Role of integrated pulmonary index in respiratory monitoring of spontaneously breathing COVID-19 patients with moderate to severe respiratory symptoms.

Background & objective: Most of the COVID-19 patients suffered from moderate to severe respiratory symptoms. Many of them needed oxygen supplementation or even mechanical ventilation. There is little data available about the use of either end-tidal CO2 (EtCO2) or integrated pulmonary index (IPI) in these patients. The aim of this study to investigate the difference in IPI values for subjects requiring mechanical ventilation compared to those managed without ventilation and the correlation between EtCO2 and SpO2. Methods: This prospective observational study involved adult COVID-19 patients admitted to the ICU with moderate to severe respiratory symptoms. All patients were connected to a portable respiratory monitor with the IPI algorithm (Medtronic Capnostream 35) and treated according to a standardized protocol. Oxygen flow was adjusted to maintain oxygen saturation (92–96%). If the respiratory rate did not fall below 30 breaths per minute and/or the SpO2 did not reach the target, non-invasive ventilation (NIV) was initiated. Patients with NIV failure was eligible for invasive mechanical ventilation. Results: SpO2 was significantly lower, while RR was significantly higher in intubated group compared to nonintubated group (P < 0.001 and 0.018, respectively). However, IPI, EtCO2, and HR did not differ among both groups. There was a significant positive correlation between EtCO2 and SpO2 at baseline before oxygen therapy (r = 0.419; P = 0.007). There was a significant negative correlation between CT score and SpO2 (r = -0.408; P = 0.01); however, there was no correlation between CT score and both IPI and end tidal CO2 at baseline (r = 0.017; P = 0.9). Conclusion: The integrated pulmonary index cannot be used as a single parameter for assessing respiratory severity in COVID-19 patients. [ABSTRACT FROM AUTHOR]