Does The Use of Ethyl Chloride Improve Patient-Reported Pain Scores With Negative Pressure Wound Therapy Dressing Changes? A Prospective, Randomized Controlled Trial.

BACKGROUND: Negative pressure wound therapy (NPWT) is commonly used for surgical incisions and large wounds, particularly in the context of trauma. Research has shown that patients report that the most painful aspect of NPWT is related to foam dressing changes. This study aimed to determine whether topical use of the vapocoolant anesthetic ethyl chloride would impact patient-reported pain during these procedures. METHODS: This study was a single-blinded, placebo-controlled randomized trial in patients who were undergoing NPWT foam dressing change following surgery performed by the orthopedic trauma team. A total of 100 patients were randomized to receive ethyl chloride topical anesthetic spray or placebo (tissue culture grade water) during dressing change. The outcome measure specified prior to enrollment was a mean decrease in patient-reported pain of 1.7 points using a numeric rating scale. Baseline and procedural characteristics were collected to investigate contributions to patient-reported pain. We hypothesized that the use of ethyl chloride would decrease patient reported pain scores. RESULTS: Significantly more females were randomized to the receive vapocoolant; remaining baseline and procedural characteristics were similar between groups. The median time for NPWT drape removal was 2.0 minutes in both groups (p = 0.66). The postprocedural pain reported by patients was significantly lower in the experimental group compared with placebo (median, 5.0 vs. 7.0; p = 0.03). Multivariate analysis adjusting for potential confounders showed treatment group to be the strongest predictor of postprocedure pain (p = 0.002). Additionally, a generalized linear model suggests that treatment group was the strongest predictor of change in pain score as reported by patients prior to and immediately following dressing change. CONCLUSIONS: Use of vapocoolant spray during NPWT dressing change for orthopedic trauma wounds and surgical incisions was feasible and resulted in significant reduction in patient-reported pain associated with the procedure. LEVEL OF EVIDENCE: Therapeutic, Level I.

Comparison of the Effects of Vapocoolant Spray and Topical Anesthetic Cream on Pain During Intraarticular Injection of the Shoulder: A Randomized Double-Blind Controlled Trial.

OBJECTIVE: This study was performed to compare the effects of a vapocoolant spray and a eutectic mixture of local anesthetics (EMLA) cream on reducing pain during intra-articular (IA) injection of the shoulder. DESIGN: Double-blind randomized placebo-controlled clinical trial. SETTING: University hospital. PARTICIPANTS: Patients (N=63) who underwent IA injection of the shoulder joint were randomized into the spray group, EMLA group, or placebo group. INTERVENTION: Placebo cream+vapocoolant spray (spray group), EMLA cream+placebo spray (EMLA group), or placebo cream+placebo spray (placebo group) before IA injection. MAIN OUTCOME MEASURES: A 100-mm visual analog scale (VAS) for injection pain and 5-point Likert scales for participant satisfaction and preference for repeated use were administered immediately after IA injection. RESULTS: The VAS scores for pain during IA injection were 30.0 (95% CI, 19.7-41.2) in the spray group, 50.0 (95% CI, 37.7-63.0) in the EMLA group, and 53.8 (95% CI, 41.6-65.0) in the placebo group (F=6.403, P<.01). The spray group showed significantly better Likert scale scores than the placebo group for participant satisfaction (P=.003) and preference for repeated use (P<.001). CONCLUSIONS: Vapocoolant spray was effective in reducing pain during IA injection of the shoulder.

Ethyl chloride spray for musculoskeletal ultrasound-guided injections: An alternative to subcutaneous injection of local anesthetic solution.

Ultrasound-guided injections such as steroid injections are common procedures involving the musculoskeletal system. They are usually performed after a subcutaneous injection of local anesthetic (LA), which can be painful. In 126 consecutive patients, local anesthesia was performed using ethyl chloride spray prior to a therapeutic ultrasound-guided injection in joints, tendons, or bursae. Ninety-nine (78.5%) patients found the use of ethyl chloride spray helpful. The use of ethyl chloride spray is an effective, patient-friendly alternative to the standard injection of local aesthetic for ultrasound-guided therapeutic musculoskeletal injections with the advantage of a lower cost of $0.18 per procedure.

