PEARLS 214, November 2009, written by Brian R McAvoy

Clinical question
How effective are local anaesthetic agent wound infiltration/irrigation and/or abdominal nerve block on post-caesarean section pain and the mother's wellbeing and interaction with her baby?  

Bottom line
In general, local anaesthetic wound infiltration was of benefit in women having a caesarean section requiring regional anaesthetics because of a reduction in the use of opioid analgesia compared to placebo (ranging from 22% to 52% across the 3 trials reviewed). Women undergoing general anaesthesia who had wound infiltration with local anaesthetics and peritoneal spraying required lower amounts of opioids in the first 24 hours post surgery compared to saline control. Those who had a general anaesthetic and abdominal wall nerve block had reduced pain scores within the first 24 hours post surgery. Non-steroidal antiinflammatory drugs provided additional pain relief but with more side effects of pruritus. There was no report of side effects in infants following local anaesthetic infiltration but the number of women studied was small.  

Caveat
Significant results must be regarded with caution because of testing at multiple times, and the results being mostly based on single trials involving few women. The longer theatre time and cost of the local anaesthetic may be offset by less use of postoperative analgesia.  

Context
Caesarean section delivery is becoming more frequent. Postoperative opioids cause sedation and may interfere with bonding, and they can transfer to breast milk, also sedating the newborn infant.  

Cochrane Systematic Review
Bamigboye AA and Hofmeyr GJ. Local anaesthetic wound infiltration and abdominal nerves block during caesarean section for postoperative pain relief. Cochrane Reviews 2009, Issue 3. Article No. CD006954. DOI: 10.1002/14651858.CD006954.pub2. This review contains 20 studies involving 1150 participants.