title: Topical ethyl chloride to reduce pain associated with venous catheterization: a randomized crossover trial.
abstract: OBJECTIVE
  To compare pain associated with venous catheterization after administration of topical ethyl chloride vs placebo among emergency department health care providers.
  
  
  METHODS
  We conducted a randomized, double-blind, placebo-controlled, crossover trial among a convenience sample of health care provider volunteers in a tertiary care urban emergency department. We randomly allocated subjects to initial treatment (ethyl chloride vs sterile water aerosol spray) and catheterization site (left or right antecubital fossa). After venous catheterization placement and discontinuation, subjects underwent a 5-minute washout period. All subjects then underwent venous catheterization in the contralateral antecubital fossa after administration of the alternative agent. We measured all outcomes after discontinuation of the second catheter. The primary outcome was difference in pain verbal numeric rating scale score (0-10) between the 2 agents. Secondary outcomes included preferred agent (binary) and future willingness to use agent on patients (5-point Likert scale).
  
  
  RESULTS
  Thirty-eight health care providers were recruited; all completed the study. Median pain verbal numeric rating scale scores were 4 (interquartile range, 2-5) for placebo vs 2 (1-4) for ethyl chloride. The effect size for pain reduction with ethyl chloride compared with placebo was 2 (95% confidence interval, 0.5-2; P = .001). Most subjects (68.4%) preferred ethyl chloride to placebo. Five-point Likert scale scores measuring willingness to use preferred product on future patients were higher by 2 (95% confidence interval, 1-3) among subjects preferring ethyl chloride vs placebo.
  
  
  CONCLUSIONS
  We found that topical ethyl chloride yields a greater reduction in pain associated with venous catheterization compared with topical placebo.
authors.affiliation: Department of Emergency Medicine, San Antonio Uniformed Services Health Education Consortium, 3551 Roger Brooke Dr., Joint Base San Antonio, TX.
authors.forename: Kurt
authors.initials: K
authors.lastname: Fossum
authors.affiliation: Department of Emergency Medicine, San Antonio Uniformed Services Health Education Consortium, 3551 Roger Brooke Dr., Joint Base San Antonio, TX.
authors.forename: Sue L
authors.initials: SL
authors.lastname: Love
authors.affiliation: Department of Emergency Medicine, San Antonio Uniformed Services Health Education Consortium, 3551 Roger Brooke Dr., Joint Base San Antonio, TX. Electronic address: Michael.D.April@post.harvard.edu.
authors.forename: Michael D
authors.initials: MD
authors.lastname: April
mesh_terms: D000279:Administration, Cutaneous; D000293:Adolescent; D000328:Adult; D000368:Aged; D000779:Anesthetics, Local / Q000627:therapeutic use*; D002406:Catheterization, Peripheral / Q000009:adverse effects*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004636:Emergency Service, Hospital; D005018:Ethyl Chloride / Q000627:therapeutic use*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000175:diagnosis / Q000188:drug therapy* / Q000209:etiology; D010147:Pain Measurement; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000779:Anesthetics, Local; D005018:Ethyl Chloride