ABSTRACT
The continuous transport of the necessary supply of oxygen to the tissues is the most important function of cardiovascular and respiratory systems. Clinical evaluation of hypoxic respiratory failure should include a careful analysis of the etiology of the hypoxic insult, and its impact on oxygen delivery and oxygen consumption. Patterns of hypoxia are distinguished by the contributions of impaired oxygen availability, diffusion, ventilation perfusion mismatch, or intrapulmonary shunting, as well as impaired central or peripheral circulation, oxygen carriage in the blood, or oxygen utilization by tissues. This chapter describes a decision support tool developed for the systematic assessment of critically ill, hypoxic neonates, utilizing targeted neonatal echocardiography, oxygen reduction testing, a number of noninvasive monitoring parameters and end-organ markers of flow autoregulation or of metabolic stress, and classic physiological calculations to disambiguate hypoxia etiologies.
