title: Pulsed electromagnetic fields dosing impacts postoperative pain in breast reduction patients.
abstract: BACKGROUND
  Pulsed electromagnetic fields (PEMF) reduce postoperative pain and narcotic requirements in breast augmentation, reduction, and reconstruction patients. PEMF enhances both calmodulin-dependent nitric oxide and/or cyclic guanosine monophosphate signaling and phosphodiesterase activity, which blocks cyclic guanosine monophosphate. The clinical effect of these competing responses on PEMF dosing is not known.
  
  
  METHODS
  Two prospective, nonrandomized, active cohorts of breast reduction patients, with 15 min PEMF per 2 h; "Q2 (active)", and 5 min PEMF per 20 min; "5/20 (active)", dosing regimens were added to a previously reported double-blind clinical study wherein 20 min PEMF per 4 h, "Q4 (active)", dosing significantly accelerated postoperative pain reduction compared with Q4 shams. Postoperative visual analog scale pain scores and narcotic use were compared with results from the previous study.
  
  
  RESULTS
  Visual analog scale scores at 24 h were 43% and 35% of pain at 1 h in the Q4 (active) and Q2 (active) cohorts, respectively (P < 0.01). Pain at 24 h in the 5/20 (active) cohort was 87% of pain at 1 h, compared with 74% in the Q4 (sham) cohort (P = 0.451). Concomitantly, narcotic usage in the 5/20 (active) and Q4 (sham) cohorts was not different (P = 0.478), and 2-fold higher than the Q4 (active) and Q2 (active) cohorts (P < 0.02).
  
  
  CONCLUSIONS
  This prospective study shows Q4/Q2, but not 5/20 PEMF dosing, accelerated postoperative pain reduction compared with historical shams. The 5/20 (active) regimen increases NO 4-fold faster than the Q4 (active) regimen, possibly accelerating phosphodiesterase inhibition of cyclic guanosine monophosphate sufficiently to block the PEMF effect. This study helps define the dosing limits of clinically useful PEMF signals.
authors.affiliation: Division of Plastic and Reconstructive Surgery, Columbia University Medical Center, New York, New York.
authors.forename: Erin M
authors.initials: EM
authors.lastname: Taylor
authors.affiliation: Division of Plastic and Reconstructive Surgery, Columbia University Medical Center, New York, New York.
authors.forename: Krista L
authors.initials: KL
authors.lastname: Hardy
authors.affiliation: Division of Plastic and Reconstructive Surgery, Columbia University Medical Center, New York, New York.
authors.forename: Amanda
authors.initials: A
authors.lastname: Alonso
authors.affiliation: Departments of Biomedical Engineering and Orthopedics, Columbia University, Mount Sinai School of Medicine, New York, New York.
authors.forename: Arthur A
authors.initials: AA
authors.lastname: Pilla
authors.affiliation: Division of Plastic and Reconstructive Surgery, Columbia University Medical Center, New York, New York. Electronic address: chr2111@cumc.columbia.edu.
authors.forename: Christine H
authors.initials: CH
authors.lastname: Rohde
mesh_terms: D000328:Adult; D002147:Calmodulin / Q000378:metabolism; D004311:Double-Blind Method; D004599:Electric Stimulation Therapy / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods*; D004574:Electromagnetic Fields; D005260:Female; D006801:Humans; D016462:Mammaplasty / Q000009:adverse effects* / Q000379:methods*; D009569:Nitric Oxide / Q000378:metabolism; D010147:Pain Measurement; D010149:Postoperative Pain / Q000175:diagnosis / Q000378:metabolism / Q000628:therapy*; D011446:Prospective Studies; D015398:Signal Transduction / Q000502:physiology; D016896:Treatment Outcome
chemical_list: D002147:Calmodulin; D009569:Nitric Oxide
keywords: Breast reduction; Calmodulin; Nitric oxide; PEMF; Postoperative pain; Signaling