The article (1) provides an excellent overview of a difficult, often somewhat neglected problem that also plays a role in intensive care medicine. However, the proposed preparation of a 3% sodium chloride (NaCl) solution is sometimes not easy to carry out. I think measuring exactly 318 mL during an emergency situation is not always feasible. My simpler solution is based on the calculation that 500 mL of a 3% NaCl solution must contain 15 g NaCl. So, if one lets 150 mL run out of an infusion bottle containing 500 mL of 5% glucose, and replaces it with 150 mL of a 10% NaCl solution, a 3% NaCl solution is prepared. This procedure prevents an excessive chloride concentration. Are there any objections to this?
What should be the initial rate of infusion of the 3% solution in patients with or without additional fluid deficiency in the case of severe neurological symptoms?
In my opinion, the recommendation to initially compensate for a possibly existing potassium deficit before therapy of hyponatremia is often hardly practicable in case of severe neurological symptoms. Should a confused or convulsing patient, whose cerebral condition could probably be improved by administrating a NaCl solution, really receive an intravenous potassium replacement—possibly over several hours—before beginning the actual treatment of the underlying disease? Here, 30 mmol/h is the maximum permissible rate of potassium replacement via central venous catheter. I remember patients with hyponatremia who would not have tolerated this for long. What would you recommend in this case ?
Prof. Dr. med. Friedrich Lübbecke
|1.||Lambeck J, Hieber M, Dreßing A, Niesen WD: Central pontine myelinolysis and osmotic demyelination syndrome. Dtsch Arztebl Int 2019; 116: 600–6 VOLLTEXT|