[Use of EMLA cream in premature and full-term newborn infants. Study of efficacy and tolerance]

Topical anaesthesia for needle-related pain in newborn infants

BACKGROUND

Hospitalised newborn neonates frequently undergo painful invasive procedures that involve penetration of the skin and other tissues by a needle. One intervention that can be used prior to a needle insertion procedure is application of a topical local anaesthetic.

OBJECTIVES

To evaluate the efficacy and safety of topical anaesthetics such as amethocaine and EMLA in newborn term or preterm infants requiring an invasive procedure involving puncture of skin and other tissues with a needle.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase and CINAHL up to 15 May 2016; previous reviews including cross-references, abstracts, and conference proceedings. We contacted expert informants. We contacted authors directly to obtain additional data. We imposed no language restrictions.

SELECTION CRITERIA

Randomised, quasi-randomised controlled trials, and cluster and cross-over randomised trials that compared the topical anaesthetics amethocaine and eutectic mixture of local anaesthetics (EMLA) in terms of anaesthetic efficacy and safety in newborn term or preterm infants requiring an invasive procedure involving puncture of skin and other tissues with a needle DATA COLLECTION AND ANALYSIS: From the reports of the clinical trials we extracted data regarding clinical outcomes including pain, number of infants with methaemoglobin level 5% and above, number of needle prick attempts prior to successful needle-related procedure, crying, time taken to complete the procedure, episodes of apnoea, episodes of bradycardia, episodes of oxygen desaturation, neurodevelopmental disability and other adverse events.

MAIN RESULTS

Eight small randomised controlled trials met the inclusion criteria (n = 506). These studies compared either EMLA and placebo or amethocaine and placebo. No studies compared EMLA and amethocaine. We were unable to meta-analyse the outcome of pain due to differing outcome measures and methods of reporting. For EMLA, two individual studies reported a statistically significant reduction in pain compared to placebo during lumbar puncture and venepuncture. Three studies found no statistical difference between the groups during heel lancing. For amethocaine, three studies reported a statistically significant reduction in pain compared to placebo during venepuncture and one study reported a statistically significant reduction in pain compared to placebo during cannulation. One study reported no statistical difference between the two groups during intramuscular injection.One study reported no statistical difference between EMLA and the placebo group for successful venepuncture at first attempt. One study similarly reported no statistically significant difference between Amethocaine and the placebo group for successful cannulation at first attempt.Risk for local redness, swelling or blanching was significantly higher with EMLA (typical risk ratio (RR) 1.65, 95% confidence interval (CI) 1.24 to 2.19; typical risk difference (RD) 0.17, 95% CI 0.09 to 0.26; n = 272; number needed to treat for an additional harmful outcome (NNTH) 6, 95% CI 4 to 11; I² = 92% indicating considerable heterogeneity) although not for amethocaine (typical RR 2.11, 95% CI 0.72 to 6.16; typical RD 0.05, 95% CI -0.02 to 0.11, n = 221). These local skin reactions for EMLA and amethocaine were reported as short-lasting. Two studies reported no methaemoglobinaemia with single application of EMLA. The quality of the evidence on outcomes assessed according to GRADE was low to moderate.

AUTHORS' CONCLUSIONS

Overall, all the trials were small, and the effects of uncertain clinical significance. The evidence regarding the effectiveness or safety of the interventions studied is inadequate to support clinical recommendations. There has been no evaluation regarding any long-term effects of topical anaesthetics in newborn infants.High quality studies evaluating the efficacy and safety of topical anaesthetics such as amethocaine and EMLA for needle-related pain in newborn term or preterm infants are required. These studies should aim to determine efficacy of these topical anaesthetics and on homogenous groups of infants for gestational age. While there was no methaemoglobinaemia in the studies that reported methaemoglobin, the efficacy and safety of EMLA, especially in very preterm infants, and for repeated application, need to be further evaluated in future studies.

Analgesic effects of EMLA cream and oral sucrose during venipuncture in preterm infants

OBJECTIVE

The goal of this study was to compare the analgesic effect of sucrose with that of the combination of sucrose and the local anesthetic cream EMLA during venipuncture in preterm neonates.

