Prolonged administration of isoflurane to pediatric patients during mechanical ventilation.

We undertook a prospective study of the effectiveness and potential toxicities of isoflurane sedation in pediatric patients undergoing mechanical ventilation who required large doses of opioids for sedation were considered eligible. Ten patients (ages 3 wk to 19 yr) received continuous isoflurane sedation for a mean duration of 131 minimum alveolar concentration (MAC)-hours (range 13-497 MAC-hours). The mean peak inorganic fluoride (F-) concentration was 11.0 microM, and the highest F- concentration was 26.1 microM after 441 MAC-hours. Only one patient had a measured F- concentration greater than 20 microM. No abnormalities were noted in serum creatinine or osmolality. Creatinine clearances were available for five patients who received a mean of 193 MAC-hours of isoflurane (range 33-497 MAC-hours), and only one patient had a persistent decrease from baseline of more than 20%. Five patients demonstrated an abstinence syndrome which consisted of nonpurposeful movements and extreme agitation. All of these patients had received at least 70 MAC-hours of isoflurane. Our experience indicates that isoflurane can effectively provide sedation to pediatric patients for prolonged periods without significant adverse effects on cardiovascular, hepatic, or renal function.