Effect of adding more than 3% oxygen to carbon dioxide pneumoperitoneum on adhesion formation in a laparoscopic mouse model.

Objective: To investigate the effect of the addition of 3% or higher oxygen concentrations to the carbon dioxide (CO2) pneumoperitoneum.

Design: Prospective, randomized trial.

Setting: Academic research center.

Animal(s): Female Naval Medical Research Institute mice (n = 100).

Intervention(s): Sixty minutes of CO2 pneumoperitoneum with 0%, 3%, 6%, 9%, or 12% oxygen; induction of adhesions by the creation of standardized peritoneal lesions during laparoscopy.

Main Outcome Measure(s): Adhesions were quantitatively and qualitatively scored after 7 days during laparotomy to determine [1] the effect of 60 minutes of CO2 pneumoperitoneum with 0%, 3%, 6%, 9%, or 12% oxygen on adhesion formation, and [2] the effect of duration of CO2 pneumoperitoneum and insufflation pressure on adhesion formation with the addition of 0%, 3%, and 12% oxygen.

Result(s): Compared with a CO2 pneumoperitoneum with 3% oxygen, adhesion formation is greater when either no oxygen or more than 3% oxygen is added to the CO2 pneumoperitoneum. These effects persisted at higher insufflation pressures and longer duration of pneumoperitoneum, both known to increase adhesion formation with pure CO2.

Conclusion(s): This study confirms that adhesion formation is decreased with the addition of 3% oxygen to the CO2 pneumoperitoneum. The addition of higher oxygen concentrations, however, is deleterious. Adhesions always increase with time and duration of the pneumoperitoneum.