Effect‐site concentration of propofol for reduction of remifentanil‐induced cough

This study examined the effectiveness of different propofol infusion target concentrations on cough suppression, during a target-controlled remifentanil infusion. Four hundred patients were randomly assigned to receive propofol target effect-site concentrations of 0, 3.0, 4.5, or 6.0 μg.ml -1 . When the propofol effect-site concentration reached the target, remifentanil was administered at a target effect-site concentration of 4.0 ng.ml -1 . Episodes of cough were recorded over a 2-min period after remifentanil commencement, and graded as mild (1-2), moderate (3-4), or severe (5 or more). The overall incidence of cough was significantly decreased in by propofol 6.0 μg.ml -1 compared with 0 or 3.0 μg.ml -1 propofol (p < 0.001). The incidence of severe cough was significantly lower with propofol 6.0 μg.ml -1 compared with 3.0 μg.ml -1 (p = 0.03). A propofol target effect-site concentration of 6.0 μg.ml -1 effectively suppressed remifentanil-induced cough when remifentanil was administrated at a target effect-site concentration of 4.0 ng.ml -1 .