[Shoulder pain after laparoscopic cholecystectomy]

To detect the mechanism of shoulder pain after laparoscopic cholecystectomy(LC).

Ninety patients who had receive LC were randomly divided into three groups (each 30 patients): group A, no management after LC; group B, absorption of residual CO2 after LC; group C, O2 insufflation for three times followed by complete absorption of CO2 after LC. PO2 and PCO2 before and after LC were recorded. Postoperative shoulder pain was assessed with shoulder pain's rate and level.

The PO2 difference of group C between before and after LC was significant as compared to groups A and B(P < 0.05). Postoperative shoulder pain developed in 13 patients (43.33%) of group A, in 8 (26.67%) of group B, and 21 (70%) of group C (P > 0.05 A vs B; P < 0.05 A vs C; and P < 0.01 B vs C). The shoulder pain's level was higher in group C than in groups A and B.

Direct irritation to the diaphragm due to the residual CO2 pneumoperitoneum is not the main cause of shoulder pain. The excessive traction of the triangular ligament and over-stretching of the diaphragmatic fibers due to insufflation are the main cause of shoulder pain.