Abstract
Background: Presence of a hemodynamically significant ductus arteriosus is common in preterm infants and left atria enlargement is used as a surrogate marker. Cardiothoracic ratio may not be a reliable indicator of left atria enlargement given its posterior location.
Aims: To assess the ability of angle of naso-gastric tube deviation to discriminate between babies with and without a hemodynamically significant ductus arteriosus.
Methodology and data analysis: Retrospective chart review and radiographic measurements of frontal chest radiographs for babies with hemodynamically significant ductus arteriosus that was proven by echocardiography (ECHO) (Group I) compared with individually matched babies with no hemodynamically significant ductus arteriosus matching on corrected gestation age. Unrotated frontal chest radiographs done within 72 hours of echo and gestational age matched frontal chest radiographs for Control (Group II) were assessed for measurements of angle of naso-gastric tube deviation and carinal angle by digital imaging technique.
Results: A total of 32 babies were enrolled in each group. Mean naso-gastric tube angle was significantly greater in babies from group I, with average difference 4.5° (95% CI 3° to 6°. Angle greater than 9° increased the odds of being a Group I baby (Odds ratio 25.9, 95% CI 3.4–198).
Conclusions: Measurement of naso-gastric tube angle deviation may be helpful in babies with hemodynamically significant ductus arteriosus and left heart volume overload.