Comparison of respiratory effects of tramadol and pethidine.
Tramadol is a centrally acting opioid with a low affinity for mu-opioid receptors, which has been claimed not to depress respiration as do the classic opioids. The respiratory effects of intravenous (i.v.) pethidine (0.6 mg kg-1) and tramadol (0.6 mg kg-1) were compared in 36 ASA Grade I-II patients in a placebo-controlled double-blind study. After induction of anaesthesia with propofol followed by suxamethonium-facilitated endotracheal intubation, the patients spontaneously breathed halothane in 70% nitrous oxide and oxygen via a non-rebreathing valve. Inspiratory and expiratory oxygen, and end-tidal carbon dioxide concentrations (PETCO2), tidal volume (VT), minute volume of ventilation (MV) and respiratory rate were monitored by a side-stream spirometry at an end-tidal halothane of 0.3%. The recordings were collected before surgery. Pethidine caused significant respiratory depression seen as an increase in fractional inspiratory-expiratory oxygen difference and PETCO2 and as a decrease in MV and respiratory rate. However, the effects of tramadol were similar to those of a placebo. Tidal volume was not affected by any study drug. In conclusion, tramadol 0.6 mg kg-1 was shown not to be associated with respiratory depression, unlike equipotent dose of pethidine in this setting.
Tarkkila
P
P
Department of Anaesthesia, Helsinki University Hospital, Finland.
Tuominen
M
M
Lindgren
L
L
D000328:Adult; D000701:Analgesics, Opioid / Q000009:adverse effects*; D001784:Blood Gas Analysis; D002245:Carbon Dioxide / Q000097:blood; D003864:Depression, Chemical; D004311:Double-Blind Method; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008297:Male; D008614:Meperidine / Q000009:adverse effects*; D008875:Middle Aged; D012119:Respiration / Q000187:drug effects*; D012129:Respiratory Function Tests; D014147:Tramadol / Q000009:adverse effects*
D000701:Analgesics, Opioid; D002245:Carbon Dioxide; D014147:Tramadol; D008614:Meperidine