METHODS

This randomized, double-blind prospective study included infants younger than 37 weeks' gestational age during 1 routine venipuncture for blood sampling. Each child randomly received either sucrose plus application of a placebo cream (S group) or sucrose plus EMLA cream (S+E group) before venipuncture. Venipuncture-induced pain was assessed through videotapes of the procedures by using the Douleur Aiguë Nouveau-né (DAN) behavioral scale. Pain was assessed at 2 phases: during venipuncture (from needle introduction to its removal) and during the recovery period (30 seconds after needle removal). Pain scores over time and between treatments were compared by using repeated-measures analysis of variance.

RESULTS

The study included 76 children (37 in the S group, 39 in the S+E group). Mean (SD) DAN pain scores for the S group and the S+E group were 7.7 (2.1) and 6.4 (2.5), respectively, during venipuncture and 7.1 (2.8) and 5.7 (3.3) during the postinjection period. A significant time and treatment effect in favor of the S+E group was observed.

CONCLUSION

The combination of sucrose and EMLA cream revealed a higher analgesic effect than sucrose alone during venipuncture in these preterm infants.

Topical anesthesia in neonates: clinical practices and practical considerations

During the past two decades there has been a substantial increase in the number and types of topical anesthetics available. Options for the prevention of neonatal pain associated with skin-breaking procedures were previously limited to injections of lidocaine hydrochloride. Topical anesthetics are now available as creams, gels, and a heat-activated patch system. Although lidocaine injection continues to be widely used for pain associated with circumcision, lumbar puncture, or placement of central venous lines, practical information regarding the use of newer agents in the neonate is needed. This review seeks to expand the options for topical anesthesia in neonates.

Sensorial saturation for neonatal analgesia

AIM

Sensorial saturation (SS) is a procedure in which touch, massage, taste, voice, smell, and sight compete with pain, producing almost complete analgesia during heel prick in neonates. SS is an apparently complex maneuvre, but when correctly explained it is easily learnt. In the present paper, we studied its feasibility, assessing whether a long training is really needed to achieve good results.

MATERIALS AND METHODS

We enrolled 66 consecutive babies and divided them randomly into 3 groups which received the following forms of analgesia: glucose plus sucking (A), SS performed by nurses (B), SS performed by mothers (C). We did not use perfume on the caregivers' hands, so that babies could smell the natural scent of the hands. We assessed pain level by the ABC scale.

RESULTS

Median scores of groups A, B, and C were: 1 (0 to 6), 0 (0 to 4), and 0 (0 to 6), respectively. Mean scores were: 0.6, 0.6, and 1.7 and standard errors were 0.38, 0.22, and 0.32, respectively. Scores of groups B and C were significantly lower than that of A (P=0.03 and 0.006, respectively). No significant difference was found between values of scores of groups B and C.

CONCLUSIONS

Even without the use of perfume on the hands, SS was effective as an analgesic maneuvre. It made no difference whether SS was performed by mothers who applied it for the first time or experienced nurses. SS is rapid to learn and any caregiver (mother, pediatrician or nurse) can effectively use it.

Analgesia and local anesthesia during invasive procedures in the neonate

BACKGROUND

Preterm and full-term neonates admitted to the neonatal intensive care unit or elsewhere in the hospital are routinely subjected to invasive procedures that can cause acute pain. Despite published data on the complex behavioral, physiologic, and biochemical responses of these neonates and the detrimental short- and long-term clinical outcomes of exposure to repetitive pain, clinical use of pain-control measures in neonates undergoing invasive procedures remains sporadic and suboptimal. As part of the Newborn Drug Development Initiative, the US Food and Drug Administration and the National Institute of Child Health and Human Development invited a group of international experts to form the Neonatal Pain Control Group to review the therapeutic options for pain management associated with the most commonly performed invasive procedures in neonates and to identify research priorities in this area.

OBJECTIVE

The goal of this article was to review and synthesize the published clinical evidence for the management of pain caused by invasive procedures in preterm and full-term neonates.

METHODS

Clinical studies examining various therapies for procedural pain in neonates were identified by searches of MEDLINE (1980-2004), the Cochrane Controlled Trials Register (The Cochrane Library, Issue 1, 2004), the reference lists of review articles, and personal files. The search terms included specific drug names, infant-newborn, infant-preterm, and pain, using the explode function for each key word. The English-language literature was reviewed, and case reports and small case series were discarded.

