Effect of ice water ingestion on asthmatic children after exercise challenge.

Both exercise and ice water ingestion are known to be trigger factors for an asthma attack in ethnic Chinese asthmatic children. The purpose of this study was to investigate whether ice water ingestion further deteriorates pulmonary function of asthmatic children after exercise. Thirty Chinese asthmatic children underwent exercise challenge by ergocyclometer for 6 minutes and then were further challenged by immediate ingestion of ice water (200 ml, 0-4 degrees C), warm water (200 ml, 37 degrees C) or no ingestion on three different days in one week. Each patient completed the three different water ingestion tests after exercise challenge. The FEV1, FEF25-75%, and PEF tests were performed at baseline and again at 5, 15, 30, 60, 90 minutes after exercise plus water ingestion challenge. After the spirometric test at 90 minutes, 3 puffs (0.6 mg) of hexoprenaline from a metered dose inhaler were given and then a further spirometric test was performed 15 minutes later. The FEV1 and PEF were significantly decreased after exercise plus the 3 different water ingestion challenge except for the FEV1 in the patients who ingested nothing (p = 0.051) and PEF in the patients who ingested warm water (p = 0.163). FEF25-75% of the three tests was not significantly decreased. Exercise-induced asthma (EIA) developed in about two thirds of the 30 patients, regardless of whether ice water, warm water or nothing at all was ingested after exercise challenge. There was no statistically significant difference in spirometric data among the 3 different water tests at various time points. The mean percentage increase of FEV1, FEF25-75% and PEF after bronchodilator therapy were all the lowest in the ice water test, and the greatest in the warm water test. A statistically significant difference was found between ice water and warm water tests for FEV1 and PEF (p = 0.0293 and p = 0.0308 respectively). In conclusion, about two thirds of the asthmatic children in this series had EIA. Those who ingested warm water after exercise had a better bronchodilator response than those who ingested ice water.