Outcomes After Stage I Norwood Palliation in a Recently Established Program Can Achieve Results Similar to Longer Established Services.

BACKGROUND: Infants with hypoplastic left heart syndrome (HLHS) or similar single ventricle cardiac lesions require a three-stage surgical approach, the first step being the Stage I Norwood procedure. The Queensland Children's Hospital (QCH) in Australia is a tertiary hospital providing the only cardiac surgical service to children in Queensland and northern New South Wales. OBJECTIVE: To review the centre's outcomes of Norwood procedures performed in the last 6 years. MATERIALS AND METHODS: We retrospectively evaluated all infants undergoing the stage I Norwood procedure between January 2015 and August 2021. Mortality, intensive care length of stay, events of cardiac arrest following surgery and duration of mechanical ventilation were calculated and analysed for subgroups depending on type of pulmonary shunt type (right-ventricle-to-pulmonary-artery shunt [RVPAS] vs the modified Blalock-Taussig shunt [MBTS]). RESULTS: Forty-nine (49) patients were included. Overall survival to stage two operation (Glenn) was 90%. Both shunts were used evenly with the RVPA conduit preferred for HLHS and the MBTS largely chosen for hypoplastic left heart variants. In univariable analysis there was no difference in cardiac arrest or mortality rate for the patient with a RVPAS compared to the patient with a MBTS. CONCLUSION: We show that a recently established Norwood program can achieve results that are comparable to those reported by longer established centres, and the international literature.

Antithrombin Dosing Guidelines in Children Underestimate Dose Needed for Plasma Level Increase.

OBJECTIVES: Antithrombin is a cofactor in the coagulation cascade with mild anticoagulant activity and facilitates the action of heparin as an anticoagulant. Antithrombin concentrate dosing guidelines vary but most commonly suggest that each unit of antithrombin concentrate per body weight increases the plasma antithrombin level by 1.5% to 2.2% (depending on manufacturer). We aimed to establish a dosing recommendation dependent on age and disease state. DESIGN: A retrospective analysis of all antithrombin concentrate doses over a period of 5 years. We calculated the increase any respective antithrombin concentrate dose achieved, indexed by body weight, and performed a multivariable analysis to establish independent factors associated with the effectiveness of antithrombin concentrate. SETTING: A PICU at a university-affiliated children's hospital. PATIENTS: One hundred fifty-five patients treated in a PICU. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The effect of 562 doses of antithrombin concentrate on plasma antithrombin levels administered to 155 patients, of which 414 (73.7%) antithrombin concentrate doses administered during extracorporeal life support treatment, were analyzed. For all patients, each unit of antithrombin concentrate/kg increased plasma antithrombin level by 0.86% (SD 0.47%). Plasma antithrombin level increase was influenced by body weight (increase of 0.76% [interquartile range, 0.6-0.92%] for patients < 5 kg; 1.38% [interquartile range, 1.11-2.10%] for > 20 kg), disease state (liver failure having the poorest antithrombin increase) and whether patients were treated with extracorporeal circulatory support (less antithrombin increase on extracorporeal life support). Heparin dose at the time of administration did not influence with amount of change in antithrombin level. CONCLUSIONS: Current antithrombin concentrate dosing guidelines overestimate the effect on plasma antithrombin level in critically ill children. Current recommendations result in under-dosing of antithrombin concentrate administration. Age, disease state, and extracorporeal life support should be taken into consideration when administering antithrombin concentrate.