RESULTS

The most commonly performed invasive procedures in neonates included heel lancing, venipuncture, IV or arterial cannulation, chest tube placement, tracheal intubation or suctioning, lumbar puncture, circumcision, and SC or IM injection. Various drug classes were examined critically, including opioid analgesics, sedative/hypnotic drugs, nonsteroidal anti-inflammatory drugs and acetaminophen, injectable and topical local anesthetics, and sucrose. Research considerations related to each drug category were identified, potential obstacles to the systematic study of these drugs were discussed, and current gaps in knowledge were enumerated to define future research needs. Discussions relating to the optimal design for and ethical constraints on the study of neonatal pain will be published separately. Well-designed clinical trials investigating currently available and new therapies for acute pain in neonates will provide the scientific framework for effective pain management in neonates undergoing invasive procedures.

[Multicentric study on neonatal medical pain management in the Nord-Pas-de-Calais]

The aim of this study was to describe pain management for newborn infants in neonatal intensive care units and neonatal units in the Nord-Pas-de-Calais.

PATIENTS AND METHODS

A questionnaire was distributed to the 52 physicians practising in the six neonatal intensive care units and six neonatal units. The questions were in reference to pain assessment, treatment and prevention.

RESULTS

Forty questionnaires were completed (77%). Eleven units proclaimed an interest in neonatal pain management. The tool for assessing pain was the EDIN scale (Echelle Douleur Inconfort Nouveau-né, neonatal pain and discomfort scale). Analgesic treatment was administered in 100% of cases for the insertion of chest tube, in 92% of cases for the insertion of percutaneous central catheter in a ventilated newborn infant and in 91% of cases for necrotizing enterocolitis requiring a mechanical ventilation. Prescribed analgesic drugs were propacetamol, nalbuphin or fentanyl; a sedation by midazolam or diazepam was occasionally associated. Emla cream was used before lumbar puncture in 80% of cases in the neonatal intensive care units and in 92% of cases in the neonatal units. Three neonatal intensive care units and four neonatal units administered a sucrose solution for blood samples.

CONCLUSION

At the time of study, the interest in the pain of the physicians working in neonatal intensive care units and neonatal units was inadequate to guarantee an optimum management of pain in newborn infants. Physicians' approach remained heterogeneous.

Benefit and risks of local anesthetics in infants and children

Regional anesthesia has become a routine part of the practice of anesthesiology in infants and children. Local anesthetic toxicity is extremely rare in infants and children; however, seizures, dysrhythmias, cardiovascular collapse, and transient neuropathic symptoms have been reported. Infants and children may be at increased risk from local anesthetics compared with adults. Larger volumes of local anesthetics are used for epidural anesthesia in infants and children than in adults. Metabolism and elimination of local anesthetics can be delayed in neonates, who also have decreased plasma concentrations of alpha(1)-acid glycoprotein, leading to increased concentrations of unbound bupivacaine. Most regional anesthetic procedures in infants and children are performed with the patient heavily sedated or anesthetized; because of this, and because a test dose is not a particularly sensitive marker of intravenous injection in the anesthetized patient, detection of intravascular local anesthetic injection is extremely difficult. The same local anesthetics used in adult anesthetic practice are also used in infants and children. Because of its extremely short duration of action, chloroprocaine has been used primarily for continuous epidural techniques in infants and children. The use of tetracaine has generally been limited to spinal and topical anesthesia. Lidocaine (lignocaine) has been used extensively in infants and children for topical, regional, plexus, epidural and spinal anesthesia. The association between prilocaine and methemoglobinemia has generally restricted prilocaine use in infants and children to the eutectic mixture of local anesthetics (EMLA). Because of its greater degree of motor block compared with other long-acting local anesthetics, etidocaine has generally been limited to plexus blocks in infants and children. Mepivacaine has been used for both plexus and epidural anesthesia in infants and children. Because postoperative analgesia is often the primary justification for regional anesthesia in infants and children, bupivacaine, a long-acting local anesthetic, is the most commonly reported local anesthetic for pediatric regional anesthesia. Given the lower toxic threshold of bupivacaine compared with other local anesthetics, the risk-benefit ratio of bupivacaine may be greater than that of other local anesthetics. Two new enantiomerically pure local anesthetics, ropivacaine and levobupivacaine, offer clinical profiles comparable to that of bupivacaine but without its lower toxic threshold. The extreme rarity of major toxicity from local anesthetics suggests that widespread replacement of bupivacaine with ropivacaine or levobupivacaine is probably not necessary. However, there are clinical situations, including prolonged local anesthetic infusions, use in neonates, impaired hepatic metabolic function, and anesthetic techniques requiring a large mass of local anesthetic, where replacement of bupivacaine with ropivacaine, levobupivacaine or (for continuous techniques) chloroprocaine appears prudent.

