Lung Ultrasound Signs to Diagnose and Discriminate Interstitial Syndromes in ICU Patients: A Diagnostic Accuracy Study in Two Cohorts

Micah L A Heldeweg*, Marry R Smit, Shelley R Kramer-Elliott, Mark E Haaksma, Jasper M Smit, Laura A Hagens, Nanon F L Heijnen, Annemijn H Jonkman, Frederique Paulus, Marcus J Schultz, Armand R J Girbes, Leo M A Heunks, Lieuwe D J Bos, Pieter R Tuinman

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

5 Citations (Web of Science)


OBJECTIVES: To determine the diagnostic accuracy of lung ultrasound signs for both the diagnosis of interstitial syndrome and for the discrimination of noncardiogenic interstitial syndrome (NCIS) from cardiogenic pulmonary edema (CPE) in a mixed ICU population.

DESIGN: A prospective diagnostic accuracy study with derivation and validation cohorts.

SETTING: Three academic mixed ICUs in the Netherlands.

PATIENTS: Consecutive adult ICU patients that received a lung ultrasound examination.


MEASUREMENTS AND MAIN RESULT: The reference standard was the diagnosis of interstitial syndrome (NCIS or CPE) or noninterstitial syndromes (other pulmonary diagnoses and no pulmonary diagnoses) based on full post-hoc clinical chart review except lung ultrasound. The index test was a lung ultrasound examination performed and scored by a researcher blinded to clinical information. A total of 101 patients were included in the derivation and 122 in validation cohort. In the derivation cohort, patients with interstitial syndrome (n = 56) were reliably discriminated from other patients based on the presence of a B-pattern (defined as greater than or equal to 3 B-lines in one frame) with an accuracy of 94.7% (sensitivity, 90.9%; specificity, 91.1%). For discrimination of NCIS (n = 29) from CPE (n = 27), the presence of bilateral pleural line abnormalities (at least two: fragmented, thickened or irregular) had the highest diagnostic accuracy (94.6%; sensitivity, 89.3%; specificity, 100%). A diagnostic algorithm (Bedside Lung Ultrasound for Interstitial Syndrome Hierarchy protocol) using B-pattern and bilateral pleural abnormalities had an accuracy of 0.86 (95% CI, 0.77-0.95) for diagnosis and discrimination of interstitial syndromes. In the validation cohort, which included 122 patients with interstitial syndrome, bilateral pleural line abnormalities discriminated NCIS (n = 98) from CPE (n = 24) with a sensitivity of 31% (95% CI, 21-40%) and a specificity of 100% (95% CI, 86-100%).

CONCLUSIONS: Lung ultrasound can diagnose and discriminate interstitial syndromes in ICU patients with moderate-to-good accuracy. Pleural line abnormalities are highly specific for NCIS, but sensitivity is limited.

Original languageEnglish
Pages (from-to)1607-1617
JournalCritical Care Medicine
Issue number11
Early online date22 Jul 2022
Publication statusPublished - Nov 2022

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