Postpartum hemorrhage: Aortic compression to reduce pelvic bleeding

Abdominal aortic tourniquet. The AAT is a corset-like device with an interior pneumatic bladder that is designed to provide sustained compression over the abdomen, therefore compressing the abdominal aorta and reducing blood flow to the pelvis and extremities. In one study with human volunteers, a median pressure of 180 mm Hg (range, 150–230 mm Hg) was associated with cessation of blood flow in the common femoral artery in 7 of 9 volunteers and a decrease in blood flow in all participants as determined by pulsed-wave Doppler ultrasound.⁶ Participants reported moderate to severe discomfort when the AAT was inflated to a pressure sufficient to stop blood flow in the femoral artery. The AAT device may not be as effective in individuals with an elevated body mass index and excessive abdominal girth.⁷ In obstetric postpartum hemorrhage, abdominal pressure also has been reported to reduce hemorrhage and femoral artery blood flow. Using a corset-like abdominal binder with an internal spring to provide continuous pressure over the anterior abdomen, Soltan and Sadekreported a beneficial effect of abdominal pressure in the management of severe postpartum hemorrhage in a large observational study in Egypt.^8,9

Nonpneumatic antishock garment. The NASG has been studied extensively as a method to help safely transport a woman with severe postpartum hemorrhage to an emergency facility. The NASG is a neoprene and Velcro device with panels for the lower extremities, pelvis, and abdomen (FIGURE 1). The device also has an abdominal segment that includes a compression ball to provide continuous abdominal pressure. When the panels are closed, blood flow to the extremities and pelvis is reduced. In a study of 10 postpartum volunteers, application of the NASG caused decreased blood flow in the internal iliac artery as measured by Doppler ultrasound, but blood flow did not stop completely.¹⁰ In an observational study of women with postpartum hemorrhage, use of the NASG device in combination with usual interventions resulted in a decrease in blood loss.¹¹

In a cluster randomized trial, 38 birth centers in Africa were randomly assigned to standard management of obstetric hemorrhage or the same protocol plus use of the NASG prior to transport to a regional emergency surgical center. Compared with the group receiving standard management alone, the women who received standard management plus the NASG device had a nonsignificant reduction in maternal mortality (odds ratio, 0.54; 95% confidence interval [CI], 0.14–2.05; P = .37) and a significantly more rapid recovery from hypovolemic shock (hazard ratio, 1.25; 95% CI, 1.02–1.52; P = .03).¹² The International Federation of Gynecology and Obstetrics has issued a guideline supporting the use of the device in the management of obstetric hemorrhage in appropriate settings.¹³

Aortic compression in the setting of an open abdominal incision

During cesarean delivery, the surgeon has access to the abdominal aorta via the open abdominal incision and can directly apply pressure to the aorta at sites ranging from above the sacral promontory to the subdiaphragmatic aorta. Although aortic compression is occasionally noted as a potential intervention to help with the management of postpartum hemorrhage, there is very little literature on this intervention.¹ In one case report of an emergency laparotomy in a Jehovah’s Witness patient with a placenta previa, uterine rupture, massive hemorrhage (hematocrit nadir of 6%), and hypovolemic shock, direct pressure applied to the infradiaphragmatic aorta and pelvic organs permitted the anesthesiologist to stabilize the patient’s cardiovascular status, facilitating the patient’s recovery from shock.¹⁴ The authors of the case concluded that compression of the aorta and pelvic organs can be lifesaving and is underutilized in the management of uncontrolled obstetric hemorrhage. Other case reports also recommend considering the use of aortic compression to permit the anesthesia team to resuscitate a bleeding patient.¹⁵

There is very little published guidance on how to perform aortic compression at cesarean delivery. Techniques for aortic compression include using a closed fist or the heel of the hand to compress the aorta against the lumbosacral spine. Alternatively, use a moist rolled-up surgical towel or laparotomy sponge to compress the aorta against the lumbosacral spine. With a low transverse abdominal incision, the aorta just above the lumbosacral promontory is closest to the surgeon (aorta zone III) (FIGURE 2). If a vertical abdominal incision has been made, the subdiaphragmatic aorta may be within reach of the surgeon (aorta zone II). If an anesthesiologist asks you to apply aortic compression, it is likely that the patient is hypotensive. In this setting, reducing blood flow through the aorta can be achieved with less pressure than required for successful aortic compression in a healthy volunteer.

Prolonged aortic compression that completely obstructs blood flow may result in downstream ischemia. This is illustrated by leg ischemia and amputation that have occurred following the use of the resuscitative endovascular balloon occlusion of the aorta (REBOA) occlusion device.¹⁶ Another strategy that has been used in the management of massive hemorrhage, when immediate replacement of clotting factors is not possible, is damage control surgery, a technique in which capillary and venous bleeding is controlled by placing pelvic packs or a pelvic umbrella pressure pack and sending the patient to the intensive care unit for resuscitation.¹⁷ With damage control surgery, a second procedure is planned to remove the packs after the patient has been stabilized.

With knowledge and practice comes preparedness

Hopefully you will never be asked by an anesthesiologist to stop operating and initiate aortic compression. With effective preprocedure preparation and rapid institution of standard postpartum hemorrhage techniques, it is unlikely aortic compression ever will be needed. If an unusually difficult case triggers a request for aortic compression, you have the knowledge and skills to provide that service.

Share your thoughts! Send your Letter to the Editor to rbarbieri@mdedge.com. Please include your name and the city and state in which you practice.