This randomised double blind multicentre trial including 382 patients aimed to determine whether acetazolamide reduces mechanical ventilation duration in critically ill patients with COPD and metabolic alkalosis. Acetazolamide (500-1000 mg, twice daily) was compared with placebo administered intravenously in cases of pure or mixed metabolic alkalosis, initiated within 48 hours of ICU admission and continued during the ICU stay for a maximum of 28 days.
The primary outcome was the duration of invasive mechanical ventilation via endotracheal intubation or tracheotomy. Secondary outcomes included changes in arterial blood gas and respiratory parameters, weaning duration, adverse events, use of non-invasive ventilation after extubation, successful weaning, the duration of ICU stay, and in-ICU mortality.
The results showed that for the acetazolamide group (n = 187), compared with the placebo group (n = 193), no significant between-group differences were found for median duration of mechanical ventilation (−16.0 hours; 95% CI, −36.5 to 4.0 hours; P = .17), duration of weaning off mechanical ventilation (−0.9 hours; 95% CI, −4.3 to 1.3 hours; P = .36), daily changes of minute-ventilation (−0.0 L/min; 95% CI, −0.2 to 0.2 L/min; P = .72), or partial carbon-dioxide pressure in arterial blood (−0.3 mm Hg; 95% CI, −0.8 to 0.2 mm Hg; P = .25), although daily changes of serum bicarbonate (between-group difference, −0.8 mEq/L; 95% CI, −1.2 to −0.5 mEq/L; P < .001) and number of days with metabolic alkalosis (between-group difference, −1; 95% CI, −2 to −1 days; P < .001) decreased significantly more in the acetazolamide group. Other secondary outcomes also did not differ significantly between groups.
Among patients with COPD receiving invasive mechanical ventilation, the use of acetazolamide, compared with placebo, did not result in a statistically significant reduction in the duration of invasive mechanical ventilation. However, the magnitude of the difference was clinically important, and it is possible that the study was underpowered to establish statistical significance.
The full text of this article is available in JAMA volume 315 issue 5 of which there is a paper copy in Rotherham Hospital Healthcare Library. The content page of this issue of JAMA is available via this link. However, you will require a personal subscription to access the full text from this site.