Original researchThe late effect of intraoperative wound infiltration with local anaesthetic in surgical patients; is there any? A randomized control trial

•Intraoperative wound infiltration (IOWI) with local anaesthetic (LA) is commonly in clinical practice.•Apart from the immediate action it has been supported that a down regulation of pain receptors may lead to longer effects.•This RCT aimed to answer this question: i.e whether there is a late effect of the wound infiltration with local anaesthetic.•IOWI with LA offers no further benefit apart from that of the immediate PO period. There is no late effect for pain control.

IntroductionIntraoperative wound infiltration with local anaesthetic is commonly used. Apart from the obvious immediate action it has been supported that a possible down regulation of pain receptors may lead to longer effects. Our aim was to compare the use of local anaesthetic versus placebo in order to assess if indeed there is a late beneficial effect.MethodsWe conducted an RCT involving 400 consecutive general surgery patients randomized in 2 groups: Group A = placebo, Group B = wound infiltration with 15 ml of ropivacaine 10%. We recorded the preoperative and postoperative pain for the 1st week as well as the type and quantity of the analgesia used during the study period.ResultsNo significant difference was found between the groups in all known confounding factors recorded. No significant difference was found in the intensity of postoperative pain. More people of group A required NSAIDs during the first 3 PO days while more people of Group B required stronger painkillers. For those patients who underwent a non urgent operation and especially laparoscopic surgery higher pain score was recorded in the group B from the 3rd PO day onwards.DiscussionIntraoperative local infiltration of the wound with local anaesthetic offers no further benefit for the general surgery apart from that of the immediate PO period. There is no late effect for pain control. Considering that during the immediate postoperative period stronger systematic painkillers are given the intraoperative, infiltration of the wound with the local anaesthetic under study offers no obvious benefit.