Comparison of respiratory effects of tramadol and oxycodone.

STUDY

OBJECTIVE

To compare the respiratory effects of tramadol and oxycodone.

DESIGN

Placebo-controlled, double-blind randomized study.

SETTING

IV Department of Surgery, Helsinki University Central Hospital.

PATIENTS: 36 ASA physical status I and II patients undergoing minor surgery with general anesthesia.

INTERVENTIONS: The respiratory effects of intravenous (i.v.) tramadol 0.6 mg/kg and oxycodone 0.04 mg/kg were compared after induction of anesthesia with propofol and succinylcholine-facilitated endotracheal intubation. Patients spontaneously breathed halothane in 70% nitrous oxide and oxygen via a nonrebreathing valve. The trial drugs or placebo were given after recovery from neuromuscular block.

MEASUREMENTS AND MAIN

RESULTS

Inspiratory and expiratory oxygen and end-tidal carbon dioxide concentrations (ETCO2), tidal volume (VT) minute volume of ventilation (VE), and respiratory rate (RR) were recorded by side-stream spirometry with end-tidal halothane of 0.3% for 30 minutes before surgery. Oxycodone caused a significant respiratory depression seen as an increase in the inspiratory-expiratory oxygen difference and ETCO2 and as a decrease in VE and RR. On the contrary, the effect of tramadol were similar to those of placebo. VT was not affected by any study drug.

CONCLUSION

Tramadol was not associated with respiratory depression in the present setting.