A critical review of the topical local anesthetic amethocaine (Ametop) for pediatric pain

Topical anesthetics for needle-related pain in adults and children (TOPIC): a mini-review

Purpose

Healthcare professionals (HCP) perform various needle procedures that can be distressing and painful for children and adults. Even though many strategies have been proven effective in reducing distress and pain, topical anesthetic use before needle procedures is uncommon. However, there are limited studies in the existing literature comparing specifically liposomal lidocaine and tetracaine hydrochloride topical creams.

Source

This systematic review analyzed studies on the use of two anesthetic creams, Liposomal Lidocaine (Maxilene®) and Tetracaine hydrochloride (Ametop™), in children and adults undergoing a needle-related procedure. Databases searched: PubMed, CINAHL, ClinicalTrials. Only randomized controlled trials (RCT) and Controlled Clinical Trials (CCT) studies were included. Cochrane Collaboration's Risk of Bias assessment tool was used. Strictly minimally invasive procedures were included to standardize different skin needle interventions.

Principal findings

Only one study with 60 participants was available to be included in this review. No statistically significant difference was found in the mean pain score among both interventions. The outcomes of self-reported distress during cannulation and on HCP satisfaction were not reported. However, physiological characteristics associated with stress/anxiety and on cannulation success rate were reported and did not show statistical significance.

Conclusion

Little to no evidence regarding the most efficient cream between liposomal lidocaine and tetracaine hydrochloride for pain management during needle-related procedures was found. Further studies, particularly RCT with larger sample sizes and standardized outcome measures, are needed to confirm the relative efficacy of either anesthetic cream.

Effect of Acupressure on Pain during Inferior Alveolar Nerve Block Injection in Children Aged 5-10 Years Old - An Experimental Study

Background

Acupressure, which is related to acupuncture, is a noninvasive therapy suitable for use in children. However, data examining acupressure's effects on the pain of local anesthetic injection in children are sparse.

Objectives

The purpose of this study was to evaluate acupressure's effects on the pain of local anesthetic injection in children.

Methods

This randomized, double-blind, parallel-group clinical study included 37 5- to 10-year-olds who had an inferior alveolar nerve block (IANB) for a mandibular extraction and were randomized to one of two groups: acupressure (study group) or non-acupressure (control group). The Wong-Baker FACES Pain Rating Scale (WBFPS) and the Sound, Eye, Motor (SEM) scale were utilized for subjective and objective pain assessment during injection.

Results

The objective and subjective assessment of pain during injection significantly differed between the groups, with the acupressure group displaying lower scores.

Conclusion

Acupressure at the extra one point (EX-HN1) reduced pain during IANB injection in 5- to 10-year-olds and can be used as an adjunct to conventional measures like topical anesthesia to reduce pain.

Comparative Evaluation of Reduction in Pain Perception Using 5% Topical LA vs Freezed Cone as a Preparatory Agent for Intraoral Injection in Children and Effect of VRD as Distraction Technique

Aim

To compare freezed cone and 5% lignocaine as a numbing agent before intraoral injection and evaluate the effect of virtual reality distraction (VRD) as a distraction technique in reducing pain perception in children.

Study design

Around 60 children of 6-11 years old undergoing treatment for the extraction or any pulp therapy of primary tooth were selected. Freezed cone and 5% lidocaine were used to decrease the pain during local anesthesia (LA). VRD was used as a distraction method and to analyze the pain perception, Wong-Baker Faces Pain Rating Scale was used.

Materials and methods

Each child was randomly assigned to receive ice as a topical anesthetic or lignocaine 5% as a topical anesthetic agent. The pain perception was evaluated after the injection of 2% lignocaine hydrochloride (HCL). The primary researcher evaluated the pain during injection using the sound, eye, motor (SEM) scale. The pain experienced during injection was evaluated using Wong-Baker Faces Pain Rating Scale.

Results

In the freezed cone group with the VRD technique, maximum responded to the less pain score. On the contrary, many responded to higher pain scores in the freezed cone group without the VRD technique.

Conclusion

It was concluded that the VRD technique can be used for distraction and the frozen ice cone can be an alternative method to reduce the pain perception during LA.

How to cite this article

Singh R, Gupta N, Gambhir N. Comparative Evaluation of Reduction in Pain Perception Using 5% Topical LA vs Freezed Cone as a Preparatory Agent for Intraoral Injection in Children and Effect of VRD as Distraction Technique. Int J Clin Pediatr Dent 2022;15(5):558-563.

Managing acute pain in children presenting to the emergency department without opioids

Pediatric pain is challenging to assess and manage. Frequently underestimated in children, untreated pain may have consequences including increased fear, anxiety, and psychological issues. With the current opioid crisis, emergency physicians must be knowledgeable in both pharmacologic and non‐pharmacologic approaches to address pain and anxiety in children that lead to enhanced patient cooperation and family satisfaction. This document focuses pain management and distress mitigation strategies for the brief diagnostic and therapeutic procedures commonly performed.

Efficacy of external cold and a vibrating device in reducing pain and anxiety during local anaesthesia

Background and Aim:

To evaluate and compare the efficacy of external cold and a vibrating device in reducing the pain and anxiety amidst children receiving maxillary infiltration anaesthesia over conventional methods.

