New Wound Infiltration Technique Comparable to Epidural Analgesia in Reducing Postoperative Pain

Analgesia after abdominal surgery can be tricky, as good pain relief is often difficult to tailor to each patient’s needs. Traditional epidural analgesia is an option that causes less nausea and vomiting than opioids, but it isn’t always effective — given that one in four patients is unresponsive — and on rare occasions, patients experience epidural hematoma.

Wound infiltration with local anesthetic delivered continuously by catheter is increasingly popular, as it is generally less likely to cause systemic complications, and it lacks the side effects of opioids.

To determine whether that newer local anesthetic technique is superior to traditional epidural analgesia, researchers at the Royal Infirmary of Edinburgh in the United Kingdom conducted a meta-analysis comparing the two methods. The authors compared each method’s ability to relieve postoperative pain using a numerical rating scale, and they also investigated opiate requirements, nausea and vomiting, urinary retention, local catheter-related complications, and treatment failure for both techniques.

The researchers conducted their comparisons by using nine randomized controlled studies (n=505 patients). They found that patients’ resting pain scores at 24 hours and 48 hours after surgery — as well as those time points after surgery with movement — were similar for both epidural and wound infiltration analgesia. While epidural analgesia trended toward reduced pain scores on movement and reduced opiate requirements, those findings were insignificant. Patients in the wound catheter group had a lower incidence of urinary retention, though both patient groups had few catheter-related complications.

The researchers concluded that local anesthetic wound infiltration was associated with pain scores comparable to those obtained through epidural analgesia. Therefore, local anesthetic wound infiltration appears to be an acceptable alternative to epidural analgesia.