Abstract
Decreased functional residual capacity (FRC) reportedly plays a role in postoperative hypoxemia, a common problem following surgery under general anesthesia that can persist for several days after upper abdominal procedures. In recent years, laparoscopy has been preferentially performed over laparotomy in consideration of invasiveness, but laparoscopic upper abdominal surgery entails a risk of decreased FRC due to induced cranial displacement of the diaphragm. We report herein changes in FRC during laparoscopic upper abdominal surgery in adult and elderly patients. FRC was measured immediately post-intubation and pre-extubation in patients 20∼55 years old (adult group; n = 11) and ≥ 70 years old (elderly group; n = 9) using the nitrogen washout method with an Engstrom Carestation(GE Healthcare). Both groups exhibited a significant decrease in FRC between immediately post-intubation (about 2400 ml) and immediately pre-extubation (p < 0.05). A significant difference in the rate of intraoperative FRC decrease was also observed between adult and elderly groups (14.1 ± 7.8% vs. 23.6 ± 9.7%; p < 0.05). Investigation of correlations between the rate of FRC decrease and patient characteristics and preoperative respiratory function test results revealed positive linear correlations between the rate of FRC decrease and age, operative time, anesthesia time and FEV1.0% and negative linear correlations with the remaining four parameters. However, a significant difference was only observed for age (p < 0.05). The study revealed a significant decrease in FRC, during minimally invasive laparoscopic upper abdominal surgery. Furthermore, the rate of intraoperative decrease was greater in the elderly group.
