[Shoulder-tip pain during cesarean section under combined spinal-epidural anesthesia]

Although shoulder-tip pain during cesarean section has been reported, little is known about this entity. We investigated the incidence of shoulder-tip pain in patients undergoing cesarean delivery under combined spinal-epidural anesthesia (CSEA). Next, we studied whether head-up position during surgery reduced the incidence of shoulder-tip pain due to prevention of the spread of blood and amniotic fluid from the subphrenic space.

Women with ASA physical status I or II undergoing elective or emergency cesarean delivery under CSEA at our hospital were enrolled in this study. In all women, it was investigated whether shoulder-tip pain occurred or not during and after cesarean delivery. In some of the parturient women in this study, 2 to 5 degree head-up position was employed during the operation (head-up group). We compared the frequency of shoulder-tip pain in the head-up group with that in women who were maintained in a horizontal position (horizontal group).

One hundred and twelve of the 242 women recruited to this study experienced shoulder-tip pain. The pain was usually mild to moderate and was relieved in a few days, but 14 patients experienced severe pain as "can not breathe". One hundred and twenty-six of the 160 women lying on an operating table in a head-up position were classified as a head-up group. Shoulder-tip pain was less frequent in the head-up group than horizontal group (50/126 vs. 62/164, P < 0.05).

This study showed that women undergoing cesarean section under CSEA experience shoulder-tip pain with great frequency. Head-up position during surgery decreases shoulder-tip pain during and after cesarean delivery. The results suggest that one of the causes of this pain is the presence of blood or amniotic fluid in the subdiaphragmatic region.