Continuous monitoring of intrinsic PEEP based on expired CO₂ kinetics: an experimental validation study.

ABSTRACT:

Background

Quantification of intrinsic PEEP (PEEPi) has important implications for patients subjected to invasive mechanical ventilation. A new non-invasive breath-by-breath method (etCO₂D) for determination of PEEPi is evaluated.

Methods

In 12 mechanically ventilated pigs, dynamic hyperinflation was induced by interposing a resistance in the endotracheal tube. Airway pressure, flow, and exhaled CO₂ were measured at the airway opening. Combining different I:E ratios, respiratory rates, and tidal volumes, 52 different levels of PEEPi (range 1.8-11.7 cmH₂O; mean 8.45?±?0.32 cmH₂O) were studied. The etCO₂D is based on the detection of the end-tidal dilution of the capnogram. This is measured at the airway opening by means of a CO₂ sensor in which a 2-mm leak is added to the sensing chamber. This allows to detect a capnogram dilution with fresh air when the pressure coming from the ventilator exceeds the PEEPi. This method was compared with the occlusion method.

Results

The etCO₂D method detected PEEPi step changes of 0.2 cmH₂O. Reference and etCO₂D PEEPi presented a good correlation (R² 0.80, P?ConclusionsThe etCO₂D method is a promising accurate simple way of continuously measure and monitor PEEPi. Its clinical validity needs, however, to be confirmed in clinical studies and in conditions with heterogeneous lung diseases.

SUBMITTER: Heili-Frades S 

PROVIDER: S-EPMC6540388 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature