Measurement of dead space in COVID-19 Patients under mechanical ventilation and its relationship with disease severity markers

Abstract

Dead space is the volume of inhaled air that does not participate in gas exchange, because it remains in the airways. Several studies show that it does not occur in patients with covid-19 and classic ARDS which has a direct effect on microvasculature of the lung, and this respiratory failure causes behaviors different from classic ARDS, so that applying peep in these patients is not as effective as classic ARDS. The aim of our study is to measure the amount of dead space in patients with COVID-19 under mechanical ventilation and its relationship with disease severity indicators. Method: The statistical population included 50 patients with covid-19 infection under mechanical ventilation hospitalized in Imam Reza Hospital from 2018 to 2019. In order to conduct this research, patients hospitalized in Imam Reza Hospital who are under mechanical ventilation were included in the study. The required information includes: personal characteristics and previous disease history, indicators related to the severity of the disease collected in the form of the relevant checklist. Next, the amount of dead space will be measured for each patient. For this purpose, a combination of airflow and mainstream capnography was used, which can be used to calculate the amount of dead space. Results: Studies show that age and gender variables were not related to dead space. Only the weight variable had a significant relationship with the dead space. Also, there was no significant relationship between WBC, PLT, N/L, Cr, AST, ALT, LDH, CRP and ESR variables with dead space. HTN, COPD, CKD and CHF variables also had no significant relationship with dead space. Only the DM variable had a significant relationship with dead space. No significant relationship was found between P-Plateau, Compliance and RR total dead space variables. The variables of SatO2, intensity of involvement and hemodynamics of the patient also had no significant relationship with dead space. Only the CO2 intensity variable had a significant relationship with dead space.