Sequential Oxygen Therapy in COVID-19 Diabetic Patients: A Retrospective Cohort Study
Authors: Suryawanshi Chhaya M , Mahanta Dipanjali 
Published: March 2024

Introduction: Acute respiratory failure is the most common clinical feature in patients with severe Coronavirus Disease -2019 (COVID-19) who are admitted to an Intensive Care Unit (ICU) and may require invasive mechanical ventilation, which is generally linked with a high fatality rate. Patients with established co-morbidities, such as diabetes, invariably fall into the category of patients with severe disease presentation and rapid disease progression. Aim: To study the clinical outcomes of COVID-19 diabetic patients after sequential oxygen therapy using a reservoir bag mask, High Frequency Nasal Oxygen (HFNO), and Non-invasive Ventilation (NIV). Materials and Methods: In this retrospective cohort study, adhering to the STROBE statement criteria, the authors included 150 patients suffering from COVID-19 acute respiratory failure, who were known diabetics, divided into three groups based on admission oxygen saturation and Respiratory Rate (RR) for Non-Rebreather Bag-Mask (NRBM) therapy, HFNO, and NIV. For two weeks, all patients were monitored, and measures such as Saturation of peripheral Oxygen (SpO2 ), Respiratory Rate (RR) escalation of oxygen requirement, glycaemic management, compliance and problems with continued oxygen therapy, the need for invasive mechanical ventilation, and mortality were recorded. The recorded parameters among the three groups were compared using Analysis of Variance (ANOVA) test. Results: Among the demographic parameters recorded, the authors noted that individuals older than 50-55 years of either sex were admitted for HFNO (56.02±11.71 years) and NIV (54.28±14.67 years) therapy, whereas no such preponderance was noted among the two genders. Significant results were noted in all three groups in terms of the escalation of oxygen fraction (FiO2) requirements on the 10th day of observation (NRBM 12.63±2.48%, HFNO 37.74±13.56%, NIV 82.44±11.11%). The need for tracheal intubation was higher in patients in the NIV group (10) compared to the HFNO (9) and NRBM (1) groups. Patients whose blood sugar levels remained uncontrolled throughout the course of observation in the study were disparagingly seen to have been a part of the HFNO and NIV groups, and hence the subsequent mortality. Conclusion: There was a steady escalation of mean oxygen requirements in all three groups of oxygen therapy over the course of two weeks, coinciding with the ensuing ‘cytokine storm’ associated with Severe Acute Respiratory SyndromeCoronavirus- 2 (SARS-CoV-2) infection. This trend of escalation of oxygen requirement also in turn coincided with the raised glycaemic charting trends of the patients over the same course of two weeks, delineating those individuals with diabetes mellitus, in view of their compromised immunity and innate pro -inflammatory state, are more prone to develop severe form of the disease with more serious complications, which may even lead to mortality. With regards to the compliance, NRBM & HFNO provided best results in comparison to NIV. The rates of complications were also noted to be higher with the use of NIV in this instance.