Comparison of the effects of vapocoolant spray and topical anesthetic cream on pain during needle electromyography in the medial gastrocnemius

18F-ASEM PET/MRI targeting alpha7-nicotinic acetylcholine receptor can reveal skeletal muscle denervation

BACKGROUND

The increased expression of the nicotinic acetylcholine receptor (nAChR) in muscle denervation is thought to be associated with electrophysiological acetylcholine supersensitivity after nerve injury. Hence, we investigated the utility of the 18F-ASEM alpha7-nAChR targeting radiotracer as a new diagnostic method by visualizing skeletal muscle denervation in mouse models of sciatic nerve injury.

METHODS

Ten-week-old C57BL/6 male mice were utilized. The mice were anesthetized, and the left sciatic nerve was resected after splitting the gluteal muscle. One week (n = 11) and three weeks (n = 6) after the denervation, 18F-ASEM positron emission tomography/magnetic resonance imaging (PET/MRI) was acquired. Maximum standardized uptake values (SUVmax) of the tibialis anterior muscle were measured for the denervated side and the control side. Autoradiographic evaluation was performed to measure the mean counts of the denervated and control tibialis anterior muscles at one week. In addition, immunohistochemistry was used to identify alpha7-nAChR-positive areas in denervated and control tibialis anterior muscles at one week (n = 6). Furthermore, a blocking study was conducted with methyllycaconitine (MLA, n = 5).

RESULTS

18F-ASEM PET/MRI showed significantly increased 18F-ASEM uptake in the denervated tibialis anterior muscle relative to the control side one week and three weeks post-denervation. SUVmax of the denervated muscles at one week and three weeks showed significantly higher uptake than the control (P = 0.0033 and 0.0277, respectively). The relative uptake by autoradiography for the denervated muscle was significantly higher than in the control, and immunohistochemistry revealed significantly greater alpha7-nAChR expression in the denervated muscle (P = 0.0277). In addition, the blocking study showed no significant 18F-ASEM uptake in the denervated side when compared to the control (P = 0.0796).

CONCLUSIONS

Our results suggest that nAChR imaging with 18F-ASEM has potential as a noninvasive diagnostic method for peripheral nervous system disorders.

Evaluation of vapocoolant spray effect on pain reduction during digital nerve block: A randomized clinical trial

INTRODUCTION

The digital nerve block is an effective method of anesthesia before minor surgical interventions on the fingers. However, patients may experience a lot of pain and anxiety during this procedure. The efficacy of topical vapocoolant spray during minor procedures has been demonstrated in previous studies. we aimed to evaluate the effectiveness of topical vapocoolant spray in reducing pain during digital nerve block.

METHODS

This prospective, randomized clinical study was conducted to evaluate the effectiveness of vapocoolant spray application in reducing pain during digital block. The patients were categorized into 2 groups as spray-treated and control group. A routine digital block process was applied to the control group. Spray application was performed in two groups of 50 each, in a manner of bilateral and unilateral to the finger. Demographic data of the patients, such as gender, age, dominant hand, injury patterns, injection site and injury sites, were recorded. After the application, the patients' visual analog scale (VAS) was evaluated.

RESULTS

Of the participants, 100 were randomly assigned to the vapocoolant spray-treated group, and 50 were included in the control group. The VAS pain score during penetration in both spray groups was significantly lower than the control group (p < 0.001). Pain change during penetration was found to be significantly lower in the bilateral spray-treated group compared to the control group (p < 0.001). Pain change during infiltration was significantly lower in both spray groups compared to the control group (p < 0.001).

CONCLUSIONS

Spray application prior to digital nerve blocking can be used to reduce needle penetration pain associated with this procedure and pain associated with local anesthetic infiltration.

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.

Nonexperimental Xenobiotics: Unintended Consequences of Intentionally Administered Substances in Terrestrial Animal Models

Review of the use of nonexperimental xenobiotics in terrestrial animal models and the potential unintended consequences of these compounds, including drug-related side effects and adverse reactions.

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.

