Unilateral vocal cord paralysis following patent ductus arteriosus ligation in extremely low-birth-weight infants

Objective: To determine if unilateral vocal cord paralysis (UVCP) following patent ductus arteriosus (PDA) ligation is associated with respiratory and swallowing morbidities in extremely low-birth-weight (ELBW) infants. Design: Case-control study. Setting: Tertiary care neonatal intensive care units and pediatric hospital. Participants: Twenty-three infants undergoing PDA ligation (subdivided into the main study group of 12 infants with UVCP and 11 without paralysis) and 12 weight- and gestational age-matched ELBW controls. Main Outcome Measures: Incidence of UVCP, time requiring supplemental oxygen and ventilatory support, length of hospital stay, incidence and duration of tube feeding following discharge, and incidence of chronic lung disease. Results: The overall incidence of UVCP was 52% (12/23), increasing to 67% (12/18) in ELBW infants. Infants without UVCP following PDA ligation were heavier (P=.006), with a more advanced gestational age (P=.03). Patients with UVCP required longer tube feeding (relative risk, 8.25; 95% confidence interval, 1.93-46.98; P=.003), supplemental oxygen (P=.004), and ventilatory support (P=.001) and had a longer hospital stay (P<.001). In comparison to matched controls, infants with UVCP required longer tube feeding (relative risk, 9.00; 95% confidence interval, 2.08-51.30; P=.003), supplemental oxygen (P=.03), and ventilatory support (P=.002) and had a longer hospital stay (P<.001). Conclusions: There was a high incidence of occurrence of UVCP (67%) associated with PDA ligation in ELBW infants. Unilateral vocal cord paralysis following PDA ligation does seem to be associated with increased requirements for tube feeding, respiratory support, and hospital stay in these ELBW infants.