Respiratory- and voice symptoms among extremely preterm born children with prolonged ventilator dependency

Introduction: Extremely preterm born (EPB) infants are prone to a patent ductus arteriosus (PDA), and these infants often need prolonged invasive ventilation (IV), both of which might influence laryngeal function leading to abnormal voice characteristics and/or respiratory symptoms. Aim: Study associations between days on invasive ventilation, PDA surgery and voice/respiratory related symptoms in EPB children. Method: We surveyed a national cohort of 372 EPB children at 11 years of age. Parents of 91/143 children with PDA responded, 35 of them had undergone PDA surgery. The questions were based on the International Study of Asthma and Allergies in Childhood (ISAAC) and the Voice Handicap Index questionnaires with outcomes assessed using logistic regression, reporting odds ratios (95% confidence intervals). Result: Days on IV was associated with increased OR of a voice that is hoarse OR 1.11 (1.05-1.18), weak OR 1.05 (1.01-1.09), cracks when shouting OR 1.06 (1.02-1.10), influences singing OR 1.06 (1.02-1.11) and influences social participation OR 1.04 (1.01-1.08). Days on IV was also associated with breathing problems and grinding sound during physical exertion, both OR 1.05 (1.01-1.09), but not with wheeze during or after physical activity OR 1.01 (0.98-1.05). Adjusted for PDA surgery, OR for all variables except “weak voice” and “influences social participation” was reduced, but still associated with days on IV. Conclusion: Days on IV was associated with increased odds of voice/respiratory related symptoms in 11 years old EPB children. PDA surgery influenced most of the associations, suggesting causal factors also related to PDA surgery.