Only Some Cases Are Like Severe ARDS

Speaking in a��webinar hosted by the European Society of Anaesthesiology (ESA) April 9, he noted that, based on what the numbers say, one would think the patient would be “gasping or almost in a coma.”

“But when you go and see the patient, he is awake, he is speaking to you, he doesn’t look as bad” as his data would suggest, and “you are really starting to ask yourself why you should intubate such a patient,” Massimiliano said.

He added that that, “at least at the beginning, it is not the ARDS we used to know…it’s a different respiratory failure.” But he warned that COVID-19 patients can “suddenly deteriorate.”

Report on 150 Patients With COVID-19

In their latest study, Gattinoni and colleagues report on 150 patients with COVID-19 pneumonia. More than half of these patients had near-normal respiratory system compliance despite having severe hypoxemia, a finding that was corroborated by other colleagues working in Northern Italy.

Analyzing the cases further, they determined that there were different patterns of COVID-19, depending on the interaction of three factors:

•   The severity of the infection, the host response, the physiologic reserve, and comorbidities

•   The ventilatory responsiveness to hypoxemia

•   The length of time between symptom onset and presenting to the hospital

Gattinoni and collegues say that consideration of these factors led them to develop the view that there are two distinct COVID-19 phenotypes, Type L and Type H.

Type L was characterized by:

•   Low elastane (high compliance)

•   A low ventilation-to-perfusion ratio, with a near-normal pulmonary artery pressure

•   A low lung weight on computed tomography (CT)

•   Low lung recruitability, with a very low proportion of non-aerated lung tissue

These Type L patients may stay in this phenotype for a period of time and then either improve or worsen, in which case they shift to the opposite end of the phenotypic spectrum and develop Type H disease, the team notes.

Type H patients were found to have:

•   High elastane, linked to increased edema

•   High right-to-left shunt

•   High lung weight, with a >1.5 kg increase on CT