The September issue of the journal Anesthesiology features a study showing that "continuous wound infusion" with the local anesthetic ropivacaine reduces pain, morphine use, and hospital time after colorectal cancer surgery. "This method offers a new way to efficiently and simply manage pain after open major abdominal surgery," comments lead author Dr. Marc Beaussier of St-Antoine University Hospital, Paris.
The study included 42 patients undergoing surgery for colorectal cancer. Toward the end of the procedure, a special multi-holed catheter (tube) was placed in the deepest layer of the surgical wound, outside the abdominal cavity. Patients were then randomly assigned to receive one of two solutions through the catheter: a solution containing the widely used local anesthetic ropivacaine or an inactive placebo solution.
Treatment continued for the first 48 hours after surgery. Both groups received patient-controlled morphine, the standard treatment for pain after major surgery.
Pain scores after surgery, both at rest and during coughing, were significantly lower for patients receiving ropivacaine. Patients in the ropivacaine group also had better sleep quality the first two nights after surgery, compared with the placebo group.
Patients receiving ropivacaine also needed less morphine to control pain in the days following surgery—another key indicator of improved pain control. Rates of common morphine side effects were similar between groups, although a larger study might have detected a significant difference.
Some indicators of postoperative recovery were also better in the ropivacaine group. Normal bowel function returned an average of one day earlier in patients receiving ropivacaine, compared to the placebo group. This is important, because patients cannot be sent home from the hospital before bowel function has resumed.
The average hospital stay was also shorter for patients receiving ropivacaine: just under five days, compared to more than six days for the placebo group. Throughout the study, ropivacaine levels in the patients' blood remained well within safe limits.
The new results suggest that the deep local anesthesia using a multi-holed catheter is an effective new option for pain control after surgery for colorectal cancer and other abdominal operations. "This technique is simple, efficient, and safe," says Dr. Beaussier. "It does not need specific supervision and could be proposed to almost all patients." With the reduction in hospital stay, cost savings could be expected as well.
In an accompanying editorial, Drs. Henrik Kehlet and Spencer S. Liu write, "The peripheral use of continuous wound infusion of local anesthetics represents an effective analgesic technique which due to its simplicity may find its way to be an important instrument in our analgesic armamentarium across several major surgical procedures." Further studies will be needed to compare continuous wound infusion with other local anesthetic techniques, and to document the other benefits beyond pain control.