A Randomized, Double-Blind Trial to Determine if Vapocoolant in the Adult Population Improves Patient Perception of Pain With Peripheral Intravascular Access.

The purpose of this study was to investigate whether the use of a topical anesthetic spray (vapocoolant) at the site of intravenous access reduces pain and anxiety associated with peripheral intravenous (PIV) catheter insertion in an adult emergency department population. A randomized, double-blind, placebo-controlled, single-center trial, conducted from July to August, in an adult emergency department where 72 patients with orders for PIV insertion receiving either topical vapocoolant spray (n = 38) or placebo spray (n = 34). Vapocoolant or placebo was applied to the intravenous site and allowed to evaporate before cleansing and insertion. The primary outcome was patient perception of pain and anxiety with PIV needle insertion using a 0-10 Likert scale. Secondary outcomes included patient/staff preference or desire for vapocoolant/placebo use in future procedures and staff perception of patient pain and anxiety. Patient groups did not vary significantly in the history of intravenous access, nor anxiety preprocedure, and the sprays did not affect ability to obtain intravenous access. Patient perception of pain did not vary significantly between vapocoolant (2) and placebo populations (2.5), nor did the scores vary significantly for patient-forecasted anxiety in future procedures using the same methods (0.5 for vapocoolant, 0 for placebo; p > 0.05). Eighty-nine percent of nurses and patients would use vapocoolant in future procedures, whereas 74% would use placebo; the difference was not significant (p > 0.05). No skin blanching or lesions were noted. Among adult patients in the Parkland Emergency Department receiving PIV access, no significant differences in pain relief or alleviation of anxiety were found between treatment using a topical anesthetic spray or placebo.

[Ethyl chloride aerosol spray for local anesthesia before arterial puncture: randomized placebo-controlled trial]. / Eficacia del cloruro de etilo en aerosol como anestésico local previo a la punción arterial: ensayo clínico aleatorizado controlado con placebo.

OBJECTIVES: To compare the efficacy of an ethyl chloride aerosol spray to a placebo spray applied in the emergency department to the skin to reduce pain from arterial puncture for blood gas analysis. MATERIAL AND METHODS: Single-blind, randomized placebo-controlled trial in an emergency department of Hospital de Basurto in Bilbao, Spain. We included 126 patients for whom arterial blood gas analysis had been ordered. They were randomly assigned to receive application of the experimental ethyl chloride spray (n=66) or a placebo aerosol spray of a solution of alcohol in water (n=60). The assigned spray was applied just before arterial puncture. The main outcome variable was pain intensity reported on an 11-point numeric rating scale. RESULTS: The median (interquartile range) pain level was 2 (1-5) in the experimental arm and 2 (1-4.5) in the placebo arm (P=.72). CONCLUSION: Topical application of an ethyl chloride spray did not reduce pain caused by arterial puncture.

OBJETIVO: Evaluar la eficacia del cloruro de etilo en aerosol aplicado sobre la piel frente a placebo para disminuir el dolor provocado por una punción arterial durante la realización de una gasometría en el servicio de urgencias (SU). METODO: Ensayo clínico aleatorizado, simple ciego y controlado con placebo realizado en el SU del Hospital de Basurto (Bilbao, España). Se incluyeron 126 pacientes a los que se les había solicitado una gasometría arterial, asignándoles al azar al grupo de tratamiento tópico experimental con cloruro de etilo en aerosol (n = 66) o al grupo control con mezcla hidroalcohólica en aerosol (n = 60), ambos administrados inmediatamente antes de la punción arterial. La variable de resultado principal fue la intensidad del dolor autopercibido por el paciente medida por la escala NRS-11. RESULTADOS: El dolor percibido por el paciente tuvo una mediana (rango intercuartílico) de 2 (1-5) en el grupo tratado con cloruro de etilo y de 2 (1-4,5) en el grupo placebo (p = 0,72). CONCLUSIONES: La aplicación de cloruro de etilo tópico no reduce el dolor por punción arterial.

Use and Effectiveness of Ethyl Chloride for Hand Injections.

