Mechanical Power as a Marker for Risk of Weaning Failure Following Ventilation

Normalized mechanical power accurately predicted risk of weaning failure following prolonged mechanical ventilation, according to the results of a recent study published in BMC Pulmonary Medicine.

This prospective observational study examined associations between mechanical power (either absolute or normalized to dynamic lung-thorax compliance), and risk for weaning failure following prolonged mechanical ventilation. Mechanical power was determined both at the beginning and end of weaning.

Among the 130 prolonged mechanically ventilated, tracheotomized patients included in the study, 44 patients (33.8%) experienced weaning failure. Absolute mechanical power could not be used to accurately predict outcomes. However, normalized mechanical power had moderate diagnostic accuracy, with even more improvement when incorporating PaCO₂.

The study authors wrote, “In conclusion, mechanical power normalized to dynamic lung thorax compliance, a surrogate for the applied power per unit of ventilated lung volume, may serve as an estimate of the workload imposed on respiratory muscles during spontaneous breathing, thereby predicting patients’ ability to wean from prolonged tracheostomy ventilation.”

They added, “Future changes in clinical practice of tracheostomy weaning could involve weaning protocols including this new predictor in order to help clinicians in guiding the weaning process ([for example,] to control the degree of daily extension of spontaneous breathing), with the aim of reducing weaning duration.”

Reference

Ghiani A, Paderewska J, Walcher S, Neurohr C. Mechanical power normalized to lung-thorax compliance predicts prolonged ventilation weaning failure: a prospective study. BMC Pulm Med. 2021;21(1):202. Published online June 17, 2021. doi:10.1186/s12890-021-01566-8