Doxapram improves pulmonary function after upper abdominal surgery |
| |
Authors: | L. Bj rk,M. Arborelius,H. Renck,B. Rosberg |
| |
Affiliation: | L. Björk,M. Arborelius,H. Renck,B. Rosberg |
| |
Abstract: | The effects of doxapram on postoperative pulmonary function were studied in 40 ASA I and II patients randomly allocated to receive either doxapram 1.8 mg· kg-1. h-1 or placebo for 2 h immediately after elective cholecystectomy. The two groups displayed similar reductions of carbon dioxide production at 2 h and 6 h postoperatively, whereas oxygen consumption remained at preoperative levels for 24 h. Minute ventilation was similarly reduced in the two groups at 2 h and 6 h postoperatively, with corresponding increases in Paco2. Pao2 was similarly and significantly decreased in both groups postoperatively, whereas P(A-a)o2 remained unchanged at 2 h and 6 h in doxapram-treated patients. FRC was reduced postoperatively in both groups, significantly more so in the control group at 6 h. Various indices of intrapulmonary gas distribution, including the functional (nitrogen) dead space, underwent similar changes in the two groups. By contrast, the physiological dead space was reduced in doxapram-treated patients at 2 h, 6 h and 24 h postoperatively, whereas no significant changes were seen in the control group. The ventilatory equivalent for CO2 was significantly lower in the doxapram-treated group, implying higher ventilatory efficiency. Our findings indicate that infusion of doxapram postoperatively attenuates the impairment of pulmonary function postoperatively, chiefly via effects on V'A/Q' ratios. No side effects of doxapram were observed. |
| |
Keywords: | Doxapram metabolism postoperative period nausea pain sedation pulmonary function functional residual capacity pulmonary gas exchange respiratory dead space ventilation-perfusion ratio |
|
|