Pressure Control Surrogate Formula for Estimating Mechanical Power in ARDS Is Associated With Mortality
Year: 2024
Type: article
Study design: Observational Study
Abstract: Background: Mechanical power (MP) applied to the respiratory system (MP RS ) is associated with ventilator-induced lung injury (VILI) and ARDS mortality. Absent automated ventilator MP RS measurements, the alternative is clinically unwieldy equations. However, simplified surrogate formulas are now available and accurately reflect values produced by airway pressure-volume curves. This retrospective, observational study examined whether the surrogate pressure -control equation alone could accurately assess mortality risk in subjects with ARDS managed almost exclusively with volume control (VC) ventilation. Methods: Nine hundred and forty-eight subjects were studied in whom invasive mechanical ventilation and implementation of ARDS Network ventilator protocols commenced ≤ 24 h after ARDS onset and who survived > 24 h. MP RS was calculated as 0.098 x breathing frequency x tidal volume x (PEEP + driving pressure). MP RS was assessed as a risk factor for hospital mortality and compared between non-survivors and survivors across Berlin definition classifications. In addition, mortality was compared across 4 MP RS thresholds associated with VILI or mortality (ie, 15, 20, 25, and 30 J/min). Results: MP RS was associated with increased mortality risk: odds ratio (95% CI) of 1.06 (1.04–1.07) J/min ( P < .001). Median MP RS differentiated non-survivors from survivors in mild (24.7 J/min vs 18.5 J/min, respectively, P = .034), moderate (25.7 J/min vs 21.3 J/min, respectively, P < .001), and severe ARDS (28.7 J/min vs 23.5 J/min, respectively, P < .001). Across 4 MP RS thresholds, mortality increased from 23–29% when MP RS was ≤ threshold versus 38–51% when MP RS was > threshold ( P < .001). In the > cohort, the odds ratio (95% CI) increased from 2.03 (1.34–3.12) to 2.51 (1.87–3.33). Conclusion: The pressure control surrogate formula is sufficiently accurate to assess mortality in ARDS, even when using VC ventilation. In our subjects when MP RS exceeds established cutoff values for VILI or mortality risk, we found mortality risk consistently increased by a factor of > 2.0.
Source: Respiratory Care
Authors: Richard H. Kallet, Michael S. Lipnick
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
OpenAlex ID: W4402312770