Mechanical Power in H Type COVID-19 Pneumonia: A Prospective Observational Study

ABSTRACT

Aim and background: Mechanical Power in ARDS has predictive value for both VILI and mortality. Driving pressure and mechanical power are two new targets in the mechanical ventilation of ARDS patients. COVID-19 pneumonia has two different phenotypes H type and L type which have different lung compliance, elasticity, and recrutability with different ventilatory strategies. We want to observe how Mechanical Power behaves in H type COVID-19 ARDS and its correlation with compliance and driving pressure. Objective: To study the correlation of Mechanical Power with Driving Pressure and Compliance in H type of COVID-19 pneumonia. Materials and methods: It is a prospective observational study conducted in COVID-19 patients admitted to the Medical Intensive Care unit. We included 65 adult COVID-19 patients aged between 18 and 70 years requiring invasive mechanical ventilation for at least 24 hours. Patients who developed spontaneous pneumothorax and pneumomediastinum before initiation of mechanical ventilation were excluded. Patients were categorised to H type based on lung compliance (<40 mL/cmH2O), recrutability, and lung weight. The Mechanical Power was calculated using the following equation, MP = 0.098 ∼ TV ∼ RR (Paw-1/2 for). Paw-peak airway pressure, for-driving pressure, TV-tidal volume, RR-respiratory rate. The variables are taken at 3 different time intervals in the first 24 hours of invasive mechanical ventilation. All patients are ventilated according to ARDSNET protocol. The Driving pressure and compliance were recorded. The correlation of Mechanical Power with Driving pressure and Compliance were analysed using Pearson Correlation. Results: The mean age of the patients was 57.04 ) 13.96 years (mean ) SD), gender distribution 75% were males and 25% were females. A positive correlation was observed between Mechanical power and Driving pressure (Pearson correlation 0.245) which is statistically significant p = 0.049. A negative correlation was observed between Mechanical power and Compliance (Pearson correlation 0.183) which is not statistically significant. Conclusion: The Mechanical Power and Driving pressure the new targets of Ventilator-Induced Lung Injury (VILI) and also predictors of mortality in ARDS patients. The positive correlation between Mechanical Power and Driving pressure was observed in H type of COVID-19 patients which behaves similar to other ARDS and independent risk factors of mortality in H type of COVID-19 ARDS too.