Comparison of High Flow Nasal Cannula and Continuous Positive Airway Pressure in COVID-19 Patients With Acute Respiratory Distress Syndrome in Critical Care Unit: A Randomized Control Study

Abstract

Background and objective Acute hypoxic respiratory failure in coronavirus disease 2019 (COVID-19) pneumonia has been treated with oxygen delivered by oxygen masks and non-invasive ventilation (NIV) with continuous positive airway pressure (CPAP), and more recently with high-flow nasal cannula (HFNC) devices. There is a paucity of randomized controlled trials to compare the efficacy of CPAP with HFNC in COVID-19 pneumonia. We conceptualized a randomized control study to compare the efficacy of HFNC and CPAP in reducing the need for invasive mechanical ventilation, estimation of mechanical ventilation-free days, and risk of intubation in COVID-19 patients with hypoxic respiratory failure. Methodology One hundred consecutive patients who satisfied the inclusion criteria were included in the trial. The patients were then randomly allocated to receive either CPAP or HFNC with settings as per the study protocol. The patients were deemed to have achieved the study endpoint when they were intubated due to any reason or successfully weaned from NIV to conventional oxygen therapies. The number of patients who required invasive ventilation and the number of invasive ventilation-free days were recorded and analyzed. Results Nineteen (38%) patients in the CPAP group and 30 (60%) patients in the HFNC group required invasive mechanical ventilation and the difference was statistically significant (p = 0.03, 95%CI: 0.1829-0.9129). The median number of days free of invasive mechanical ventilation in the CPAP group (median=5 (interquartile range (IQR(=5,6)) was more than in the HFNC group (median=4 (IQR=3,4)) and this difference was statistically significant (p<0.000). The secondary analysis of risk evaluation for intubation done using the Cox regression model showed no significant factors that could have contributed to intubation in the study population. The Kaplan-Meyer curve was used to express the probability of a patient getting intubated and the calculated hazard ratio was 2.29. Conclusion The administration of CPAP significantly reduced the intubation rate and prolonged invasive mechanical ventilation-free period in COVID-19 patients with hypoxic respiratory failure. We also inferred a two-fold increase in the risk of intubation in patients receiving HFNC compared to CPAP.

Keywords: acute hypoxic respiratory failure; continuous positive airway pressure (cpap); covid-19; high flow nasal cannula (hfnc); invasive mechanical ventilation.

Figure 1. Flowchart depicting workflow and patient management

PS: pressure support; Fi02: fractional concentration of inspired oxygen; ABG: arterial blood gas; VAS: visual analogue scale; NRBM: Non-rebreathing mask

Figure 2. CONSORT flow diagram

CONSORT: Consolidated Standards of Reporting Trials

Figure 3. Kaplan-Meier survival curve

CPAP: continuous positive airway pressure; HFNC: high-flow nasal cannula

Figure 4. Trend of modified Borg score over time

HR: hour; CPAP: continuous positive airway pressure; HFNC: high-flow nasal cannula

Figure 5. Mean of VAS score of patient discomfort

HR: hour; CPAP: continuous positive airway pressure; HFNC: high-flow nasal cannula; VAS: visual analogue scale

Figure 6. Comparison of respiratory rate over time

HR: hour; CPAP: continuous positive airway pressure; HFNC: high-flow nasal cannula

Figure 7. PaO2/FiO2 ratio

HR: hour; PaO2: partial pressure of oxygen; FiO2: fraction of inspired oxygen; CPAP: continuous positive airway pressure; HFNC: high-flow nasal cannula