Ventilatory Differences among ARDS Due to Viral Pneumonia: A Pilot Study

INTRODUCTION: Acute respiratory distress syndrome (ARDS) is classified based on factors such as the inflammatory state, time course, and radiographic presentation. It has been suggested that clinical outcomes may vary depending on the specific etiology. We aimed to investigate whether outcomes differ based on various viral etiologies. OBJECTIVES: 1. To assess whether there are differences in maternal mortality rates based on the etiology of viral pneumonia. 2. To evaluate the differences in the ventilatory support required for patients based on different etiological agents of viral pneumonia. MATERIALS AND METHODS: The electronic database from 2007 to 2022 was analyzed to study the ICU admission of pregnant women with viral pneumonia, confirmed through laboratory PCR testing. RESULTS: A total of fifty-six women were admitted, including 42 with A/H1N1pdm and 14 with SARS-CoV-2. The APACHE-II scores were similar between the two groups. The all-cause maternal mortality rates between the two groups were similar (21.4% vs 28.6%, p = 0.44). Ventilatory support was required for all patients with A/H1N1pdm, whereas 78.6% of those with SARS-CoV-2 required it (p = 0.013). When compared to other studies involving pregnant women in the ICU, 15% required NIV for a median duration of 4.7 days.(1) Among the 28 patients with A/H1N1pdm, 71.4% were successfully ventilated using non-invasive ventilation (NIV) alone. In comparison, only 50% of the 8 patients with SARS-CoV-2 achieved successful ventilation with NIV. The odds ratio for successful NIV was 1.4 (95% CI 0.37–5.4) in favour of A/H1N1pdm. The COVIDPREG study indicated that 39% received NIV alone with a median duration of 4 days.(2) The total duration of NIV in our study was 3 days. At the time of admission, 14 patients with A/H1N1pdm and 3 patients with SARS-CoV-2 required intubation. The mortality rates for these groups were 71.4% for A/H1N1pdm and 33.3% for COVID-19, resulting in an odds ratio of 2.14 (95% CI 0.19 – 23.7) in favour of SARS-CoV-2. A study of H1N1 from the US among pregnant women showed that 67% required invasive ventilation.(3) Multiple studies of pregnant women with COVID showed that the need for invasive ventilation was 40–72%.(4–6) Additionally, the duration of ventilation was 12 days (range: 4–18 days) for SARS-CoV-2 patients and 4 days (range: 2–7 days) for A/H1N1pdm patients (p<0.001). CONCLUSIONS: Duration of ventilation was higher among pregnant women with ARDS due to A/H1N1pdm. Larger studies are needed to understand any differences in ventilatory management better.