Ventilation-Perfusion Matching in Early-stage Prone Position Ventilation

Ventilation-Perfusion Matching in Early-stage Prone Position Ventilation: A Comparison Between COVID-19 ARDS and ARDS From Other Etiologies

Prone positioning has been widely used in critical care medicine to improve oxygenation in patients with acute respiratory distress syndrome (ARDS). This study aimed to compare the effect of pronation on lung ventilation-perfusion matching between COVID19-associated acute respiratory distress syndrome (CARDS) and ARDS from other etiologies (non-CARDS) using electrical impedance tomography (EIT).

In this prospective study, both COVID19-associated ARDS (CARDS) patients and patients with ARDS from other etiologies (non-CARDS) were enrolled. Electrical impedance tomography (EIT) was used to evaluate the changes in ventilation and perfusion between supine and prone positions. Baseline values of the area of DeadSpace, shunt, ventilation-perfusion matching (VQmatch) were identified at the time of enrollment. Within the defined VQmatch region, the global inhomogeneity index (VQmatch-GI) was calculated to assess the degree of uniformity within the region. Prone position was applied immediately after the baseline data were collected. After 2 hours of proning, another EIT examination was conducted. Parameters such as DeadSpace, shunt, VQmatch, and other common measurements before and after pronation were taken and compared to evaluate the effect of prone positioning on CARDS and non-CARDS patients.

Inclusion Criteria:

• Above the age of 18
• Diagnosed with ARDS based on the Berlin Definition of ARDS
• Under mechanical ventilation

Exclusion Criteria:

• Contraindications to EIT examination and prone position
• Refusal of signing the informed consent