18 F-FDG uptake in denervated muscles of patients with peripheral nerve injury

OBJECTIVE

We aimed to investigate the clinical significance of increased uptake in ¹⁸ F-fluorodeoxyglucose positron emission tomography in patients with peripheral nerve lesions.

METHODS

We selected patients with unilateral peripheral nerve lesions confirmed with electromyography who had undergone ¹⁸ F-fluorodeoxyglucose positron emission tomography covering the lesions. In the denervated muscles and their contralateral corresponding pairs, a mean (SUVmean) and maximum standardized uptake value (SUVmax) were obtained from ¹⁸ F-fluorodeoxyglucose positron emission tomography images. We analyzed the difference in these values between the denervated and normal muscles. The lesion-to-normal ratio of the SUVmean (LNRmean) between each muscle pair was also obtained. Subgroup analysis was performed to find whether these three parameters were related to severity, abundance of abnormal spontaneous activity, and etiology.

RESULTS

Twenty-three patients with 38 denervated muscles were included. Compared to their normal counterparts, the denervated muscles showed significantly higher SUVmax (1.33 ± 0.49 vs. 1.10 ± 0.37, n = 38, P < 0.001) and SUVmean (0.91 ± 0.31 vs. 0.77 ± 0.28, n = 38, P < 0.001). The muscles with severe neuropathy showed significantly higher LNRmean than those with mild neuropathy (1.30 ± 0.36, n = 19 vs. 1.11 ± 0.24, n = 19; P = 0.046), and the muscles with traumatic neuropathy showed significantly higher LNRmean than those with nontraumatic neuropathy (1.32 ± 0.28, n = 13 vs. 1.14 ± 0.33, n = 23; P = 0.015).

INTERPRETATION

Denervated muscles with peripheral nerve injury showed higher uptake than normal muscles in ¹⁸ F-fluorodeoxyglucose positron emission tomography, and this was associated with severity and etiology.

Effects of Vapocoolant Spray Prior to SC LMWH Injection: An Experimental Study

The aim of this study was to evaluate the effects of vapocoolant spray administration prior to subcutaneous (SC) low molecular weight heparin injection on local ecchymosis, hematoma, and pain. This randomized controlled study was carried out on 64 patients (n = 128 injections) in an orthopedics and traumatology clinic. After randomization, vapocoolant spray and then heparin injection was applied on one arm. The second necessary dose of heparin was applied to his or her other arm as a placebo by a water spray. Then, the pain of the patients was assessed. After 2 days, ecchymosis and hematoma were evaluated. Significant lower pain scores were determined in applications in which the vapocoolant spray was used. There was no statically significant difference between the mean diameter values of ecchymosis in both arm groups. There was no hematoma on the injection site after injections. However, this method did not create any significant reductive effect on ecchymosis. Nurses are advised to take advantage of vapocoolant spray effects prior to SC heparin injection.

18F-FDG positron emission tomography as a novel diagnostic tool for peripheral nerve injury

BACKGROUND

Glucose hypermetabolism in denervated skeletal muscle suggests the potential for developing a diagnostic tool for peripheral nerve injuries. Herein, we investigated the characteristics and molecular mechanism of this phenomenon.

NEW METHOD

Temporal course of glucose hypermetabolism and development of abnormal spontaneous activities (ASA) through electromyography (EMG) were investigated in rats with complete sciatic nerve injuries. Rats with partial sciatic nerve injuries were used to investigate the relationship between nerve injury severity and change in glucose metabolism. Rapamycin-treated rats were used to study molecular mechanism. Mean lesion-to-normal count ratios (LNR_mean) was calculated as a numeric value of the ¹⁸F-FDG uptake.

RESULTS

Glucose hypermetabolism began 2 days after nerve injury and lasted up to 12 weeks, with the maximum increase at 1 week after denervation (10-fold increase compared to sham-operated muscle; LNR_mean, sham, 1.360 ± 0.452; denervation, 10.340 ± 4.094; n = 5; P < 0.05). The metabolic changes showed similar temporal characteristics to ASA on EMG. The signal intensity of ¹⁸F-FDG uptake in denervated skeletal muscle was strongly related to nerve injury severity in a partial nerve injury model (Pearson correlation coefficient 0.63, P < 0.05). Suppression of mTOR by rapamycin treatment reduced the increase in peak glucose hypermetabolism in muscle denervation.

