Patient-controlled extradural analgesia after caesarean section: a comparison between tramadol, sufentanil and a mixture of both.

In a double-blind randomised study into post-operative pain relief by extradural PCA, 66 Caesarean section patients were divided in to three groups to receive either sufentanil (2 µ g/ml), tramadol (10 mg/ml) or a mixture of both. After a loading dose of 10 ml, patients were allowed to ask for additional boluses of 2.5 ml, respecting a lock-out time of 10 min and a 1-h limit of 10 ml.