COMPARATIVE CARBON-DIOXIDE OUTPUT THROUGH INJURED AND NONINJURED PERITONEUM DURING LAPAROSCOPIC PROCEDURES

Tension pneumoperitoneum may force gas into a small injured vessel if the opening is kept patent by surrounding tissues. However, the amount of carbon dioxide (CO2) that penetrates through injured or noninjured peritoneum has not been systematically determined. In 25 patients und ergoing elective laparoscopic ultrasonography and cholecystectomy, CO2 output ((V) over dot CO2) and O-2 uptake ((V) over dot O-2) were meas ured at baseline and during anesthesia, pneumoperitoneum neum, laparos copic surgical procedure (Surgery), and after hemostasis of the surgic al field (Postsurgery). Before anesthesia, (V) over dot (V) over dot O -2/BSA and (V) over dot O-2/BSA were 97.7 +/- 11.3 and 116.0 +/- 10.0 ml min(-1) m(-2), respectively. During anesthesia, they fell to 72.3 /- 6.0 and 89.8 +/- 7.6 ml.min(-1)m(-2), respectively (p < 0.05). VCO2 /BSA increased to 96.0 +/- 11.1 at pneumoperitoneum (p<0.05) and incre ased further to 126.1 +/- 11.0 ml.min(-1)m(-2) at Surgery. It fell to 111.7 +/- 10.9 ml min(-1) m(-2) Postsurgery. (V)over dot O-2/BSA remai ned unchanged during pneumoperitoneum. Minute volume increased from 2. 24 +/- 0.20 in anesthesia to 2.89 +/- 0.25, 4.01 +/- 0.32, and 3.46 +/ - 0.28 L min(-1) m(-2) during pneumoperitoneum, Surgery, and Postsurge ry, respectively, to maintain PaCO2. We conclude that the amount of CO 2 absorbed following pneumoperitoneum prior to surgery is lower than t hat during Surgery or Postsurgery. The amount of CO2 absorbed through the surgical field was 2.3 times higher than that through the nonsurgi cal field while that from the peritoneum after hemostasis of surgical field was 1.6 times higher.