Does neuromuscular blockade affect the assessment of pelvic organ prolapse?

The purpose of this study was to determine if anesthesia with neuromuscular blockade alters the Pelvic Organ Prolapse Quantification (POP-Q) examination.

A prospective, multi-center trial was conducted of women undergoing pelvic surgery. A POP-Q examination performed pre-operatively was compared with an examination performed intra-operatively under neuromuscular blockade. For the latter examination, an Allis clamp was used to apply gentle traction until the point being examined did not undergo further descent. International Continence Society (ICS) stages and individual POP-Q points were compared using a paired sample t test. A sample size of 32 provided 80% power to detect a clinically significant difference between office and operating room measurements (Sample Power, SPSS, 1997).

Of 153 women, 76% received general endotracheal anesthesia and 21% laryngeal mask airway. With an increase of 3 cm, the apical compartment was significantly more prolapsed in the operating room (OR; p < 0.05); however, a comparison of the mean values demonstrated a larger change in means for all points except total vaginal length. When separated into anterior, apical, and posterior compartments, the ICS stages were systematically different in the OR than in the office for all stages (p < 0.0005).

Neuromuscular blockade leads to significantly greater increases in POP-Q examination measurements compared with the office measurements, and this increase is most pronounced apically.