The Effective Pressure Value of an Inflatable Wedge in Preventing Postoperative Backache following Surgical Operation in the Lithotomy Position

Koo, Hui Wan; Son, Ji Seon; Choe, Huhn; Han, Young Jin; Lee, Jun Rae; Lee, Jeong Woo

Abstract

BACKGROUND: Backache is a common complication following anesthesia and surgery. Previous studies indicated that the use of a lumbosacral wedge was effective in reducing the incidence of postoperative backache. We investigated the effective inflation pressure of an inflatable wedge in preventing postoperative backache following spinal anesthesia and surgery in the lithotomy position.
METHODS
A pilot study established a mean comfortable pressure for the wedge when used to support the lumbar curvature. In males and females, the mean pressure values were 23.6 +/- 3.1 mmHg and 18.9 +/- 3.7 mmHg, respectively. The design of the main study was a randomized, controlled trial involving the use of a wedge intra-operatively in patients undergoing spinal anesthesia and urological surgery in the lithotomy position. Fifty male and 50 female patients were included in the main study and randomly allocated to the control or study group. In the study group, the wedge was inserted immediately after the induction of anesthesia and maintained during surgery. On the first day after surgery, all patients were asked whether they had backache. If there was backache, the degree of pain was noted using the numeric rating scale (NRS).
RESULTS
In the study and control groups of male patients, the incidence of backache was 16% and 24%, respectively. There was no significant difference between the two groups. In the study and control groups of female patients, the incidence of backache was 20% and 52%, respectively (P < 0.05). Where backache occurred, there was no significant difference in its severity between the study and control groups.
CONCLUSIONS
The effective pressure value of an inflatable wedge in preventing postoperative backache following spinal anesthesia and surgical operation in lithotomy position was 19 mmHg in female patients.