Truth or Myth: Intra-abdominal Pressure Increases in the Lithotomy Position

Area of Science:

• Urology
• Gynecology
• Anesthesiology

Background:

• Intra-abdominal pressure (IAP) can be affected by patient positioning during surgery.
• Understanding these changes is crucial for patient safety and comfort.

Purpose of the Study:

• To investigate the differences in IAP across supine, low lithotomy, and high lithotomy positions.
• To determine the clinical significance of these positional changes in IAP.

Main Methods:

• A prospective cohort study was conducted with 29 women undergoing surgery for prolapse or stress incontinence.
• Intra-abdominal pressure was measured using a urodynamic catheter in the vagina or rectum across three positions: supine, low lithotomy (45°), and high lithotomy (90°).

Main Results:

• Mean IAP was 18.6 cmH2O ± 7.6 in the supine position, 17.7 cmH2O ± 6.6 in low lithotomy, and 17.1 cmH2O ± 6.3 in high lithotomy.
• A statistically significant decrease in IAP was observed from the supine to high lithotomy positions (1.4 cmH2O) and supine to low lithotomy positions (0.9 cmH2O).
• These changes were not considered clinically significant, as a 5 cmH2O difference is typically required.

Conclusions:

• Patient positioning in low or high lithotomy does not lead to a clinically significant increase in intra-abdominal pressure.
• Surgeons and anesthesiologists can consider using stirrups for patient positioning while awake, potentially minimizing discomfort and nerve injury risk.