Urinary arginine vasopressin in asthma: consideration of fluid therapy.

To elucidate the role of antidiuretic hormone (ADH) on water and electrolyte balance in patients with asthmatic attacks, urinary arginine vasopressin (AVP) was assayed in 28 asthmatic patients. In a 3-year-old girl with status asthmaticus who developed a grand mal seizure in association with hyponatremia, urinary AVP levels remained high and fluctuated before convulsion; the cause of the convulsion was considered to be water intoxication due to inappropriate ADH secretion. In 19 of 28 patients with moderately severe asthmatic attacks, increases in urinary AVP levels occurred before treatment (300 +/- 80 pg/ml vs. 40 +/- 24 pg/ml (normal controls), p less than 0.01); elevated AVP levels tended to fall in response to intravenous fluid therapy (appropriate ADH secretion) in 2 of 6 patients, but did not fall (inappropriate ADH secretion) in the remaining patients. It is concluded that inappropriate ADH secretion may occur in asthmatic attacks, and that in such a condition there seems to be a potential risk of water intoxication during fluid therapy, as demonstrated in the present patient.