Lung Ultrasonography in Diagnosis of Transient Tachypnea of the Newborn: Limitations and Pitfalls

Recent Advances in Pathophysiology and Management of Transient Tachypnea of Newborn

Transient tachypnea of newborn (TTN) results from failure of the newborn to effectively clear the fetal lung fluid soon after birth. TTN represents the most common etiology of respiratory distress in term gestation newborns and sometimes requires admission to the neonatal intensive care unit. TTN can lead to maternal-infant separation, the need for respiratory support, extended unnecessary exposure to antibiotics and prolonged hospital stays. Recent evidence also suggests that TTN may be associated with wheezing syndromes later in childhood. New imaging modalities such as lung ultrasound can help in the diagnosis of TTN and early management with distending pressure using continuous positive airway pressure may prevent exacerbation of respiratory distress.

Assessment of thoracic ultrasound in complementary diagnosis and in follow up of community-acquired pneumonia (cap)

Background

Chest X-ray (CXR) is the primary diagnostic tool for community-acquired pneumonia (CAP). Some authors recently proposed that thoracic ultrasound (TUS) could valuably flank or even reliably substitute CXR in the diagnosis and follow-up of CAP. We investigated the clinical utility of TUS in a large sample of patients with CAP, to challenge the hypothesis that it may be a substitute for CXR.

Methods

Out of 645 consecutive patients with a CXR-confirmed CAP diagnosed in the emergency room of our hospital over a three-years period, 510 were subsequently admitted to our department of Internal Medicine. These patients were evaluated by TUS by a well-trained operator who was blinded of the initial diagnosis. TUS scans were performed both at admission and repeated at day 4-6th and 9-14th during stay.

Results

TUS identified 375/510 (73.5%) of CXR-confirmed lesions, mostly located in posterior-basal or mid-thoracic areas of the lungs. Pleural effusion was detected in 26.9% of patients by CXR and in 30.4% by TUS. TUS documented the change in size of the consolidated areas as follows: 6.3 ± 3.4 cm at time 0, 2.5 ± 1.8 at 4-6 d, 0.9 ± 1.4 at 9-14 d. Out of the 12 patients with delayed CAP healing, 7 of them turned out to have lung cancer.

Conclusions

TUS allowed to detect lung consolidations in over 70% of patients with CXR-confirmed CAP, but it gave false negative results in 26.5% of cases. Our longitudinal results confirm the role of TUS in the follow-up of detectable lesions. Thus, TUS should be regarded as a complementary and monitoring tool in pneumonia, instead of a primary imaging modality.