COMPARISON WITH EXISTING METHOD

Metabolic changes in ¹⁸F-FDG PET scans have a wider time span than abnormalities on EMG after denervation and it is correlated with the severity of nerve injury assessed by NCS.

CONCLUSIONS

¹⁸F-FDG PET may be used to diagnose and evaluate peripheral nerve injuries.

Comparison between Vapocoolant Spray and Eutectic Mixture of Local Anesthetics Cream in Reducing Pain during Spinal Injections

Background

Eutectic mixture of local anesthetics (EMLA) cream is often used for local anesthesia during spinal injections. However, this agent has delayed onset of action while vapocoolant spray serves more advantages. The vapocoolant spray containing ethyl chloride has fast onset and is safe, low cost, and widely available. This study aimed at comparing the effectiveness of vapocoolant spray and EMLA cream in reducing pain for spinal injections.

Methods

This was an experimental study on 94 subjects with 47 subjects treated with EMLA cream and 47 subjects treated with vapocoolant spray. The effectiveness of anesthesia was assessed by using Numeric Pain Rating Scale (NPRS) and patient movement during the surgery.

Results

This study found that the pain scale was NPRS 0 (0–3) for the EMLA group and NPRS 0 (0–4) for the vapocoolant spray group. There was no significant difference between two groups for pain scale according to the Mann–Whitney U test. For patient movement, the movement was reported only in one (2.1%) patient in the EMLA group and one (2.1%) patient in the vapocoolant spray group. Based on Fisher's test, there was no significant difference between the two groups for patient movement.

Conclusions

Both EMLA cream and vapocoolant spray were equally effective in reducing pain during spinal injection. There was no difference in degree of pain reduction and patient movement between the EMLA cream group and the vapocoolant spray group during spinal injection.

The provision of written information and its effect on levels of pain and anxiety during electrodiagnostic studies: A randomised controlled trial

Objective

The provision of written information is a low-cost and readily available intervention that has been found to reduce pain and anxiety in a variety of clinical settings. The current study was undertaken to determine if information provision may improve patients’ experience during conventional electrodiagnostic studies.

Methods

128 participants were recruited from a tertiary teaching hospital who were referred for electrodiagnostic studies. They were randomized into 2 groups where the intervention group was provided with written information about the electrodiagnostic testing. Patients were invited to complete a questionnaire that included pain and anxiety using a visual analogue scale (VAS) following the testing. All participants underwent nerve conduction studies (NCS) whilst a subset also underwent subsequent needle electromyography (EMG).

Results

Those who received information had a statistically significant lower perception of anxiety during NCS, whilst only females who received information had a statistically significant lower perception of pain to both NCS and EMG.

Conclusions

The provision of written information can reduce the degree of pain and anxiety experienced during electrodiagnostic testing.

Significance

Improving patient comfort and tolerability during electrodiagnostic testing may have practical implications towards more reliable and accurate results obtained from such investigations that may in turn improve patient diagnosis and management.

[The Effect of Pain Relieving Intervention During Infiltration among Gamma Knife Surgery Patients for Stereotactic Frame Fixation]

PURPOSE

This study aimed to compare the effects of three interventions on pain, blood pressure, and pulse rate during infiltration anesthesia in patients about to undergo gamma knife surgeries.

METHODS

The three interventions employed in a university-affiliated Hospital in J City, South Korea were as follows: EMLA cream plus Vapocoolant spray (Vapocoolant, n=30), EMLA cream plus 10.0% Lidocaine spray (Lidocaine, n=30), and EMLA cream only (EMLA, n=30). The equivalent control-group pre test - post test study design was used. Pain was assessed subjectively using the numeric rating scale (NRS) and objectively using a Galvanic Skin Response (GSR) tester. NRS scores were assessed after infiltration anesthesia and the GSR was assessed during infiltration anesthesia. Blood pressure and pulse rate were assessed twice: before and after infiltration anesthesia. Data were collected between August 3, 2016 and March 24, 2017.

