Prediction of Extubation Readiness Using Transthoracic Ultrasound in Preterm Infants

ABSTRACT Objective To test the hypothesis that a lung ultrasound severity score (LUSsc) and assessment of left ventricular eccentricity index of the interventricular septum (LVEI) by focused heart ultrasound can predict extubation success in mechanically ventilated preterm infants with respiratory distress syndrome (RDS). Design Prospective observational study of premature infants <34 weeks’ of gestation age supported with mechanical ventilation due to RDS. LUSsc and LVEI were performed on postnatal days 3 and 7 by an investigator who was masked to infants’ ventilator parameters and clinical conditions. RDS was classified based on LUSsc into mild (score 0–9) and moderate-severe (score 10–18). A receiver operator curve was constructed to assess the ability to predict extubation success. Pearson’s correlation was performed between LVEI and pulmonary artery pressure (PAP). Setting Level III neonatal intensive care unit, Cairo, Egypt. Results A total of 104 studies were performed to 66 infants; of them 39 had mild RDS (LUSsc 0–9) and 65 had moderate-severe RDS (score ≥10). LUSsc predicted extubation success with a sensitivity and a specificity of 91% and 69%; the positive and negative predictive values were 61% and 94%, respectively. Area under the curve (AUC) was 0.83 (CI: 0.75-0.91). LVEI did not differ between infants that succeeded and failed extubation. However, it correlated with pulmonary artery pressure during both systole (r=0.62) and diastole (r=0.53) and with hemodynamically significant patent ductus arteriosus (r=0.27 and r=0.46, respectively). Conclusion LUSsc predicts extubation success in preterm infants with RDS whereas LVEI correlates with high PAP.