title: The role of a flash of light for attenuation of venous cannulation pain: a prospective, randomized, placebo-controlled study.
abstract: BACKGROUND
  Venous cannulation is often performed without any analgesia, even though pain experienced during this procedure is at times very distressing. Various pharmacological and nonpharmacological measures have been tried with variable results to minimize venous cannulation pain. We designed the present study to evaluate the efficacy of a flash of light on attenuating venous cannulation pain.
  
  
  METHODS
  Ninety adults (15-60 yr), ASA physical status I and II, of either sex, undergoing elective laparoscopic cholecystectomy, were included in this prospective and randomized study. Patients were divided into three groups of 30 each. Group I (control); Group II (distraction): photographed without a flash of light; and Group III (flash): photographed with a flash of light just before venous cannulation of a vein on the dorsum of the nondominant hand. Immediately after the photograph, venous cannulation was performed using an 18-gauge cannula.
  
  
  RESULTS
  Two patients from each group could not be cannulated on their first attempt and were therefore dropped from subsequent analysis. The incidence of venous cannulation pain in the flash group was lower, i.e., 50% (14 of 28) when compared to 100% (28 of 28) observed in the other two study groups (P < 0.01). Severity of venous cannulation pain as assessed by the Visual Analog Scale scores (between 0 and 100; where 0 = no pain and 100 = worst imaginable pain) presented as median (interquartile range) were reduced in the flash [10(20)] and distraction [20(10)] groups compared with the control group [40(20)] (P < 0.01). The severity of venous cannulation pain was also reduced in the flash group compared with the distraction group (P < 0.01).
  
  
  CONCLUSIONS
  We conclude that a flash of light before venous cannulation is a safe, effective, and easy-to-use method for minimizing venous cannulation pain.
authors.affiliation: Department of Anaesthesiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow 226014, India. aagarwal@sgpgi.ac.in
authors.forename: Anil
authors.initials: A
authors.lastname: Agarwal
authors.forename: Ghanshyam
authors.initials: G
authors.lastname: Yadav
authors.forename: Devendra
authors.initials: D
authors.lastname: Gupta
authors.forename: Manish
authors.initials: M
authors.lastname: Tandon
authors.forename: Prabhat Kumar
authors.initials: PK
authors.lastname: Singh
authors.forename: Uttam
authors.initials: U
authors.lastname: Singh
mesh_terms: D000293:Adolescent; D000328:Adult; D002406:Catheterization, Peripheral / Q000009:adverse effects*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D010147:Pain Measurement; D010781:Photography; D010789:Phototherapy; D011446:Prospective Studies; D012720:Severity of Illness Index