Method:

A sum of thirty subjects aged between 5 and 10 years who had undergone dental procedures requiring maxillary infiltration were enrolled in the current split-mouth randomised control study. The control intervention constitutes infiltration of 1.8 mL of 2% lignocaine in addition to 1:100,000 adrenaline (Lox, Neon Laboratories Mumbai, India) whereas, the experimental group used external cold and a vibrating device (Buzzy®, MMJ Labs, Atlanta, GA, USA) in annexation to the control protocol. Simultaneous to LA administration, pulse rate was employed as an objective measure and the subjective measure was recorded using RMS Pictorial Scale (RMS-PS) for the child’s discomfort. To document the child’s pain as anticipated by the dentist the revised face, limbs, arms, cry and consolability (FLACC-R) scale was employed.

Result:

Lower pain sensation and anxiety was recorded in the experimental group using Buzzy when compared to control.

Conclusion:

External cold in adjacent with vibrations might be efficient in lowering pain as well as anxiety in children experiencing infiltration dental anaesthesia though further research work is requisite with a larger sample size.

Children's Pain During IV Induction: A Randomized-Controlled Trial With the MEDi® Robot

OBJECTIVE

This study examined the impact of a humanoid robot (MEDi®) programmed to teach deep breathing as a coping strategy, on children's pain and fear as primary and secondary outcomes, respectively, during intravenous (IV) line placement. The completion of IV induction was also examined as an exploratory outcome.

METHODS

In this randomized controlled, two-armed trial, 137 children (4-12 years) were recruited in Short Stay Surgery at a tertiary pediatric hospital. Patients were randomly assigned to standard care (SC) with Ametop© only (N = 60) or SC and robot-facilitated intervention (N = 59) before induction. Pain and fear before, during, and after IV insertion were rated by patients and observers.

RESULTS

No significant differences were found between groups and there were no changes over time for pain or fear (ps > .05). Exploratory analyses show that patients in the MEDi® group were 5.04 times more likely to complete IV induction, compared to SC, Fisher's exact test: X2 (1) = 4.85, p = .04, φc = 0.22, odds ratio = 5.04, 95% CI [1.06, 24.00].

CONCLUSION

This study was the first to examine children's IV induction experience when provided MEDi® support. Reasons for nonsignificance, limitations, and research suggestions were made.

Antinociceptive effect of vapocoolant medium stream spray on hotplate latency in rat pups

BACKGROUND

Heel sticks account for most blood tests performed in neonates without analgesia because topical local anesthetics are ineffective on heel glabrous skin. We investigated the antinociceptive effect of an alternative topical analgesic, a vapocoolant spray, on hind paw glabrous skin of rat pups. The spray was applied by two methods: method 1 for 4 s at a distance of 8 cm and method 2 for 10 s at a distance of 18 cm.

METHODS

The rat pups were randomized to either method 1 (n = 32) or method 2 (n = 31). Vapocoolant spray was applied to one hind paw randomly, and saline spray was applied to the contralateral paw. The paws were exposed to a hotplate test to measure withdrawal latency time before and 30 s after the spray applications. Additionally, rat pups were tested for tissue toxicity in method 1 (n = 20) and method 2 (n = 20) after application of the vapocoolant spray before heel sticks three times a day for two consecutive days. Analyses of spray and method effects on hotplate withdrawal latency time were determined by nonparametric Wilcoxon tests to assess paired difference between vapocoolant spray and saline spray and to compare difference in medians between the two methods.

RESULTS

Method 1 and method 2 vapocoolant spray applications significantly prolonged the withdrawal latency time compared with saline, a median difference of 0.6 s (IQR 0.1-1.2) for method 1 and 9.5 s (IQR 5.5-10.7) for method 2 (a 15-fold longer latency time with method 2). Method-2 produced significantly longer withdrawal latency time than method 1 with a difference in median time of 8.9 s (CI: 95% 7.3-10.4 s, P < .0001). No histopathological changes were detected.

CONCLUSIONS

Compared with method- 1, the vapocoolant spray in method 2 produced significantly longer withdrawal latency time that is clinically applicable to collecting blood samples after a heel stick.

The efficacy of administrating a sweet-tasting solution for reducing the pain related to dental injections in children: A randomized controlled trial

BACKGROUND

Anaesthetic injections are an unpleasant experience for children in the dental office. Oral intake of sweet substances by newborns has been shown to be effective in reducing pain.

AIM

The purpose of this study was to determine whether a prior administration of a sweet-tasting solution has an effect on dental injection pain.

DESIGN

A total of 56 healthy children needing bilateral maxillary primary canine extraction were included in this split-mouth randomized clinical trial. In the test side, dental injection (local infiltration) was applied after the patient received a sweet-tasting solution, while in the control side sterile water was administered. The patients' demographic characteristics, body mass index (BMI), and sweet taste preference were recorded. Pain perception during injection was measured using visual analogue scale (VAS) and sound, eye, body movement (SEM).

RESULTS

Mean VAS (28.30 ± 6.43) and SEM (2.14 ± 0.78) in the test side were lower than the control side (45.80 ± 7.17 and 2.95 ± 1.00). It was shown that higher BMI was associated with reduction in the analgesic effect, while the individual's tendency to sweetness increased pain reduction.

