In a recent article published in Obstetrics and Gynecology, researchers showed that inhaled nitric oxide 200 (iNO200) improves oxygenation in pregnant patients with coronavirus disease 2019 (COVID-19) with severe pneumonia.
Study: High-dose inhaled nitric oxide for the treatment of pregnant patients with spontaneous respiration with severe coronavirus pneumonia 2019 (COVID-19). Image credit: Pressmaster / Shutterstock
Fund
Due to increased oxygen requirements during pregnancy and related immunological, physiological, and hormonal alterations, pregnant women are likely to develop hypoxic respiratory failure due to COVID-19. Randomized clinical trials in pregnant women with COVID-19 have not yet explored any respiratory therapy for adjunct supplemental oxygenation.
iNO is used as a rescue treatment for severe hypoxemia among intubated patients suffering from respiratory failure, including those associated with coronavirus 2 (SARS-CoV-2) infection of severe acute respiratory syndrome. In addition, nitric oxide has antiviral effects towards SARS-CoV-2.
The authors of the present study previously treated six pregnant non-intubated COVID-19 pregnant patients with severe pneumonia hospitalized at Massachusetts General Hospital (MGH) during the first SARS-CoV-2 wave with about 200 ppm iNO (iNO200) administered. by means of a tight fit. mask for half an hour, twice a day. Safe administration of 39 iNO200 treatments resulted in improved systemic oxygenation and a reduction in respiratory rate. These findings led to the implementation of iNO200 in MGH as a therapy for COVID-19 pneumonia during pregnancy.
About the study
In the current work, the researchers evaluated whether iNO200 improves respiratory function and outcomes in hospitalized pregnant patients with severe COVID-19 pneumonia to further explore the efficacy and safety of iNO200 among pregnant patients with SARS-CoV- 2.
The team used information from pregnant patients admitted to four academic hospitals from March 2020 to December 2021 for severe SARS-CoV-2 bilateral pneumonia. They established the Delivery of iNO network, also known as the DELFiNO network, which includes four university hospitals in Boston, Massachusetts (Boston Medical Center, Beth Israel Deaconess Medical Center, Tufts Medical Center, and MGH).
All institutions in the DELFiNO network have comparable access to modern methods for managing respiratory failure, such as extracorporeal membrane oxygenation (ECMO). Only one facility (MGH) had access to the single, unlabeled use of iNO therapy, known as iNO200 treatment. The researchers identified two groups: those receiving the standard of care alone (SoC cohort) and those receiving iNO200 for half an hour twice a day along with only SoC (iNO200 group).
The default primary outcome was the number of days without oxygen supplements at 28 days after hospitalization. Secondary outcomes include length of hospital stay, intubation rate, and length of stay in the intensive care unit (ICU). Multivariate-adjusted regression assessments considered body mass index, age, gestational age, remdesivir use, steroids, and research center.
Results
The results of the study indicated that 51 women in the SoC group and 20 women in the iNO200 arm were hospitalized with severe bilateral pneumonia for SARS-CoV-2, representing 71 pregnant patients.
The team showed that inhalation of iNO200 increased oxygenation and decreased tachypnea. Subjects treated with iNO200 had more days without oxygen supplements, averaging 24 days ranging from 23 to 26 days, compared with patients receiving SoC alone, who had 22 days without oxygen supplements range from 14 to 24.
In multivariate adjustment studies, iNO200 was associated with 63.2% more days without oxygen supplements, 59.7% shorter length of stay in the ICU, and 63.6% more. short of hospital stay. According to current research, iNO200 was associated with a faster recovery of respiratory care, such as rapid weaning from oxygen therapy.
In addition, no iNO200-related adverse events were observed during the 144 iNO200 treatments. The maximum methaemoglobin level measured was 5.3% and fell rapidly after the end of treatment. In fact, in the present research, the clinical and echocardiographic evaluation did not detect any evidence of rebound pulmonary hypertension, heart failure, or hypotension, possibly due to short exposure, i.e., 30 minutes to treatments with iNO200.
In particular, according to serum creatinine concentrations, none of the participants in the trial who received iNO200 showed signs of acute kidney injury. Because they did not notice adverse obstetric or neonatal outcomes, the researchers believe that giving iNO200 to pregnant patients for half an hour twice a day while monitoring them closely was a safe respiratory intervention in severe COVID-19-associated pneumonia.
Conclusions
Overall, the authors found that iNO200 was connected with better oxygenation and decreased dyspnea among pregnant patients with SARS-CoV-2 with severe pneumonia in the present study. In addition, iNO200 was related to a shorter length of hospital stay and ICU and oxygen supplementation compared to SoC only. Among pregnant patients with COVID-19 pneumonia, this new respiratory intervention was viable, and both mothers and infants experienced no adverse effects.
In summary, iNO200 could be an efficient respiratory therapy for tachypneic and hypoxemic pregnant patients hospitalized with severe bilateral pneumonia by SARS-CoV-2 to increase oxygenation and reduce respiratory rate. Randomized controlled trials are needed to evaluate improved outcomes with iNO200, given current findings and the lack of therapeutic studies among severe pregnant pneumonic patients.