Pain perception and effectiveness of the eutectic mixture of local anesthetics in children undergoing venipuncture

New Lidocaine-Based Pharmaceutical Cocrystals: Preparation, Characterization, and Influence of the Racemic vs. Enantiopure Coformer on the Physico-Chemical Properties

This study describes the preparation, characterization, and influence of the enantiopure vs. racemic coformer on the physico-chemical properties of a pharmaceutical cocrystal. For that purpose, two new 1:1 cocrystals, namely lidocaine:dl-menthol and lidocaine:d-menthol, were prepared. The menthol racemate-based cocrystal was evaluated by means of X-ray diffraction, infrared spectroscopy, Raman, thermal analysis, and solubility experiments. The results were exhaustively compared with the first menthol-based pharmaceutical cocrystal, i.e., lidocaine:l-menthol, discovered in our group 12 years ago. Furthermore, the stable lidocaine/dl-menthol phase diagram has been screened, thoroughly evaluated, and compared to the enantiopure phase diagram. Thus, it has been proven that the racemic vs. enantiopure coformer leads to increased solubility and improved dissolution of lidocaine due to the low stable form induced by menthol molecular disorder in the lidocaine:dl-menthol cocrystal. To date, the 1:1 lidocaine:dl-menthol cocrystal is the third menthol-based pharmaceutical cocrystal, after the 1:1 lidocaine:l-menthol and the 1:2 lopinavir:l-menthol cocrystals reported in 2010 and 2022, respectively. Overall, this study shows promising potential for designing new materials with both improved characteristics and functional properties in the fields of pharmaceutical sciences and crystal engineering.

Chronic and cancer pain management

PURPOSE OF REVIEW

Chronic pain management in children is not recognized and treated adequately. The purpose of this review is to recognize some common chronic pain problems in children and offer guidelines for their management.

RECENT FINDINGS

This points to newer research in understanding complex regional pain syndromes-type 1 in children. This review will also discuss some recent findings regarding pain management techniques in children particularly the use of intravenous regional anesthesia for sympathetic blockade for complex regional pain syndromes-type 1. Cancer pain and headache with a logical step ladder management will be discussed.

SUMMARY

Although the under-treatment of chronic pain in children is still prevalent, it is important to understand the mechanisms and management of common pain problems in children and adolescents.

Morbidity assessment in sand flea disease (tungiasis)

Tungiasis, caused by the sand flea Tunga penetrans, is a health problem in many impoverished communities in Latin America, the Caribbean, and sub-Saharan Africa. Sand flea disease is associated with a broad spectrum of clinical and histological pathology. The factors determining the disease burden in endemic communities are not well understood, and severity of clinical pathology has never been assessed quantitatively. Thus, two severity scores were developed: one for acute disease and one for chronic sequels. These scores were evaluated in a cohort of 70 severely infested patients living in a shantytown in Fortaleza, a capital city in Northeast Brazil. Patients were examined during a period of 25 days and followed-up after a twice daily application of a plant-based repellent to prevent reinfestation. The severity score for acute disease symptoms significantly correlated with the infestation rate and the number of embedded fleas. It turned zero when reinfestation was prevented. The score for chronic disease also significantly correlated with the infestation rate. Tungiasis is associated with considerable acute and chronic morbidity. The degree of acute morbidity is directly related to the number of embedded sand fleas. When transmission is interrupted, the chronic morbidity reflects the infestation rates individuals have experienced in the past.

Pain- and distress-reducing interventions for venepuncture in children

OBJECTIVE

To compare the effect of eutectic mixture of local anaesthetics (EMLA) and a placebo cream on reported pain and observed distress associated with venepuncture, and to investigate effects of procedural information before and distraction during venepuncture.

METHODS

Children 3-12 years of age undergoing venepuncture under five experimental and a control condition reported their pain at venepuncture on visual scales. Distress was observed when the child entered the waiting room, just before, and during venepuncture.

RESULTS

Distress increased over the measurement occasions, but a distress-reducing effect of EMLA only was found at the actual venepuncture. The placebo diminished the reported pain, but the effect of EMLA was larger. Procedural information and distraction showed no effects.

