[Different opioids in patients at cardiovascular risk. Comparison of central and peripheral hemodynamic adverse...

Efficient analgesia may be the major objective in the cardiovascular risk patient following myocardial infarction, acute occlusion of peripheral vessels, or dissection/perforation of major abdominal vessels. It was the purpose of the study to investigate the haemodynamic and respiratory side effects of eight different opioids in 57 circulatory risk patients prior to major vascular surgery. METHODS. Patients were randomly allocated to eight groups, each receiving a different opioid within a clinical, equipotent dose range (buprenorphine, fentanyl, morphine, nalbuphine, pentazocine, pethidine, tramadol, alfentanil). A complete haemodynamic and blood gas status was obtained prior to as well as 5, 10, 15, and 20 min following opioid administration. Monitoring included a complete invasive haemodynamic and blood gas status. Statistical evaluation was performed by 1- and 2-factorial ANOVA (P < 0.05). RESULTS. Significant time effects (changes from baseline at the time of measurement) were observed for heart rate and total peripheral resistance, while significant group (group-specific differences in the course of values at the different times of measurements) and time effects were noted for mean pulmonary artery pressure, pulmonary capillary wedge pressure, stroke volume index, and PaO2. No major effects were observed following morphine, fentanyl, alfentanil, tramadol, and nalbuphine. Buprenorphine caused distinct respiratory depression accompanied by an increase in pulmonary vascular tone. Pentazocine and pethidine caused a significant increase in MPAP and peripheral vascular resistance while pethidine also produced marked respiratory depression. CONCLUSIONS. For interpretation of the results, factors such as respiratory depression, histamine release, secretion of endogenous catecholamines, and hypoxia-induced pulmonary vasoconstriction have to be discussed. Tramadol, an opioid with moderate potency, seems to offer some advantages due to its minor cardiovascular and respiratory side effects.