Pain relief for neonatal circumcision

Circumcision is a painful procedure that many newborn males undergo in the first few days after birth. Interventions are available to reduce pain at circumcision; however, many newborns are circumcised without pain management.

The objective of this review was to assess the effectiveness and safety of interventions for reducing pain at neonatal circumcision.

We searched Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 2, 2004), MEDLINE (1966 - April 2004), EMBASE (1988 - 2004 week 19), CINAHL (1982 - May week 1 2004), Dissertation Abstracts (1986 - May 2004), Proceedings of the World Congress on Pain (1993 - 1999), and reference lists of articles. Language restrictions were not imposed.

Randomised controlled trials comparing pain interventions with placebo or no treatment or comparing two active pain interventions in male term or preterm infants undergoing circumcision.

Two independent reviewers assessed trial quality and extracted data. Ten authors were contacted for additional information. Adverse effects information was obtained from the trial reports. For meta-analysis, data on a continuous scale were reported as weighted mean difference (WMD) or, when the units were not compatible, as standardized mean difference.

Thirty-five trials involving 1,984 newborns were included. Thirty-three trials enrolled healthy, full term neonates, and two enrolled infants born preterm. Fourteen trials involving 592 newborns compared dorsal penile nerve block (DPNB) with placebo or no treatment. Compared to placebo/no treatment, DPNB demonstrated significantly lower heart rate [WMD -35 bpm, 95% CI -41 to -30], decreased time crying [WMD -54 %, 95% CI -64 to -44], and increased oxygen saturation [WMD 3.2 %, 95% CI 2.7 to 3.7]. Six trials involving 190 newborns compared eutectic mixture of analgesics (EMLA) with placebo. EMLA demonstrated significantly lower facial action scores [WMD -46.5, 95% CI -80.4 to -12.6], decreased time crying [WMD - 15.8 %, 95% CI -20.8 to -6.8] and lower heart rate [WMD -15 bpm, 95% CI -19 to -10]. DPNB, compared with EMLA in four trials involving 164 newborns, demonstrated significantly lower heart rate [WMD -17 bpm, 95% CI -23 to -11] and pain scores. When compared with sucrose in two trials involving 126 newborns, DPNB demonstrated less time crying [MD -166 s, 95% CI -211 to -121], and lower heart rate [WMD -27 bpm, 95% CI -33 to -20]. Results obtained for trials comparing oral sucrose and oral analgesics to placebo, and trials of environmental modification were either inconsistent or were not significantly different. Adverse effects included gagging, choking, and emesis in placebo/untreated groups. Minor bleeding, swelling and hematoma were reported with DPNB. Erythema and mild skin pallor were observed with the use of EMLA. Methaemoglobin levels were evaluated in two trials of EMLA, and results were within normal limits.

DPNB was the most frequently studied intervention and was the most effective for circumcision pain. Compared to placebo, EMLA was also effective, but was not as effective as DPNB. Both interventions appear to be safe for use in newborns. None of the studied interventions completely eliminated the pain response to circumcision.