Postoperative intra-abdominal hypertension predicts worse hospital outcomes in children after cardiac surgery: a pilot study†.

Objectives: Our goal was to determine the incidence and characteristics of postoperative intra-abdominal hypertension (IAH) in paediatric patients undergoing open-heart surgery.

Methods: This single-centre study included consecutive children (aged <16 years) who underwent open-heart surgery between July 2020 and February 2021. Patients who entered the study were followed until in-hospital death or hospital discharge. The study consisted of 2 parts. Part I was a prospective observational cohort study that was designed to discover the association between exposures and IAH. Postoperative intra-abdominal pressure was measured immediately after admission to the intensive care unit and every 6 h thereafter. Part II was a cross-sectional study to compare the hospital-related adverse outcomes between the IAH and the no-IAH cohorts.

Results: Postoperatively, 24.7% (38/154) of the patients exhibited IAH, whereas 3.9% (6/154) developed abdominal compartment syndrome. The majority (29/38, 76.3%) of IAH cases occurred within the first 24 h in the intensive care unit. Multivariable analysis showed that the Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery score [odds ratio (OR) = 1.86, 95% confidence interval (CI) 1.23-2.83, P = 0.004], right-sided heart lesion (OR = 5.60, 95% CI 2.34-13.43, P < 0.001), redo sternotomy (OR = 4.35, 95% CI 1.64-11.57, P = 0.003), high baseline intra-abdominal pressure (OR = 1.43, 95% CI 1.11-1.83, P = 0.005), prolonged cardiopulmonary bypass duration (OR = 1.01, 95% CI 1.00-1.01, P = 0.005) and deep hypothermic circulatory arrest (OR = 5.14, 95% CI 1.15-22.98, P = 0.032) were independent predictors of IAH occurrence. IAH was associated with greater inotropic support (P < 0.001), more gastrointestinal complications (P = 0.001), sepsis (P = 0.003), multiple organ dysfunction syndrome (P < 0.001) and prolonged intensive care unit stay (z = -4.916, P < 0.001) and hospitalization (z = -4.710, P < 0.001). The occurrence of a composite outcome (P = 0.009) was significantly increased in patients with IAH.

Conclusions: IAH is common in children undergoing cardiac surgery and is associated with worse hospital outcomes. Several factors may be associated with the development of IAH, including basic cardiac physiology and perioperative factors.

Trial Information: This study was registered in the Chinese Clinical Trial Registry (Trial number: ChiCTR2000034322)URL site: https://www.chictr.org.cn/hvshowproject.html?id=41363&v=1.4.