[Value of morphine derivatives administered by the peridural route per- and postoperatively]

The existence of opiate receptors in the spinal cord led the authors to seek a clinical application. 1 - A peroperative injection of morphine was administered in 170 cases: 0.005 mg/kg of fentanyl in 105 cases and 0.05 mg/kg of morphine in 65 cases. In addition to usual surveillance (blood pressure, heart rate and central venous pressure), more extensive haemodynamic investigations were undertaken in 20 patients using a Swan-Ganz catheter. Blood concentrations (11 cases) and CSF concentrations (2 cases for each time of measurement) were determined in the case of fentanyl. In 20 patients (10 of whom had received fentanyl and 10 morphine) there was sophisticated cardio-respiratory surveillance postoperatively. 2 - 0.05 mg/kg or morphine (404 cases), 50 mg of pethidine (10 cases) and 0.1 mg of fentanyl (10 cases) were injected postoperatively. A comparison was made of the analgesia obtained. After three types of anaesthesia: epidural with bupivacaine with intubation (10 cases), halothane with intubation (10 cases) and neuroleptanaesthesia (10 cases), an injection was given of 0.05 mg/kg of morphine, with cardiorespiratory surveillance. Results were as follows: 1 - There were no significant variations in haemodynamic parameters peroperatively, indicative of adequate analgesia. Blood concentrations of fentanyl were as follows: 3.2 +/- 2.1 ng/ml after 10 minutes, 2 +/- 1.7 ng/ml after one hour, 1.4 +/- 1 ng/ml after two hours and 0.4 +/- 0.3 ng/ml after four hours. CSF concentrations were much higher; 34 ng/ml after one hour, 30 ng/ml after two and three hours and 25 ng/ml after four hours. No cardio-respiratory depression was seen after the peroperative injection of morphine. 2- The duration of analgesia following a postoperative injection of a morphine derivative was as follows: morphine 17.3 +/- 3.9 hours, pethidine 3.5 +/- 0.5 hours, and fentanyl 5.1 +/- 0.7 hours. The epidural injection of morphine after neuroleptoanaesthesia caused respiratory depression in two of the 10 cases, with a rise in pCO2 of 0.45 and 0.52 KPa. The results are discussed and compared with those of other authors. In conclusion, the authors emphasize the advantages of this method which makes it possible to obtain with smaller doses analgesia of longer duration than following a systemic injection of morphine, whilst at the same time decreasing the side effects.