Self working water-based instrument for positive expiratory pressure by resistance device and its effectiveness in improving oxygenation in acute pulmonary edema, during the COVID 19 pandemic: A pilot study

Background: About 20% to 67% of COVID 19 infected patients who are admitted to the hospitals and 100% of mechanically ventilated patients suffer from acute respiratory distress syndrome. Extrinsic positive expiratory pressure (PEP) can improve oxygenation by direct and indirect mechanisms, thus reducing the need of medical oxygen. But high-budget and sophisticated machines are required to provide this positive airway pressure, adding on to the treatment cost of the patient and investment expenditure by the health-care facilities. We have designed a simple self-working device called self-working water-based instrument for positive expiratory pressure by resistance (SWIPER) device which can provide a PEP. The objective of this study was to assess the effectiveness of this device in improving oxygenation in patients with acute pulmonary edema, which was quantified using pulse oximetry. Methods: Patients who were admitted to the medical intensive care unit during the study period, with an acute pulmonary edema-a diagnosis which was made clinico-radiologically, were chosen as the subjects for the study. Once the patients were critically stabilized by the already existing treatment protocols, the SWIPER device was applied. Results: The device was introduced on 15 patients who were selected after applying the inclusion-exclusion criteria of the study. The mean age of the study group was 65 years (men-64 years, Women-66 years). Eight of them had cardiogenic pulmonary edema whereas seven of them had nephrogenic pulmonary edema. The median baseline SpO2level was 90% (86%, 94%) and the median plateau SpO2level after using the SWIPER device was 94% (91%, 99%) (*P < 0.001). The mean rise in SpO2on using the device was 6% (1.89) which was clinically significant. Conclusion: SWIPER device is effective in significantly increasing the SpO2 in patients with acute pulmonary edema by providing a PEP. This device is not a replacement for the existing positive airway pressure-providing electrical devices. However, SWIPER devices will definitely come in handy in resource-limited settings in providing better treatment and care till the standard therapeutic measures are obtained. It will also help in significantly reducing the medical oxygen consumption in managing such patients.