Effect of surgical incision on pain and respiratory function after abdominal surgery: a randomized clinical trial

The aim of the present study was to assess the severity of respiratory disturbances occurring after abdominal surgery and to identify surgical incisions that entail the least respiratory complications and postoperative pain.

A total of 105 patients divided into two groups were included in this randomized clinical trial. Seventy-five patients in the first group underwent upper abdominal surgery, and were operated on by use of vertical, oblique, transverse and elliptic incision. The remaining 30 patients in the second group were submitted to low abdominal surgery by use of vertical and oblique incision. Arterial blood gases and pulmonary shunt development were determined at 12 h preoperatively, and at 6 h, 72 h and 144 h postoperatively. During the postoperative course, VAS-pain score and use of tramadol were observed according to the type of surgical incision employed.

Most severe respiratory disturbances in terms of PaO2 decrease, activating compensatory hyperventilation, pulmonary shunt increase, the highest VAS-pain score and consumption of tramadol were induced by the following upper abdominal incisions: transversal laparotomy according to Orr, elliptic periumbilical laparotomy, upper midline laparotomy, transrectal laparotomy and subcostal laparotomy. In the group of low abdominal surgery (low midline laparotomy and inguinal incision) consumption of tramadol was statistically significantly lower, but no statistically significant differences were recorded between the baseline preoperative and postoperative values of PaO2, PaCO2 and pulmonary shunt.

All low abdominal incisions were found to entail statistically significantly less respiratory disturbances, lower VAS-pain score and lower tramadol use when compared to upper abdominal incisions. The upper abdominal incisions observed caused substantial respiratory disturbances including hypoxia, hyperventilation and pulmonary shunt increase.