Bronchopulmonary dysplasia: Clinical grading in relation to ventilation/perfusion mismatch measured by single photon emission computed tomography

Abstract

Bronchopulmonary dysplasia (BPD) is a significant cause of morbidity in the preterm population. Clinical severity grading based on the need for supplemental oxygen and/or need for positive airway pressure at 36 weeks postmenstrual age does not yield reproducible predictive values for later pulmonary morbidity. Single photon emission computed tomography (SPECT) was used to measure the distribution of lung ventilation (V) and perfusion (Q) in 30 BPD preterm infants at a median age of 37 weeks postmenstrual age. The V and Q were traced with 5 MBq Technegas and Technetium-labeled albumin macro aggregates, respectively, and the V/Q match-mismatch was used to quantify the extent of lung function impairment. The latter was then compared with the clinical severity grading at 36 weeks, and time spent on mechanical ventilation, continuous positive airway pressure (CPAP) and supplemental oxygen. Of those with mild and moderate BPD 3/9 and 3/11 patients, respectively, showed significant V/Q mismatches. By contrast, 4/10 patients with severe BPD showed a satisfactory V/Q matching distribution. An unsatisfactory V/Q match was not correlated with time spent on supplemental oxygen or CPAP, but was significantly negatively correlated with time spent on mechanical ventilation. SPECT provides unique additional information about regional lung function. The results suggest that the current clinical severity grading can be improved and/or complemented with SPECT.

Ten‐year‐old children with a history of bronchopulmonary dysplasia have regional abnormalities in ventilation perfusion matching

“…It is characterized by alveolar growth inhibition resulting in a reduced alveolar surface area. We have previously shown that at 36 weeks’ postconceptional age, most of the infants with BPD had abnormalities in ventilation/perfusion (V/Q) matching . Recent evidence indicates that alveolar size and number increase during childhood and young adulthood, suggesting a potential for pulmonary recovery after the neonatal period in survivors with BPD .…”

Ventilation/perfusion distributions revisited

“…They also assessed the effects of inhaled anesthetic administration on these distributions during spontaneous breathing [12]. More recently, similar methods have been applied to assess bronchopulmonary dysplasia [13] and in a mouse model of cigarette exposure [14].…”

Newer Imaging Techniques for Bronchopulmonary Dysplasia

“…35,36 Fig. 4 is an example of a ventilation scan demonstrating uneven radiotracer distribution in the lungs of a 6-month-old BPD survivor.…”