Sodium chloride

Side effects & warnings

CONTRAINDICATIONS (BSAVA Part B p.285, verbatim): Do not use if zeolite is used in the filtration system as this will cause the release of absorbed ammonia into the environment. ADVERSE REACTIONS (BSAVA Part B p.285, verbatim): Peripheral oedema is more likely to occur after crystalloids because muscle and subcutaneous capillaries are less permeable to protein. Normal saline contains higher amounts of chloride than plasma, which will increase the risk of acidosis. The degree of acidosis is not likely to be a problem in a healthy patient but acidosis may be exacerbated in a compromised patient. Hypertonic saline administered at fluid rates >1 ml/kg/min can cause a vagally mediated bradycardia, therefore the rate of fluid administration must be carefully controlled. The ophthalmic ointment may cause a stinging sensation. SAFETY AND HANDLING (BSAVA Part B p.285, verbatim): Hypertonic saline solutions should be regarded as drugs and not as intravenous fluids and should be stored separately to prevent confusion. ACTION (BSAVA Part B p.285, verbatim): Expands plasma volume and replaces lost extracellular fluid. In freshwater aquaria and ponds, nitrite toxicity resulting from poor water quality causes oxidation of haemoglobin to methaemoglobin. Chloride ions inhibit nitrite absorption through the gill epithelium and reduce the toxic effect in fish. It also reduces the osmotic pressure between the freshwater environment and the fish tissues. USE (BSAVA Part B p.285, verbatim): When used for fluid replacement NaCl (0.45% and 0.9%) will expand the plasma volume compartment. Compared with colloids, 2.5 to 3.0 times as much fluid must be given because the crystalloid is distributed to other sites. Normal saline is also the treatment of choice for patients with hypercalcaemia or hyperchloraemic alkalosis. Sodium chloride solutions are often used as a drug diluent. Hypertonic saline is used to expand the circulating blood volume rapidly in animals with shock, particularly during the preoperative period. The hypertonic ophthalmic ointment is used in the management of corneal oedema. Hypertonic saline solutions have very high sodium concentrations and it is important to monitor serum sodium concentrations before and after their administration; maintenance with an isotonic crystalloid is usually required after administration to correct electrolyte and fluid disturbances created by the administration of the hypertonic solution. Oral sodium supplementation is recommended by some authors in the long- term management of hypoadrenocorticism. Used for the treatment of external protozoans in amphibians and fish. Used as a short-term bath to control external bacterial an SOURCE: Ramsey I, ed. BSAVA Small Animal Formulary, 10th ed. Part B: Exotic Pets. Gloucester: British Small Animal Veterinary Association; 2023. p.285.