Vapocoolant Spray Versus Lidocaine Infiltration for Radial Artery Cannulation: A Prospective, Randomized, Controlled Clinical Trial.

OBJECTIVES: Local infiltration with lidocaine is a frequently used measure to prevent pain during arterial cannulation. Its administration is associated with pain. Vapocoolants like ethyl chloride or alkanes also affect rapid-onset anesthesia. However, their administration causes less discomfort compared with administration of lidocaine. The effectiveness of vapocoolants in mitigating discomfort associated with arterial cannulation never has been studied. The authors therefore compared vapocoolant with lidocaine for reducing discomfort caused by arterial cannulation. DESIGN: Prospective, randomized, controlled study. SETTING: University hospital, single center. PARTICIPANTS: One hundred sixty adult patients requiring arterial cannulation before induction of general anesthesia for cardiac surgery or carotid endarterectomy. INTERVENTIONS: Patients received either lidocaine infiltration or vapocoolant spray prior to arterial cannulation. Overall discomfort resulting from the whole procedure (applying local/topical anesthesia followed by arterial puncture) was rated on a 0 to 10 numerical rating scale. Puncture failure rate and time required for the intervention also were recorded. MEASUREMENTS AND MAIN RESULTS: One hundred forty-three patients were included in the per-protocol analysis. Mean pain scores in the vapocoolant group were 3.4 (±1.58) compared with 4.5 (±2.29) in the lidocaine group (difference 1.1±0.33; p = 0.032; Mann-Whitney U-test). The higher puncture failure rate in the lidocaine group (n = 11 v 4) was not significant (p = 0.06; Fisher's exact test). The time required for the intervention was longer in the lidocaine group (138±44 s v 128±44 s; p = 0.019; Mann-Whitney U-test). CONCLUSIONS: Vapocoolant spray is an alternative to lidocaine infiltration to mitigate discomfort associated with arterial cannulation.

Effect of topical vapocoolant spray on perioperative pain response of unweaned calves to ear tagging and ear notching.

OBJECTIVE: To evaluate the efficacy of a vapocoolant spray to provide local anaesthesia for calves during ear tagging and ear notching. STUDY DESIGN: Randomized study. ANIMALS: Twenty Black Angus calves aged 4-16 weeks old. METHODS: Temperature validation studies using thermocouples and a temperature data logger were conducted on dead and live tissue to determine optimal spray distance and duration to achieve tissue anaesthesia (<10 °C). A behavioural trial was conducted to assess efficacy for ear tagging and ear notching. Calves (n = 20) were randomly assigned to the vapocoolant spray (VS) or the water spray (WS) group. A 3 second spray was administered from 10 cm to both sides of the ear immediately prior to ear tagging and ear notching. A numerical rating scale (NRS) was used to score behavioural response to each procedure, with responses categorized from 0 (no response) to 3 (severe). RESULTS: Temperature and tissue validation studies indicated that a vapocoolant spray reduced dead and live tissue temperature to below nociceptive threshold levels (10 °C) for 10-16 seconds. Univariate analysis indicated that ear notching was more painful than ear tagging [odds ratio (OR) = 19.2, 95% confidence interval (CI): 5.34-68.99, p < 0.001]. When adjusted for the multivariate model, there was a significant effect of treatment, with WS calves showing higher pain response scores than VS calves (OR = 4.08, 95% CI: 1.34-12.42, p = 0.011). Ear notching resulted in greater pain response scores than ear tagging (OR = 23.19, 95% CI: 6.18-87.05, p < 0.001). CONCLUSIONS: and clinical relevance Vapocoolant spray induced local anaesthesia and significantly reduced the pain response to ear tagging and ear notching in calves. Ear notching is more painful than ear tagging. Cryoanaesthesia is an effective option for reducing the perioperative pain associated with these simple husbandry procedures.

Clinical Comparison: Fast-Acting and Traditional Topical Dental Anesthetic.

