Effects of non-invasive respiratory supports on inspiratory effort in moderate-severe COVID-19 patients. A randomized physiological study

Gioacchino Schifino; Maria L Vega; Lara Pisani; Irene Prediletto; Vito Catalanotti; Vittoria Comellini; Ilaria Bassi; Maurizio Zompatori; Marco Vito Ranieri; Stefano Nava

doi:10.1016/j.ejim.2022.04.012

Effects of non-invasive respiratory supports on inspiratory effort in moderate-severe COVID-19 patients. A randomized physiological study

Eur J Intern Med. 2022 Jun:100:110-118. doi: 10.1016/j.ejim.2022.04.012. Epub 2022 Apr 22.

Affiliations

¹ IRCCS Azienda Ospedaliero Universitaria di Bologna, University Hospital Sant´Orsola-Malpighi- Respiratory and Critical Care Unit- Bologna, Italy; Alma Mater Studiorum, University of Bologna, Department of Clinical Integrated and Experimental Medicine (DIMES), Bologna, Italy.
² IRCCS MultiMedica, Division of Radiology Sesto, San Giovanni, Lombardia, Italy.
³ IRCCS Azienda Ospedaliero Universitaria di Bologna, University Hospital Sant´Orsola-Malpighi- Respiratory and Critical Care Unit- Bologna, Italy; Alma Mater Studiorum, University of Bologna, Department of Clinical Integrated and Experimental Medicine (DIMES), Bologna, Italy. Electronic address: stefanava@gmail.com.

Abstract

Rationale and objective: Various forms of Non-invasive respiratory support (NRS) have been used during COVID-19, to treat Hypoxemic Acute Respiratory Failure (HARF), but it has been suggested that the occurrence of strenuous inspiratory efforts may cause Self Induced Lung Injury(P-SILI). The aim of this investigation was to record esophageal pressure, when starting NRS application, so as to better understand the potential risk of the patients in terms of P-SILI and ventilator induced lung injury (VILI).

Methods and measurements: 21 patients with early de-novo respiratory failure due to COVID-19, underwent three 30 min trials applied in random order: high-flow nasal cannula (HFNC), continuous positive airway pressure (CPAP), and non-invasive ventilation (NIV). After each trial, standard oxygen therapy was reinstituted using a Venturi mask (VM). 15 patients accepted a nasogastric tube placement. Esophageal Pressure (ΔPes) and dynamic transpulmonary driving pressure (ΔPLDyn), together with the breathing pattern using a bioelectrical impedance monitor were recorded. Arterial blood gases were collected in all patients.

Main results: No statistically significant differences in breathing pattern and PaCO₂ were found. PaO₂/FiO₂ ratio improved significantly during NIV and CPAP vs VM. NIV was the only NRS to reduce significantly ΔPes vs. VM (-10,2 ±5 cmH20 vs -3,9 ±3,4). No differences were found in ΔPLDyn between NRS (10,2±5; 9,9±3,8; 7,6±4,3; 8,8±3,6 during VM, HFNC, CPAP and NIV respectively). Minute ventilation (Ve) was directly dependent on the patient's inspiratory effort, irrespective of the NRS applied. 14% of patients were intubated, none of them showing a reduction in ΔPes during NRS.

Conclusions: In the early phase of HARF due to COVID-19, the inspiratory effort may not be markedly elevated and the application of NIV and CPAP ameliorates oxygenation vs VM. NIV was superior in reducing ΔPes, maintaining ΔPLDyn within a range of potential safety.

Keywords: COVID 19; Hypoxemic acute respiratory failure; Non invasive respiratory supports.

Publication types

Randomized Controlled Trial

MeSH terms

COVID-19* / therapy
Humans
Hypoxia / therapy
Noninvasive Ventilation* / methods
Oxygen Inhalation Therapy / methods
Respiratory Insufficiency* / therapy