PURPOSE: Limited literature supports using ethyl chloride topical spray as an anesthetic for hand injections whereas documented risks include frostbite, skin irritation, and inhalation toxicity. We hypothesize that ethyl chloride spray imparts no benefit to patients' perception of pain or anxiety for routine hand injections. METHODS: We first surveyed all members of the American Society for Surgery of the Hand to discern the prevalence of ethyl chloride use during routine injections. We then performed a prospective, randomized, study at 2 institutions evaluating the efficacy of ethyl chloride spray compared with "routine injection" (no topical spray) in patients indicated for a hand injection. All patients completed a pre- and postinjection 11-point questionnaire that inquired about various components of pain and anxiety. RESULTS: A total of 2,083 (73% response rate) American Society for Surgery of the Hand members responded to the survey and revealed that 59% of hand surgeons always or often use ethyl chloride, and 24% never use it. There were no differences for region or practice setting, but experienced surgeons were less likely to routinely use ethyl chloride (35%) compared with younger surgeons (66%). Among 151 patients participating in the clinical study (75 with ethyl chloride), there were no differences for any outcome measure assessed. Injection pain in the spray and no-spray groups, pain after 1 minute, and overall anxiety were equivalent. Subgroup analysis demonstrated no effect of sex, anticipated anxiety, or pain threshold. CONCLUSIONS: Ethyl chloride is widely used among hand surgeons but imparts no benefit for routine hand injections in the clinical setting. The potential risks and costs of ethyl chloride use may outweigh its benefits. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic II.

Adverse effects of vapocoolant and topical anesthesia for tail biopsy of preweanling mice.

Tail biopsy of laboratory mice for genotyping purposes has been studied extensively to develop refinements for this common procedure. Our prior work assessed tail vertebral development in different mouse strains (age, 3 to 42 d) and analyzed behavior and activity in mice (age, 21 to 45 d) biopsied under isoflurane anesthesia. To assess the effects of biopsy on preweanling mice, we here evaluated BALB/cAnNCrl mice (n = 80; age, 18 to 21 d) that received topical vapocoolant (ethyl chloride), topical anesthetic (Cetacaine), or isoflurane anesthesia before undergoing a 5-mm or sham biopsy. Control mice did not receive any anesthetic intervention. Regardless of the anesthetic used, acute observation scores indicative of distress were increased at 10 min after biopsy, and locomotor activity was decreased, in biopsied compared with control mice. Acute observation scores at 10 min after biopsy were higher in mice that received ethyl chloride compared with isoflurane or no anesthesia. Microscopic analysis revealed that inflammatory changes in the distal tail remained elevated until 7 d after biopsy and were higher in tails exposed to ethyl chloride. Our findings indicate that vapocoolant, topical anesthesia, and inhaled isoflurane do not enhance the wellbeing of preweanling mice undergoing tail biopsy. Due to the lack of appreciable benefits and the presence of notable adverse effects, using vapocoolants or Cetacaine for this tail biopsy procedure in laboratory mice is unadvisable and we encourage the removal of these agents from institutional tail biopsy guidelines.

Acute reversible neurologic deficits due to ethyl chloride sniffing: a case report and review of literature.

Ethyl chloride (CH3CH2Cl) or chloroethane is a colorless volatile halogenated hydrocarbon gas found in many commercially available solvents, and it may be used as an inhalant of abuse. Neurologic toxicity has been reported, as well as deaths. We present a case of a 47-year-old HIV-positive man who presented with acute reversible neurologic deficits secondary to inhalational exposure to ethyl chloride. Laboratory studies and neuroimaging are nondiagnostic in ethyl chloride-induced neurotoxicity and thus requires a high index of clinical suspicion. The mainstay of treatment is supportive with withdrawal of the offending agent and observation for resolution of neurologic symptoms.

Effects of spray and stretch on postneedling soreness and sensitivity after dry needling of a latent myofascial trigger point.