CONCLUSIONS

EMLA reduces pain from venepuncture. The placebo effect probably results from desirable responding. Behavioural distress is a more direct measure than self-reported pain. More sophisticated designs should be used for the provision of procedural information and distraction.

Topical Anesthetics for Dermal Instrumentation: A Systematic Review of Randomized, Controlled Trials

STUDY OBJECTIVE

We compare the analgesic efficacy of topical anesthetics for dermal instrumentation with conventional infiltrated local anesthesia and also compare topically available amide and ester agents with a eutectic mixture of local anesthetics (EMLA).

METHODS

We conducted a systematic review of randomized, controlled trials. Relevant literature was identified through searches of MEDLINE, Cochrane Central Register of Controlled Trials, and the Excerpta Medica Database Drugs and Pharmacology. We limited the type of procedures to puncture of intact skin with a needle. The primary outcome was analgesic efficacy, reflected in the patient's self-report of pain intensity during dermal instrumentation. Where possible, quantitative methods were used to summarize the results.

RESULTS

We identified 25 randomized controlled trials including 2,096 subjects. The results of the trials comparing the efficacy of EMLA with infiltrated local anesthetic were inconsistent. Qualitative analysis demonstrated comparable analgesic efficacy between liposome-encapsulated lidocaine and EMLA. The weighted mean difference in 100-mm visual analogue scale pain scores favored topical tetracaine over EMLA (-8.1 mm; 95% confidence interval -15.6 mm to -0.6 mm). Liposome-encapsulated tetracaine provided greater analgesia than EMLA according to the weighted mean difference in 100-mm visual analogue scale scores (-10.9 mm; 95% confidence interval -15.9 mm to -5.9 mm).

CONCLUSION

EMLA may be an effective, noninvasive means of analgesia before dermal procedures. However, we identified 3 topical anesthetics that are at least as efficacious as EMLA: tetracaine, liposome-encapsulated tetracaine, and liposome-encapsulated lidocaine. Liposomal lidocaine is commercially available in the United States and offers a more rapid onset and less expensive alternative to EMLA.

Improved application of Lidocaine/Prilocaine cream in children. A randomized and prospectively controlled study of two application regimes

Intravenous cannulation in children aged 6-12 years is less painful after a 90-min application of a Lidocaine/ Prilocaine cream followed by a 30-min interval without cream, than cannulation immediately after a 60-min application.

BACKGROUND

Sixty-min application of an eutectic mixture of 25 mg g(-1) Lidocaine and 25 mg g(-1) Prilocaine cream is widely used in both adults and children to alleviate pain related to intravenous cannulation. However, studies have shown that this is not the optimal procedure in adults. Inspired by the results from these studies, the aim of the present study was to find an improved application regime for children.

METHODS

In this prospective, randomized, and single-blind study 60 Caucasian children, aged 6-12 years, presenting for an i.v. cannulation were included. The children were allocated to either a 60-min application of anaesthetic cream followed by i.v. cannulation (Group A) or to a 90-min application followed by an interval of 30 min before cannulation (Group B). No sedatives or analgesics were given. The children scored their pain by a faces scale with four faces.

RESULTS

The i.v. cannulations in Group B were less painful than the cannulations in Group A (Mann-Whitney test, P = 0.01). There was no difference between the two groups as regards problems when performing the cannulations.

CONCLUSION

i.v. cannulation after application of anaesthetic cream for 90 min followed by a 30-min interval is less painful than the widely used 60-min application directly followed by cannulation.

Incorporating psychological approaches into routine paediatric venepuncture

Studies of paediatric procedural distress have flourished over the past two decades, with psychological intervention strategies showing consistently high efficacy in reducing pain and fear. This review concentrates briefly on the acquisition and treatment of fear, arguing that what is witnessed clinically is not needle fear or phobia, but anticipatory or procedural distress. The main focus is on how such procedures could be amended to incorporate psychological techniques routinely, outlining specific guidelines for clinical practice.

