Change in Diaphragmatic Thickness During the Respiratory Cycle Predicts Extubation Success at Various Levels of Pressure Support Ventilation.

Publication/Presentation Date

8-1-2016

Abstract

PURPOSE: Ultrasonographic assessment of diaphragm function with patients on low levels of pressure support (PS) predicts extubation outcomes, but similar information regarding extubation success under other conditions is lacking. The purpose of this study was to determine whether ultrasound (US) measurements of the diaphragm made on various levels of PS can predict time until successful extubation.

METHODS: Fifty-six intubated patients underwent ultrasound of the right hemidiaphragm during a PS wean at varying levels of pressure support (PS 5/5 cm of H2O, 10/5 cm of H2O, and 15/5 cm of H2O). The diaphragm was visualized using a 7.5-10 mHz transducer in the zone of apposition of the diaphragm to the lower rib cage. The percent change in diaphragm thickness between end-expiration and end-inspiration (∆tdi%) was calculated at each level of PS.

RESULTS: ∆tdi% >20 is a robust predictor of extubation success within 48 h of US at PS 5/5 cm of H2O and 10/5 cm of H2O (sensitivity 84.6 and 88.9 % and specificity 79.0 and 75.0 %, respectively). At PS greater than 10/5 cm of H2O, its predictive power was greatly diminished. Of nine patients who were extubated with ∆tdi% below the cutoff, 66.6 % required emergent reintubation in the next two days.

CONCLUSIONS: Diaphragm US is a valid predictor of extubation success at some but not all PS settings. Using a ∆tdi% of 20 % on PS levels up to 10/5 cm of H2O may reduce both unnecessarily prolonged intubations and prevent emergent reintubations.

Volume

194

Issue

4

First Page

519

Last Page

525

ISSN

1432-1750

Disciplines

Medicine and Health Sciences

PubMedID

27422706

Department(s)

Department of Medicine

Document Type

Article

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