OBJECTIVES: To investigate (1) the effect of spray and stretch versus control on reducing postneedling soreness of 1 latent myofascial trigger point (MTrP) and (2) whether higher levels of psychological distress are associated with increased postneedling pain intensity. DESIGN: A 72-hour follow-up, single-blind randomized controlled trial. SETTING: University community. PARTICIPANTS: Healthy volunteers (N=70; 40 men, 30 women) aged 18 to 36 years (mean age, 21±4y) with latent MTrP in 1 upper trapezius muscle. INTERVENTION: All subjects received a dry needling application over the upper trapezius muscle. Then, participants were randomly divided into 2 groups: an intervention group, which received spray and stretch over the needled trapezius muscle, and a control group, which did not receive any intervention. MAIN OUTCOME MEASURES: Visual analog scale (at postneedling, posttreatment, and 6, 12, 24, 48, and 72h after needling), pressure pain threshold (at preneedling, postneedling, and 24 and 48h after needling). Psychological distress was evaluated by using the Symptom Checklist-90-Revised. RESULTS: Repeated-measures analysis of variance demonstrated a significant interaction between group and time (F3,204.8=3.19; P<.05; ηp(2)=.04) for changes in postneedling soreness. Between-group differences were significant only immediately after intervention (P=.002), and there were no differences found between groups after 6 hours of the intervention (P>.05). Repeated measures of covariance showed that none of the psychological covariates affected these results. Somatization, anxiety, interpersonal sensitivity, and hostility were significantly correlated (P<.05) with postneedling pain intensity. Repeated-measures analysis of variance did not show a significant effect of spray and stretch on mechanical hyperalgesia (F2.6,175=1.9; P=.131; ηp(2)=.02). CONCLUSIONS: The spray and stretch had a short-term (<6h) effect in reducing postneedling soreness of a latent MTrP. Pressure pain threshold did not significantly change after spray and stretch. Psychological factors are related to postneedling pain.

Effects of ethyl chloride spray on pain and parameters of needle electromyography in the upper extremity.

OBJECTIVE: The aim of this study was to compare the effects of ethyl chloride and placebo sprays for reducing pain induced by needle electromyography and changes in parameters of the motor unit action potential during needle electromyography of the upper extremity. DESIGN: Sixty patients were randomized into the ethyl chloride or placebo spray groups. In both groups, spray was applied just before needle electromyography of the flexor carpi radialis, and a visual analog scale to evaluate the pain of needle electromyography and a five-point Likert scale for patient satisfaction and preference for reexamination were compared between the two groups. Then, changes in the amplitude, phases, turns, and duration of the motor unit action potential during needle electromyography of the biceps brachii were compared before and after spraying in each group. RESULTS: The visual analog scale was significantly lower, and patient satisfaction and preference for reexamination were significantly higher in the ethyl chloride spray group. Among the parameters of the motor unit action potential, there were no significant changes except for an increased duration after spraying with ethyl chloride. CONCLUSIONS: Ethyl chloride spray can effectively reduce pain, but it must be used with caution because it may affect parameters of the motor unit action potential during needle electromyography.

Evaluate the usage of different advanced endodontic instruments and techniques in pediatric dentistry.

OBJECTIVE: The purpose of study is to find the prevalence of usage of different advanced endodontic instruments and techniques in pediatric dentistry. MATERIALS AND METHODS: A self-administered, structured questionnaire written in English validated through a pretested survey was randomly mailed to the postgraduate students in different dental colleges. A total of 182 of the complete filled questionnaires were returned with response rate of 68.2%. The data were analyzed using the SPSS version 15.0. The Student's t-test and ANOVA test were used as test of significance. Karl Pearson's correlation test was used to assess years of education and usage of endodontic instruments. RESULTS: There was a limited use of new endodontic technologies in the present study. The highest positive response to the usage of advanced endodontic instruments was related to NiTi rotary files with highest number seen among 3rd year students. A linear relationship was found between years of postgraduation and usage of advanced endodontic instruments using Karl Pearson's correlation coefficient. CLINICAL SIGNIFICANCE: Based on the results of the present study, it seems that the usage of advanced endodontic instruments is not up to the level. Also we found increased use of new technologies with years of postgraduation.

Comparison of changes in facial skin temperature caused by ethyl chloride spraying, ice block rubbing and cold gel packing in healthy subjects.