CONCLUSIONS

Sweet taste administration before dental injections in children helps to control the associated pain. This effect is influenced by the individual's sweet taste tendency and BMI.

The Effect of Topical Anesthetic Gel versus Relaxation Exercise in Controlling the Pain of Anterior Maxillary Injection

Background and Aim:

Adequate intraoral anesthesia is a major prerequisite for many dental procedures. Bubble breath exercise, distraction, and play therapy technique may be used as relaxation exercises to decrease pain. This study aimed to compare the efficacy of bubble breath exercise versus topical anesthetic gel in controlling the pain of anterior maxillary infiltration.

Methods:

This crossover clinical trial was performed on 50 children aged 10-12 years. Subjects received a total of 100 maxillary injections (two per person) in the buccal mucosal area of canine teeth of both sides at intervals of 2 to 3 days. On one side, the injection was performed after applying 20% benzocaine gel. On the other side, a similar injection was performed after the bubble breath exercise. The injection solution was 1/4 of 1.8 mL cartridge of 2% lidocaine containing 1:200,000 epinephrine using a 30-gauge needle. The pain was measured immediately after anesthesia injection using a Visual Analogue Scale (VAS). Data analysis was carried out using SPSS Version 18.0 (IBM Inc., Chicago, IL, USA). Wilcoxon signed-rank tests were used to compare with the 10-mm visual analog scale (VAS) scores obtained from all participants. The level of significance was considered at 5% (p <0.05). The correlation between gender and pain score (VAS) for the two methods was analyzed using the Mann-Whitney U test.

Results:

The results showed no statistically significant difference between injection pain after topical anesthetic gel application and injection pain after bubble breath exercise (p value=0.30). Also, no statistically significant difference was found between injection pain after gel application and injection pain after bubble breath exercise in boys (p value=0.59) or girls (p value=0.32). There were statistically significant differences between boys and girls in terms of injection pain after gel application (p value=0.001) and also injection pain after e bubble breath exercise (pvalue=0.004).

Conclusion:

There is no significant difference between perceived injection pain after bubble breath exercise and after applying the topical anesthetic gel. Furthermore, future studies should explore the role of age, dental fear, and anxiety, previous painful experiences, the pain thresholds.

Effect of tetracaine on dynamic reorganization of lipid membranes

To understand the intrinsic influence of a drug on lipid membranes is of critical importance in pharmacological science. Herein, we report fluorescence microscopy analysis of the interaction between the local anesthetic tetracaine (TTC) and planar supported lipid bilayers (SLBs), as model membranes. Our results show that TTC increases lipid chain mobility, destabilizes the SLBs and remarkably induces membrane disruption and solubilization. Upon TTC binding, a local curvature change in the bilayer was observed, which led to the subsequent formation of up to 20-μm-long flexible lipid tubules as well as the formation of micron-size holes. Quantitative analysis revealed that membrane solubilization process can be divided into two distinct different stages as a function of TTC concentration. In the first stage (<800 μM), the bilayer disruption profiles fit well to a Langmuir isotherm, while in the second stage (800 μM-25 mM), TTC solubilizes the membrane in a detergent-like manner. Notably, the onset of membrane solubilization occurred below the critical micelle concentration (cmc) of TTC, indicating a local accumulation of the drug in the membrane. Additionally, cholesterol increases the insertion of TTC into the membrane and thus promotes the solubilization effect of TTC on lipid bilayers. These findings may help to elucidate the possible mechanisms of TTC interaction with lipid membranes, the dose dependent toxicity attributed to local anesthetics, as well as provide valuable information for drug development and modification.

Neurotoxicity secondary to local tetracaine use

INTRODUCTION

Systemic reactions from local tetracaine use are often an anomaly - not only is tetracaine short-acting and quickly metabolized by the pseudocholinesterase system leading to very limited systemic uptake, but most adverse reactions are usually associated with dental or spinal anesthesia. Furthermore, reactions to local anesthetics manifest in standard allergy-type reactions. When local anesthetics lead to nervous or cardiac system abnormalities, it is termed a local anesthetic systemic toxicity - an event with an incidence currently estimated to be 0.03%.

CASE PRESENTATION

We present a case of a 56-year-old female who experienced a systemic reaction to tetracaine 1% while undergoing a fine needle biopsy of a thyroid nodule. The patient had previous allergic reactions to lidocaine. Upon conclusion of the procedure, the patient began convulsing and became rigid and non-verbal. She was able to move all extremities, had no respiratory distress, no swelling, hives, or redness, and was swallowing without difficulty. After about 5 min, the patient began to improve and experienced reversal of all previous symptoms. Her physical exam and labs were otherwise normal, she returned to her baseline functioning, and was discharged without any medical interventions.

DISCUSSION

This case illustrates a case of LAST in a patient with previous Lidocaine allergy without any other obvious risk factors. There have been no cases of cross-reaction between lidocaine and tetracaine so it explores the possibility of patients having cross reaction to those two different kinds of local anesthetic.