Effect of multisensory stimulation on analgesia in term neonates: a randomized controlled trial

Many attempts have been made to obtain safe and effective analgesia in newborns. Oral glucose-water has been found to have analgesic properties in neonates. We investigated whether other sensory stimulation added to oral glucose provided more effective analgesia than oral glucose alone. In a randomized prospective double-blind trial, we studied 120 term newborns during heel prick. The babies were divided randomly into six groups of 20, and each group was treated with a different procedure during heel prick: A) control; B) 1 mL 33% oral glucose given 2 min before the heel prick; C) sucking; D) 1 mL 33% oral glucose plus sucking; E) multisensory stimulation including 1 mL 33% oral glucose (sensorial saturation); F) multisensory stimulation without oral glucose. Sensorial saturation consisted in massage, voice, eye contact, and perfume smelling during heel prick. Each heel prick was filmed and assigned a point score according to the Douleur Aiguë du Nouveau-né (DAN) neonatal acute pain scale. Camera recording began 30 s before the heel prick, so it was impossible for the scorers to distinguish procedure A (control) from B (glucose given 2 min before), C (sucking water) from D (sucking glucose), and E (multisensory stimulation and glucose) from F (multisensory stimulation and water) from the video. Procedure E (multisensory stimulation and glucose) was found to be the most effective procedure, and the analgesia was even more effective than that produced by procedure D (sucking glucose). We conclude that sensorial saturation is an effective analgesic technique that potentiates the analgesic effect of oral sugar. It can be used for minor painful procedures on newborns.

Does topical amethocaine gel reduce the pain of venepuncture in newborn infants? A randomised double blind controlled trial

BACKGROUND

Topical amethocaine provides effective pain relief during venepuncture in children, and has been shown to have a local anaesthetic action in the newborn.

AIM

To investigate the effect of topical amethocaine on the pain of venepuncture in the newborn.

DESIGN

Randomised double blind placebo controlled trial.

SUBJECTS

Forty newborn infants, gestation 27-41 weeks (median 33), age 2-17 days (median 7), undergoing routine venepuncture.

METHOD

A 1.5 g portion of 4% (w/w) amethocaine gel (Ametop; Smith and Nephew, Hull, UK) or placebo was applied to the skin under occlusion for one hour, then wiped away. Venepuncture was performed five minutes later. Facial reaction and cry were recorded on videotape. Pain was assessed using a validated adaptation of the neonatal facial coding system. Five features were scored at one second intervals for five seconds before and after venepuncture. No or minimal pain was defined as a cumulative score of below 10 (out of 25) in the five seconds after needle insertion. Each author scored the tapes independently.

RESULTS

There was close agreement on scoring of the tapes. One infant was excluded because of restlessness before the venepuncture. Of 19 amethocaine treated infants, 16 (84%) showed little or no pain compared with six of 20 (30%) in the placebo group (p = 0.001). The median cumulative neonatal facial coding system score over five seconds after needle insertion was 3 compared with 16 in the placebo group (p = 0.001). Of the 19 amethocaine treated infants, 15 (79%) did not cry compared with five of 20 (25%) placebo treated infants (p = 0.001). No local reaction to amethocaine was seen.

CONCLUSION

Topical amethocaine provides effective pain relief during venepuncture in the newborn.

Topical use of local anesthetics in neonates

INTRODUCTION

Various local anesthetics as in lidocaine ointment, amethocaine cream and EMLA cream are used topically for minor invasive interventions, such as venipuncture, both in children and adults. Since neonates have a nervous system that, albeit immature, enables them to feel pain, analgesia for these procedures is also indicated. Several studies in neonates have been carried out to establish effectiveness and safety of topically applied local anesthetics. These studies are reviewed in order to assess effectiveness and safety.

METHODS

A Medline search was made in order to review all studies on effectiveness and safety of topical use of local anesthetics in neonates. Effectivity or safety studies using local anesthetics for circumcision were rejected.

RESULTS

Seven studies on effectiveness were found: Three studies examined lidocaine ointment and four examined EMLA cream. Effectiveness of lidocaine ointment was questionable in two studies and negative in one. Effectiveness of EMLA cream was positive in two studies and negative in the other two. Four studies were found on safety of EMLA cream. All studies indicated that use of EMLA cream was safe.

