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Expiratory flow limitation during mechanical ventilation: real-time detection and physiological subtypes
Detajin Junhasavasdikul1, Akarawut Kasemchaiyanun2,3, Tanakorn Tassaneyasin2
1Division of Pulmonary and Pulmonary Critical Care, Department of Medicine, Faculty of Medicine Ramathibodi Hospital, Mahidol University, 270 Rama 6 Rd. Rajthevi, Bangkok, Thailand. detajin@yahoo.com.
Critical Care (London, England)
|May 22, 2024
Summary
A new expiratory resistance (Rex) analysis method accurately detects tidal expiratory flow limitation (EFLT) during mechanical ventilation, agreeing with the PEEP reduction maneuver and identifying distinct EFLT subtypes.
Area of Science:
- Critical Care Medicine
- Respiratory Physiology
- Mechanical Ventilation
Background:
- Tidal expiratory flow limitation (EFLT) complicates mechanical ventilation and requires specific maneuvers for diagnosis.
- Instantaneous analysis of expiratory resistance (Rex) offers a potential method to detect EFLT without altering ventilator settings.
Purpose of the Study:
- To assess the agreement between EFLT detection using Rex analysis and the established PEEP reduction maneuver.
- To explore the patterns of expiratory resistance (Rex) and their association with EFLT.
Main Methods:
- A PEEP reduction maneuver was performed on 339 adult medical patients on mechanical ventilation to detect EFLT.
- Instantaneous expiratory resistance (Rex) was calculated and analyzed offline, validated on an independent dataset.
Main Results:
- The PEEP reduction maneuver identified EFLT in 16.5% of patients, who had higher mortality.
- The Rex method showed 90.3% agreement with the PEEP reduction maneuver in the primary dataset and 91.4% in the validation dataset.
- Three Rex patterns were identified, differentiating EFLT related to airway disease (early EFLT) from non-airway diseases like obesity (late EFLT).
Conclusions:
- The Rex method demonstrates excellent agreement with the PEEP reduction maneuver for detecting EFLT.
- Rex analysis enables real-time detection of EFLT and identifies two distinct subtypes of EFLT.
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