Vapocoolant Spray Is Equally Effective as EMLA Cream in Reducing Immunization Pain in School-aged Children

Background. Untreated immunization pain causes undue distress and contributes to underimmunization through physician, and possibly parental, resistance to multiple simultaneous injections. Objective. To compare the efficacies of two pain management methods in reducing immediate immunization injection pain and distress in school-aged children. Design. A randomized, controlled clinical trial of eutectic mixture of local anesthetics (EMLA) cream and vapocoolant spray. Patients. Children aged 4 to 6 years and scheduled to receive diphtheria and tetanus toxoids and acellular pertussis vaccine (DTaP) during health supervision visits. Interventions. Enrolled children were randomized to one of three treatment groups: 1) EMLA cream 1 distraction; 2) vapocoolant spray 1 distraction; or 3) distraction alone (control). The specific pharmacologic pain control interventions consisted of EMLA cream (2.5% lidocaine, 2.5% prilocaine [Astra Pharmaceutical Products, Inc, Westborough, MA] $15.00/patient; applied 60 minutes before injection) and vapocoolant spray (Fluori-Methane [Gebauer Company, Cleveland, OH] $0.50/patient; applied via spray-saturated cotton ball for 15 seconds immediately before injection). Main Outcome Measures. The blinded investigator (BI) measured (by edited videotape) cry duration and the number of pain behaviors using the Observational Scale of Behavioral Distress. Pain visual analog scales (linear and faces scales) were completed by the child, parent, nurse, and the BI. Results. Sixty-two children, aged 4.5 6 0.4 years (mean 6 SD) were randomized. The three treatment groups had similar subject characteristics. All pain measures and cry duration were similar for EMLA and vapocoolant spray. Both EMLA and spray were significantly better than control. Results for spray vs control: cry duration (seconds): 8.5 6 21.0 vs 38.6 6 50.5; number of pain behaviors: 1.2 6 1.9 vs. 3.1 6 2.1; child-scored faces scale: 2.0 6 2.4 vs. 4.1 6 2.3; parent-scored faces scale: 1.6 6 1.6 vs. 3.0 6 1.7; nurse-scored faces scale: 1.6 6 1.2 vs. 3.1 6 1.4; and BI-scored faces scale: 1.0 6 1.5 vs. 2.4 6 1.4. Conclusions. When combined with distraction, vapocoolant spray significantly reduces immediate injection pain compared with distraction alone, and is equally effective as, less expensive, and faster-acting than EMLA cream. As an effective, inexpensive, and convenient pain control method, vapocoolant spray may help overcome physician and parent resistance to multiple injections that leads to missed opportunities to immunize. Pediatrics 1997;100(6). URL: http://www.pediatrics.org/ cgi/content/full/100/6/e5; pain control, EMLA cream, vapocoolant spray, immunization. ABBREVIATIONS. AHCPR, Agency for Health Care Policy and Research; EMLA, eutectic mixture of local anesthetics; DTaP, diphtheria and tetanus toxoids and acellular pertussis vaccine; VAS, visual analog scales. Despite recent advances in the assessment and management of acute pediatric pain, outlined in the clinical practice guideline of the Agency for Health Care Policy and Research (AHCPR),1 children continue to be subjected to the pain and distress of immunization injections.2–6 Parents, as well as their children, experience distress related to untreated immunization pain.6 In addition to undue pain and distress, lack of pain control for injections is a barrier to immunization. Many physicians withhold scheduled vaccines out of concern for the excessive pain of simultaneous immunizations.7–11 We recently showed that children scheduled for three immunization injections were significantly more likely to miss a vaccine than children scheduled for fewer than three.12 This finding suggests that the number of scheduled injections during well-care visits is independently associated with missed opportunities to immunize. Parents’ concerns about injection pain may also contribute to underimmunization through their poor compliance with preventive health care visits.10,13,14 Missed opportunities by physicians combined with appointments not kept account for nearly the total underimmunization rate,15 which far exceeds the target levels set by Healthy People 2000,16 especially among disadvantaged youth.17,18 Reasons for inadequate pain control for immunization are unclear. One possible explanation is that physicians may have negative attitudes toward the applicability of available pain control methods. A topical anesthetic cream, EMLA, or eutectic mixture of local anesthetics, (2.5% lidocaine, 2.5% prilocaine, [Astra Pharmaceutical Products, Inc, Westborough, MA]), is approved for use in reducing the pain of pediatric procedures, including injection. Despite its proven efficacy,19–22 EMLA cream has not been widely accepted for control of immunization pain possibly due to its delayed onset of anesthesia (60 From the *Division of General Academic Pediatrics, Department of Pediatrics, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; and the ‡Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania. An abstract of this paper was presented at the Pediatric Academic Societies’ Annual Meeting in Washington, DC on May 3, 1997. Received for publication Mar 26, 1997; accepted Jul 28, 1997. Reprint requests to (E.C.R.) Children’s Hospital of Pittsburgh, 3705 Fifth Ave, Pittsburgh, PA 15213-2583. PEDIATRICS (ISSN 0031 4005). Copyright © 1997 by the American Acad-