Flush hypertension during infusion of saline

Salt-sensitivity is present in approximately half of the population with essential hypertension.1 Among several methods used to diagnose salt-sensitivity, Weinberger’s saline infusion test is widely accepted; this test compares the blood pressure (BP) measured after infusing 2 l of isotonic saline over 4 h with the BP measured during a salt-restricted diet and administration of three 40-mg doses of oral furosemide. A 10 mmHg or greater difference in mean BP between the salt-loaded and salt-depleted phases of the test is defined salt-sensitivity.2 In three patients to be described, infusion of isotonic saline induced a surge of BP far in excess to the mild hypertensive effect required to diagnose salt-sensitive hypertension. Such episodes are not well described in the literature. Patient 1A 96-year-old woman was referred with the diagnosis of left lower lobe pneumonia. Amoxicillin/clavulanate intravenous (i.v.) 1 g × 3/day was started. Notable in the patient’s medical history were multi-infarct dementia, dysphagia, grade I arterial hypertension, vitamin B12 and iron deficiency. Her regular medications were simvastatin 20 mg, furosemide 40 mg, vitamin B12 and ferum sulfate 160 mg/day. The patient’s BP readings on the day of admission were 185/90, 139/77, 145/65 mmHg, the heart rate 72 bpm, temperature 38.6°C. The serum creatinine was 0.7 mg/dl, WBC 12 300/mm3, polymorphonuclear leukocytes 79%. Two days later, the temperature returned to normal but the abdomen became distended with no passage of stool or gas and high-pitched bowel sounds suggesting intestinal obstruction or pseudoobstruction. On plain abdominal X-ray, the colon was distended, air visible in all colonic segments including the rectosigmoid and the maximum cecal diameter 7 cm. The BP was 138/70 mmHg. Serum levels of sodium, potassium, calcium and thyrotropin were within the normal range. On surgical consultation, a diagnosis of colonic pseudoobstruction was posited and conservative management recommended. The patient was kept fasted and i.v. saline was started. Four hours later, she became …