A novel non-invasive method to detect excessively high respiratory effort and dynamic transpulmonary driving pressure during mechanical ventilation.

ABSTRACT: BACKGROUND:Excessive respiratory muscle effort during mechanical ventilation may cause patient self-inflicted lung injury and load-induced diaphragm myotrauma, but there are no non-invasive methods to reliably detect elevated transpulmonary driving pressure and elevated respiratory muscle effort during assisted ventilation. We hypothesized that the swing in airway pressure generated by respiratory muscle effort under assisted ventilation when the airway is briefly occluded (?Pocc) could be used as a highly feasible non-invasive technique to screen for these conditions. METHODS:Respiratory muscle pressure (Pmus), dynamic transpulmonary driving pressure (?PL,dyn, the difference between peak and end-expiratory transpulmonary pressure), and ?Pocc were measured daily in mechanically ventilated patients in two ICUs in Toronto, Canada. A conversion factor to predict ?PL,dyn and Pmus from ?Pocc was derived and validated using cross-validation. External validity was assessed in an independent cohort (Nanjing, China). RESULTS:Fifty-two daily recordings were collected in 16 patients. In this sample, Pmus and ?PL were frequently excessively high: Pmus exceeded 10?cm H2O on 84% of study days and ?PL,dyn exceeded 15?cm H2O on 53% of study days. ?Pocc measurements accurately detected Pmus >?10?cm H2O (AUROC 0.92, 95% CI 0.83-0.97) and ?PL,dyn?>?15?cm H2O (AUROC 0.93, 95% CI 0.86-0.99). In the external validation cohort (n?=?12), estimating Pmus and ?PL,dyn from ?Pocc measurements detected excessively high Pmus and ?PL,dyn with similar accuracy (AUROC ??0.94). CONCLUSIONS:Measuring ?Pocc enables accurate non-invasive detection of elevated respiratory muscle pressure and transpulmonary driving pressure. Excessive respiratory effort and transpulmonary driving pressure may be frequent in spontaneously breathing ventilated patients.

SUBMITTER: Bertoni M 

PROVIDER: S-EPMC6836358 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature