Lung and diaphragm ultrasound as predictors of successful weaning from nasal continuous positive airway pressure in preterm infants.

OBJECTIVE: Assessment of the utility of lung and diaphragm ultrasound in the prediction of successful weaning from nasal continuous positive airway pressure (NCPAP) in preterm infants. STUDY DESIGN: This prospective cohort study was conducted on preterm infants who were considered ready for weaning off NCPAP. Lung and diaphragm ultrasound were performed just before and 3 h after weaning off NCPAP. The primary outcome was to evaluate the accuracy of lung ultrasound (LUS) in predicting successful weaning from NCPAP. RESULTS: Out of 65 enrolled preterm infants, 30 (46.2%) were successfully weaned from NCPAP to room air. The successful weaning group had higher gestational ages, lower incidences of previous invasive mechanical ventilation, and treated hemodynamically significant patent ductus arteriosus before the trial weaning. A LUS score of ≤6, measured before discontinuation of NCPAP, exhibited a predictive sensitivity of 80% and specificity of 75% for successful weaning (Area under the curve (AUC) = 0.865, ≤.001). When the LUS score was assessed 3 h after weaning from NCPAP, a cutoff point of ≤7 predicted successful weaning with a sensitivity and specificity of 90% and 60% respectively (AUC = 0.838, p ≤ .001). The diaphragmatic thickness fraction (DTF) was significantly lower in the successful weaning group. After adjustment for various factors, LUS score remained the only independent predictor of successful weaning. CONCLUSION: LUS score before weaning from NCPAP has a good sensitivity and specificity for predicting successful weaning from NCPAP in preterm infants. Diaphragmatic excursion and DTF were not good predictors.

Study of platelet activation, hypercoagulable state, and the association with pulmonary hypertension in children with ß-thalassemia.

BACKGROUND: The increased survival rate of thalassemic patients has led to unmasking of management related complications which were infrequently encountered. OBJECTIVE: Study the increased coagulation and platelet activation in children with ß-thalassemia, to analyze the factors that lead to such hypercoagulable state and to study pulmonary hypertension (PH) in conjunction with platelet activation and hypercoagulable state in children with ß-thalassemia. METHODS: 36 Egyptian children with ß-thalassemia with a mean age of 9.9years (±4.7 SD). In addition, 20 healthy Egyptian children matched for age and sex were enrolled as a control group. Both were subjected to clinical and laboratory assessments. Echocardiography was done to the patient group and PH was diagnosed based on calculated mean pulmonary artery pressure [MPAP] >25mmHg. RESULTS: We found that, mean±SD serum P-selectin level (platelet activator marker) was significantly higher in thalassemic patients (2337±566pg/ml) in comparison to controls (1467±247pg/ml) (P<0.001). Mean serum protein-C and antithrombin-III levels were significantly lower in thalassemic patients (1.2±1.3µg/ml, 27.3±7.5mg/dl) in comparison to controls (2.3±1.3µg/ml, 35.1±4.1mg/dl) (P=0.003 and <0.001) respectively. PH was detected in 17 (47.2%) patients and it was significantly associated with splenectomy (P=0.01) and non-transfusion dependent thalassemia (NTDT) (P=0.04). PH was positively correlated with serum levels of P-selectin (r=0.38, P=0.02), fibrinogen (r=0.41, P=0.01) and negatively correlated with serum protein-C level (r=-0.48, P=0.003). CONCLUSION: A chronic hypercoagulable state and platelet activation is present in children with ß-thalassemia. Splenectomy and transfusion infrequency are the main risk factors noted to be associated with such hypercoagulable state and platelet activation and consequently the PH among our thalassemic patients.