Cooling the soft tissue and its effect on perception of pain during infiltration and block anesthesia in children undergoing dental procedures: A comparative study

Background. This study assessed the effect of cooling the soft tissue site on the perception of pain in children undergoing local anesthesia for routine dental procedures.

Methods. One hundred children, 6‒14 years of age, were assigned to either of the two study groups, i.e., group 1 (infiltration) and group 2 (block anesthesia). One side of the arch served as the test side, where an ice pretreatment (IP) of the soft tissue of the injection site was carried out using a tube of ice for one minute, whereas the opposite side served as the control, where no ice pretreatment (WIP) was carried out. This was followed by the gradual injection of local anesthetic solution. The children’s pain perception was assessed by VAS, WB-FPRS and SEM scales. The data were analyzed statistically.

Results. WBS, VAS and SEM scores were significantly different between the WIP and IP in both groups, indicating that ice was effective in reducing the pain perception in children. Intergroup comparison revealed no significant differences (P>0.05), indicating that cooling was equally effective in infiltration and block anesthesia.

Conclusion. Cooling the soft tissue site helped decrease pain perception during injection in children.

Managing pain and distress in children undergoing brief diagnostic and therapeutic procedures

Common medical procedures to assess and treat patients can cause significant pain and distress. Clinicians should have a basic approach for minimizing pain and distress in children, particularly for frequently used diagnostic and therapeutic procedures. This statement focuses on infants (excluding care provided in the NICU), children, and youth who are undergoing common, minor but painful medical procedures. Simple, evidence-based strategies for managing pain and distress are reviewed, with guidance for integrating them into clinical practice as an essential part of health care. Health professionals are encouraged to use minimally invasive approaches and, when painful procedures are unavoidable, to combine simple pain and distress-minimizing strategies to improve the patient, parent, and health care provider experience. Health administrators are encouraged to create institutional policies, improve education and access to guidelines, create child- and youth-friendly environments, ensure availability of appropriate staff, equipment and pharmacological agents, and perform quality audits to ensure pain management is optimal.

Effect of vibration during local anesthesia administration on pain, anxiety, and behavior of pediatric patients aged 6-11 years: A crossover split-mouth study

Background

Uncooperative behavior of children due to dental anxiety may interfere with the effective delivery of dental care and compromise the quality of treatment provided. Injection of local anesthesia is one of the most anxiety-inducing stimuli in pediatric dentistry. This study aimed to compare the efficacy of a child-friendly device, having a combined effect of vibration and distraction, with the conventional method of injection on pain, anxiety, and behavior of pediatric patients aged 6–11 years.

Methods

This randomized, crossover, split-mouth study included 30 children requiring a bilateral inferior alveolar nerve block. The children were equally divided into two groups: group 1, aged 6–8 and group 2, aged 9–11 years. All children were injected with anesthesia using the conventional and device method in two separate sessions. They were assessed for anxiety by measuring the pulse rate before and during the administration of local anesthesia. Behavior was assessed using Faces, Legs, Activity, Cry, Consolability (FLACC) scale, and the child's experience while receiving anesthesia was assessed using the Wong Bakers Pain Rating Scale.

Results

Results showed that the children who received local anesthesia using the device method had a lower mean pulse rate, FLACC scores, and pain rating scores than those who received local anesthesia using the conventional method.

Conclusion

The device method was more effective than the conventional method in managing pain, anxiety, and behavior of patients aged 6–11 years. The device is a cost effective, simple, and child-friendly product for administrating local anesthesia in pediatric patients.

Acute Pediatric Pain Management in the Primary Care Office

Pain is a chief complaint in children seeking medical care, yet it may also be experienced in evaluation and treatment during office visits. Inadequate relief of children's procedural pain and distress not only affects the experience of the children and their parents, but also adversely affects procedural outcomes. Despite increasing awareness and research, management of procedural pain and anxiety in children is often inadequate. In addition, parent and patient satisfaction is often tied to pain management. Development of a pain management plan must be systematic, individualized, and multimodal. We present a review of nonpharmacologic modalities, topical and oral analgesic agents, and intranasal adjuncts for use in routine outpatient practice. [Pediatr Ann. 2018;47(3):e124-e129.].

Effect of injection site pre-cooling on pain perception in patients attending a dental camp at Life Line Express: a split mouth interventional study

Background and aim

To determine the effect of pre-cooling injection site on pain perception in patients attending a dental camp at lifeline express, Habibganj.

Methods

A split mouth interventional study assessed the effect of pre cooling the injection site in patients (n=33) requiring bilateral buccal infiltration prior to extraction. One side of the patient’s mouth received the intervention after the injection site was pre cooled with ice for 3 minutes along with topical Lidocaine, while the other mouth side of the same patient received only topical Lidocaine and served as control group. A structured proforma assessed the demographic characteristics and risk factors that influence pain perception in patients. Mann-Whitney U tests and Wicoxon rank sum test were used for statistical analysis. Statistical significance was defined at P<0.05.

Results

The results revealed a significant difference in pain perception between control and intervention group as assessed using both Heft-Parker Visual Analog Scale (median score 3.0 and 1.0) and Sound Eye Motor scale (median score=1.0 and 0.0) (P<0.01). For both the scales the assessed and self reported variables Gender, Location, Chief Complaint, Region and Arch were found to be statistically significant.