The aim of this study was to compare the effects of three cryotherapeutic modalities (ethyl chloride spraying, ice block rubbing and cold gel packing) on facial skin temperature. Thirty healthy volunteers (15 men, 15 women; mean age, 29·4 ± 3·2 years) participated in this study. Each of the three modalities was randomly applied to the skin over the right masseter muscle. The skin surface temperature was recorded at baseline and every 5 min for 60 min after the application of one of the three cryotherapeutic modalities. Immediately after application, cold gel packing demonstrated the greatest reduction in surface temperature (10·6 °C), followed by ethyl chloride spraying (4·3 °C) and ice block rubbing (3·7 °C) (P < 0·001). During the 60-min post-application period, ethyl chloride spraying and ice block rubbing produced similar skin surface temperature changes. The skin surface remained coldest for the longest period of time after cold gel packing. The median time for recovery of the baseline temperature after application of the cold gel pack was about three to four times longer than that for the other modalities (P < 0·001). Ethyl chloride spraying and ice block rubbing resulted in less reduction and faster recovery of skin surface temperature than did cold gel packing. In conclusion, ethyl chloride spraying and ice block rubbing had a limited cooling effect on the facial skin tissue and could not reduce the skin surface temperature enough for local analgesia. Moreover, the cooling effect of cold gel packing was remarkable, but not sufficient for local analgesia.

Skin sterility after application of ethyl chloride spray.

BACKGROUND: Ethyl chloride topical anesthetic spray is labeled as nonsterile, yet it is widely used during injection procedures performed in an outpatient setting. The purpose of this study was to investigate the sterility of ethyl chloride topical anesthetic spray applied before an injection. Our a priori hypothesis was that application of the spray after the skin has been prepared would not alter the sterility of the injection site. METHODS: We conducted a prospective, blinded, controlled study to assess the effect of ethyl chloride spray on skin sterility. Fifteen healthy adult subjects (age, twenty-three to sixty-one years) were prepared for mock injections into both shoulders and both knees, although no injection was actually performed. Three culture samples were obtained from each site on the skin: one before skin preparation with isopropyl alcohol, one after skin preparation and before application of ethyl chloride, and one after ethyl chloride had been sprayed on the site. In addition, the sterility of the ethyl chloride was tested directly by inoculating cultures with spray from the bottles. RESULTS: Growth occurred in 70% of the samples obtained before skin preparation, 3% of the samples obtained after skin preparation but before application of ethyl chloride, and 5% of the samples obtained after the injection site had been sprayed with ethyl chloride. The percentage of positive cultures did not increase significantly after application of ethyl chloride (p = 0.65). Spraying of ethyl chloride directly on agar plates resulted in growth on 13% of these plates compared with 11% of the control plates; this difference was also not significant (p = 0.80). CONCLUSIONS: Although ethyl chloride spray is not sterile, its application did not alter the sterility of the injection sites in the shoulder and knee.

Evaluation of common anesthetic and analgesic techniques for tail biopsy in mice.

Tail biopsy in mice is a common procedure in genetically modified mouse colonies. We evaluated the anesthetic and analgesic effects of various agents commonly used to mitigate pain after tail biopsy. We used a hot-water immersion assay to evaluate the analgesic effects of isoflurane, ice-cold ethanol, ethyl chloride, buprenorphine, and 2-point local nerve blocks before studying their effects on mice receiving tail biopsies. Mice treated with ethyl chloride spray, isoflurane and buprenorphine, and 2-point local nerve blocks demonstrated increased tail-flick latency compared with that of untreated mice. When we evaluated the behavior of adult and preweanling mice after tail biopsy, untreated mice demonstrated behavioral changes immediately after tail biopsy that lasted 30 to 60 min before returning to normal. The use of isoflurane, isoflurane and buprenorphine, buprenorphine, 2-point nerve block, or ethyl chloride spray in adult mice did not significantly improve their behavioral response to tail biopsy. Similarly, the use of buprenorphine and ethyl chloride spray in preweanling mice did not improve their behavioral response to tail biopsy compared with that of the untreated group. However, immersion in bupivacaine for 30 s after tail biopsy decreased tail grooming behavior during the first 30 min after tail biopsy. The anesthetic and analgesic regimens tested provide little benefit in adult and preweanling mice. Given that tail biopsy results in pain that lasts 30 to 60 min, investigators should carefully consider the appropriate anesthetic or analgesic regimen to incorporate into tail-biopsy procedures for mice.

