End-tidal partial pressure of carbon dioxide does not accurately reflect PaCO2 in rabbits treated with acetazolamide during anaesthesia.

Acetazolamide, a carbonic anhydrase inhibitor, may cause significant disturbances in carbon dioxide transport and elimination. In this study, end-tidal carbon dioxide monitoring has been used to study the correlation between arterial carbon dioxide (PaCO2) and end-tidal carbon dioxide partial pressure (PE'CO2) in rabbits treated with acetazolamide. A significant difference in (PaCO2-PE'CO2) developed immediately after administration of acetazolamide and persisted for more than 2 h. It is concluded that PE'CO2 did not reflect accurately PaCO2 and the ventilatory status of the rabbit which received acetazolamide within 2 h.