Abstract 15737: Passive Range of Motion Exercise to Enhance Growth in Infants Following the Norwood Procedure: A Pilot Study

Background: Growth impairment is common in infants with single ventricle (SV) physiology, especially after the Norwood operation. Passive range of motion (ROM) exercise increases somatic growth in preterm infants without adverse effects but has not been studied in infants with SV. Objective: To evaluate the safety and feasibility of a passive ROM exercise program in infants with SV physiology. Methods: Passive ROM exercise was administered to all extremities daily according to a standardized protocol, by a trained physical therapist, during post-Norwood hospitalization for up to 21 days or until discharge. Vital signs were measured pre-, intra- and post-procedure and height and weight were measured at baseline, 14 and 21 days, and 3 months of age or at the time of their pre-Glenn visit. Feasibility was determined by percent of days that medium (50-75%) or high (>75%) completion of the ROM exercise was performed. Adverse events (AE) were collected up to 3 months of age or pre-Glenn visit; all were adjudicated by the medical monitor. Results: Of 20 infants enrolled at 3 institutions, 70% were male. Parents voluntarily withdrew 1 subject on day 3. Median age at enrollment was 8 days (5-23), with the first ROM exercise started on a median post op day 4 (2-12). Median hospital length of stay following surgery was 15 days (9-131), allowing for an average of 13.4 in-hospital days/patient (3-21) for attempted ROM exercise. High completion of the exercise protocol across all subjects was achieved on 88% of eligible days and medium completion was achieved on an additional 2% of the days. Of 11 AE’s reported in 6 subjects; all were expected and one was determined to be possibly related to the study intervention (midsternal wound dehiscence). There were no clinically significant changes in vital signs. At 3 months, weight for age z-score (-0.84 ±1.2) and length for age z-score (-0.83 ±1.31) were higher than previous reports in SV populations. Conclusion: A passive ROM exercise program is safe and feasible in infants with SV physiology and may improve growth following Norwood operation. Larger studies are required to explore the optimal duration of passive ROM exercise and its effect on growth.