Study discusses possible causes for Silent Hypoxemia condition in COVID-19 clients. Findings might avoid unneeded intubation and ventilation.
A brand-new research study offers possible descriptions for COVID-19 clients who provide with exceptionally low, otherwise dangerous levels of oxygen, however no indications of dyspnea (problem breathing). This brand-new understanding of the condition, referred to as quiet hypoxemia or “happy hypoxia,” might avoid unneeded intubation and ventilation in clients throughout the existing and predicted 2nd wave of coronavirus.
The condition “is especially bewildering to physicians as it defies basic biology,” stated Martin J. Tobin, MD, Loyola Medicine and Edward J. Hines Jr. VA Hospital pulmonologist and crucial care expert, and teacher, Loyola University Chicago Stritch School of Medicine. Dr. Tobin is lead author of the research study, “Why COVID-19 Silent Hypoxemia is Baffling to Physicians,” appearing just recently in the online American Journal of Respiratory and Critical Care Medicine.
“In some instances, the patient is comfortable and using a phone at a point when the physician is about to insert a breathing (endotracheal) tube and connect the patient to a mechanical ventilator,” stated Dr. Tobin, “which while potentially lifesaving carries its own set of risks.”
The research study consisted of 16 COVID-19 clients with really low levels of oxygen (as low as 50%; regular blood oxygen saturation is in between 95 and 100%), without shortness of breath or dyspnea, and discovered that “a number of pathophysiological systems represent the majority of, if not all, cases of quiet hypoxemia. This consists of the preliminary evaluation of a client’s oxygen level with a pulse oximeter.
“While a pulse oximeter is remarkably accurate when oxygen readings are high, it markedly exaggerates the severity of low levels of oxygen when readings are low,” stated Dr. Tobin. “Another factor is how the brain responds to low levels of oxygen. As oxygen levels drop in patients with COVID-19, the brain does not respond until oxygen falls to very low levels — at which point a patient typically becomes short of breath,” he stated.
In addition, majority of the clients had low levels of co2, which might reduce the effect of an incredibly low oxygen level.
“It is also possible that the coronavirus is exerting a peculiar action on how the body senses low levels of oxygen,” stated Dr. Tobin, which might be connected to the absence of odor, experienced by two-thirds of COVID-19 clients.
While acknowledging that additional research study is required, the research study concludes that “features about COVID-19 that physicians find baffling become less strange when viewed in the light of long-established principles of respiratory physiology.”
“This new information may help to avoid unnecessary endotracheal intubation and mechanical ventilation, which presents risks, when the ongoing and much anticipated second wave of COVID-19 emerges,” stated Dr. Tobin.
Reference: “Why COVID-19 Silent Hypoxemia is Baffling to Physicians” by Martin J. Tobin, Franco Laghi and Amal Jubran, 15 June 2020, American Journal of Respiratory and Critical Care Medicine.
DOI: 10.1164/rccm.202006-2157CP