Conclusion

Pre cooling injection site reduced pain perception in patients.

A Clinical Audit to Assess the Efficacy of the Coolsense® Pain Numbing Applicator for Intravenous Cannulation in Children

The Coolsense® device is a topical applicator that is used to anaesthetise the skin before a painful procedure. It is a handheld device with a temperature-controlled head that acts on application, without chemicals, to cool and anaesthetise the site of injection. This prospective observational audit of 100 children and adolescents aged six to 18 years studied the analgesic efficacy and patient and carer satisfaction rating of the device during intravenous cannulation and complications arising from its use. The audit demonstrated effective skin analgesia for intravenous cannulation in children and adolescents. Ninety-four percent of patients rated the pain during cannulation as less than or equal to three on a numerical pain rating scale of zero to ten. Patient and carer satisfaction with the device and cannulation success rates were high; 66% of patients and 82% of carers ‘really liked’ the device and 28% of patients and 12% of carers ‘liked’ it. Ninety-five percent of patients were cannulated on the first attempt. The incidence of complications using the device was low. The Coolsense device appears to be a useful tool that provides effective analgesia for intravenous cannulation in children with minimal complications. Comparative studies with topical local anaesthesia creams are warranted.

A randomized controlled trial comparing Ametop™ with placebo for reducing pain associated with local anesthetic skin infiltration before neuraxial anesthesia in parturients

BACKGROUND

Between 10-22% of the general population experience needle phobia. Needle phobic parturients are at increased risk of adverse outcomes. We assessed the efficacy of topical Ametop™ (tetracaine 4%) gel in reducing the pain associated with local anesthetic skin infiltration before neuraxial block in non-laboring women.

METHODS

This was a prospective, randomized, double-blind, placebo-controlled study. Ametop™ or placebo was applied to the skin of the lower back at least 20min before neuraxial block using a standardized technique with 1% lidocaine skin infiltration. The primary outcome was numeric pain score (0-10) 30s after lidocaine infiltration. Groups were compared using Welch's t-test.

RESULTS

Thirty-six subjects in each group were analyzed. There was a statistically significant difference in the mean (standard deviation) pain score between the Ametop™ and the placebo groups: 2.36±1.80 and 3.51±2.22, respectively (P=0.019). There were no significant adverse events.

CONCLUSION

The mean numeric pain score in the Ametop™ group was 33% lower compared to the placebo group. Topical Ametop™ gel applied at least 20min before local anesthetic infiltration of the skin prior to neuraxial block in elective cesarean delivery may be a useful adjunct in needle phobic women.

Investigating how the attributes of self-associated drug complexes influence the passive transport of molecules through biological membranes

Relatively little is known about how drug self-association influences absorption into the human body. This study presented two hydrophobic membranes with a series of solutions containing different types of tetracaine aggregates with the aim of understanding how the attributes of supramolecular aggregate formation influenced passive membrane transport. The data showed that aqueous solutions of the unprotonated form of tetracaine displayed a significantly higher (p < 0.05) passive membrane transport compared to solutions with mixtures of the unprotonated and protonated drug microspecies (e.g. transport through the skin was 0.96 ± 0.31 μg cm⁻² min⁻¹ and 1.59 ± 0.26 μg cm⁻² min⁻¹ respectively). However, despite an enhanced rate of drug transport and a better membrane partitioning the unionised molecules showed a significantly longer (p < 0.05) lag time to membrane penetration compared solutions rich in the ionised microspecies. Analytical characterisation of the solutions applied to the apical surface of the membranes in the transport studies showed that larger tetracaine aggregates with smaller surface charge gave rise to the longer lag times. These large aggregates demonstrated more extensive intermolecular bonding and therefore, it was suggest that it was the enhanced propensity of the unionised species to form tightly bound drug aggregates that caused the delay in the membrane penetration.

The immediate effects of lidocaine iontophoresis using interferential current on pressure sense threshold and tactile sensation

Iontophoresis is the noninvasive delivery of ions using direct current. The direct current has some disadvantages such as skin burning. Interferential current is a kind of alternating current without limitations of direct current; so the purpose of this study is to investigate and compare the effects of lidocaine, interferential current and lidocaine iontophoresis using interferential current. 30 healthy women aged 20-24 years participated in this randomized clinical trial study. Pressure, tactile and pain thresholds were evaluated before and after the application of treatment methods. Pressure, tactile and pain sensitivity increased significantly after the application of lidocaine alone (p < 0.005) and lidocaine iontophoresis using interferential current (p < 0.0001). Lidocaine iontophoresis using interferential current can increase perception threshold of pain, tactile stimulus and pressure sense more significantly than lidocaine and interferential current alone.

Comparative Efficacy and Patient Preference of Topical Anaesthetics in Dermatological Laser Treatments and Skin Microneedling

Background:

Topical anaesthetics are effective for patients undergoing superficial dermatological and laser procedures. Our objective was to compare the efficacy and patient preference of three commonly used topical anaesthetics: (2.5% lidocaine/2.5% prilocaine cream (EMLA^®), 4% tetracaine gel (Ametop™) and 4% liposomal lidocaine gel (LMX4^®)) in patients undergoing laser procedures and skin microneedling.

