Richard P. Lion, DO, MPH, FAAP Division of Pediatric Critical Care, Loma Linda University.
Saul Flores, MD, FAAP, FACC Section of Critical Care and Cardiology, Texas Children’s Hospital
Rohit S. Loomba, MD Division of Pediatric Cardiac Critical Care, Advocate Children’s Hospital, Chicago Medical School
Intended as Cardiac ICU Content for Pediatric Cardiac Learning Center
This section describes a framework for thought that may be helpful when managing patients in a pediatric cardiac intensive care unit. Such a framework is important as urgent situations with hemodynamic compromise in a patient who’s care involves multiple team members can be a difficult situation to manage clinically and interpersonally. A routine method of thought in approaching such situations can help with navigating such situations.
Background and Introduction
The pediatric cardiac intensive care unit (PCICU) is a setting where cardiac morphology, function, and physiology are intimately intertwined. Congenital anatomic malformations of the heart perturb circulatory physiology in a manner not encountered elsewhere, creating high risk of morbidity and mortality. Thus, it is in the PCICU that some of the most unique and critically ill patients receive care [1, 2].
With the continued growth of complex congenital heart malformations able to be palliated or repaired, the number of clinical scenarios that may be encountered in the CICU is difficult to quantify [1, 3, 4]. Add the presence of extracardiac anomalies or pathologies and this number can increase exponentially. An estimated 1.35 million patients are born with Congenital Heart Disease (CHD) annually, with survival for even the most complex lesions expected to be ~ 90% in developed countries, shifting focus towards improved neurodevelopmental and psychosocial outcomes and resource utilization [3-9].
With improved survival comes an increased burden for CHD care provision both inside and outside the CICU [10,11]. Current providers and learners (physician and nursing students, residents and fellows) alike are responsible for understanding the individual medical and surgical treatment options for each CHD lesion. Thus, these patients, while no less complex, are being increasingly thrust into the care of the unfamiliar [12, 13].
While time and experience are requisite precursors for a certain level of mastery and knowledge attainment, even in the authors’ own experiences with advanced cardiac intensive care training, we felt there lacked a systematic approach to CHD comprehension. Therefore, we sought to develop a thoughtful and logical approach to clinical management in the CICU to optimize provider ability and patient outcome.
The goal of this manuscript is hypothesis-driven and proof-of-concept in nature, an attempt at creating this “systematic framework approach to CHD management” or “physiologic primer” and offering it for consideration and commentary. The intended audience includes providers, educators and learners of congenital heart disease medicine with a shared goal for improving care through accessible knowledge and education.
CHD results from failure of expected embryologic maturation, segmentation and physiologic transition of the fetal bulbus cordis into the chambered, segmented neonatal heart[14, 15]. What results is the inability to provide separate pathways for de-oxygenated and oxygenated blood to effectively circulate, due to portions or in some cases all of these pathways being underdeveloped, resulting in ineffective mixing of blood and oxygen exchange.
The “sequential segmental approach” has greatly aided in providing a systematic framework for the abnormal anatomic development of CHD lesions [16, 17]. By limiting the variability to discrete segments such as atrial, valvular, ventricular and great arterial relationships, the learner can process every future lesion encountered through this approach to successfully identify CHD anatomy . We hope to accomplish the same with the physiologic framework that follows: The Seven Physiologic Principles of Congenital Heart Disease, The Six Physiologic States of Congenital Heart Disease, and The Seven Questions to Answer for Every Congenital Heart Disease Lesion.
The Seven Physiologic Principles of Congenital Heart Disease
The seven physiologic principles of CHD build upon one another in a similar fashion to the sequential segmental approach to anatomy, and are given further elucidation below, utilizing “Critical” Pulmonary Stenosis (PS) and “Critical” Coarctation of the Aorta (CoA) as relative examples.
1. Blood Follows the Path of Least Resistance
2. Lack of Blood Flow causes Lack of Heart Growth
3. Left Sided Obstructions cause Left Sided Underdevelopment
5. “Critical” Lesions are Both Ductal and Intracardiac Mixing Dependent
6. “Critical” Left and Right Sided Obstructions Do Not Occur Together
7. Being Blue is Better than Being Gray
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