Complications of Exteriorization Compared with In Situ Uterine Repair at Cesarean Delivery under Spinal Anesthesia
Abstract & Commentary
By John C. Hobbins, MD, Professor and Chief of Obstetrics, University of Colorado Health Sciences Center, Denver, is Associate Editor for OB/GYN Clinical Alert.
Dr. Hobbins reports no financial relationship to this field of study.
Synopsis: Exteriorization increases pain, nausea, and vomiting vs in situ repairs during Cesarean section.
Source: Siddiqui M, et al. Complications of exteriorized compared with in situ uterine repair at cesarean delivery under spinal anesthesia. Obstet and Gynecol. 2007;110:570-575.
It is still common practice to exteriorize the uterus during repair of the uterine incision during cesarean section. The rationale to support this maneuver is that it makes the job easier, faster, and it decreases blood loss.
Investigators from Toronto recently set out to test the concept and to see if there was a downside to uterine exteriorization. They invited 79 healthy patients about to have a scheduled Cesarean section to participate in a study in which half had their uteri exteriorized during uterine reconstruction and half did not. The authors attempted to standardize as many therapeutic variables as possible between groups. Spinal anesthesia was maintained at a level below T5; hypotension was scrupulously avoided by early administration of phenylephrine; oxytocin was given uniformly with delivery of the shoulder; and assisted delivery of the placenta was undertaken in all patients.
The authors' primary outcome was the incidence of intra- and post-operative nausea and vomiting. However, many other variables were evaluated.
The incidence of nausea and vomiting was 38% vs 18%; tachycardia was 18% vs 3%; hypotension was 28% vs 15%; and perceived and observed pain was 26% vs 13%—all higher in the "exteriorized" patients. The odds ratio for tachycardia, in particular, was 8.3.
All this was happening while the median time of uterine repair was, although significant, only one minute shorter. The average total operation time (36 minutes vs 37 minutes) and estimated blood loss (625 cc vs 653 cc) were not a statistically significant different between groups. The authors' conclusion was that "uterine repair should be done in utero where possible."
It is very satisfying to have the uterus out and beautifully exposed while closing the incision with what now is back in vogue—two layers. However, if this convenience makes the patient more uncomfortable and more vulnerable to tachycardia and hypotension without any downside, why do it? The authors noted that the greatest effect on the maternal cardiovascular system seemed to occur when the uterus was reinserted into the abdominal cavity. This could be due to compression on the inferior vena cava. The visceral pain seemed to coincide with traction on the uterus, activating unmyelinated neural fibers as powerful stimulators of nausea and vomiting.
Obviously, the study should give us some pause for thought as we are about to lift the uterus out of the abdomen during cesarean section. It seems that it will only add, on average, one extra minute to the procedure if we leave it in.