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 PaCO 2 were found. PaO 2 /FiO 2 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.
【저자키워드】 COVID 19, Hypoxemic acute respiratory failure, Non invasive respiratory supports., 【초록키워드】 COVID-19, Respiratory failure, Trial, Ventilation, nasal, Lung injury, COVID, Patient, non-invasive ventilation, HFNC, respiratory, patients, pressure, CPAP, Respiratory Support, Oxygenation, positive airway pressure, arterial blood, induced, Inspiratory effort, Intubated, ventilator, self, failure, minute, early phase, standard oxygen therapy, potential risk, rationale, statistically significant difference, treat, random, MONITOR, driving, NIV, invasive, P-SILI, Occurrence, collected, significantly, the patient, form, elevated, applied, reducing, dependent on, suggested, reduce, reduction in, were recorded, PaO, 【제목키워드】 Randomized, COVID-19 patients, physiological, Inspiratory effort, Non-invasive respiratory support, Effect, moderate-severe,