Updates on Wound Infiltration Use for Postoperative Pain Management: A Narrative Review

Overview

This narrative review updates the evidence on wound infiltration for pain after surgery in adults. It covers both single injection of local anaesthetic into the surgical wound and continuous infusion through catheters placed in the wound. It is a focused synthesis of published studies, not a formal guideline. Studies were not graded, and children and plastic surgery were excluded. The authors aim to encourage wound infiltration as one step in multimodal pain management.

Technique

Effective infiltration requires knowing the anatomy and where the pain comes from in each procedure. The anaesthetic is placed systematically in all tissue layers along the whole wound, under direct vision before closure, or along the planned incision. In abdominal surgery, deeper infiltration between the muscle and the peritoneum works better than superficial injection. Infiltration before the incision is theoretically preferable but rarely studied, and in practice it is usually done at the end of surgery. Continuous infiltration prolongs pain relief and reduces opioid use more than a single injection, but it needs catheters, pumps and trained staff. The only contraindications are infection at the site, true allergy and patient refusal.

Safety

The main risk is systemic toxicity from the local anaesthetic. The total dose should therefore be calculated across all techniques used, based on ideal body weight and individual risk factors, and given in small increments with resuscitation measures at hand. Other complications, such as wound infection, haematoma, bruising and catheter problems, are uncommon. Infection rates do not exceed the usual rate for each operation, provided catheters are handled with aseptic, non-touch technique.

Evidence by type of surgery

The review covers cardiac, thoracic, abdominal, breast, thyroid, neurosurgical, urological, gynaecological, orthopaedic, day-case and trauma surgery. Benefit is best documented in open abdominal procedures such as caesarean section, colorectal surgery, hysterectomy and hernia repair, and in laparoscopic gallbladder removal, cancer breast surgery, laminectomy, bunion surgery and radical prostatectomy. This matches procedure-specific international recommendations. In other areas results are mixed, and some nerve blocks give better pain relief.

Implications

The place of wound infiltration in enhanced recovery (ERAS) protocols varies between specialties. The authors see it as a simple, low-cost and safe option, especially when other regional techniques are contraindicated and in frail, older or obese patients. They propose a checklist for planning and follow-up and call for research on individualised dosing, longer-acting formulations and possible immune effects in cancer surgery.