title: Effect of topical alkane vapocoolant spray on pain with intravenous cannulation in patients in emergency departments: randomised double blind placebo controlled trial.
abstract: OBJECTIVE
  To assess the efficacy, acceptability, and safety of a topical alkane vapocoolant in reducing pain during intravenous cannulation in adults.
  
  
  METHODS
  Randomised double blind placebo controlled trial.
  
  
  METHODS
  Emergency department of a metropolitan teaching hospital.
  
  
  METHODS
  201 adult patients (54% male), mean (SD) age 58.2 (19.5) years, who required intravenous cannulation.
  
  
  METHODS
  Less than 15 seconds before cannulation, the skin area was sprayed with either water (control, n=98) or vapocoolant (intervention, n=103), from a distance of 12 cm for 2 seconds. The intervention spray was a blend of propane, butane, and pentane.
  
  
  METHODS
  Pain with cannulation and discomfort with spray, measured with a 100 mm visual analogue scale.
  
  
  RESULTS
  Groups did not differ significantly in age, sex, indication for or site of cannulation, cannula size, or who cannulated the patient (P>0.05). Median (interquartile range) pain scores for cannulation in the control and intervention groups were 36 (19-51) and 12 (5-40) mm, respectively (P<0.001), and 59 (60%) and 33 (32%) reported pain scores >or=30 mm (P<0.001). Scores for spray discomfort also differed significantly (P<0.001) because of skewing to the right within the intervention group. The median discomfort scores, however, were 0 mm in both groups. Success rates for first cannulation attempt did not differ between groups (P=0.39). Thirty four (39%) and 62 (62%) patients said they would choose the spray they received for analgesia in the future (P=0.002). At follow-up at five days, two patients in the intervention group reported transient skin redness.
  
  
  CONCLUSIONS
  Topical alkane vapocoolant spray is effective, acceptable, and safe in reducing pain with peripheral intravenous cannulation in adults in the emergency department.
  
  
  BACKGROUND
  Australian Clinical Trials ACTRN12607000470493.
authors.affiliation: University of Melbourne, Parkville, Victoria, Australia 3052.
authors.forename: Ramzi
authors.initials: R
authors.lastname: Hijazi
authors.forename: David
authors.initials: D
authors.lastname: Taylor
authors.forename: Joanna
authors.initials: J
authors.lastname: Richardson
mesh_terms: D000287:Administration, Topical; D000328:Adult; D000336:Aerosols; D000368:Aged; D000473:Alkanes / Q000008:administration & dosage*; D000779:Anesthetics, Local / Q000008:administration & dosage*; D002404:Catheterization / Q000009:adverse effects*; D002648:Child; D050785:Cryoanesthesia / Q000379:methods; D004311:Double-Blind Method; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000517:prevention & control*; D016896:Treatment Outcome
chemical_list: D000336:Aerosols; D000473:Alkanes; D000779:Anesthetics, Local