Partition of respiratory mechanics in patients with acute respiratory distress syndrome and association with outcome: a multicentre clinical study

Abstract

Purpose In acute respiratory distress syndrome (ARDS), physiological parameters associated with outcome may help defining targets for mechanical ventilation. This study aimed to address whether transpulmonary pressures ( P L ), including transpulmonary driving pressure (DP L ), elastance-derived plateau P L , and directly-measured end-expiratory P L , are better associated with 60-day outcome than airway driving pressure (DP aw ). We also tested the combination of oxygenation and stretch index [PaO 2 /(FiO 2 *DP aw )]. Methods Prospective, observational, multicentre registry of ARDS patients. Respiratory mechanics were measured early after intubation at 6 kg/ml tidal volume. We compared the predictive power of the parameters for mortality at day-60 through receiver operating characteristic (ROC) and assessed their association with 60-day mortality through unadjusted and adjusted Cox regressions. Finally, each parameter was dichotomized, and Kaplan–Meier survival curves were compared. Results 385 patients were enrolled 2 [1–4] days from intubation (esophageal pressure and arterial blood gases in 302 and 318 patients). As continuous variables, DP aw , DP L , and oxygenation stretch index were associated with 60-day mortality after adjustment for age and Sequential Organ Failure Assessment, whereas elastance-derived plateau P L was not. DP aw and DP L performed equally in ROC analysis ( P = 0.0835). DP aw had the best-fit Cox regression model. When dichotomizing the variables, DP aw ≥ 15, DP L ≥ 12, plateau P L ≥ 24, and oxygenation stretch index < 10 exhibited lower 60-day survival probability. Directly measured end-expiratory P L ≥ 0 was associated with better outcome in obese patients. Conclusion DP L was equivalent predictor of outcome than DP aw . Our study supports the soundness of limiting lung and airway driving pressure and maintaining positive end-expiratory P L in obese patients. Supplementary Information The online version contains supplementary material available at 10.1007/s00134-022-06724-y.

Advanced Point-of-care Bedside Monitoring for Acute Respiratory Failure

“…32 Limiting the elastance-derived inspiratory transpulmonary pressure under 20 to 25 cm H 2 O seems a reasonable approach to avoid overdistention in the nondependent lung regions (table 1). 19 Consistent with previous results, 33 a transpulmonary driving pressure 12 cm H 2 O or greater, rather than an elastance-derived inspiratory transpulmonary pressure of 24 cm H 2 O or more, has been demonstrated to be a risk factor for mortality at 60 days (table 1).…”

Respiratory Monitoring During Mechanical Ventilation: The Present and the Future

“…68 It is generally advisable for P L not to exceed 20-25 cmH 2 O, and to target DP aw < 15 cmH 2 O and DP L <12 cmH 2 O. 54,61,68…”

Ten rules for optimizing ventilatory settings and targets in post-cardiac arrest patients

“…Recently, the concept of mechanical power (MP), the mechanical energy delivered per time by the ventilator on the respiratory system or the lung, has also been proposed as an important component of mechanical ventilation settings. High MP was found associated with worse outcomes in non-acute respiratory distress syndrome (ARDS) [ 29 ] and ARDS patients [ 30 ], but this effect has not been completely elucidated in post-CA patients [ 28 ]. Additionally, the optimal ventilatory targets, i.e., oxygen and carbon dioxide levels in post-CA patients, still deserve to be clarified [ 3 ].…”