title: A randomised controlled trial of the effect of biphasic or monophasic waveform on the incidence and severity of cutaneous burns following external direct current cardioversion.
abstract: OBJECTIVE
  Cutaneous burns are a common cause of morbidity following direct current (DC) cardioversion. We designed a prospective randomised double-blinded controlled study to determine the effect of biphasic or monophasic waveform on the pain and inflammation occurring after elective cardioversion.
  
  
  METHODS
  One hundred and thirty nine patients undergoing elective DC cardioversion were randomised to receive monophasic (HP Codemaster XL; 100, 200, 300, 360, and 360 J) or biphasic (Welch Allyn-MRL PIC defibrillator; 70, 100, 150, 200, and 300 J) waveforms. Two hours after DC cardioversion, skin temperature, erythema index and sensory threshold to light and sharp touch was measured at the centre and edge of paddle sites. Visual analogue pain score (VAS) was recorded at 2 and 24 h.
  
  
  RESULTS
  There was significantly less pain following biphasic cardioversion as assessed by VAS at both 2 h (p < 0.001; 95% confidence intervals of difference of medians (CI) 0.2-0.8 cm) and 24 h (p = 0.004; 95% CI 0.0-0.4 cm). There was significantly less erythema in patients receiving biphasic cardioversion at the edge of the sternal site (p = 0.046; 95% CI 0.41-4.5). There was no difference in any other variable at any site between biphasic and monophasic cardioversion.
  
  
  CONCLUSIONS
  The use of a biphasic waveform for DC cardioversion reduces the inflammation and pain of burns as measured by erythema index and visual analogue scale.
authors.affiliation: Shackleton Department of Anaesthetics, Southampton University Hospitals NHS Trust, Tremona Road, Southampton SO16 6YD, UK. jjsa@amblers.org
authors.forename: Jonathan J S
authors.initials: JJ
authors.lastname: Ambler
authors.forename: Charles D
authors.initials: CD
authors.lastname: Deakin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000628:therapy*; D001282:Atrial Flutter / Q000628:therapy*; D002058:Burns, Electric / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D047548:Defibrillators / Q000009:adverse effects*; D004311:Double-Blind Method; D004554:Electric Countershock / Q000009:adverse effects* / Q000295:instrumentation; D004739:England; D004890:Erythema / Q000209:etiology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000209:etiology; D010147:Pain Measurement; D017288:Pain Threshold; D011446:Prospective Studies; D012720:Severity of Illness Index; D012867:Skin / Q000293:injuries* / Q000503:physiopathology; D012881:Skin Temperature; D013997:Time Factors