title: Correlation of radiographic thoracic area and oxygenation impairment in bronchopulmonary dysplasia.
abstract: We hypothesized that radiographically-assessed hyperinflation in bronchopulmonary dysplasia (BPD) is related to the degree of oxygenation impairment. Our objective was to explore the relation of chest radiographic thoracic area (CRTA) with right-to-left shunt, right shift of the oxyhemoglobin dissociation curve and ventilation/perfusion ratio (VA/Q) in infants with BPD. Twenty-two infants born at median (IQR) gestation of 26 (24-28) weeks with BPD were prospectively studied at 39 (30-69) days. Inspired oxygen (FiO2) was varied to obtain transcutaneous oxygen saturation (SpO2) values between 85 and 96%. Shunt, shift and VA/Q were derived by plotting and analysing pairs of SpO2 and FiO2. CRTA was measured by free hand-tracing the perimeter of the thoracic area in anterio-posterior chest radiographs. Median (IQR) shunt was 8 (1-14)%, shift was 13 (11-19)kPa and VA/Q 0.42 (0.30-0.48). Median (IQR) CRTA/kg was 2495 (1962-2838)mm(2) and was significantly related to shift (r=0.674, p<0.001), VA/Q (r=-0.633, p<0.001), weight at study (r=-0.457, p=0.003) and day of life (r=-0.406, p=0.009), but not to shunt. CRTA in BPD is significantly related to oxygenation impairment as quantified by shift and VA/Q. CRTA can be used as a simple radiographic test to quantify BPD severity.
authors.affiliation: Department of Obstetrics and Gynaecology, University of Cambridge, Cambridge, UK; Neonatal Intensive Care Unit, Cambridge University Hospitals, Cambridge, UK. Electronic address: theodore.dassios@kcl.ac.uk.
authors.forename: Theodore
authors.initials: T
authors.lastname: Dassios
authors.affiliation: Neonatal Intensive Care Unit, Cambridge University Hospitals, Cambridge, UK.
authors.forename: Anna
authors.initials: A
authors.lastname: Curley
authors.affiliation: Department of Radiology, Cambridge University Hospitals, Cambridge, UK.
authors.forename: Miltiadis
authors.initials: M
authors.lastname: Krokidis
authors.affiliation: Department of Obstetrics and Gynaecology, University of Cambridge, Cambridge, UK.
authors.forename: Colin
authors.initials: C
authors.lastname: Morley
authors.affiliation: Department of Paediatrics, Cambridge University Hospitals, Cambridge, UK.
authors.forename: Robert
authors.initials: R
authors.lastname: Ross-Russell
mesh_terms: D001997:Bronchopulmonary Dysplasia / Q000150:complications / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000150:complications / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D007091:Image Processing, Computer-Assisted; D007223:Infant; D062071:Infant, Extremely Premature; D007231:Infant, Newborn; D008297:Male; D010100:Oxygen / Q000378:metabolism; D011446:Prospective Studies; D013902:Radiography, Thoracic; D012119:Respiration; D012720:Severity of Illness Index
chemical_list: D010100:Oxygen
keywords: Bronchopulmonary dysplasia; Chest radiograph; Shift; Shunt; Ventilation/perfusion ratio