[Plethysmographic study on sympathetic block in peridural anaesthesia and peridural morphine analgesia (author's transl)].

Plethysmographic measurements were performed in 10 patients after peridural anaesthesia and peridural morphine analgesia. The arterial blood flow was increased after peridural anaesthesia. No increased venous pooling followed. After peridural morphine analgesia there are no changes of arterial blood flow and venous capacity. The peridural morphine analgesia represents no haemodynamic risk, because there is no sympathetic block