Potential for the lung recruitment and the risk of lung overdistension during 21 days of mechanical ventilation in patients with COVID-19 after noninvasive ventilation failure: the COVID-VENT observational trial

BMC Anesthesiol. 2022 Mar 4;22(1):59. doi: 10.1186/s12871-022-01600-0.

Abstract

Background: Data on the lung respiratory mechanics and gas exchange in the time course of COVID-19-associated respiratory failure is limited. This study aimed to explore respiratory mechanics and gas exchange, the lung recruitability and risk of overdistension during the time course of mechanical ventilation.

Methods: This was a prospective observational study in critically ill mechanically ventilated patients (n = 116) with COVID-19 admitted into Intensive Care Units of Sechenov University. The primary endpoints were: «optimum» positive end-expiratory pressure (PEEP) level balanced between the lowest driving pressure and the highest SpO2 and number of patients with recruitable lung on Days 1 and 7 of mechanical ventilation. We measured driving pressure at different levels of PEEP (14, 12, 10 and 8 cmH2O) with preset tidal volume, and with the increase of tidal volume by 100 ml and 200 ml at preset PEEP level, and calculated static respiratory system compliance (CRS), PaO2/FiO2, alveolar dead space and ventilatory ratio on Days 1, 3, 5, 7, 10, 14 and 21.

Results: The «optimum» PEEP levels on Day 1 were 11.0 (10.0-12.8) cmH2O and 10.0 (9.0-12.0) cmH2O on Day 7. Positive response to recruitment was observed on Day 1 in 27.6% and on Day 7 in 9.2% of patients. PEEP increase from 10 to 14 cmH2O and VT increase by 100 and 200 ml led to a significant decrease in CRS from Day 1 to Day 14 (p < 0.05). Ventilatory ratio was 2.2 (1.7-2,7) in non-survivors and in 1.9 (1.6-2.6) survivors on Day 1 and decreased on Day 7 in survivors only (p < 0.01). PaO2/FiO2 was 105.5 (76.2-141.7) mmHg in non-survivors on Day 1 and 136.6 (106.7-160.8) in survivors (p = 0.002). In survivors, PaO2/FiO2 rose on Day 3 (p = 0.008) and then between Days 7 and 10 (p = 0.046).

Conclusion: Lung recruitability was low in COVID-19 and decreased during the course of the disease, but lung overdistension occurred at «intermediate» PEEP and VT levels. In survivors gas exchange improvements after Day 7 mismatched CRS.

Trial registration: ClinicalTrials.gov, NCT04445961 . Registered 24 June 2020-Retrospectively registered.

Keywords: Acute respiratory distress syndrome; COVID-19; Lung recruitability; Lung strain; PEEP; Volutrauma.

Publication types

  • Multicenter Study
  • Observational Study

MeSH terms

  • Aged
  • COVID-19 / epidemiology*
  • COVID-19 / physiopathology
  • COVID-19 / therapy*
  • Critical Care / methods
  • Female
  • Humans
  • Lung / physiopathology*
  • Male
  • Middle Aged
  • Noninvasive Ventilation / statistics & numerical data
  • Positive-Pressure Respiration
  • Prospective Studies
  • Respiration, Artificial / statistics & numerical data*
  • Respiratory Insufficiency / epidemiology*
  • Respiratory Insufficiency / physiopathology
  • Respiratory Mechanics
  • Russia / epidemiology
  • SARS-CoV-2
  • Survival Analysis
  • Tidal Volume
  • Treatment Failure

Associated data

  • ClinicalTrials.gov/NCT04445961