The diaphragm is the fundamental muscle of the respiratory system. The diaphragmatic dysfunction is present in 60% of critical patients at hospital admission and up to 80% after prolonged mechanical ventilation and difficult weaning.

Risk factors associated with diaphragm dysfunction and atrophy are sepsis, trauma, sedatives, steroids, and muscle relaxants.

The main pathology characteristics of diaphragm biopsies of mechanically ventilated patients are atrophy and a reduction in contractility, determining an impact on the clinical outcome.

Shi et al. found a higher section area of the diaphragm muscle fiber in biopsies of post mortem COVID-19 patients versus negative patients, independently from days of mechanical ventilation.

The hypothesis of our study is to identify different clusters of pathological presentation in post-mortem COVID-19 mechanically ventilated patients.

Inclusion Criteria:

• patients deceased in the intensive care unit positive to SARS-CoV-2 and mechanically ventilated
• post-mortem examination of the diaphragm

Exclusion Criteria:

• patients with a terminal disease and a prognosis of less than 48 hours at admission.

Deceased COVID-19 patients admitted to the intensive care unit and mechanically ventilated.