Lidocaine iontophoresis versus eutectic mixture of local anesthetics (EMLA) for IV placement in children

Pain during venipuncture is a major source of concern to children and their caretakers. Iontophoresis is a novel technique that uses an electrical current to facilitate movement of solute ions (lidocaine) across the stratum corneum barrier to provide dermal analgesia. In this study, we compared dermal analgesia provided by lidocaine iontophoresis and eutectic mixture of local anesthetics (EMLA). After informed consent, 26 children, aged 7-16 yr, who required venous cannulation on multiple occasions, were enrolled in this prospective, randomized, crossover study to receive EMLA and iontophoresis on separate occasions. During a third session, each subject received his or her preferred treatment. Pain during venipuncture was assessed by the subject, parent, observer, and technician performing the procedure, by use of a 100-mm visual analog scale. The observer also used the Children's Hospital of Eastern Ontario Pain Scale to rate the subject's pain. Ratings of subject satisfaction were also assessed. There were no significant differences between the two groups in the subject-rated visual analog scale or the Children's Hospital of Eastern Ontario Pain Scale scores. Eleven (50%; 95% confidence interval [CI], 31%-69%) of the 22 subjects who completed both sessions preferred iontophoresis. Five subjects (23%; 95% CI, 10%-44%), including two who did not tolerate treatment with iontophoresis, preferred EMLA, and six (27%; 95% CI, 13%-48%) had no preference for the intervention to provide dermal analgesia. We conclude that lidocaine iontophoresis provides similar pain relief for insertion of IV catheters as EMLA and is a useful noninvasive alternative to establish dermal analgesia for venous cannulation.

IMPLICATIONS

Iontophoresis is a technique that uses an electrical current to facilitate movement of solute ions (lidocaine) across the stratum corneum barrier to provide dermal analgesia. Lidocaine iontophoresis provides similar pain relief for insertion of IV catheters as eutectic mixture of local anesthetics and is a useful noninvasive alternative to establish dermal analgesia for venous cannulation.

A clinical study to evaluate the efficacy of ELA-Max (4% liposomal lidocaine) as compared with eutectic mixture of local anesthetics cream for pain reduction of venipuncture in children

OBJECTIVE

A double-randomized, blinded crossover trial was performed to assess the efficacy of ELA-Max (4% liposomal lidocaine) as compared with eutectic mixture of local anesthetics (EMLA) for pain relief during pediatric venipuncture procedures. Safety was assessed by evaluation for topical or systemic effects and measurement of serum lidocaine concentrations.

METHODS

A total of 120 children who were scheduled for repeat venipuncture for non-study-related reasons at 2 sites participated in the study. Patients were doubly randomized to treatment regimen (study medication application time of either 30 or 60 minutes) and to the order of application of the topical anesthetics for each venipuncture. The primary outcome measures were the child's rating of pain immediately after the venipuncture procedures using a 100-mm visual analog scale (VAS) tool and the parent's and blinded research observer's Observed Behavioral Distress scores.

RESULTS

Both ELA-Max and EMLA seemed to alleviate venipuncture pain. There was no clinically or statistically significant difference in the patient VAS scores within the 30-minute or 60-minute treatment groups, and there was no clinical or statistical difference in VAS scores between the 30-minute ELA-Max treatment without occlusion and the 60-minute EMLA treatment with occlusion. There were no clinically or statistically significant differences between treatment with ELA-Max and EMLA in parental or blinded researcher Observed Behavioral Distress scores, the most frequent response at any observation time being "no distress."

CONCLUSION

This study demonstrates that a 30-minute application of ELA-Max without occlusion is as safe and as effective for ameliorating pain associated with venipuncture as a 60-minute application of the prescription product EMLA requiring occlusion.

Use of lidocaine-prilocaine patch to decrease intramuscular injection pain does not adversely affect the antibody response to diphtheria-tetanus-acellular pertussis-inactivated poliovirus-Haemophilus influenzae type b conjugate and hepatitis B vaccines in infants from birth to six months of age

BACKGROUND

Topical lidocaine-prilocaine (EMLA) effectively decreases the pain associated with minor procedures including immunization, although the effect on the antibody response to diphtheria-tetanus-acellular pertussis-inactivated poliovirus-Haemophilus influenzae type b conjugate (DTaP-IPV-Hib) and hepatitis B vaccines has not been assessed.