A randomized, nonblinded clinical trial compared the effectiveness of an application method of a fast-acting refrigerant topical agent to a 20% benzocaine gel topical. In a split-mouth design, right and left anterior middle superior alveolar injections (N = 30) were administered with a 27-gauge needle at least 24 hours apart with preinjection topicals. Using a cotton-tipped applicator, a refrigerant topical was applied for 5 seconds and 20% benzocaine gel for 2 minutes on opposite sides at 2 separate appointments. Subjects self-reported pain perception after each injection using a visual analog scale (VAS). The mean VAS ratings demonstrated no significant difference between the 5-second application of the refrigerant (M = 16.2, SD = 17.7) and the 2-minute application of 20% benzocaine topical gel anesthetic (M = 17.9, SD = 18.2). Fifty-seven percent of the subjects reported greater pain reduction with the refrigerant, 33% reported greater pain reduction with 20% benzocaine, and 10% reported no difference. Results suggest the described method of application of a refrigerant as an oral topical anesthetic has a faster onset and provides similar benefit in pain reduction compared with 20% benzocaine gel. The refrigerant was easy to accomplish and well received by subjects, indicating potential for routine use in dentistry.

Intrarectal ice application prior to transrectal prostate biopsy: a prospective randomised trial accessing pain and collateral effects.

OBJECTIVES: To analyze the efficacy of intrarectal ice application as an anesthetic method prior to transrectal ultrasound (TRUS) guided prostate biopsy. MATERIALS AND METHODS: A total of 120 consecutive men were included into the study prospectively. Patients were equally randomized as group 1 and 2 with 60 patients each. Ice was applied as an anesthetic method 5 minutes before procedure to the patients in group 1. Patients in group 2 were applied 10 mL of 2% lidocaine gel 10 minutes before procedure. Twelve core biopsy procedure was performed for all patients. The pain level was evaluated using a visual analogue scale (VAS). RESULTS: Median pain score was 3.5 (1-8) in group 1 and 5 (1-8) in group 2. There is significantly difference between groups regarding the mean sense of pain level during the procedure. (p=0.007) There was also no difference in complications between two groups about presence and duration of macroscopic hematuria and rectal bleeding. CONCLUSIONS: Intrarectal ice application prior to TRUS prostate biopsy has an effect on reducing pain. Development of new techniques about cold effect or ice can make this method more useful and decrease complication rates.

The effect of cold-air anesthesia during fractionated carbon-dioxide laser treatment: Prospective study and review of the literature.

BACKGROUND: Forced cold-air anesthesia has been reported to decrease the discomfort associated with various dermatologic laser therapies. OBJECTIVE: We sought to evaluate the effect of cold-air anesthesia on patient comfort during ablative fractionated carbon-dioxide (CO(2)) laser treatment for photoaging. METHODS: We conducted a prospective split-face study to evaluate the effect of cold-air anesthesia on patient comfort during ablative fractionated CO(2) laser treatment for photoaging. Both patients and physicians rated the perceived discomfort of the treatment on each half of the face on a pain scale of 0 to 10. In addition, patients were asked to evaluate the side effects of the procedure (erythema, edema, crusting, scaling) on each half of the face. At 6 months posttreatment, blinded physician photograph evaluation was performed of 5 clinical indicators of photoaging. RESULTS: For the side of the face treated with topical anesthesia alone, the mean patient-reported pain score was 7.47. On the side treated with cold-air anesthesia and topical anesthesia, the mean pain score was 4.27 (P < .01). For the side treated with topical anesthesia alone, the mean physician-reported pain score was 7.8, relative to the side treated with cold-air anesthesia and topical anesthesia, for which the mean physician-reported pain score was 3.73 (P < .01). LIMITATIONS: Although significant differences were found in pain tolerance with fractionated CO(2) laser with the use and absence of forced-air cooling, additional large-scale studies are needed to confirm the device's use in patient tolerability and side-effect profile. CONCLUSION: The use of forced cold-air device in conjunction with topical anesthesia provides a well-accepted modality for patient comfort during ablative fractionated CO(2) resurfacing.

Analgesia for amniocentesis or chorionic villus sampling.

