En ung kvinne som ikke våknet etter omfattende operasjon.

BACKGROUND Cystic echinococcosis (CE) caused by Echinococcus granulosus, significantly impacts health globally, but is a rare disease in Norway. CE is treated with a combination of anthelmintics and surgery, or percutaneous drainage. CASE PRESENTATION A woman in her thirties underwent extensive surgery due to disseminated CE in the abdominal cavity and liver. Due to intraoperative cyst rupture with contamination of the abdominal cavity, peritoneal lavage with hypertonic saline (20 % NaCl), a scolicidal agent, was performed for ten minutes before irrigation with physiological saline. Immediately after surgery, the patient was haemodynamically unstable and did not awake. Blood level of sodium was found to be severely increased at 188 mmol/L (ref 137−144 mmol/L). Hypotonic fluids (5 % glucose) were immediately administered intravenously to correct the acute hypernatraemia. CT scan of the head did not show signs of bleeding or oedema. The sodium level was normalised on postoperative day three and the patient was discharged without any neurological sequelae. INTERPRETATION Our patient developed iatrogenic acute severe hypernatraemia following abdominal lavage with hypertonic saline. Acute severe hypernatraemia is potentially lethal. Hypertonic saline must be used intraoperatively with great caution. Regular blood tests to detect hypernatraemia and monitor other electrolyte disturbances should be mandatory.