Settings and Design:

This was a prospective, double-blind study of patients undergoing laser and skin microneedling procedures at a laser unit in a tertiary referral dermatology centre.

Materials and Methods:

All 29 patients had three topical anaesthetics applied under occlusion for 1 hour prior to the procedure, at different treatment sites within the same anatomical zone. A self-assessment numerical pain rating scale was given to each patient to rate the pain during the procedure and each patient was asked to specify their preferred choice of topical anaesthetic at the end of the procedure.

Statistical Analysis:

Parametric data (mean pain scores and frequency of topical anaesthetic agent of choice) were compared using the paired samples t-test. A P-value of ≤0.05 was considered as statistically significant.

Results and Conclusions:

Patients reported a mean (±SD; 95% confidence interval) pain score of 5 (±2.58; 3.66-6.46) with Ametop™, 4.38 (±2.53; 2.64-4.89) with EMLA^® and 3.91 (±1.95; 2.65-4.76) with LMX4^®. There was no statistically significant difference in pain scores between the different topical anaesthetics. The majority of patients preferred LMX4^® as their choice of topical anaesthetic for dermatological laser and skin microneedling procedures.

Application of a topical vapocoolant spray decreases pain at the site of initial intradermal anaesthetic injection during ultrasound-guided breast needle biopsy

AIM

To assess whether the application of a topical vapocoolant spray immediately prior to initial intradermal anaesthetic injection during ultrasound-guided breast biopsy decreases pain at the site of the initial injection.

MATERIALS AND METHODS

In this institutional review board-approved, Health Insurance Portability and Accountability Act (HIPAA)-compliant study, 50 women aged 49.1 ± 1.6 years (mean ± standard error) were recruited and provided written informed consent. Participants served as their own controls and were blinded as to whether a topical vapocoolant spray or a placebo was used immediately prior to the initial local anaesthetic injection at two separate biopsy sites. With the exception of the application of vapocoolant or placebo, the entire ultrasound-guided procedure was performed according to a routine protocol. Participants recorded pain at initial injection site on a visual analogue scale. General linear mixed models for repeated measures analysis of variance and a 0.05 significance level were used.

RESULTS

Application of topical vapocoolant spray was shown to significantly decrease pain at the site of initial intradermal anaesthetic injection as compared to placebo (p<0.001). Treatment effect was independent of age of the subject, race/ethnicity, operator, type of biopsy device, and histopathology result. No complications from vapocoolant spray use were reported.

CONCLUSION

Application of a topical vapocoolant spray immediately prior to initial intradermal anaesthetic injection during ultrasound-guided breast biopsy significantly decreases pain at the site of the initial injection and could contribute to improve the patient's overall procedural experience.

Pain management in newborns

As a standard of care for preterm/term newborns effective pain management may improve their clinical and neurodevelopmental outcomes. Neonatal pain is assessed using context-specific, validated, and objective pain methods, despite the limitations of currently available tools. Therapeutic approaches reducing invasive procedures and using pharmacologic, behavioral, or environmental measures are used to manage neonatal pain. Nonpharmacologic approaches like kangaroo care, facilitated tucking, non-nutritive sucking, sucrose, and others can be used for procedural pain or adjunctive therapy. Local/topical anesthetics, opioids, NSAIDs/acetaminophen and other sedative/anesthetic agents can be incorporated into NICU protocols for managing moderate/severe pain or distress in all newborns.

Transdermal analgesia with local anesthetics in children: review, update and future directions

Topical local anesthetics in one form or another have been used for the past 20 years to alleviate the skin pain associated with needle puncture and venous cannulation in children. Although the application of topical anesthetic creams is painless compared with traditional local anesthetic infiltration of the skin and subcutaneous tissues prior to venipuncture and minor skin procedures, they remain underutilized, primarily due to their slow analgesic onset and inconsistent effectiveness. For a topical local anesthetic to be of practical use in busy clinical settings, it must be easy to apply, have minimal side effects, not require cumbersome equipment and be reasonably cost effective. Until recently, limitations in one or all of these areas have dissuaded pediatric practitioners from their routine use. However, recent advances in transdermal delivery technologies, have led to the emergence of a number of new delivery approaches that accelerate the onset time to 20 min or less and provide more consistent and deeper sensory skin analgesia. Although still in the early stages of investigation, technologies that promote the flux of drugs of all sizes through the skin by creating transient microchannels show great promise in circumventing the skin barrier and promoting the transdermal delivery of not only local anesthetics but also other drugs. Ultimately, the rationale to change clinical practice and use a new transdermal delivery system will depend upon the cost, ease of use, frequency of adverse events and the benefits to the patient relative to an alternative method.

Common office procedures and analgesia considerations

This article reviews common office procedures and analgesia considerations for pediatric outpatients. Layer times of onset of analgesics to coincide with procedures. Pediatric procedural distress is multimodal. Always address parent and child fear and attention, along with pain.

