HIGH INTRAABDOMINAL PRESSURE INCREASES PLASMA-CATECHOLAMINE CONCENTRATIONS DURING PNEUMOPERITONEUM FOR LAPAROSCOPIC PROCEDURES

Background: Laparoscopic procedures are associated with several compli cations, such as hemodynamic, respiratory, and endocrine complications . In our previous clinical study, plasma epinephrine and norepinephrin e concentrations remained unchanged after the insertion of a Veress ne edle, but increased significantly immediately after insufflation with carbon dioxide into the peritoneum. The mechanisms for this increase a re unknown. Objective: To investigate whether gas insufflation during pneumoperitoneum affects plasma catecholamine concentrations during la paroscopic procedures. Design: Experimental study in pigs. Main Outcom e Measures: The plasma concentrations of epinephrine and norepinephrin e were measured in the pigs before and after pneumoperitoneum. The mea n arterial pressure, heart rate, cardiac output, and arterial blood ga s levels were measured, and the systemic vascular resistance was calcu lated. Intervention: Air, nitrous oxide, or carbon dioxide were insuff lated in turn into the peritoneal cavity of supine pigs. Thereafter, c arbon dioxide was insufflated into the peritoneal cavity while the pig was in the left lateral decubitus position, and then in the right lat eral decubitus position. Measures were performed before pneumoperitone um and at the intra-abdominal pressures of 10 mm Hg and 20 mm Hg. One hour of resting time was allowed between each procedure. Results: As c ompared with baseline values, the plasma concentrations of epinephrine and norepinephrine remained unchanged at 10 mm Hg but increased signi ficantly at 20 mm Hg regardless of the gas used for the pneumoperitone um (P<.05). The type of gas and differences in the position of the ani mals had no effect on the plasma epinephrine and norepinephrine concen trations. Conclusions: Excessive intra-abdominal pressure, but not the type of gas or body position, increases plasma catecholamine concentr ations during the insufflation of gas into the abdominal cavity. There fore, excessive insufflation of the pneumoperitoneum should be avoided .