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

OBJECTIVES: To determine the incidence and characteristics of postoperative intra-abdominal hypertension 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, which 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 IAH and No-IAH cohort.

RESULTS: Postoperatively, 24.7% (38/154) of the patients exhibited intra-abdominal hypertension, while 3.9% (6/154) developed abdominal compartment syndrome. The majority (29/38, 76.3%) of intra-abdominal hypertension cases occurred within the first 24 hours in the intensive care unit. Multivariable analysis showed that The Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery score (OR = 1.86, 95% 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 intra-abdominal hypertension occurrence. Intra-abdominal hypertension 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 hospitalisation (z=-4.710, p < 0.001). The occurrence of composite outcome (p = 0.009) was significantly increased in patients with intra-abdominal hypertension.

CONCLUSIONS: Intra-abdominal hypertension is common in children undergoing cardiac surgery and is associated with worse hospital outcomes. Several factors may be associated with the development of intra-abdominal hypertension, including basic cardiac physiology and perioperative factors.