Acute neurological injury in pediatric patients with single-ventricle congenital heart disease
Authors: Lang Shih-Shan , Valeri Amber , Storm Phillip B. , Heuer Gregory G. , Tucker Alexander M. , Kennedy Benjamin C. , Kozyak Benjamin W. , Sinha Anjuli , Kilbaugh Todd J. , Huh Jimmy W. 
Published: July 2021

OBJECTIVE
Single-ventricle congenital heart disease (CHD) in pediatric patients with Glenn and Fontan physiology represents a unique physiology requiring the surgical diversion of the systemic venous return from the superior vena cava (Glenn) and then the inferior vena cava (Fontan) directly to the pulmonary arteries. Because many of these patients are on chronic anticoagulation therapy and may have right-to-left shunts, arrhythmias, or lymphatic disorders that predispose them to bleeding and/or clotting, they are at risk of experiencing neurological injury requiring intubation and positive pressure ventilation, which can significantly hamper pulmonary blood flow and cardiac output. The aim of this study was to describe the complex neurological and cardiopulmonary interactions of these pediatric patients after acute central nervous system (CNS) injury.

METHODS
The authors retrospectively analyzed the records of pediatric patients who had been admitted to a quaternary children’s hospital with CHD palliated to bidirectional Glenn (BDG) or Fontan circulation and acute CNS injury and who had undergone intubation and mechanical ventilation. Patients who had been admitted from 2005 to 2019 were included in the study. Clinical characteristics, surgical outcomes, cardiovascular and pulmonary data, and intracranial pressure data were collected and analyzed.

RESULTS
Nine pediatric single-ventricle patients met the study inclusion criteria. All had undergone the BDG procedure, and the majority (78%) were status post Fontan palliation. The mean age was 7.4 years (range 1.3–17.3 years). At the time of acute CNS injury, which included traumatic brain injury, intracranial hemorrhage, and cerebral infarct, the median time interval from the most recent cardiac surgical procedure was 3 years (range 2 weeks–11 years). Maintaining normocarbia to mild hypercarbia for most patients during intubation periods did not cause neurological deterioration, and hemodynamic profiles were more favorable as compared to periods of hypocarbia. Hypocarbia was associated with unfavorable hemodynamics but was necessary to decrease intracranial hypertension. Most patients were managed using low mean airway pressure (MAWP) in order to minimize the impact on preload and cardiac output.

CONCLUSIONS
The authors highlight the complex neurological and cardiopulmonary interactions with respect to partial pressure of arterial CO2 (PaCO2) and MAWP when pediatric CHD patients with single-ventricle physiology require mechanical ventilation. The study data demonstrated that tight control of PaCO2 and minimizing MAWP with the goal of early extubation may be beneficial in this population. A multidisciplinary team of pediatric critical care intensivists, cardiac intensivists and anesthesiologists, and pediatric neurosurgeons and neurologists are recommended to ensure the best possible outcomes.