Ethyl chloride spray for sensory relief for botulinum toxin injections of the hands and feet.

BACKGROUND: Botulinum toxin injections are effective in the treatment of palmar and plantar hyperhidrosis, but discomfort has limited its use. OBJECTIVE: To study the use of ethyl chloride medium-stream spray in reducing injection discomfort. METHODS: We used ethyl chloride medium-stream spray, in conjunction with precooling by frozen ice packs, in our No Sweat Clinic for our most recent 51 consecutive cases of botulinum toxin injection. RESULTS: Ethyl chloride spray greatly facilitated the injection procedure, and all patients completed the injections without hesitation or delay. CONCLUSION: Ethyl chloride medium-stream spray, in conjunction with precooling by frozen ice packs, is highly effective in reducing painful injection sensations. Its use is safe, economical, and easy to learn and does not require special equipment.

Reducing immunization discomfort in 4- to 6-year-old children: a randomized clinical trial.

OBJECTIVE: The goal was to test a multifaceted distraction method designed to reduce injection-associated pain in school-aged children. METHODS: A clinical trial evaluated 41 children, 4 to 6 years of age, who were given 3 standard prekindergarten immunizations; 21 were assigned randomly to an office routine control group, whereas 20 received a multifaceted, discomfort-reducing intervention. The intervention added verbal suggestions of diminished sensation and a visual focusing activity to the use of ethyl chloride, an established pain-reducing measure. The distraction materials used for the intervention consisted of topical ethyl chloride spray, an improvised, plastic, multipronged arm gripper, and a vibrating instrument descending on the contralateral arm, which provided the focusing task and visual distraction. RESULTS: According to patient and parent Faces Pain Scale-Revised scores and nonblinded, video-taped observations scored according to the face-legs-activity-crying-consolability method, the intervention group showed highly significant reductions in pain and discomfort, compared with the control group (patient self-report, P < .0013; parent report, P < .0002; observation score, P < .0001). CONCLUSION: This multifaceted distraction intervention reduced significantly the pain and discomfort of childhood immunizations in children 4 to 6 years of age.

A randomized controlled trial of vapocoolant for pediatric immunization distress relief.

OBJECTIVES: The purpose of this study was to evaluate the effectiveness of vapocoolant for preschoolers' immunization injection pain relief. METHODS: Fifty-seven 4 to 6-year-old children were randomized into vapocoolant alone or typical care conditions. Pain was measured at the baseline and at injection via self-report, caregiver report, nurse report, and by an observational scale. RESULTS: Self-report of pain suggested that children in the vapocoolant alone condition demonstrated stronger increases in pain from baseline to injection than children in the typical care condition. All other measures showed significant increases in pain from baseline to injection, but no other measures indicated treatment effects. DISCUSSION: This study revealed that vapocoolant is not an effective pain management intervention for children's intramuscular injections.

Alternatives to sedation for painful procedures.

Conscious sedation is used frequently to perform procedures that may be undertaken with or without minimal sedation. Fracture manipulation can be performed with minimal discomfort in the awake patient using various techniques-for example, intravenous regional anesthesia, nerve blocks, and hematoma blocks. These have been used for many years and are very safe. They may require some specific equipment (eg, automatic tourniquet) to perform the anesthesia but patients have the same results and are able to go home much quicker because sedation is not used.Use of topical anesthesia for both intact skin and wounds has been used over many years. Its use now should be standard. Nerve blocks can also be used to anesthetize specific areas which may be difficult to use topical anesthesia (eg, lip, hand, etc) or are painful because of injection directly into the wound. These may include infraorbital nerve blocks for lip lacerations, ulna or median nerve blocks for hand injuries, and so on. Other novel approaches to topical anesthesia have seen the use of iontophoresis (again requires specific expensive equipment), jet injection of lidocaine, or "freeze sprays." Each has its own advantages and disadvantages.Femoral nerve block is a useful intervention for analgesia in patients with femoral fractures and can obviate the need for parenteral analgesia and allows excellent analgesia particularly during x-ray examination.Thus, it is important to remember that there are alternatives to conscious sedation which gives good analgesia during the procedure and allows the patient to be discharged sooner.