Intraoperative local anaesthesia for reduction of postoperative pain following general anaesthesia for dental treatment in children and adolescents.

Whilst carrying out dental procedures under general anaesthesia (GA), practitioners routinely give local anaesthetics (LA) intraoperatively to children. Local anaesthetics are used to help manage postoperative pain and reduce bleeding and the physiological response to procedures. Studies of effectiveness of intraoperative LA to date have reported contradictory results. To assess the effects of intraoperative local anaesthesia for reducing postoperative pain following general anaesthesia for dental treatment in children and young people aged 17 years or younger. We searched the following electronic databases: the Cochrane Oral Health Group Trials Register; the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2013, Issue 12), MEDLINE via OVID (1946 to 02 January 2014), EMBASE via OVID (1980 to 02 January 2014) and Web of Science Conference Proceedings (1990 to 02 January 2014). We searched for ongoing trials in the US National Institutes of Health Register, the metaRegister of Controlled Trials (mRCT) and the International Federation of Pharmaceutical Manufacturers & Associations (IFPMA) Clinical Trials Portal. We did not place any restrictions on the language or date of publication when searching the electronic databases. Randomised controlled trials in which local anaesthetic was given intraoperatively under general anaesthesia for dental treatment of children and young people aged 17 years or younger. We used standard methodological procedures expected by The Cochrane Collaboration. We performed data extraction and assessment of risk of bias independently and in duplicate. We contacted authors to clarify omissions in trial reports. In the 'Summary of findings' tables, we elected to report the outcomes pain, distress, postoperative bleeding, and physiological parameters related to the general anaesthetic, as we considered these to be the outcomes of greatest importance to readers of the review. We included 14 trials in this review, with 1152 randomised participants. The studies were published between 1990 and 2009 and were conducted in the United Kingdom, Egypt, Saudi Arabia, and the United States. The age of participants ranged from 2 to 40 years. Three studies were at an overall high risk of bias, seven studies were at an unclear risk of bias, and we judged four studies to be at low risk of bias. The clinical heterogeneity of the included studies precluded pooling of studies in terms of method of administration of LA (e.g., intraligamental injection, infiltration injection, or topical delivery) and variation in the use of supplementary analgesics and follow-up time.Of the seven studies where administration of LA was by infiltration injection, six studies (very low-quality body of evidence, 542 participants analysed, 1 study had overall high risk of bias, 4 studies had overall unclear risk of bias, 1 study had overall low risk of bias) measured postoperative pain. The results were equivocal. There was a decrease in bleeding and increase in soft tissue damage in the LA groups, but we did not judge this to be clinically significant.In the 2 studies where administration of LA was by intraligamental injection, there was no difference in mean pain scores, and they did not report any soft tissue damage (very low-quality body of evidence, 115 participants analysed, 1 study had overall high risk of bias, 1 study had overall unclear risk of bias).One 3-armed study (very low-quality body of evidence, 54 participants analysed, overall high risk of bias) compared the effects of intraligamental and infiltration LA injection with no treatment. There was no evidence of a mean difference in pain, distress, or postoperative anxiety among the three groups.Four studies (very low-quality body of evidence, 343 participants analysed, 2 studies had overall low risk of bias, 2 studies had overall unclear risk of bias) evaluated the effects of topical LA compared with no treatment or placebo. One study (overall unclear risk of bias) with a no-treatment comparator reported lower mean pain in the LA group; all other studies reported no difference in mean pain scores. Two studies reported on bleeding (overall unclear risk of bias): One study reported a clinically insignificant increase in bleeding with no treatment; the other reported no difference.None of the studies reported on participant or child satisfaction. In this review, it was difficult to reach firm conclusions as to the benefit of using local anaesthetic for dental treatment under general anaesthesia. The information reported in the included studies was comprehensive and applicable to the review question, but ultimately it was not sufficient to address the objective of the review. We were unable to pool the included studies in a meta-analysis because of substantial variation in outcome measures, interventions, and treatment types. The use of supplementary analgesia further obscured the effect of local anaesthetics.Based on the literature review and the results of this review, we recommend further randomised controlled trials that minimise bias through adequate allocation concealment and blinding of participants and assessors, and assess the effect of intraoperative local anaesthetic on the volume and type of anaesthetic used and on the cardiovascular system in participants receiving supplementary analgesics as well. Researchers should give consideration to the impact of any changes on the health and well-being of the participant and report baseline measures of pain or distress, or both, and preoperative anxiety.