The effects of different levels of ventilation on the action of pancuronium in man.

The effect of carbon dioxide on the neuromuscular blocking effect of the non-depolarizing muscle relaxants tubocurarine and gallamine has been known for some time. Kalow (1954) noted that the action of tubocurarine on an isolated muscle preparation was increased by lowering the pH. Payne (1958) found that in the anaesthetized cat the activity of tubocurarine was increased with a reduction of pH. Baraka (1964) and Katz and Wolf (1964) noted a delay in recovery from tubocurarine of patients with an acidosis. Walts, Lebowitz and Dillon (1967), however, found no significant difference in the response of patients to tubocurarine whether ventilation was controlled (mean Paco, 18.9 mm Hg) or assisted (mean Paco^ 49.2mm Hg). Both Baraka (1967) and Walts, Lebowitz and Dillon (1967) showed that the action of gallamine was antagonized by carbon dioxide.