Silent Hypoxia in COVID-19 Pneumonia: State of Knowledge, Pathophysiology, Mechanisms, and Management.

Patients with COVID-19 often present with life-threatening hypoxemia without dyspnea or signs of respiratory distress. Termed silent or happy hypoxia, it has puzzled clinicians and challenged and defied our understanding of normal respiratory physiology. A range of host- and pathogen-related factors appears to contribute to its development, including SARS-CoV-2's ability to produce different COVID-19 phenotypes; induce endothelial damage and elicit a vascular distress response; invade cells of the central nervous system and disrupt normal interoception and response; and modulate transcription factors involved in hypoxic responses. Because hypoxemia in COVID-19 is associated with increased mortality risk and poorer survival, early detection and prompt treatment is essential to prevent potential complications. Interventions to prevent hypoxemia and improve oxygen delivery to the blood and the tissues include home pulse-oximetry monitoring, optimization of patient positioning, judicious use of supplemental oxygen, breathing control exercises, and timely and appropriate use of ventilatory modalities and adjuncts.

Comprehensive Review of Cardiovascular Involvement in COVID-19.

COVID-19 has emerged as one of the most devastating and clinically significant infectious diseases of the last decade. It has reached global pandemic status at an unprecedented pace and has placed significant demands on health care systems worldwide. Although COVID-19 primarily affects the lungs, epidemiologic reports have shown that the disease affects other vital organs of the body, including the heart, vasculature, kidneys, brain, and the hematopoietic system. Of importance is the emerging awareness of the effects of COVID-19 on the cardiovascular system. The current state of knowledge regarding cardiac involvement in COVID-19 is presented in this article, with particular focus on the cardiovascular manifestations and complications of COVID-19 infection. The mechanistic insights of disease causation and the relevant pathophysiology involved in COVID-19 as they affect the heart are explored and described. Relevant practice essentials and clinical management implications for patients with COVID-19 with a cardiac pathology are presented in light of recent evidence.