Microvascular flow alterations in critically ill COVID-19 patients: A prospective study

Area of Science:

• Critical Care Medicine
• Microcirculation Research
• Infectious Diseases

Background:

• Limited data exists on the microcirculatory patterns of critically ill COVID-19 patients.
• Understanding these patterns is crucial for managing severe disease progression.

Purpose of the Study:

• To compare sublingual microcirculation parameters in critically ill COVID-19 patients based on disease severity.
• To identify potential differences in microvascular function between severe and critical COVID-19 cases.

Main Methods:

• A single-center prospective study involving 43 critically ill COVID-19 patients admitted to the ICU.
• Sublingual microcirculation was assessed using IDF microscopy within 48 hours of ICU admission.
• Key parameters measured included microcirculatory flow index (MFI), proportion of perfused vessel (PPV), total vessel density (TVD), De Backer score (DBS), perfused vessel density (PVD), and heterogeneity index (HI).

Main Results:

• Patients in the critical group (n=29) exhibited significantly higher MFI, DBS, and PVD compared to the severe group (n=14).
• The critical group, all on mechanical ventilation, showed higher PaCO2 levels correlating with microcirculatory parameters.
• Proportion of perfused vessel, heterogeneity index, and total vessel density were similar between the severe and critical groups.

Conclusions:

• Critically ill COVID-19 patients requiring mechanical ventilation may have increased red blood cell velocity compared to severe, non-ventilated patients.
• Microcirculatory alterations, particularly in flow and perfusion, are associated with COVID-19 severity.