Aortic Compression Trial to Reduce Blood Loss at Cesarean Section (ACT)

Aortic Compression Trial - a Randomized Controlled Trial to Reduce Blood Loss at Cesarean Section (ACT)

The ACT trial investigates if manual external aortic compression is an effective and acceptable preventive measure to reduce severe postpartum hemorrhage (PPH) in cesarean section. Severe PPH is a maternal blood loss ≥1000 ml at childbirth. Severe PPH causes maternal mortality and morbidity. Severe PPH is more common in cesarean sections than in vaginal births. Routine oxytocin intravenous injection and swift placenta delivery through cord traction is recommended to prevent PPH. Manual external aortic compression is used in other obstetric situations to temporise blood loss and could be used prophylactically during cesarean section until bleeding control is attained. The Cochrane Library stated in 2020 that mechanical methods for the prevention and treatment of PPH, including aortic compression, urgently need scientific evaluation. The ACT trial is a multicenter randomised controlled trial including aiming to include 2232 patients in four Swedish regions running over two years. The trial includes patients undergoing cesarean section. The intervention is routine manual external aortic compression immediately after the baby is delivered and the comparison is no routine external aortic compression. The primary outcome is proportion of patients with a calculated blood loss ≥1000 ml perioperatively or blood transfusion within 2 days. Secondary outcomes are mortality, serious morbidity (for example hysterectomy), surgery duration, hospital stay duration, patient experience, neonatal outcomes, and postnatal maternal health (depression, breastfeeding). If proven effective and acceptable, external aortic compression is a simple and low-cost measure that could reduce severe PPH and improve obstetric care worldwide.

The assistant surgeon or nurse places heel of the hand or fist over the abdominal aorta immediately after the baby is born while the surgeon helps the baby out, the placenta is expulsed or fetched, and the surgeon gains control over bleeding. The compression should be held until controlled bleedning, for example until the first layer of the uterine incision is sutured. Maximum time of aortic compression is 20 minutes, then a 5 minute break is required, after which compression may be reapplied.

No routine aortic compression. If deemed vital to the mother, aortic compression should be exerted. Aortic compression may be exerted if bleeding exceeds 1000 ml.

Calculated estimated blood loss greater than 1000 ml or a red-cell transfusion within 2 days after delivery. The calculated estimated blood loss = the estimated blood volume × (preoperative hematocrit - postoperative hematocrit) ÷ preoperative hematocrit. The estimated blood volume in milliliters is calculated as the admission body weight in kilograms × 85.

Difference between prepoerative (0-48 h) and postpartum (24-48 h) B-Hemoglobin and erythrocyte volume fraction.

Composite outcome including hysterectomy, intensive care, ischemic heart disease/heart failure, pulmonary edema, venous thromboembolism, cerebral insult.

Inclusion Criteria: Planned cesarean delivery, live fetus/fetuses if multiple pregnancy, gestational week 34+0 or more, signed informed consent. Exclusion Criteria: Preoperative B-Hemoglobin <100 g/l, planned hysterectomy in the same procedure as the planned cesarean delivery, other condition as deemed by attending surgeon.

Anonymized data will be shared with other researchers for a joint publication or for systematic review purposes with due citation.

Kellie FJ, Wandabwa JN, Mousa HA, Weeks AD. Mechanical and surgical interventions for treating primary postpartum haemorrhage. Cochrane Database Syst Rev. 2020 Jul 1;7(7):CD013663. doi: 10.1002/14651858.CD013663.

Swedish network for national clinical studies in Obstetrics and Gynecology, information about ACT in Swedish