A controlled trail of doxapram in acute respiratory failure.

The efficacy of a respiratory stimulant (doxapram) in antagonizing carbon dioxide retention associated with controlled oxygen therapy (28 per cent) in acute-on-chronic respiratory failure was assessed by a double-blind crossover trial in eight patients. PaCO2 rose in egery case during the placebo in the initial treatment period (mean increase 10 mm Hg). In those patients receiving doxapram initially PaCO2 fell in three and rose in one (mean decrease 4 mm Hg). All who has shown a rise in PaCO2 during the initial period on placebo showed a fall in the subsequent period on doxapram. In the six patients who completed the study, mean PaCO2 at the end of the doxapram period was significantly lower than the end of the placebo period (60 mm Hg against 67 mm M Hg). In three patients the rise in PaCO2 was accompanied by significant impairment in the level of consciousness which was reversed during the doxapram period. PaCO2 was not significantly different during either treatment period. No serious unwanted effects were encountered.