title: Venous gas embolism--a comparison of carbon dioxide and helium in pigs.
abstract: OBJECTIVE
  The use of helium for insufflation during laparoscopic surgery avoids hypercarbia and acidosis associated with absorbed CO2, but the effects of helium gas embolism are unknown. We compared the effects of CO2 with He gas embolism on survival, haemodynamic variables, oxygenation, and ventilation in pigs.
  
  
  METHODS
  Anaesthetized juvenile pigs were given progressively larger boluses of either CO2 (n = 5) or He (n = 4) into the right atrium. Measurements of haemodynamic variables, oxygenation, and PETCO2 were made before and after each gas injection.
  
  
  RESULTS
  All animals survived injection of 300 ml CO2 while no animal survived more than 120 ml He (P < 0.01). Mean arterial pressure decreased more after 60 ml He (99 +/- 14 to 44 +/- 20 mmHg) than after 60 ml CO2 (110 +/- 12 to 88 +/- 14 mmHg, P < 0.001). Cardiac output did not change at any injection volume. The PETCO2 decreased more after 60 ml He (30 +/- 2 to 3 +/- 6 mmHg) than after 60 ml CO2 (35 +/- 3 to 30 +/- 3 mmHg, P < 0.001). Only the He group showed a decrease in PaO2 (190 +/- 51 to 68 +/- 22 mmHg at 60 ml, P < 0.05).
  
  
  CONCLUSIONS
  Helium gas embolism has a greater deleterious effect than CO2 gas embolism on survival, MAP, PETCO2, and PaO2. These different effects of gas embolism should be recognized when considering the use of helium or other insoluble gases for abdominal laparoscopic insufflation.
authors.affiliation: Division of General Surgery, St. Paul's Hospital, Vancouver, British Columbia, Canada.
authors.forename: B
authors.initials: B
authors.lastname: Rudston-Brown
authors.forename: P N
authors.initials: PN
authors.lastname: Draper
authors.forename: B
authors.initials: B
authors.lastname: Warriner
authors.forename: K R
authors.initials: KR
authors.lastname: Walley
authors.forename: P T
authors.initials: PT
authors.lastname: Phang
mesh_terms: D000758:Anesthesia; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D002245:Carbon Dioxide / Q000009:adverse effects*; D002302:Cardiac Output / Q000187:drug effects / Q000502:physiology; D004618:Embolism, Air / Q000503:physiopathology*; D006371:Helium / Q000009:adverse effects*; D010101:Oxygen Consumption / Q000502:physiology; D015656:Respiratory Mechanics / Q000502:physiology; D013552:Swine
chemical_list: D002245:Carbon Dioxide; D006371:Helium