BACKGROUND: Besides risks of miscarriage, pregnant women undergoing amniocentesis or chorionic villus sampling (CVS) are also concerned about pain associated with these procedures. Currently, approaches to analgesia can be categorised in two broad categories - non-pharmacological and pharmacological agents. OBJECTIVES: To evaluate whether different methods of analgesia have any impact on pain reduction during amniocentesis or chorionic villus sampling (CVS). SEARCH METHODS: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 August 2011). SELECTION CRITERIA: All randomised trials comparing different method of analgesia for amniocentesis or CVS. We also include trials with quasi-randomised designs, but analyse and report their results separately. DATA COLLECTION AND ANALYSIS: Both review authors assessed eligibility and trial quality and performed data extraction. MAIN RESULTS: We included a total of five randomised studies (involving 805 women) evaluating different methods of analgesia for amniocentesis; there were no studies in women undergoing CVS.One RCT (N = 203) and one quasi-randomised study (N = 220) compared infiltrative local anaesthesia with no anaesthesia and found no statistical difference in experienced pain on the visual analogue scale (VAS) (mean differences (MD) -2.50 and 1.20; 95% confidence interval (CI) -6.98 to 1.98 and -2.67 to 5.07).One study (N = 200) compared light leg rubbing versus no intervention during amniocentesis and found no change in experienced anxiety (MD 0.2; 95% CI -0.63 to 1.03) or VAS pain score (MD 0.3; 95% CI -0.35 to 0.95) during amniocentesis.Another study with 62 patients did not find any benefit of using subfreezing temperature needle during amniocentesis in terms of decreased VAS pain score (MD -0.8; 95% CI -1.8 to 0.2). In addition, there was no difference between anticipated and actual pain (MD 0.4; 95% CI -0.82 to 1.62) (before/after comparison).There was also no difference in VAS pain scores in the study with 120 participants comparing lidocaine-prilocaine analgesic cream to placebo cream before amniocentesis (MD -0.6; 95% CI -1.44 to 0.24). AUTHORS' CONCLUSIONS: In general, women who undergo amniocentesis could be informed that pain during procedure is minor and that there is currently insufficient evidence to support the use of local anaesthetics, leg rubbing or subfreezing the needle for pain reduction during procedure.

Comparative study between cold air analgesia and supraorbital and supratrochlear nerve block for the management of pain during photodynamic therapy for actinic keratoses of the frontotemporal zone.

BACKGROUND: Photodynamic therapy (PDT) is an effective treatment for actinic keratoses, Bowen's disease and basal cell carcinoma. The main drawback of PDT is pain during application. OBJECTIVES: To compare the efficacy of supratrochlear and supraorbital nerve block with cold air analgesia to control the pain experienced during PDT. METHODS: A controlled open clinical trial was conducted in 34 patients having multiple actinic keratoses in the frontal region treated with PDT. On one side of the frontal region the supratrochlear and supraorbital nerves were blocked, while on the other side cold air was used as the method of analgesia. Pain was recorded on a visual analogue scale after treatment. RESULTS: Thirty-one of 34 patients reported less pain in the zone treated with nerve block. This difference was statistically significant. CONCLUSIONS: Nerve block is superior to cold air and is an easy, safe, effective means of controlling the pain associated with PDT.

Reduction of pain and anxiety prior to botulinum toxin injections with a new topical anesthetic method.

PURPOSE: To evaluate the safety and efficacy of vapocoolants (topical skin refrigerants) to induce skin anesthesia and relieve patient anxiety and pain prior to cosmetic botulinum injections. METHODS: A paired (split-face) design was used in 52 patients where patient side (left vs. right) was randomized to receive either vapocoolant spray or no treatment control to test the study hypothesis of better anesthetic efficacy of vapocoolant spray versus no treatment control. A pain and anxiety questionnaire was administered before, during, and after the injections. RESULTS: A considerable percentage of patients either expected pain (35% of naïve patients expected moderate pain) or had experienced pain from their prior treatment (35% had experienced moderate pain). Among naïve patients, 15% had moderate or severe anxiety and among experienced patients, 31% had moderate anxiety. Pain was a factor in delaying the scheduling of cosmetic botulinum toxin treatments in 19% of naïve patients and 31% of experienced patients. Pain reported from actual injections was higher than what was anticipated prior to treatment. There was a significant reduction in pain at injection sites treated with vapocoolant (p < 0.001, paired t test). Overall, 67% of all patients reported that the vapocoolant method had less pain than no anesthesia and 54% preferred vapocoolant for their next treatment. Overall, 6% of all patients would schedule their next botulinum toxin treatment sooner if vapocoolant were available. CONCLUSIONS: Vapocoolants represent a safe and effective means to reduce patient discomfort and anxiety before and during botulinum toxin type A treatments for glabellar area indications.

