Closure of patent ductus arteriosus and respiratory function changes in ventilated preterm infants

BACKGROUND: Active treatment of a haemodynamically significant patent ductus arteriosus (PDA) can be undertaken either pharmacologically or surgically. The effect of PDA treatment on respiratory function and ventilation parameters has not been adequately described. We aimed to report respiratory function changes following PDA treatment using composite respiratory physiological indices. METHODS: /Q), right-to-left shunt and arterial to end tidal carbon dioxide gradient were calculated before and after successful pharmacological or surgical treatment of PDA. RESULTS: /Q and shunt significantly decreased post-treatment compared to pre-treatment [0.27 (0.17 - 0.43) versus 0.40 (0.26 - 0.57), p = 0.034 and 0 (0 - 3) % versus 5 (1 - 11) % respectively]. The carbon dioxide gradient was not significantly different post-treatment compared to pre-treatment. CONCLUSION: PDA treatment in ventilated preterm infants was associated with an increase in the oxygen requirement during ventilation, a worsening of the ventilation to perfusion matching while it had a positive effect in reducing the level of the intrapulmonary right-to-left shunting.