Abstract
Background: Mechanical insufflation-exsufflation (MI-E) applied through the endotracheal tube (ETT) can effectively eliminate airway secretions in intubated patients. However, the effect of the interface (ETT vs. facemask) on expiratory airflow generated by MI-E has not been investigated. This study aimed to investigate the effect of the ETT on peak expiratory flow (PEF), along with other associated factors that could influence PEF generated by MI-E.
Methods: Intubated participants received two sessions of MI-E via ETT therapy per day for two consecutive days. One MI-E session consisted of five sets of either constant (+40/-40 cmH2O) or incremental (+30/-30 to +50/-50 cmH2O) pressure applications. Following extubation, MI-E sessions were repeated using facemask. Expiratory airflow during MI-E therapy was continuously measured and every PEF during each application was analysed using linear mixed-effect and generalised linear mixed models.
Results: A total of 12 participants (nine [75.0%] men; mean [SD] age, 74.0 [10.2] years) completed all MI-E sessions with both ETT and facemask interfaces. The PEF generated during MI-E treatment was influenced by the interface (ETT vs. facemask), pressure gradient, and number of session repetitions. Adjusted mean PEF values for MI-E via ETT and facemask at +40/-40 cmH2O were -2.521 and -3.114 L/s, respectively, and -2.956 and -3.364 L/s at +50/-50 cmH2O, respectively. At a pressure gradient of +40/-40 cmH2O, only 172 of 528 MI-E trials via ETT (32.6%) achieved a PEF faster than -2.7 L/s, whereas 304 of 343 MI-E trials via facemask (88.6%) exceeded PEF < -2.7L/s.
Conclusions: MI-E via ETT generated slower PEF than via facemask, suggesting that a higher-pressure protocol should be prescribed for intubated patients. An insufflation-exsufflation pressure up to +50/-50 cmH2O could be considered to produce a PEF faster than 2.7 L/s, and the applications were safe and feasible for patients under invasive mechanical ventilation.
- mechanical insufflation-exsufflation
- cough assist
- expiratory flow
- endotracheal tube
- mechanical ventilation
- respiratory therapy
Footnotes
- Corresponding author: Hyung-Ik Shin, Department of Rehabilitation Medicine, Seoul National University College of Medicine, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul 03080, Republic of Korea, E-mail: hyungik1{at}snu.ac.kr, Tel: +82-2-2072-3218, Fax: +82-2-743-7478
- Received March 30, 2021.
- Accepted July 3, 2021.
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