Bronchopulmonary dysplasia: clinical grading in relation to ventilation/perfusion mismatch measured by single photon emission computed tomography.
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.
Department of Woman and Child Health, Karolinska Institute, Stockholm, Sweden; Department of Neonatology, Karolinska University Hospital, Stockholm, Sweden.
Malin
M
Kjellberg
Karin
K
Björkman
Malin
M
Rohdin
Alejandro
A
Sanchez-Crespo
Baldvin
B
Jonsson
D001997:Bronchopulmonary Dysplasia / Q000000981:diagnostic imaging*; D015331:Cohort Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D007223:Infant; D062071:Infant, Extremely Premature; D007231:Infant, Newborn; D007234:Infant, Premature; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D012720:Severity of Illness Index; D013670:Sodium Pertechnetate Tc 99m; D015899:Tomography, Emission-Computed, Single-Photon; D014692:Ventilation-Perfusion Ratio
C056708:Technegas; D013670:Sodium Pertechnetate Tc 99m
BPD; SPECT; V/Q; bronchopulmonary dysplasia; clinical grading; lung function; perfusion; preterm; ventilation