Respiratory support in patients with COVID-19 (outside intensive care unit). A position paper of the Respiratory Support and Chronic Care Group of the French Society of Respiratory Diseases

Abstract

With first cases noted towards the end of 2019 in China, COVID-19 infection was rapidly become a devastating pandemic. Even if most patients present with a mild to moderate form of the disease, the estimated prevalence of COVID-19-related severe acute respiratory failure (ARF) is 15-20% and 2-12% needed intubation and mechanical ventilation. In addition to mechanical ventilation some other techniques of respiratory support could be used in some forms of COVID-19 related ARF. This position paper of the Respiratory Support and Chronic Care Group of the French Society of Respiratory Diseases is intended to help respiratory clinicians involved in care of COVID-19 pandemic in the rational use of non-invasive techniques such as oxygen therapy, CPAP, non-invasive ventilation and high flow oxygen therapy in managing patients outside intensive care unit (ICU). The aims are: (1) to focus both on the place of each technique and in describing practical tips (types of devices and circuit assemblies) aimed to limit the risk of caregivers when using those techniques at high risk spreading of viral particles; (2) to propose a step-by-step strategy to manage ARF outside ICU.

Keywords: Acute respiratory failure; COVID-19; High flow oxygen therapy; Non invasive ventilation; Oxygen.

Fig. 1

Different ventilator circuit assemblies to reduce viral spreading. (a) Ventilator using double circuit with an integrated expiratory valve. The filter* must be interposed between the expiratory arm and the ventilator. (b) Ventilator using single-limb circuit with an active expiratory valve: the filter* must be interposed between the mask and the expiratory valve. (c) Ventilator using single limb circuit with intentional leaks. Not-vented mask must be preferred if available. In this case a deported exhalation port (Whisper Swivel or similar) must be added. The filter* must be interposed between the mask and the deported exhalation port. If a non-vented mask is not available an alternative is to seal the intentional leak of the vented mask. In the last case caution must be taken not to block anti-asphyxia valve. I: inspiratory arm; E: expiratory arm. * There are not published studies comparing the efficacy of different filters.

Fig. 2

Different devices providing non-invasive CPAP therapy.

Fig. 3

Different devices providing HFOT therapy.

Fig. 4

Flow chart strategy for managing ARF in COVID-19 patients (modified from ABG: Arterial Blood Gases; COPD: chronic obstructive pulmonary disease; RR: respiratory rate; HFOT: high flow oxygen therapy; CPAP: continuous positive airway pressure; NIV: non-invasive ventilation; EPAP: expiratory positive airway pressure; EI: endotracheal intubation).