Kunal Babla1, Donovan Duffy1, Ramona Dumitru1, Justin Richards1, Anay Kulkarni2. 1. Neonatal Intensive Care Unit, St George's University Hospital NHS Trust, Blackshaw Road, London, SW17 0QT, UK. 2. Neonatal Intensive Care Unit, St George's University Hospital NHS Trust, Blackshaw Road, London, SW17 0QT, UK. Anay.Kulkarni@stgeorges.nhs.uk.
Abstract
Diameter of the patent ductus arteriosus (PDA) on transthoracic echocardiography (TTE) is used as a marker of haemodynamic significance. We aimed to assess the intra- and inter-observer variability in PDA diameter in babies born at ≤ 30 weeks' gestation. TTEs for 56 infants were performed by a single neonatologist. Cineloops were stored without measurement annotations. PDAs were measured on 2-dimensional (2D) and Colour Doppler. A second, blinded neonatologist repeated measurements on the same cineloops. The scanning neonatologist repeated measurements at a later date, blinded to original measurements. Inter-observer results showed repeatability coefficients of 1.57 (2D) and 2.18 (Colour), and repeatability index of 73% (2D) and 91% (Colour). Intra-observer results showed repeatability coefficients of 0.99 (2D) and 1.32 (Colour), and repeatability index of 43% (2D) and 49% (Colour). Conclusion: There is significant inter- and intra-observer variability in measurements of PDA diameter, even on the same cineloops. We advise caution when using diameter alone as a marker of haemodynamic significance, and recommend using multiple parameters to determine haemodynamic significance of PDA. What is Known: • PDA is associated with numerous comorbidities such as bronchopulmonary dysplasia, necrotising enterocolitis, intraventricular haemorrhage and mortality. • PDA diameter is commonly measured on transthoracic echocardiography and used as a marker of haemodynamic significance. • A previous, smaller study has shown there may be poor repeatability of PDA diameter measurements in serial echocardiograms. What is New: • There is significant inter-observer variability in 2D and Colour Doppler measurements of PDA internal diameter on TTE in preterm infants. • There is moderate intra-observer correlation of repeated measurements on the same imaging in both 2D and Colour Doppler imaging.
Diameter of the patent ductus arteriosus (PDA) on transthoracic echocardiography (TTE) is used as a marker of haemodynamic significance. We aimed to assess the intra- and inter-observer variability in PDA diameter in babies born at ≤ 30 weeks' gestation. TTEs for 56 infants were performed by a single neonatologist. Cineloops were stored without measurement annotations. PDAs were measured on 2-dimensional (2D) and Colour Doppler. A second, blinded neonatologist repeated measurements on the same cineloops. The scanning neonatologist repeated measurements at a later date, blinded to original measurements. Inter-observer results showed repeatability coefficients of 1.57 (2D) and 2.18 (Colour), and repeatability index of 73% (2D) and 91% (Colour). Intra-observer results showed repeatability coefficients of 0.99 (2D) and 1.32 (Colour), and repeatability index of 43% (2D) and 49% (Colour). Conclusion: There is significant inter- and intra-observer variability in measurements of PDA diameter, even on the same cineloops. We advise caution when using diameter alone as a marker of haemodynamic significance, and recommend using multiple parameters to determine haemodynamic significance of PDA. What is Known: • PDA is associated with numerous comorbidities such as bronchopulmonary dysplasia, necrotising enterocolitis, intraventricular haemorrhage and mortality. • PDA diameter is commonly measured on transthoracic echocardiography and used as a marker of haemodynamic significance. • A previous, smaller study has shown there may be poor repeatability of PDA diameter measurements in serial echocardiograms. What is New: • There is significant inter-observer variability in 2D and Colour Doppler measurements of PDA internal diameter on TTE in preterm infants. • There is moderate intra-observer correlation of repeated measurements on the same imaging in both 2D and Colour Doppler imaging.