Covid-19 severe hypoxemic pneumonia: a clinical experience using high-flow nasal oxygen therapy as first-line management

Beduneau, Gaëtan; Boyer, Déborah; Guitard, Pierre-Gildas; Gouin, Philippe; Carpentier, Dorothée; Grangé, Steven; Veber, Benoit; Girault, Christophe; Tamion, Fabienne

Purpose: To report a French experience in patients admitted to Intensive Care Unit (ICU) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) requiring high fractional concentration of inspired oxygen supported by high flow nasal cannula (HFNC) as first-line therapy. Methods: Retrospective cohort study conducted in two ICUs of a French university hospital. All consecutive patients admitted during 28-days after the first admission for SARS-CoV-2 pneumonia were screened. Demographic, clinical, respiratory support, specific therapeutics, ICU length-of-stay and survival data were collected. Results: Data of 43 patients were analyzed: mainly men (72%), median age 61 (51-69) years, median body mass index of 28 (25-31) kg/m2, median simplified acute physiology score (SAPS II) of 29 (22-37) and median PaO2/fraction of inspired oxygen (FiO2) (P/F) ratio of 146 (100-189) mmHg. HFNC was initiated at ICU admission in 76% of patients. Median flow was 50 (45-50) L/min and median FiO2 was 0.6 (0.5-0.8). 79% of patients presented at least one comorbidity, mainly hypertension (58%). At day (D) 28, 32% of patients required invasive mechanical ventilation, 3 patients died in ICU. Risk factors for intubation were diabetes (10% vs 43%, p=0.04) and extensive lesions on chest computed tomography (CT) (p=0.023). Patients with more than 25% of lesions on chest CT were more frequently intubated during ICU stay (p=0.012). At ICU admission (D1), patients with higher SAPS II and Sequential Organ Failure Assessment (SOFA) scores (respectively 39 (28-50) vs 27 (22-31), p=0.0031 and 5 (2-8) vs 2 (2-2.2), p=0.0019), and a lower P/F ratio (98 (63-109) vs 178 (126-206), p=0.0005) were more frequently intubated.Among non-intubated patients, the median lowest P/F was 131 (85-180) mmHg. Four caregivers had to stop working following coronavirus 2 contamination, but did not require hospitalization. Conclusion: Our clinical experience supports the use of HFNC as first line-therapy in patients with SARS-COV-2 pneumonia for whom face mask oxygen does not provide adequate respiratory support.