Written by Chris Thom
Spoon Feed
Lung ultrasound has high accuracy in predicting extubation success in NICU patients undergoing invasive ventilation.
Ultrasound as a tool to prevent unsuccessful extubation
This was a prospective observational study of 92 neonates undergoing invasive ventilation for respiratory purposes. A trained investigator performed lung ultrasound (LUS) 30 minutes prior to extubation and then again 2 hours after extubation. A 12 zone LUS protocol was utilized and the images were reviewed offline by 2 neonatologists with extensive LUS experience. These neonatologists utilized a scoring system of 0 to 36 points based on the number of B-lines and/or consolidated lung per field. The treating NICU physician was blinded to the LUS findings and determined extubation based on usual care.
Seventy-four of the 92 neonates were extubated successfully, with 18 patients failing extubation. Using the ideal threshold score, the sensitivity of pre-extubation LUS to predict extubation failure was 83%, and specificity was 95%. The sensitivity of post-extubation LUS to predict extubation failure was 83%, and specificity was 97%. LUS performed slightly better in the > 28 week subcohort versus the < 28 week subcohort. A logistic regression analysis demonstrated that LUS maintained its predictive value even when accounting for the variables of gestational age, birth weight, and pCO2 after extubation.
How will this change my practice?
Point-of-care ultrasound is finding a growing role in neonatal intensive care, particularly with lung and vascular applications. This current study adds to the potential use cases for POCUS, alongside a growing body of literature that shows promise for the role of LUS in predicting surfactant need in neonates. Existing adult literature also supports the idea of LUS as an additional tool for predicting extubation success. LUS in neonates has the additional advantage of using objective scoring systems that provides an objective blueprint for the degree of fluid and consolidation in the lung tissue. A RCT comparing usual care to LUS guided care for neonatal ventilation weaning would be helpful at this stage.
Ultrasound acquisition pro-tips:
The authors here note the nuance and importance of a high-frequency ultrasound probe for this neonatal application. In adult medicine, a lower frequency probe can often be used for B-line identification and other LUS diagnostics. However, given the very superficial nature of the neonatal lung, the authors note that expert consensus recommends at least a 10 MHz probe for this application. Recognizing B-lines is easy to do, as one can look for the echogenic lines that reverberate posteriorly from the lung pleura to the bottom of ultrasound imaging screen. Increased fluid on neonatal lung can appear as consolidation and as “white lung”, wherein the B-lines become confluent. This suggests a higher degree of lung parenchymal fluid.
Source
Associations Between Quantitative Lung Ultrasound and Successful Extubation in Infants. J Ultrasound Med. 2025 Apr 26. doi: 10.1002/jum.16715. Epub ahead of print. PMID: 40285664