Arrhythmia associated with tetracaine in an extremely low birth weight premature infant

Infants in NICUs undergo a variety of painful procedures. The management of pain has become an integral part of newborn infant care with the use of both systemic and topical agents to provide analgesia and anesthesia for procedural pain. Tetracaine and prilocaine-lidocaine are the 2 topical anesthetics most frequently used. Tetracaine belongs to an ester group of local anesthetics available as a topical 4% gel (Ametop, Smith and Nephew, Canada). The major side effects reported when using topical anesthetics are cutaneous reactions. There are no definite reports of systemic toxicity in the published literature. We present a recent case of an extremely low birth weight premature infant who developed a clinically significant arrhythmia after topical tetracaine was applied before the insertion of a peripherally inserted central catheter. The infant had no other identifiable cause for the resulting bradycardia that occurred only after Ametop was applied. The cardiac symptoms resolved with treatment. This case highlights a significant potential adverse event when using topical tetracaine.

Pain during venous cannulation: Double-blind, randomized clinical trial of analgesic effect between topical amethocaine and eutectic mixture of local anesthetic

Background:

Venous cannulation is often a painful procedure for the patient. Eutectic mixture of local anesthetic (EMLA) is the commonest topical analgesic used but suffers from disadvantages such as slow onset and skin blanching, which may interfere with venous cannulation. Amethocaine is a newer topical analgesic which seems to be devoid of such problems.

Materials and Methods:

This prospective randomized double-blind study compared the analgesic efficacy of EMLA with amethocaine during venous cannulation in adults. Eighty ASA I-II patients, aged 18–65 years, were recruited. The test drug was applied on the designated site of venous cannulation and covered with an occlusive dressing for at least 60 min prior to the procedure. Data collected included visual analogue score (VAS) during first attempt at venous cannulation, the ease and success rate at cannulation, and cutaneous changes at the application site.

Results:

Mean and median VAS for the EMLA group were 27.9 ± 9.8 and 30 mm, respectively; while for the Amethocaine group were 19.1 ± 14.1 and 20 mm, respectively. Differences in VAS did not reach statistical significance. No statistically significant differences were observed in the ease and success rate at cannulation. Cutaneous changes in the form of local induration and erythema (three patients in the Amethocaine group) and blanching (eight patients in the EMLA group) were mild, localized, and required no further treatment. No patient developed severe allergic reactions.

Conclusion:

Topical EMLA and amethocaine were comparable in terms of analgesic efficacy and ease of venous cannulation in adult patients.

Syringe micro vibrator (SMV) a new device being introduced in dentistry to alleviate pain and anxiety of intraoral injections, and a comparative study with a similar device

Background

Neurologically, it is proven that stimulation of larger diameter fibers - e.g. using appropriate coldness, warmth, rubbing, pressure or vibration- can close the neural "gate" so that the central perception of itch and pain is reduced. This fact is based upon "Gate-control" theory of Melzack and Wall.

Presentation of the hypothesis

Syringe Micro Vibrator is a new design being introduced for the first time in the field of Dentistry. This device is a promising breakthrough in pain and anxiety management and may deliver solution for clinicians plagued with patient pain phobia. It has an off-set rotating micro vibration creator with ultra high frequency and ultra low altitude that can be easily placed on any standard dental syringe and some disposable syringes. This device was registered as an invention in dentistry and received Iran National Patent number of 63765.

Testing the hypothesis

By creating micro vibration, this device would be effective in reducing the pain and anxiety confronted with most types of intraoral injections as palatal, mandibular block, intraligamental and local infiltration. From the aspect of the patient pain management, this device contributes both physiologically (based on Gate Control Theory of pain) and psychologically (based on the device function as will be explained by dentist to the patient as a modern pain reducing technology). From the aspect of clinician, SMV motor provides vibrations with ultra high frequency to alleviate pain, but since it has ultra low vibration altitude, it has no adverse effect on the clinician dexterity and accuracy during injection and it does not interfere with pin point localization of injection site.

Implications of the hypothesis

Upon mounting on a conventional dental anesthesia injection syringe, SMV is switched on and the clinician then uses normal injection technique to administer the anesthetic. This device is not only a useful accessory device for ordinary patients, but also more useful for pediatric patients and those who have a phobia of intraoral injection or pain.

Pain management in newborns: from prevention to treatment

All neonates in the Neonatal Intensive Care Unit (NICU) or during the first days of life undergo painful and stressful procedures. Epidemiologic studies have shown that pain induced by these procedures is not effectively prevented or is inadequately treated. Pain experienced during the neonatal period may lead to negative outcomes, especially in preterm neonates. Prevention is the first step of pain management, and practical guidelines should be used in the NICU. Assessment must be done with adequate tools that take into account the infant's pathology and gestational age. Distinguishing between acute and prolonged pain is important for both assessment and treatment. The most common drugs that have been studied for the treatment of pain and stress are opioids, hypnosedatives, and NMDA receptor antagonists. Morphine and fentanyl are most frequently used for acute or prolonged pain in the NICU. They have potent analgesic effects and few immediate or long-term adverse effects. Midazolam is a commonly used hypnosedative, but its adverse effects limit its use. Drugs such as propofol and ketamine have been used for acute painful procedures; however, further research is needed to assess their long-term effects. Use of non-pharmacologic pain management techniques has increased in recent years. These methods are easy, inexpensive, and effective in helping newborns recover from painful procedures. Sweet solutions and non-nutritive sucking, breastfeeding, skin-to-skin mother care, swaddling, and facilitated tucking are the most commonly employed and evaluated non-pharmacologic methods. Hospitals should promote and improve parent involvement in pain management. In-service education and well organized hospital teams are crucial for successful implementation of pain protocols in newborns.

