Lung ultrasound for the diagnosis of weaning-induced pulmonary oedema
Weaning-Induced Pulmonary Oedema (WIPO) is a common cause of failure of weaning from mechanical ventilation. The change in heart-lung interactions during Spontaneous Breathing Trials (SBT) can lead to WIPO, which can be detected by pulmonary artery occlusion pressure, left ventricular filling pressure, or extravascular lung water. Detection of multiple B lines by lung ultrasound may used to detect WIPO.
To test this hypothesis, a mixed population of ICU patients was enrolled. B-lines were counted in a rib short-axis scan at four points on the anterior chest. WIPO was diagnosed a posteriori by two experts using several criteria.
43 patients were included in the cohort, who had 27% WIPO overall and 52% WIPO in patients with failed SBT. The best accuracy to diagnose WIPO was reached when delta B lines were ≥6, with 88% sensitivity and 91% specificity, and with 79% of PPV. Accuracy was similar when considering only failed SBT trials.
The authors conclude that WIPO has a high incidence in mixed population of ICU patients, and that lung ultrasound may be used to diagnose WIPO with high accuracy using a cut-off of ≥6 B-lines counted on the anterior chest.
STUDY STRENGTHS & LIMITATIONS
Study strength: the study demonstrates how a threshold of six B-lines measured on the anterior chest may be used to detect WIPO.
Study limitation: WIPO reference diagnosis was established a posteriori by two experts, following several criteria.
TAKE HOME MESSAGE
WIPO is a frequent complication of weaning from mechanical ventilation.
Lung Ultrasound may be used to detect WIPO with high accuracy, when the number of B-lines on the anterior chest increases by ≥6.
This article review was prepared and submitted by Massimiliano Greco, on behalf of the EJRC.
1) Ferré A, Guillot M, Lichtenstein D, Mezière G, Richard C, Teboul JL, Monnet X, Lung ultrasound allows the diagnosis of weaning-induced pulmonary oedema. Intensive Care Med. 2019 May;45(5):601-608. doi: 10.1007/s00134-019-05573-6. Epub 2019 Mar 12. PubMed PMID: 30863935.