What stands in the way of treating palmar hyperhidrosis as effectively as axillary hyperhidrosis with botulinum toxin type A.

Botulinum Toxin type A (BTX-A) has revolutionized the treatment of focal hyperhidrosis (HH) in recent years and has dramatically reduced the invasive surgical techniques that have been performed in the past to control severe focal HH unresponsive to topical therapies. Whereas BTX-A injections are easily performed to control axillary HH with little or no analgesia, pain management is a must during the injection of palmar and plantar HH with BTX-A because of the intense pain generated with the 30 to 40 needle punctures needed on each hand or foot through the densely innervated skin present in those areas. For that reason, many physicians who contentedly treat axillary HH with BTX-A injections, refuse to do so for palmar and plantar HH. Although pain is the major stumbling block deterring patients and physicians from choosing this treatment option, it is not the only one. Many other factors may play a role in deciding whether or not to treat palmar and plantar HH with BTX-A injections. This article reviews these factors and presents some personal data from patients who have already been treated with BTX-A injections on the palms and soles and who came back once or more for repeat treatments when the effect of BTX-A started to fade away. "Jet Anesthesia" was the pain management method used in this group.

The effect of vapocoolant spray on pain due to intravenous cannulation in children: a randomized controlled trial.

BACKGROUND: Established noninvasive pharmacologic means of alleviating pain and anxiety in children undergoing intravenous cannulation are time-consuming, and thus impractical for routine use in the emergency department. Vapocoolant sprays provide transient skin anesthesia within seconds of application. We compared the effect of a new vapocoolant spray to placebo on pain due to intravenous cannulation in children. METHODS: In this double-blind randomized controlled trial, which we conducted between June 1 and Sept. 12, 2006, 80 children aged 6-12 years received either vapocoolant spray or placebo before cannulation. Children rated their pain using a 100-mm colour visual analogue scale. Secondary outcomes included success rate on first attempt at cannulation and pain ratings by the children's parents, nurses and child life specialists. RESULTS: We found a modest but significant reduction in pain with the use of vapocoolant spray (mean difference 19 mm, 95% confidence interval [CI] 6-32 mm; p < 0.01). Cannulation on first attempt was more often successful with the use of vapocoolant spray (85.0%) than with placebo (62.5%) (mean difference 22.5%, 95% CI 3.2%-39.9%; p = 0.03). The number needed to treat to prevent 1 cannulation failure was 5 (95% CI 3-32). Parents (p = 0.04), nurses (p = 0.01) and child life specialists (p < 0.01) considered the children's pain to be reduced with the use of vapocoolant spray. INTERPRETATION: The vapocoolant spray in our study quickly and effectively reduced pain due to intravenous cannulation in children and improved the success rate of cannulation. It is an important option to reduce childhood procedural pain in emergency situations, especially when time precludes traditional interventions. (http://ClinicalTrials.gov trial register no. NCT00130650.).

Analgesic pretreatment for antibiotic skin test: vapocoolant spray vs ice cube.

OBJECTIVES: The objective of this study was to compare the efficacy of ethyl chloride spray and ice cube for the control of pain induced by the antibiotic skin test. METHODS: We performed a prospective, crossover, randomized study in which healthy adult volunteers received an intradermal skin test on both arms after different analgesic pretreatments. We assessed the pretreatment pain and discomfort after the intradermal skin injection using a 100-mm visual analogue scale. RESULTS: A total of 50 volunteers were enrolled in the study. The mean pain scores after the skin test were 32.4 +/- 17.6 and 54.7 +/- 22.4 mm, for the ice cube and vapocoolant spray pretreatment, respectively (P < .0001). The mean discomfort scores during pretreatment were 20.0 +/- 15.2 mm for ice cube and 10.5 +/- 11.5 mm for vapocoolant spray (P < .0001). Forty-five (90%) subjects preferred the ice cube pretreatment for the intradermal skin test. CONCLUSIONS: The ice cube application was significantly more effective than the vapocoolant spray in reducing the pain of the antibiotic skin test. Hence, the ice cube pretreatment is suggested for easy and fast pain reduction for the antibiotic skin test in the emergency department.

Mitigation of pain during intravenous catheter placement using a topical skin coolant in the emergency department.