DISCUSSION

The poor effectiveness found in the reviewed studies is possibly due to too long an application time, a lipophilic carrier used and difficulties in assessing pain. The time of application is often based upon studies in children. Since the skin of neonates acts more as a mucosa than as mature skin the local anesthetics are able to cross this barrier more rapidly. Also a high bloodflow in the heel enhances the uptake of the drug. The application time in neonates should therefore be reduced compared to children. The use of a lipophilic carrier should be avoided since a lipophilic carrier impedes the local anesthetic to be absorbed, leading to reduced effect. Various methods of pain assessment were being used. Since not all methods used are validated it is difficult to obtain an objective end point.

CONCLUSION AND RECOMMENDATION

The articles reviewed are non conclusive in their results of effective analgesia. Due to a lipophilic base form and a hydrophilic matrix EMLA cream is most effective. An application time of 30 minutes is recommended. In spite of the present precautions due to fear of methemoglobinemia, use of EMLA cream proved to be safe when used once a day. Since the clinical situation often requires more than one application a day, more research is needed to establish a safe and effective local anesthetic which can be applied topically several times a day in the neonate.

[Analgesia with saccharose during heel capillary prick. A randomized study in 37 newborns of over 33 weeks of amenorrhea]

BACKGROUND

To evaluate the efficiency of intraoral saccharose administration for analgesia among neonates born after at least 33 weeks of gestation.

POPULATION AND METHOD

Thirty-seven neonates from two neonatal units were tested using an objective scale of infants' pain. A double blind study of the heel prick response after saccharose vs. water administration was performed.

RESULTS

Prior administration of saccharose significantly reduced the pain reaction (1.24 vs. 2.24, P < 10(-5)).

CONCLUSION

The analgesia obtained after an intraoral saccharose administration can be useful for repeated punctures for which common procedures of analgesia are ineffective. Beyond its use for heel prick, this procedure could be proposed for venous punctures when ELMA analgesia is not possible.

Regional anesthesia and analgesia

Local and regional anesthetic techniques have a significant but limited place in the practice of infant pain control. In certain clinical circumstances, regional anesthetic techniques presumably afford many of the same advantages for the pediatric patient as in the adult patient. However, there are few controlled clinical trials on the advantages and adverse effects compared with conventional analgesic strategies. This article discusses the clinical application, effectiveness, safety, and outcomes of the available local and regional anesthetic techniques for control of postoperative and procedure-related pain in neonates and infants.

Randomised controlled trial of eutectic mixture of local anaesthetics cream for venepuncture in healthy preterm infants

AIM

To assess the safety and efficacy of EMLA cream (eutectic mixture of local anaesthetics) used to induce surface anaesthesia for venepuncture in healthy preterm infants.

METHODS

Nineteen infants, median gestational age 31 weeks (range 26-33 weeks) were assessed in a randomised, double blind, placebo controlled, cross-over trial. Changes in physiological variables (heart rate, blood pressure, oxygen saturation) and behavioural responses (neonatal facial coding system score, crying time) before and after venepuncture with EMLA cream were compared with those obtained with a placebo cream to assess efficacy. Toxicity was assessed by comparing methaemoglobin concentrations at 1 hour and 8 hours after application.

RESULTS

There was no significant difference in efficacy between EMLA and placebo creams in physiological and behavioural responses. There was no significant difference in methaemoglobin concentrations one hour after the cream had been applied. At eight hours, however, concentrations were significantly higher after EMLA than placebo (p = 0.016). There was no evidence of clinical toxicity.

CONCLUSION

This study does not support the routine use of EMLA for venepuncture in healthy preterm infants.

A systematic review of lidocaine-prilocaine cream (EMLA) in the treatment of acute pain in neonates

OBJECTIVE

Neonates routinely undergo painful cutaneous procedures as part of their medical treatment. Lidocaine-prilocaine 5% cream (EMLA) is a topical anesthetic that may be useful for diminishing the pain from these procedures. EMLA is routinely used in children and adults. There is substantial apprehension about its use in neonates because of concerns that it may cause methemoglobinemia. The objective of this review was to determine the efficacy and safety of EMLA as an analgesic for procedural pain treatment in neonates and provide evidence-based recommendations for clinical practice.

METHODS

Systematic review techniques were used. Studies were identified using manual and computer-aided searches (Medline, EMBASE, Reference Update, personal files, scientific meeting proceedings). Behavioral (eg, facial action, crying) and physiologic (eg, heart rate, oxygen saturation, blood pressure, respiratory rate) outcome data from prospective nonrandomized controlled studies and randomized controlled trials in full-term and preterm neonates were accepted for inclusion to establish efficacy of EMLA. The risk of methemoglobinemia (defined as methemoglobin concentration >5% and requiring medical intervention) was estimated from all prospective studies.

