Ultrasound of pneumothorax in neonates: Diagnostic value of the anterior transverse plane and of mirrored ribs.

INTRODUCTION: Point-of-care lung ultrasound is increasingly used to diagnose pneumothorax efficiently and safely in neonates. OBJECTIVES: This study aimed to evaluate the usefulness of the central and anterior transverse thoracic plane in the ultrasound diagnosis of pneumothorax, analyze the diagnostic value of the "mirrored ribs" sign, and evaluate the predictive value of the lung point location for the need of pleural drainage. METHODS: Retrospective cohort study of all newborns admitted to the neonatal intensive care unit of the Basurto University Hospital (Bilbao, Spain) due to respiratory distress and with ultrasound, with or without pneumothorax, between January 2014 and December 2020. RESULTS: The presence of A-lines behind the sternum in the anterior transverse plane in newborns with pneumothorax (N = 311) and controls (N = 195) was compared. A-lines were present in 98.9% of newborns with pneumothorax compared to none in the controls (p < .0001). Diagnosis of pneumothorax with the anterior transverse plane presented high interobserver reproducibility (κ = 0.92, 95% confidence interval: 0.84-1.00). In contrast, the "mirrored ribs" sign in the anterior longitudinal plane was observed in 35.6% of patients with pneumothorax and in 36.9% of controls (p = .1505). A significant association was observed between lung point location and the need for pleural drainage (p < .0001). CONCLUSIONS: A-lines in the anterior transverse plane is a simple ultrasound sign which presents high sensitivity, specificity, and reproducibility for the diagnosis of pneumothorax. The mirrored ribs sign showed low diagnostic utility. Patients with severe pneumothorax in lung ultrasound are most likely to require thoracic drainage.

The Predictive Value of Lung Ultrasound Scores in Developing Bronchopulmonary Dysplasia: A Prospective Multicenter Diagnostic Accuracy Study.

BACKGROUND: Different lung ultrasound (LUS) scanning protocols have been used, and the results in terms of diagnostic accuracy are heterogeneous. RESEARCH QUESTIONS: What is the diagnostic accuracy of the LUS score to predict moderate to severe bronchopulmonary dysplasia (msBPD)? Does scanning of posterior lung fields improve the diagnostic accuracy? STUDY DESIGN AND METHODS: This was a multicenter prospective, observational study in six centers. Two LUS aeration scores, one involving only anterolateral lung fields and the other adding the posterior fields were obtained at birth, on the third day of life (DOL), on the seventh DOL, on the 14th DOL, and on the 21st DOL. The diagnostic accuracy of both scores to predict msBPD was assessed at each time point. RESULTS: Eight hundred thirty-two LUS examinations in 298 infants were included. Both LUS score using anterolateral and posterior fields and LUS score using only anterolateral fields showed a similar moderate diagnostic accuracy to predict msBPD on the third DOL (area under the receiver operating characteristic curve [AUC] 95% CI, 0.68-0.85 vs 0.68-0.85; P = .97), seventh DOL (AUC 95% CI, 0.74-0.85 vs 0.74-0.84; P = .26), and 21st DOL (AUC 95% CI, 0.72-0.86 vs 0.74-0.88; P = .17). The LUS score using anterolateral and posterior fields was slightly more accurate at 14th DOL (AUC 95% CI, 0.69-0.83 vs 0.66-0.80; P = .01). A cutoff of 8 points in the LUS score using only anterolateral fields on the seventh DOL provided a sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of 70%, 79%, 3.3, and 0.38, respectively, to predict msBPD. Adding gestational age (GA) and sex improved the discriminative value without significant differences compared with a predictive model based on multiple clinical variables: AUC 95% CI, 0.77-0.88 vs 0.80-0.91 (P = .52). INTERPRETATION: The LUS score is able to predict msBPD from the third DOL with a moderate diagnostic accuracy. Scanning posterior lung fields slightly improved diagnostic accuracy only at the 14th DOL. Adding GA and sex improves the diagnostic accuracy of the LUS scores. The LUS score is useful to stratify BPD risk early after birth.