OBJECTIVE: Although intravenous (i.v.) line placement is a common procedure in the emergency department (ED), it is an uncomfortable experience for many patients. Topical analgesic agents are rarely used because they have long onsets of action and thereby cause unacceptable treatment delays. Cryoanaesthesia, the use of cooling agents to reduce pain, has been recognised for many years as a potential pain management strategy. The purpose of this study was to determine whether an instantaneous topical skin coolant spray reduces patient's pain during i.v. cannulation and represents a feasible alternative for cutaneous analgesia in the ED setting. METHODS: We conducted an unblinded, randomised, controlled study, in a convenience sample of ED patients. Utilising a random number generator to assign patients to the control or study group, patients over the age of 18 years who required i.v. cannulation as part of their evaluation were enrolled at two tertiary care hospitals. In both groups, i.v. lines were placed in accordance with accepted clinical standards of practice, with the single addition of the coolant spray delivered to the i.v. site before needle insertion in the study group. All study participants answered questionnaires before and after i.v. placement and rated pain during procedure on a 100 mm visual analogue scale. RESULTS: Of the 92 patients enrolled in the study, 47 (51.1%) were randomised to the study group and received the anaesthetic spray, and 45 (48.9%) were randomised to the control group and had their i.v. placed in a standard method. 66 patients were female (71.8%) and 26 (28.2%) were males. The mean pain score in the study group was 27 mm (95% confidence interval (CI) 19.9 to 34.1 mm) and 28 mm (95% CI 20.4 to 35.6 m) in the control group (p = 0.934). Subgroup analysis of female and male patients did not show significance. CONCLUSIONS: Our study failed to detect a difference in pain perception resulting from the pre-procedural application of a skin coolant associated with i.v. placement in the ED setting.

Cryoanalgesia in Patients Undergoing Nuss Repair of Pectus Excavatum: Technique Modification and Early Results.

PURPOSE: The Nuss procedure for surgical correction of pectus excavatum often causes severe postoperative pain. Cryoanalgesia of intercostal nerves is an alternative modality for pain control. We describe our modification of the cryoICE™ probe that allows for nerve ablation through the ipsilateral chest along with early results utilizing this technique. METHODS: To allow for ipsilateral nerve ablation, a 20-French chest tube was cut and secured to the cryoICE probe, thus providing insulation for the malleable end of the probe. A 3-year retrospective review of patients undergoing Nuss repair at our institution was performed. Patients who received cryoanalgesia (cryo, n = 6) were compared with a historical control cohort who did not receive cryoanalgesia (nocryo, n = 13) during Nuss repair. Hospital length of stay, postoperative narcotic requirement (PNR), and highest postoperative pain score were collected. RESULTS: Both cohorts were similar regarding age, BMI, and pectus index. The cryo group had a significantly less PNR (6.4 versus 17.9 doses, P = .05) and was discharged on average >1 day earlier than nocryo patients (3.7 versus 2.2 days, P = .01). No complications occurred in either group. CONCLUSIONS: Our technique modification simplifies previously described approaches to intercostal nerve cryoablation. Patients undergoing this adjunct benefit with less PNR and a faster discharge time.

Effectiveness of precooling the injection site using tetrafluorethane on pain perception in children.

BACKGROUND: Injection of local anesthesia is one of the most important reasons for avoidance behavior in children. Applying a topical anesthetic before injection is the most popular way to control pain; however, topical anesthetics have some shortcomings such as longer duration of action, displeasing taste, and spread of the anesthetic agent to noninjection site areas. Cryoanesthesia using refrigerant as a topical anesthesia is being studied as an alternative to overcome the shortcomings of topical anesthetics and has shown promising results. MATERIALS AND METHODS: In this split-mouth design study, 50 children of aged 8-10 years who required bilateral mandibular local anesthesia administration were selected. In the first visit, application of topical anesthetic spray (lidocaine) on one side and during the second appointment cryoanesthetic tetrafluorethane on the other side was used before local anesthetic administration. Patients were asked to report their discomfort and pain using visual analog scale (VAS) (subjective method). Patients' pain perception during injection is assessed by sound, eye, and motor (SEM) scale by the dentist (objective method). RESULTS: The results were statistically analyzed using paired Wilcoxon signed-rank test and Mann-Whitney tests. In VAS scale (subjective method), pain scores were significantly lower in tetrafluorethane group when compared with lidocaine group. In SEM scale (objective method), pain scores were lower in tetrafluorethane group when compared with lidocaine group, but it was statistically insignificant. CONCLUSION: Precooling the injection site using refrigerant tetrafluorethane spray has shown to be effective in eliminating pain before local anesthesia administration in children when compared with topical anesthetic lidocaine spray.