RESULTS

NRS scores after infiltration anesthesia and the GSR during infiltration anesthesia were significantly lower in the Vapocoolant group than in the Lidocaine and EMLA groups (F=13.56, p<.001 and F=14.43, p<.001, respectively). The increase in systolic blood pressure (F=4.77, p=.011) and in pulse rates (F=4.78, p=.011) before and after infiltration anesthesia were significantly smaller in the Vapocoolant group than in the Lidocaine and EMLA groups; however, no significant differences were observed in diastolic blood pressures (F=1.51, p=.227).

CONCLUSION

EMLA cream plus Vapocoolant spray was the most effective intervention to relieve pain and to lower increase in systolic blood pressure and pulse rate caused by infiltration anesthesia for stereotactic frame fixation. Thus, application of Vapocoolant spray in addition to EMLA cream is highly recommended as a nursing intervention for patients undergoing gamma knife surgeries.

Paracetamol 325 mg/tramadol 37.5 mg effect on pain during needle electromyography: a double-blind crossover clinical trial

Needle insertion during electromyography (EMG) may cause varying levels of pain that could lead to inaccurate assessment and premature termination of the procedure. The aim of this study is to compare paracetamol 325 mg/tramadol 37.5 mg with placebo in relieving pain before EMG. This is a randomized, crossover, placebo-controlled, double-blind clinical trial; forty-four healthy individuals, including 27 males with a mean age of 35.3 years (range 18-59 years), entered this study. The needles were inserted unilaterally 2 h after administration of two analgesic tablets of paracetamol 325 mg/tramadol 37.5 mg or two placebo tablets. The pain was scored through a 100-mm visual analog scale (VAS) immediately and 2 h after the procedure. The side effects were also recorded. Within a week, the procedure was repeated on the other upper limb, changing the treatment and placebo. The immediate and 2-h VAS scores were notably lower after administration of treatment compared to placebo (immediate pain: 17.5 ± 12.8 vs. 32.1 ± 16.0, P < 0.001; and 2-h pain: 1.6 ± 5.6 vs. 5.8 ± 7.9, P = 0. 002). There was a higher prevalence of side effects when treatment was used (48 vs. 9 %, P < 0.001). Although most symptoms were mild, transient and resolved without medical interventions, on one occasion a volunteer experienced brief loss of consciousness and one subject had severe vertigo that required hospitalization and fluid therapy. Paracetamol 325 mg/tramadol 37.5 mg administration prior to EMG could effectively alleviate pain. Further application of this medication in patients with neuromuscular disorders would warrant additional clinical trials, particularly considering the adverse events.

Feasibility of 18F-FDG PET as a noninvasive diagnostic tool of muscle denervation: a preliminary study

The purpose of this study was to confirm glucose hypermetabolism in denervated muscle and investigate the feasibility of (18)F-FDG PET scanning for the detection of muscle denervation.

METHOD

A sciatic neuropathy model in rats was created by nerve resection of the left sciatic nerve and sham operation on the other side. Eight days after denervation, small-animal PET/CT scans of the hindlimbs were acquired. Muscle denervation was confirmed by electrophysiologic and histologic study.

RESULTS

All rats showed increased (18)F-FDG uptake in the muscles of the left (denervated) lower legs. The calculated maximum lesion-to-normal counts ratio of the left lower leg anterolateral (left, 11.02 ± 2.08; right, 1.81 ± 0.40, n = 6, P < 0.01) and posterior (left, 9.81 ± 4.58; right, 1.87 ± 0.44, n = 6, P < 0.01) compartment were significantly increased. The electrophysiologic and histologic study verified muscle denervation.

CONCLUSION

Glucose hypermetabolism in muscle denervation is an obvious phenomenon. (18)F-FDG PET scanning can be used to visualize muscle denervation.