The effect of dilution and prolonged injection time on fentanyl-induced coughing

Abstract

This study was designed to evaluate the effect of diluting fentanyl 50μg.ml-1 to 25 or 10μg.ml-1 with 0.9% saline and prolonged injection time on fentanyl-induced cough. Two hundred patients requiring general anaesthesia were randomly allocated into four groups: 50μg.ml-1 (Group I), 25μg.ml-1 (Group II), 10μg.ml-1 (Group III) or 10μg.ml-1 combined with prolonged injection (Group IV). Fentanyl 3μg.kg-1 was administered within 5 s in Groups I, II, and III, or over 30 s in Group IV. Occurrence of cough was significantly reduced in Group IV (2%vs 32%, 16% and 12% in Groups I, II and III, respectively, p < 0.05). There were no statistically significant differences in the severity of coughing between the four groups (p > 0.05). We conclude that dilution of fentanyl to 10μg.ml-1 with 0.9% saline combined with a prolonged injection time eliminates fentanyl-induced cough. © 2007 The Authors Journal compilation 2007 The Association of Anaesthetists of Great Britain and Ireland.