and electrolyte requirements are complex and dynamic and should be reviewed daily on all patients.
• Intravenous fluids (IV) should only be used on patients whose fluid and electrolyte needs are not or cannot be met with enteral administration.
• Excessive administration of IV fluids may be just as harmful as under administration and is not as easy to correct.
• When prescribing IV fluids and electrolytes, all other sources of fluid and electrolyte intake need to be considered, including drugs, IV nutrition, blood and blood products. Insensible losses should also be considered when considering IV fluid and electrolyte replacement e.g. sweating (pyrexia), diarrhoea
• Electrolytes should be preferentially administered enterally or as concentrated solutions.
• In the post-operative phase, a person’s sodium and water requirements are considerably reduced.
• Oliguria is common and physiological during the post-operative period, and does not necessarily indicate hypovolaemia.
• If, after a full clinical assessment, hypovolaemia is suspected this should be correct immediately.
• Passive leg raise can be used as an easy assessment of fluid responsiveness. 
• Prescribers should be aware of the different indications for IV fluids- Resuscitation, replacement, redistribution and maintenance fluid.  Different fluid types are recommended for each.

Daily requirements to consider when prescribing maintenance IV fluids.

Prescribing 4% glucose/0.18% NaCL at 1ml/kg/hour, rounded to the nearest 10mls/hr, is an appropriate starting point.  Potassium can be added as required.

70- 80 mls/hr is appropriate for most.  Lower weight, smaller patients may need less.  Taller or obese patients should have their Ideal body weight calculated to assess fluid infusion rates.

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