Inspiratory Strength Training in Pediatric Cardiac Critical Care: A Retrospective Cohort Study

Background: Prolonged mechanical ventilation is associated with inspiratory muscle weakness and difficulty weaning from respiratory support. While decades of research have demonstrated that inspiratory strength training (IST) is beneficial in adult critical care populations, the literature on its use in pediatric cardiac critical care remains limited. We sought to evaluate the feasibility, safety, and physiologic response to IST in children in the pediatric cardiac intensive care unit (PCICU). Methods and Results: We performed a single-center retrospective cohort study of children with congenital heart disease referred for IST between January 2015 and August 2021. Feasibility was defined as completion of [≥]1 IST session following referral. Safety outcomes included physiologic events documented during IST sessions. Changes in maximal inspiratory pressure (MIP) were assessed in patients who completed [≥]2 IST sessions. Of 105 eligible patients, 93 (89%) successfully completed at least 1 IST session. Monitoring events were reviewed across 389 IST sessions and included pre-oxygenation (62%), desaturations (13%), bradycardia (7%), and hypertension (2%). All events were transient and did not require escalation of care. 84% of patients were successfully liberated from mechanical ventilation and required a median of 2 (IQR 1-4) sessions of IST. Among patients completing [≥]2 IST sessions, MIP improved signicantly over time (p>0.0001). Improvements were observed in both patients who did and did not wean from mechanical ventilation. Patients who failed to wean from mechanical ventilation had longer ventilator exposure prior to IST initiation and were more sedated at the outset of IST. Conclusions: IST was feasible and well tolerated in this medically complex PCICU cohort. High completion rates and improvements in MIP support the use of IST as a clinically deliverable intervention that can produce measurable improvements in inspiratory muscle strength during critical illness.