Uterine cooling during C-section fights uterine atony
NEW YORK - Cooling a woman's uterus during Cesarean section, after delivery of the baby and placenta, reduces blood loss and incidence of postpartum hemorrhage, report clinicians from Baylor Research Institute and Baylor University Medical Center, Dallas, Texas.
"It works incredibly well. Some physicians at our institution are adopting it outside of this study and seeing great results in their patients," principal investigator Dr. Janice Mitchell noted in an interview with Reuters Health.
The theory that uterine cooling would help reduce uterine atony is based on biological fact. "We know that in other settings and other types of smooth muscles that cooling does in fact cause contraction of the muscle," Dr. Mitchell explained.
She presented the study May 5 at the annual meeting of the American College of Obstetricians and Gynecologists (ACOG) in San Francisco.
The study team enrolled 200 women with either scheduled cesarean delivery or those requiring cesarean after a trial of labor in a randomized controlled trial. C-sections were performed in the usual manner up to externalization of the uterus for hysterotomy repair.
During repair, the uterine fundus was wrapped in either a control laparotomy sponge at 99 degrees Fahrenheit or in an icy laparotomy sponge cooled to 30 degrees Fahrenheit using a sterile slush machine (ORS Hush Slush, Ecolab). The sponges were removed after repair was complete and the remainder of the surgery was completed in the usual fashion. There were 100 women in each group.
Blood loss in the uterine cooling group was 29% less than in the control group (p<0.001), and the incidence of postpartum hemorrhage was 57% less (p=002) with uterine cooling, Dr. Mitchell reported. There was no statistically significant difference in need for uterotonic medications or blood products and no patients underwent cesarean hysterectomy.
"The clinical significance of these findings are unclear at the moment," Dr. Jack Stecher, an anesthesiologist at Baylor University Medical Center, who worked on the study, noted in an interview with Reuters Health.
"We hope to apply it on a much larger scale to see whether it decreases the need for emergency hysterectomies, blood transfusions, and even more," Dr. Mitchell added in a news release.
Uterine cooling is something that patients can conceptualize, she told Reuters Health. "They can understand, 'I sprained my ankle, I put an ice pack on it.' The uterus needs to contract, we put ice on it. It's non-threatening because it is not a pharmacologic therapy and simple to do," she said.
The Baylor team has designed a second study to see if uterine cooling might also be useful for women who need a C-section after hours in unsuccessful labor - the so called "tired uterus" effect.
"We want to analyze those patients who have had a dysfunctional labor experience to see if the cold is as effective on a uterus that has been working all day as opposed to one that hasn't gone through an all-day labor," Dr. Stecher explained in the news release.
The Baylor team also sees uses for uterine cooling beyond C-section patients, including during intrauterine balloon procedures after vaginal delivery.
"Vaginal births comprise nearly two-thirds of all deliveries, and those patients are still at risk for uterine atony and bleeding," Dr. Jamie Crowson, a nurse anesthetist at Baylor University Medical Center who worked on the study, said in the release.
"In these cases, intrauterine balloon devices inflated with saline are sometimes placed to slow and stop bleeding." Chilling those balloons could represent an opportunity to apply these findings to vaginal hemorrhage circumstances, Dr. Crowson explained.
Drs. Stecher and Crowson have applied for patent protection for the intellectual property embodied in this research that has demonstrated cooling the uterus may help decrease postpartum blood loss and avoid postpartum hemorrhage. The other authors did not report any potential conflicts of interest.References: Reuters Health