Modified Bain's Circuit as an Alternate to Non-invasive Ventilation in COVID 19

Cureus. 2022 Mar 2;14(3):e22772. doi: 10.7759/cureus.22772. eCollection 2022 Mar.

Abstract

Introduction COVID-19 is a pandemic that severely affects the lungs. Symptomatically affected individuals often become severely hypoxic, requiring non-invasive ventilation. The scarcity of resources in resource-compromised countries like India led to the adoption of novel strategies like using Bain's circuit for assisting spontaneous ventilation. This study compares the outcome when a standard circuit is replaced with a shortened Bain's circuit. Aims and objectives To compare shortened Bain's circuit and bilevel positive airway pressure (BiPAP) in spontaneously ventilated COVID 19 patients with regards to effects on hemodynamic stability and efficacy of ventilation using blood gas analysis. Methodology Twenty-four COVID patients aged between 35-70 years, requiring non-invasive ventilation but not tolerating BiPAP or not improving on BiPAP were enrolled in the study. Baseline heart rate and arterial blood gases (ABG) were recorded. Patients were then ventilated using shortened Bain's circuit. Heart rate and ABG were then recorded two hours after ventilation. Results Hemodynamic and blood gas parameters were comparable between the two groups at baseline and on BiPAP. Group A showed better hemodynamic and blood gas profiles compared to group B, but the difference was not statistically significant because of small sample size. Conclusion Shortened Bain's circuit may be a viable alternative to non-invasive ventilation in spontaneously breathing hypoxic patients with efficacy comparable to a standard Bain's circuit and reduced chances of carbon dioxide retention. Studies with a larger sample size are needed to further validate the conclusion.

Keywords: bain’s circuit; bipap; covid 19; fresh gas flow; non-invasive ventilation.