title: Gas and air embolization during hysteroscopic electrosurgical vaporization: comparison of gas generation using bipolar and monopolar electrodes in an experimental model.
abstract: OBJECTIVE
  To compare the composition of gases generated by bipolar hysteroscopic vaporizing electrodes using electrolyte-rich medium (normal saline) with those of monopolar vaporizing electrodes using nonelectrolytic medium (1.5% glycine).
  
  
  METHODS
  In vitro study (Canadian Task Force classification II-1).
  
  
  METHODS
  Laboratory.
  
  
  METHODS
  Fresh morbid bovine cardiac muscle was fully immersed in normal saline for the bipolar vaporizing electrode and 1.5% glycine for the monopolar vaporizing electrode. Standard hysteroscopic electrodes were activated at usual and maximum power outputs from radiofrequency electrosurgical generators appropriate for each system. The gases generated were captured and analyzed by gas chromatography and fast Fourier transform.
  
  
  RESULTS
  Gaseous by-products of electrosurgical vaporization of test tissues largely consisted of hydrogen, carbon monoxide, and carbon dioxide. The composition of gases generated by hysteroscopic monopolar and bipolar electrodes in this laboratory model appear to be similar.
  
  
  CONCLUSIONS
  These gases are all highly soluble in serum. This observation suggests that emboli of gaseous by-products of electrosurgery are unlikely to have an adverse impact on patients. On the other hand, air emboli, largely composed of relatively insoluble nitrogen, are more likely to result in clinically significant cardiopulmonary events.
authors.affiliation: Department of Obstetrics and Gynecology, School of Medicine, University of California, Los Angeles, USA.
authors.forename: M G
authors.initials: MG
authors.lastname: Munro
authors.forename: M
authors.initials: M
authors.lastname: Weisberg
authors.forename: E
authors.initials: E
authors.lastname: Rubinstein
mesh_terms: D000818:Animals; D002417:Cattle; D046508:Culture Techniques; D004566:Electrodes; D004598:Electrosurgery / Q000009:adverse effects* / Q000295:instrumentation* / Q000379:methods; D004618:Embolism, Air / Q000517:prevention & control*; D005260:Female; D015907:Hysteroscopy / Q000009:adverse effects* / Q000379:methods; D023421:Models, Animal; D009206:Myocardium; D012680:Sensitivity and Specificity; D014835:Volatilization