RESULTS

Eleven studies of the efficacy of EMLA were included in the analysis. Infant gestational age at the time of delivery ranged from 26 weeks to full-term. Two studies included data from both neonates and older infants. The following procedures were studied: circumcision (n = 3), heel lancing (n = 4), venipuncture (n = 1), venipuncture and arterial puncture (n = 1), lumbar puncture (n = 1), and percutaneous venous catheter placement (n = 1). Nine studies were randomized controlled trials. The total sample size for each study ranged from 13 to 110 neonates. The dose of EMLA used was 0.5 g to 2 g in 9 studies, and was not specified in the others. The duration of application ranged from 10 minutes to 3 hours. The three studies that investigated the efficacy of EMLA for decreasing the pain of circumcision used a randomized controlled trial design. All of them demonstrated significantly reduced crying time during the procedure in the infants in the EMLA group compared with the infants in the control group. Facial grimacing, assessed in two of the studies, was also significantly lower in the EMLA group. Using meta-analytic techniques, the heart rate outcome data for two studies was summarized. Increases in heart rate compared with baseline values were 12 to 27 beats per minute less for the EMLA group than in the placebo group during various stages of the surgical procedure. Three studies that investigated the pain from heel lancing were randomized controlled trials; the other was a nonrandomized controlled study. None demonstrated a significant benefit of EMLA for any of the outcome measures used to assess pain (ie, behavioral pain scores, infant crying, heart rate, blood pressure, respiratory rate, oxygenation parameters). One randomized controlled study of the pain from venipuncture showed that infants treated with EMLA had significantly lower heart rates and cry duration compared with infants treated with a placebo. In one nonrandomized study, a significantly lower behavioral pain score was observed for infants treated with EMLA compared with the control group. Infant heart rate, however, did not differ between the groups. In one randomized controlled study of pain from percutaneous venous catheter placement, EMLA resulted in a significantly lower increase in heart rate and respiratory rate. Behavioral pain scores were significantly lower during arterial puncture in one nonrandomized controlled study. EMLA did not reduce physiologic changes or behavioral pain scores in one randomized controlled trial in infants undergoing lumbar puncture. Meta-analytic techniques revealed that methemoglobin concentrations did not differ between EMLA-treated and placebo-treated infants (weighted mean di

Efficacy and safety of lidocaine-prilocaine cream for pain during circumcision

BACKGROUND

Neonatal circumcision is a painful surgical procedure often performed without analgesia. We assessed the efficacy and safety of 5 percent lidocaine-prilocaine cream (Emla) in neonates undergoing circumcision.

METHODS

We carried out a double-blind, randomized, controlled trial in 68 full-term male neonates: 38 were assigned to receive lidocaine-prilocaine cream, and 30 to receive placebo. One gram of lidocaine-prilocaine or placebo cream was applied to the penis under an occlusive dressing for 60 to 80 minutes before circumcision. Behavioral (facial activity and time spent crying) and physiologic (heart rate and blood pressure) responses were recorded during the procedure. Blood samples were obtained at various times after drug application for measurements of methemoglobin and plasma lidocaine, prilocaine, and o-toluidine (a metabolite of prilocaine).

RESULTS

A total of 68 and 59 neonates were included in the safety and efficacy analyses, respectively. Demographic characteristics such as gestational age and birth weight did not differ between the lidocaine-prilocaine and placebo groups. During circumcision, the neonates in the lidocaine-prilocaine group had less facial activity (P= 0.01), spent less time crying (P<0.001), and had smaller increases in heart rate (P=0.007) than the neonates in the placebo group. Facial-activity scores were 12 to 49 percent lower during various steps of the procedure in the lidocaine-prilocaine group. As compared with neonates in the placebo group, infants in the lidocaine-prilocaine group cried less than half as much and had heart-rate increases of 10 beats per minute less. Blood methemoglobin concentrations (expressed as a percentage of the hemoglobin concentration) were similar (1.3 percent) in both groups. Lidocaine and prilocaine were detected in plasma in 23 (61 percent) and 21 (55 percent) of the infants treated with lidocaine-prilocaine cream, respectively.

CONCLUSIONS

Lidocaine-prilocaine cream is efficacious and safe for the prevention of pain from circumcision in neonates.