Influence of nitrous oxide anesthesia on venous gas embolism with carbon dioxide and helium during pneumoperitoneum.
BACKGROUND
Gas embolism is a potential hazard during laparoscopic procedures. The aim of this study was to evaluate the effects of nitrous oxide (N(2)O) inhalation in the case of gas embolism with carbon dioxide (CO(2)) and helium during pneumoperitoneum.


METHODS
For this study, 20 anesthetized pigs were ventilated with N(2)O (67% inspired) in O(2) (n = 10) or with halothane (0.7-1.5 inspired) in O(2) (n = 10). In each group, CO(2) (n = 5) or helium (n = 5) pneumoperitoneum was established and gas embolism induced at different rates (CO(2) at 0.5, 1, or 2 ml/kg/min; helium at 0.025, 0. 05, or 0.1 ml/kg/min) through the left femoral vein a maximum of 10 min while all hemodynamic parameters were continuously monitored.


RESULTS
In the CO(2) group without N(2)O, all the animals tolerated rates of 0.5 and 1 ml/kg/min over the 10 min, whereas only 3 of 4 animals in the CO(2) group with N(2)O tolerated a rate of 0.5 ml/kg/min, and 2 of 4 animals a rate of 1 ml/kg/min. In the helium group without N(2)O, all the animals tolerated gas embolism at all rates, whereas in the helium group with N(2)O, 4 of 5 animals needed to be resuscitated at a rate of 0.1 ml/kg/min and one death occurred.


CONCLUSIONS
Inhalation of N(2)O worsens the negative cardiovascular effects of venous CO(2) or helium gas emboli and increases the risk of emboli-induced death when CO(2) or helium are used to establish pneumoperitoneum. The volume of venous venous helium gas emboli causing such effects is substantially smaller than that for venous CO(2) gas emboli.
Junghans
T
T
Department of Surgery, Humboldt-University Charité, Berlin, Germany, Schumannstr, 20-21, 10117 Berlin, Germany.
Böhm
B
B
Meyer
E
E
D000769:Anesthesia, Inhalation / Q000379:methods / Q000706:statistics & numerical data; D018685:Anesthetics, Inhalation; D000818:Animals; D002245:Carbon Dioxide / Q000009:adverse effects*; D004618:Embolism, Air / Q000209:etiology* / Q000503:physiopathology; D006371:Helium / Q000009:adverse effects*; D006439:Hemodynamics / Q000187:drug effects; D009609:Nitrous Oxide; D011028:Pneumoperitoneum, Artificial / Q000009:adverse effects* / Q000379:methods / Q000706:statistics & numerical data; D011897:Random Allocation; D018709:Statistics, Nonparametric; D013552:Swine
D018685:Anesthetics, Inhalation; D002245:Carbon Dioxide; D006371:Helium; D009609:Nitrous Oxide