– Solutions with low salt, especially sodium, should only be administered with special caution to children and close monitoring of electrolyte and fluid balance should be performed.
- Solutions containing potassium should be administered slowly and only after renal function has been established and proved adequate. In patients with renal impairment, its use must be carefully controlled by frequent determinations of plasma potassium concentrations and periodic ECGs. The infusion must be discontinued if signs of renal insufficiency develop during infusion.
- Solutions containing sodium chloride must be used with caution in patients who have an impaired ability to handle sodium and fluid such as heart disease especially with a history of congestive heart failure, patients with renal insufficiency, cirrhosis of the liver, cardio-pulmonary disease, or patients receiving salt-retaining steroids.
- Potassium supplements should be administered with caution in patients with cardiac disease particularly in digitalised patients. Rapid lowering of plasma potassium concentrations (e.g. when discontinuing the infusion) in digitalised patients can cause cardiac glycoside toxicity.
- “0.3% KCl, 0.18% NaCl, and 4% Glucose” is a slightly hypertonic solution. In the body, however, the solution can become physiologically hypotonic due to rapid glucose metabolisation (see section 4.2).
Depending on the tonicity of the solution, the volume and rate of infusion and depending on a patient's underlying clinical condition and capability to metabolise glucose, intravenous administration of these solutions can cause electrolyte disturbances most importantly hypo- or hyperosmotic hyponatraemia.
Hyponatraemia:
Patients with non-osmotic vasopressin release (e.g. in acute illness, pain, post-operative stress, infections, burns, and CNS diseases), patients with heart-, liver- and kidney diseases and patients exposed to vasopressin agonists (see section 4.5) are at particular risk of acute hyponatraemia upon infusion of hypotonic fluids.
Acute hyponatraemia can lead to acute hyponatraemic encephalopathy (brain oedema) characterized by headache, nausea, seizures, lethargy and vomiting. Patients with brain oedema are at particular risk of severe, irreversible and life-threatening brain injury.
Children, women in the fertile age and patients with reduced cerebral compliance (e.g. meningitis, intracranial bleeding, and cerebral contusion) are at particular risk of the severe and life-threatening brain swelling caused by acute hyponatraemia.
- Care must be exercised in the administration of large volume infusion of hypotonic fluids to patients with congested states or pulmonary oedema.
- As a hypotonic solution containing only 30 mmol sodium/l, the infusion should also be administered with care in patients with hypotonic dehydration and in cases of hyponatraemia.
- Caution should be exercised when the solution is administered to patients with diabetes, especially those with insulin-refractory hyperglycaemia and in patients with glucose intolerance for any other reason (see also section 4.5). Blood glucose monitoring will be required.
- Solutions containing glucose should not be administered simultaneously with, before or after an administration of blood through the same infusion equipment because of the possibility of pseudoagglutination.
- It is recommended that all intravenous apparatus be replaced at least once every 24 h.
Clinical supervision should include ECGs, regular checks of fluid balance and serum electrolytes.