OBJECTIVE

To measure the antibody response to DTaP-IPV-Hib and hepatitis B vaccines; to measure pain reduction associated with the use of the lidocaine-prilocaine (EMLA) patch; and to assess safety by comparing adverse reactions.

PARTICIPANTS AND SETTING

One hundred nine healthy 6-month-old infants (Part A of study) and 56 healthy infants birth to 2 months of age (Part B of study) undergoing primary immunization with DTaP-IPV-Hib and hepatitis B vaccines in an ambulatory setting.

DESIGN AND INTERVENTIONS

Two center, randomized, double blind, controlled trial of EMLA patch or placebo before DTaP-IPV-Hib and hepatitis B immunization. Antibody titers measured at 0 to 2, 6 and 7 months.

OUTCOME MEASURES

The primary outcome measure was the antibody response to diphtheria, tetanus, pertussis antigens, Haemophilus influenzae type b and hepatitis B by enzyme immunoassay; and poliovirus 1, 2 and 3 by neutralization. The secondary outcomes were pain scores by the Modified Behavioral Pain Scale and drug- and vaccine-associated adverse events collected with a parent diary and structured questionnaire.

RESULTS

There was no difference in the antibody response between the EMLA- and placebo-treated groups as assessed by geometric mean antibody titers, rates of seroconversion or the proportion of participants achieving protective or positive antibody titers postimmunization. At the 6-month visit, EMLA recipients had less pain after immunization (total pain score, 6.75 vs. 7.35; P = 0.005; pain score increase, 3.99 vs. 4.74; P = 0.004) than did placebo recipients. Skin pallor and erythema at the patch application site were more frequently reported after EMLA use. Rates of vaccine-associated adverse events were similar in the two groups.

CONCLUSIONS

The EMLA patch has no adverse effect on the antibody response to the vaccine antigens, is effective in reducing pain associated with DTaP-IPV-Hib and hepatitis B immunizations and does not result in any significant or unexpected adverse reactions.

Assessment of the effect of EMLA during venipuncture in the newborn by analysis of heart rate variability

The objective of this study was to investigate the effect of EMLA on the pain response when venipuncture was performed in 60 3-day-old healthy newborns. EMLA/placebo was applied to the back of the baby's hand, following a randomized, double-blind procedure. ECG and crying were recorded during the test. The incidence of crying, heart rate (HR) and spectral analysis of heart rate variability were used to characterize the reaction of the baby to the venipuncture procedure. The occurrence of crying during venipuncture did not differ significantly between the EMLA and the placebo groups. The placebo-treated group showed a statistically significant higher HR, and a decrease in variance (total power) and power in the low-frequency band (0.02-0.15 Hz) when compared with the EMLA group. We conclude that EMLA decreases the stress response during venipuncture in newborn infants.

Psychological reaction by children of various ages to hospital care and invasive procedures

Hospital care and treatment by invasive procedures produce significant psychological effects on children. Urogenital surgery deserves particular study. The developmental aspects of different ages are highly relevant. A proposed multidimensional model of contributing factors includes type of medical treatment, any previous surgery, the child's temperament, coping strategies of both child and parents and their psychological health, support from parents and staff, information and psychological preparation and age of the child. Up to now, there have been no clear recommendations as to the best age for elective surgical procedures in children according to psychological risk. In general, older children adapt better psychologically after hospital care. The literature, however, tends to advise elective surgery before 12 mo of age, based on apparent psychological adjustment in the very young after surgery and from a desire to shorten the period of living with the malformation/disorder. However, increased follow-up surgery from early interventions gives a higher risk of psychological problems. More well-controlled studies are needed before final evaluation of the impact of surgical interventions on psycho-social symptoms according to age group. In this analysis a multidimensional model is preferred.

