Conference Coverage

Gynecologic surgery insufflation pressure: Less is more



Lower insufflation pressures were associated with improved patient outcomes and reduced postanesthesia care unit utilization in a review of 598 robot-assisted gynecologic surgery procedures performed at a single center by the same surgeon, said researchers at New York University (NYU) Medical Center.

Dr. Christine Foley, minimally invasive gynecologic surgery fellow, University of Pittsburgh M. Alexander Otto/MDedge News

Dr. Christine Foley

Each incremental drop in abdominal insufflation pressure “improved intraoperative and postoperative clinical outcomes” with “faster postoperative recovery times, decreased immediate postoperative pain, and improved intraoperative respiratory parameters, without increasing duration of surgery or blood loss,” said investigator Christine Foley, MD, formerly at NYU, and now a minimally-invasive gynecologic surgery fellow at the University of Pittsburgh.

An abdominal insufflation pressure of 10 mm Hg or less was the sweet spot, she said at the meeting sponsored by AAGL.

The general surgery literature recommends operating at the lowest possible abdominal insufflation pressure to reduce postoperative pain, and that recommendation has been incorporated into enhanced recovery after surgery (ERAS) protocols. Gynecologic surgeons have not routinely followed suit, she noted. “Surgeons should consider operating at lower insufflation pressures to improve patient outcomes and PACU [postanesthesia care unit] utilization. Further research is warranted to determine if lower pressures ... should be included in ERAS protocols” for gynecologic surgery.

There’s not much in the way of data on insufflation pressures in robotic gynecologic surgery. What has been published suggests, as in general surgery, less postop pain, but at the cost of impaired visualization and greater blood loss. At the moment, robotic cases are often done at insufflation pressures above 12 mm Hg.

To get a better grasp of the issue, Dr. Foley and her team reviewed 196 hysterectomies, 275 myomectomies, and 127 endometriosis surgeries at NYU, all performed robotically by the same surgeon for benign indications. Ninety-nine cases were at 15 mm Hg; 100 at 12 mm Hg; 99 at 10 mm Hg, and 300 at 8 mm Hg.

The study did not address why the surgeon opted for different pressures in different cases. The body mass index was a mean of 27 kg/m2, and patient age was about 40 years, in all four pressure groups. There were trends for higher pressures with hysterectomies and lower pressures for endometriosis, but also considerable crossover, with more than 40% of the hysterectomies performed at 8 mm Hg, and almost 10% of the endometriosis cases done at 15 mm Hg.

Across the board, patients did better at lower pressures. Each drop in insufflation pressure correlated with a significant decrease in the initial pain score in the PACU (5.9 out of 10 points at 15 mm Hg, 5.4 at 12 mm Hg, 4.4 at 10 mm Hg, and 3.8 at 8 mm Hg, P less than .0001); lower pressures also correlated with shorter PACU stays (449 minutes, 467 minutes, 351 minutes, and 317 minutes, P less than .0001).

Surgery duration was a mean of 70 minutes across all four groups. Estimated blood loss was 114 mL at 15 mm Hg, 97.4 mL at 12 mm Hg, 127 mL 10 mm Hg, and 78.4 mL at 8 mm HG; the differences were not statistically significant. Maximum PACU pain levels favored lower pressures, and lower pressures correlated with significantly lower peak inspiratory pressures and tidal volumes.

The results argue for operating at the lowest possible pressure, Dr. Foley said, but she and her team did not address how their outcomes might have been influenced by the type of surgery the women had.

There was no external funding for the study. Dr. Foley had no relevant financial disclosures.

SOURCE: Foley C et al. 2018 AAGL Global Congress, Abstract 23.

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