Israel Medical Association Journal

Background: At the beginning of the coronavirus disease 2019 (COVID-19) pandemic, many patients presented with acute hypoxemic respiratory failure, requiring ventilatory support. One treatment method was the addition of a reservoir mask to a high flow nasal cannula (HFNC) (dual oxygenation).

Objectives: To evaluate the clinical outcomes of combining reservoir mask on top of a high-flow nasal cannula.

Methods: A retrospective cohort of adult patients who were admitted due to COVID-19 during the first year of the pandemic to Rambam Health Care Campus. The primary endpoint was 30-day mortality. Secondary endpoints were incidence of invasive positive pressure ventilation initiation and admission to the intensive care unit (ICU). Patients who received positive pressure ventilation for reasons other than hypoxemic respiratory failure or who were transferred to another facility while still on HFNC were excluded.

Results: The final analysis included 333 patients; 166 were treated with dual oxygenation and 167 with HFNC only (controls). No significant differences in baseline characteristics were noted between the groups. The dual oxygenation group was slightly older (69.2 ± 14.8 years vs. 65.6 ± 15.5 years, P = 0.034). The 30-day mortality (24.1% vs. 36.5%, P = 0.013), rates of invasive positive pressure ventilation (47% vs. 59.3%, P = 0.024), and ICU admissions (41.6% vs. 52.7%, P = 0.042) were all significantly lower in the dual oxygenation group.

Conclusions: The addition of reservoir masks to HFNC may improve the oxygenation and overall prognosis in patients with severe hypoxemia due to COVID-19.

Background: High frequency oscillatory ventilation has proved valuable in recruiting and sustaining lung volume; the combined treatment may augment nitric oxide delivery to target vessels. NO[1] therapy lowers pulmonary resistance and improves oxygenation.

Objective: To retrospectively review data on changes in oxygenation – indicated by arterial/alveolar PO₂ ratio, oxygenation index, and outcome – in a cohort of 10 infants with hypoxemic respiratory failure in whom nitric oxide inhalation was instituted in a compassionate-use protocol after deteriorated oxygenation.

Methods: NO inhalation was administered at a range of 0.12–122 days of life using the SensorMedics system in 10 infants who developed hypoxemic respiratory failure associated with a variety of lung diseases while on HFOV[2].

Results: The infants' birthweight was 1,717 ± 1,167 g and their gestational age 31.1 ± 6.5 weeks. Mean exposure to NO inhalation was 14.2 days and ranged from 3–59 days. Oxygenation index decreased from 39.3 ± 13.2 to 12.7 ± 6.9 (P < 0.0002) after NO therapy. Despite an initial prompt response to NO inhalation, two patients died of progressive intractable respiratory failure and one term infant died of extrapulmonary complications (hypoxic ischemic encephalopathy grade III and multiorgan failure).

Conclusion: Our results indicate that the combined treatment of HFOV and NO inhalation is superior to HFOV alone for improving oxygenation in a selected cohort of infants ventilated for a variety of lung diseases.