Ethyl chloride as a cryoanalgesic in pediatrics for venipuncture.

INTRODUCTION: Ethyl chloride can be used as a cryoanalgesic, but with the availability of alternative and relatively safer topical analgesics, its use has decreased. However, it still has the advantage of being quicker to apply compared with other topical analgesics, making it ideal for use in the outpatient departments. We wanted to compare the effectiveness of ethyl chloride as an analgesic during venipuncture in children. METHODS: Venipuncture was carried out using either no analgesia (NO), ethyl chloride spray (EC), or application of the topical anesthetic Ametop (TA) on children attending the phlebotomy outpatient service by experienced pediatric phlebotomists. A pain score was recorded using either the Faces scoring system or the Faces, Legs, Activity, Cry Consolability scoring system. RESULTS: A total of 55 patients were included in the study, 18 from group EC, 18 from group TA, and 19 from group NO. Thirteen patients from both groups EC and TA and 17 from group NO scored 2 or less on the pain scores. DISCUSSION: The use of ethyl chloride was as effective as topical anesthetics in preventing distress to children in venipuncture. However, in the appropriate situations, the use of NO could also be comfortable to the child if venipuncture was done by specialist pediatric phlebotomists.

[The study on freezing intercostal nerves for the relief of postoperative chest pain].

OBJECTIVE: To explore the best freezing time and the optimum analgesia modality. METHODS: In dogs, intercostal nerves were froze at -70 degrees C at different time including 30, 60, 90, 120, 180 s. Samples were got at the operative day, in 10 days and 60 days respectively, then carried on the pathology exam. In clinical study, 150 patients undergoing thoracotomy were randomly designated into 5 groups, all patients were recorded the heart rate, blood pressure, SO2, VAS, the dosage of dolantin, and observed the complications and side effects. RESULTS: At operative day, the freezing nerves appeared brown print macroscopically, and presented degeneration, necrosis of the nerve fiber microscopically with more than 90 s. After 10 days, nerves with more than 90 s became thinner than normal. After 60 days, all nerves had no obvious differentiation than normal. In clinical study, both 90 s group and 90 s with PCIA group were significantly better than 60 s group or PCIA group; The VAS of 90 s with PCIA group was significantly lower than 90 s group but had more side effects such as vomiting, nausea. CONCLUSIONS: At -70 degrees C, the freezing time should be no less than 90 s. The freezing intercostal nerves can safely and effectively relieve postoperative chest pain. The effect of analgesia of 90 s with PCIA group is the best, but has many side effects.

Vapocoolant Spray Effectiveness on Arterial Puncture Pain: A Randomized Controlled Clinical Trial.

Arterial blood gas (ABG) sampling is a painful procedure with no perfect technique for quelling the discomfort. An ideal local anesthesia should be rapid, easy to learn, inexpensive, and noninvasive. This study was aimed to compare pain levels from ABG sampling performed with vapocoolant spray in comparison to placebo. We hypothesized that pretreatment with the vapocoolant would reduce the pain of arterial puncture by at least 1 point on a 10 point verbal numeric scale. We have evaluated the effectiveness of a vapocoolant spray in achieving satisfactory pain control in patients undergoing ABG sampling in this randomized placebo controlled trial. Eighty patients were randomized to 2 groups: group A, who received vapocoolant spray, and group B, who received water spray as placebo (Control group). Puncture and spray application pain was assessed with numerical rating scale (0, the absence of pain; 10, greatest imaginable pain) and number of attempts was recorded. The pain score during ABG sampling was not lower in group A compared with group B significantly (4.78±1.761 vs. 4.90±1.837; P:0.945). This study showed that while the spray exerts more application pain, the number of attempts required for ABG sampling was not significantly lower in group A compared with group B (1.38±0.54 vs. 1.53±0.68; P=0.372). Vapocoolant spray was not effective in ABG pain reduction, had milder application pain compared to placebo (P<0.05), but did not reduce sampling attempts. At present, this spray cannot be recommended for arterial puncture anesthesia, and further study on different timing is necessary.