Canadian Journal of Anesthesia, Vol 39, 337-341, Copyright © 1992 by Canadian Anesthesiologists' Society

ARTICLES

[Peridural anesthesia for surgery of the ankle and foot: effect of the sitting position]

P Gosteli, Z Gamulin, E Van Gessel and A Forster
Departement d'Anesthesiologie, Hopital Cantonal Universitaire, Geneve, Suisse.

The effects of the sitting position on the quality of both sensory and motor blockade of segments L5 and S1 and the haemodynamic consequences during epidural anaesthesia were studied on 39 patients undergoing ankle or foot surgery. After insertion of an epidural catheter with the patient in the lateral position, 19 patients were kept sitting for 15 min following the injection of the local anaesthetic and 20 remained supine for the duration of anaesthesia (control group). All patients received a dose of 20 ml of 1.73% carbonated lidocaine with epinephrine 1:200,000. The quality and time of onset of the sensory blockade for segments L1-S2 as well as its cephalad spread were comparable in both groups. Fourteen patients of the sitting group achieved motor blockade of more than three of five myotomes compared with five patients in the supine group (P less than 0.001). The maximum decrease in mean arterial pressure occurred sooner in the sitting group (14 +/- 9 min) than in the control group (21 +/- 10 min; P less than 0.01) and was more severe (-24 +/- 10% vs -16 +/- 10% respectively; P less than 0.05). Our results indicate that placing the patient in the sitting position for 15 min after inducing epidural anaesthesia does not influence caudal sensory blockade but does increase the depth of motor blockade.