The impacts of super obesity versus morbid obesity on respiratory mechanics and simple hemodynamic parameters during bariatric surgery.

BACKGROUND

This study was designed to determine the impact of the degree of obesity on respiratory mechanics and simple hemodynamic parameters at laparoscopic bariatric surgery.

METHODS

The patients were divided into two groups, each of which included 24 patients (a morbidly obese group and a super obese group) undergoing laparoscopic bariatric surgery. Dynamic respiratory compliance, respiratory resistance, and peak inspiratory pressures were measured at four time points: 10 min after anesthesia induction (T1: induction), 10 min after pneumoperitoneum (T2: pneumoperitoneum), 10 min after terminating pneumoperitoneum (T3: end-pneumoperitoneum), and before extubation (T4: extubation). The systolic, diastolic, and mean arterial pressures and the heart rate values were measured noninvasively in T0 (10 min before operation).

RESULTS

Obesity was found to cause a statistically significant increase in respiratory resistance and a peak inspiratory pressure and a decrease in dynamic respiratory compliance. In the morbidly obese group, the lowest dynamic respiratory compliance was 37 ± 12 mL/cm H(2)O, but it was 33 ± 13 mL/cm H(2)O in the super obese group. The systolic pressure, diastolic pressure, and mean arterial pressure were found to decrease significantly in both groups.

CONCLUSIONS

Morbid obesity and super obesity have negative effects on hemodynamics and respiratory mechanics.