Tetracaine (ametop) compared to placebo for reducing pain associated with intramuscular injection of palivizumab (synagis)

Infants receive many painful immunizations before they are 2 years old. The purpose of this study was to evaluate if topical tetracaine reduces the pain of intramuscular palivizumab compared to placebo. There were two study injections, one with tetracaine and one with placebo. Pain was scored by their parents and a pediatric nurse. Topical tetracaine was not associated with a significant reduction in pain score, although it did lead to faster recovery times. Additional pain-reduction strategies are required.

Pharmacologic approaches for reducing venous access pain in children

A variety of pharmacologic options are available to clinicians who want to provide effective and safe topical local anesthesia to children undergoing venous access procedures. These options can be distinguished on the basis of how they deliver active drug through the impermeable outer layer of skin, the stratum corneum, to pain receptors located in the dermis and epidermis. Three general methodologies are typically used to bypass the stratum corneum: direct injection of local anesthetics, usually via a small-gauge hypodermic syringe; passive diffusion from topical creams or gels; and active needle-free drug strategies that enhance the rate of drug passage into the dermis and epidermis. Examples of the latter mechanisms include heat-enhanced diffusion, iontophoresis, sonophoresis, laser-assisted transdermal passage, and pressurized gas delivery of powdered drug particles. Pharmacologic options in this setting can also be distinguished on the basis of the time to onset of full anesthetic effect. Several available agents induce significant local anesthesia within 1 to 3 minutes of administration, or faster, allowing easy integration into the skin preparation and subsequent venous access procedure. In combination with nonpharmacologic approaches, these agents can be used to dramatically lessen this significant source of pediatric pain.

Pain, distress, and adult-child interaction during venipuncture in pediatric oncology: an examination of three types of venous access

This study examined pain and distress from needles in children undergoing blood sampling as a function of adult-child interaction and type of venous access (i.e., central external venous lines, internalized ports, or peripheral access via venipuncture). Participants were 55 pediatric oncology patients, aged 3-18 years, who were undergoing routine blood work. Pain ratings were obtained using the Faces Pain Scale-Revised (FPS-R) and conversation during the procedure was audio taped for coding using the Child-Adult Medical Procedure Interaction Scale-Revised (CAMPIS-R). Children's ratings of pain using the FPS-R were similar in the port (M=2.57/10, standard deviation [SD]=3.46) and peripheral (M=2.56/10, SD=3.24) groups, despite the fact that most children with internal ports were given a topical anesthetic. Similarly, there were no differences between port and peripheral groups in rates of child coping or distress, or parent and nurse observations of child pain. As would be expected, external line access was not associated with pain or distress, even among very young children, suggesting that they appropriately understood the pain rating scale. Results of the transcribed CAMPIS-R data indicate that the influences in adult-child interaction are bidirectional. Support was found for the well-established positive relationship between child distress and adult reassurance and empathy. Implications for intervention and selection of central venous access devices are discussed.

Optimizing local anesthesia for grommet insertion: eutectic mixture of local anaesthetics versus Ametop: a randomized clinical trial

OBJECTIVE

To compare the effect of eutetic mixture of local anesthetics (EMLA) with Ametop in providing local anesthesia for grommet insertion.

STUDY DESIGN

Double-blind randomized clinical trial.

SETTING

University teaching hospital.

PATIENTS

Forty-one adult patients diagnosed with otitis media with effusion were recruited into the trial and underwent grommet insertion under local anesthesia; 21 were randomly allocated to the EMLA group and 20 to the Ametop group.

MAIN OUTCOME MEASURES

The primary outcome measure of the study was the level of pain experienced by the patient. The secondary outcome measure was the overall satisfaction with the procedure. Both measures were assessed using visual analogue scales.

RESULTS

Both the topical anesthetic agents provided good pain relief during grommet insertion. There was no statistically significant difference in the pain or satisfaction scores.

CONCLUSION

Both EMLA and Ametop can provide good local anesthetic effect during grommet insertion.

Procedural pain guidelines for the newborn in the United Kingdom

OBJECTIVE

To assess the use of analgesia guidelines for newborn infants in the United Kingdom.

STUDY DESIGN

Postal questionnaire to every neonatal unit in the United Kingdom.

RESULT

A total of 192 of 244 units replied (78.7% response). Most units had a guideline for elective intubation (70%), sedation for ventilation (78%) post-operative pain (when appropriate) (74%). Less prevalent were guidelines for painful minor procedures (35%). Only 33% of units gave a sweet-tasting solution for analgesia before routine painful procedures and 12% used a topical anesthetic cream.

CONCLUSION

Since the last survey in 2000 there has been a modest increased uptake in measures to prevent pain neonatal pain in the United Kingdom, but no pain guideline was present in almost 25% of units and no guideline for routine painful procedures in the majority.