Practical application of lung ultrasound during discharge echocardiography to predict outpatient effusions after septal defect and Fontan surgery.

INTRODUCTION

Lung ultrasound findings in cardiac patients correlate with mortality, hospital length of stay, and rehospitalisation after surgery. We report a lung ultrasound protocol integrated with echocardiography and its ability to predict adverse events in children after discharge following congenital heart surgery.

METHODS

A prospective, single-blinded observational trial was performed. Subjects were consecutively identified after Fontan or septal defect repairs. Performed by cardiac sonographers at discharge, lung ultrasound scores were based on the number of B-lines. The primary outcome was subsequent development of new pericardial (≥small) or pleural (>small) effusion.

RESULTS

A total of 86 subjects were identified with adequate imaging for enrolment. Median age was 53 months. Procedures included Fontan (n = 23) and atrial (n = 30), ventricular (n = 28), and atrioventricular (n = 5) septal defect repairs. Lung ultrasound score was correlated with hospital length of stay (ρ = 0.29, p = 0.0066), discharge diuretic score (ρ = 0.38, p < 0.001), and chest tube duration (ρ = 0.25, p = 0.021); score was not correlated with age or weight. Primary outcome occurred in 12 subjects (atrial septal defect = 4, Fontan = 8). A lung ultrasound score ≥3 had a negative predictive value of 93% and an odds ratio of 24.5 (95%CI 5.3-113, p < 0.0001) for the primary outcome. Subjects following Fontan with the lung ultrasound score ≥3 had an odds ratio of 8.3 (95%CI 1.2-59.0, p < 0.036).

CONCLUSIONS

Our results suggest that lung ultrasound during discharge echocardiography has encouraging prognostic value for post-operative complications in patients deemed suitable for discharge after congenital heart surgery. Further research is needed to discern how lung ultrasound can be used for goal-directed medical therapy.