EMLA patch for intravenous cannulation in adult surgical outpatients

PURPOSE

The purpose of this study was to evaluate the effectiveness of a single-unit-dose package of the EMLA Patch for dermal analgesia during intravenous cannulation in adult, outpatients and in preventing vaso-vagal side effects.

METHODS

After giving consent, 51 ASA I-III adult outpatients participated in a randomized, double-blind, placebo-controlled, parallel-group trial to receive either an EMLA or placebo patch applied to the intravenous cannula site for 60 to 90 min. Following cannula insertion, patients and investigators rated the pain using a 100 mm VAS ruler. The incidence and severity of vaso-vagal responses, local skin reactions, and willingness to pay for the patch were also evaluated.

RESULTS

The median VAS pain score by patient assessment in the EMLA patch group was lower (8 mm; range: 0-92) than in the placebo group (25 mm; range: 0-98, P < 0.05). The median VAS pain score by investigator assessment was also lower in the EMLA patch group (15 mm; range 1-79) than in the placebo group (23 mm; range 3-81, P < 0.05). There was a notable difference in the number of vaso-vagal reactions (17 placebo vs 4 EMLA, P < 0.05). Eighty-eight percent of patients who received the EMLA patch would be willing to pay for the patch in the future compared with 69% of the placebo patch patients.

CONCLUSION

This study showed that the EMLA patch, applied for 60-90 min before venous cannulation reduced the pain of venepuncture and vaso-vagal side effects in adult outpatients.

Use of a phlebotomy service in a paediatric unit

This article evaluates the literature and research concerning venepuncture and the use of a phlebotomy service in an acute paediatric setting. It also highlights concerns expressed by nursing and medical staff about the introduction of such a service.

Nursing uniform preferences of parents and children in a paediatric setting

There is a growing movement towards more casual uniforms within paediatric nursing. However, children's and parents' preferences should be considered before deciding what type nurses should be wearing.

Sedation for the pediatric patient. A review

Safe sedation of a pediatric patient requires a thorough knowledge of the pharmacokinetics and pharmacodynamics of the drugs used to sedate the patient and the skills necessary to deal effectively with potential adverse events as a result of the sedation. The Sedation Guidelines of the American Academy of Pediatrics are reviewed. Emphasis is placed on monitoring and appropriate selection of drugs.

Eutectic lidocaine/prilocaine cream. A review of the topical anaesthetic/analgesic efficacy of a eutectic mixture of local anaesthetics (EMLA)

Eutectic lidocaine/prilocaine cream 5% is a eutectic mixture of the local anaesthetics lidocaine (lignocaine) 25 mg/g and prilocaine 25 mg/g that provides dermal anaesthesia/analgesia following topical application. The principal indication in which eutectic lidocaine/prilocaine cream has been studied is the management of pain associated with venipuncture or intravenous cannulation, where significantly greater pain relief than placebo, with equivalent efficacy to ethyl chloride spray and lidocaine infiltration, has been demonstrated. In dermatological surgery, eutectic lidocaine/prilocaine cream offers effective pain relief in children undergoing curettage of molluscum contagiosum lesions, and in adults undergoing split-skin graft harvesting. Particular benefit has also been shown with use of eutectic lidocaine/prilocaine cream in association with treatment of condylomata acuminata in both men and women, and it appears to provide a useful alternative to lidocaine infiltration in this context. Further research in such indications as paediatric lumbar puncture, minor otological surgery, and minor gynaecological, urological and andrological procedures is likely to further broaden the profile of clinical use for eutectic lidocaine/prilocaine cream. Eutectic lidocaine/prilocaine cream has a very favourable tolerability profile, transient and mild skin blanching and erythema being the most frequent adverse events to occur in association with its application to skin. The potential for inducing methaemoglobinaemia, attributed to a metabolite of the prilocaine component of the formulation, prohibits its use in infants younger than 6 months. In summary, eutectic lidocaine/prilocaine cream is a novel formulation of local anaesthetics that has proven to be effective and well-tolerated in the relief of pain associated with various minor interventions in adults and children.