Physicians in Italy report that a cohort of COVID-19 patients suffering from acute respiratory distress syndrome had well preserved lung gas volume but severe hypoxia, which they called “atypical” for ARDS.

“The primary characteristics we are observing … is the dissociation between their relatively well preserved lung mechanics and the severity of hypoxemia,” researchers wrote in a letter published by American Journal of Respiratory Critical Care Medicine. [1]

Using computed tomography, researchers measured a 3.0 ± 2.1 shunt fraction to fraction of gasless tissue ratio in eight patients, which they said indicated “remarkable” hyperperfusion of gasless tissue. [1]

The physicians said normal ventilation strategies for ARDS include high Positive End Expiratory Pressure (PEEP) and prone positioning but these were not advised given the likelihood of severe hemodynamic impairment and fluid retention plus only a modest benefit from the body positioning vs staff effort required for it. [1]

Instead, the physicians recommended the lowest possible PEEP and gentle ventilation, writing that “We need to be patient.” [1]

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1. Luciano Gattinoni L, et al. “Covid-19 Does Not Lead to a ‘Typical’ Acute Respiratory Distress Syndrome.” Amer J Resp Crit Care Med. 2020 Mar 30. doi: 10.1164/rccm.202003-0817LE. Accessed