Skin to posterior lumbar epidural space distance

To measure the clinically relevant skin to posterior lumbar epidural space distance in adult surgical patients and to correlate this distance with the patient physical factors to construct a model for the prediction of this distance using the correlation.

A cross-sectional study.

Department of Anaesthesiology, P.A.F Hospital, Islamabad over a period of 18 months from 1st January 2003 to 30th June 2004.

The study was carried out in 100 patients divided into three groups, who were scheduled for different surgical procedures. Group-I consisted of female patients scheduled for lower segment caesarian section (L.S.C.S); group-II adult non-pregnant females undergoing elective surgery and group-III adult males undergoing different surgical procedures. Epidural anaesthesia was given, using loss of resistance (LOR) technique, and skin to posterior epidural space was measured.

The mean skin to posterior lumbar epidural space distance was found to be 3.8+/-0.5 cm in group-I, 3.76+/-0.7 cm in group-II and 4.0+/-0.5 cm in group-III. Skin to posterior epidural space distance correlates best with weight of the patient.

Posterior lumbar skin to epidural space distance has been found to be less than what is normal in rest of the world. These results may be used as a guideline for performing successful epidural blocks in Pakistani population. A reliable model using patient physical factors to predict skin to posterior epidural space distance could not be constructed.