Assessment of diaphragmatic dysfunction in the critically ill patient with ultrasound: a systematic review.
OBJECTIVE
Diaphragmatic dysfunction (DD) has a high incidence in critically ill patients and is an under-recognized cause of respiratory failure and prolonged weaning from mechanical ventilation. Among different methods to assess diaphragmatic function, diaphragm ultrasonography (DU) is noninvasive, rapid, and easy to perform at the bedside. We systematically reviewed the current literature assessing the usefulness and accuracy of DU in intensive care unit (ICU) patients.


METHODS
Pubmed, Cochrane Database of Systematic Reviews, Embase, Scopus, and Google Scholar Databases were searched for pertinent studies. We included all original, peer-reviewed studies about the use of DU in ICU patients.


RESULTS
Twenty studies including 875 patients were included in the final analysis. DU was performed with different techniques to measure diaphragmatic inspiratory excursion, thickness of diaphragm (Tdi), and thickening fraction (TF). DU is feasible, highly reproducible, and allows one to detect diaphragmatic dysfunction in critically ill patients. During weaning from mechanical ventilation and spontaneous breathing trials, both diaphragmatic excursion and diaphragmatic thickening measurements have been used to predict extubation success or failure. Optimal cutoffs ranged from 10 to 14 mm for excursion and 30-36 % for thickening fraction. During assisted mechanical ventilation, diaphragmatic thickening has been found to be an accurate index of respiratory muscles workload. Observational studies suggest DU as a reliable method to assess diaphragm atrophy in patients undergoing mechanical ventilation.


CONCLUSIONS
Current literature suggests that DU could be a useful and accurate tool to detect diaphragmatic dysfunction in critically ill patients, to predict extubation success or failure, to monitor respiratory workload, and to assess atrophy in patients who are mechanically ventilated.
Department of Anesthesia and Intensive Care, ASST Melegnano-Martesana, Presidio di Cernusco sul Naviglio, Via Uboldo 21, 20063, Cernusco sul Naviglio, MI, Italy. massimo.zambon@asst-melegnano-martesana.it.
Massimo
M
Zambon
Department of Anesthesia and Intensive Care, San Raffaele Scientific Institute, Via Olgettina 60, 20132, Milan, Italy.
Massimiliano
M
Greco
Department of Anesthesia and Intensive Care, San Raffaele Scientific Institute, Via Olgettina 60, 20132, Milan, Italy.
Speranza
S
Bocchino
Department of Anesthesia and Intensive Care, San Raffaele Scientific Institute, Via Olgettina 60, 20132, Milan, Italy.
Luca
L
Cabrini
Department of Anesthesia and Intensive Care, San Raffaele Scientific Institute, Via Olgettina 60, 20132, Milan, Italy.
Paolo Federico
PF
Beccaria
Department of Anesthesia and Intensive Care, San Raffaele Scientific Institute, Via Olgettina 60, 20132, Milan, Italy.|Università Vita-Salute San Raffaele, Milan, Italy.
Alberto
A
Zangrillo
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003422:Critical Care / Q000379:methods*; D016638:Critical Illness; D003964:Diaphragm / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012131:Respiratory Insufficiency / Q000175:diagnosis* / Q000628:therapy*
Critically ill; Diaphragm; Diaphragmatic dysfunction; Respiratory monitoring; Thoracic ultrasound; Ultrasonography