(1534) The Microcirculation and Organ Dysfunction in Pediatric Patients Undergoing Cardiopulmonary Bypass

Introduction: The use of cardiopulmonary bypass (CPB) is often associated with post-operative vascular disturbance leading to organ dysfunction and sometimes death. Conventional monitoring in the post-operative period focuses on the macrocirculatory aspect of the cardiovascular system. Yet, restoration of the macrocirculation does not ensure recruitment of the microcirculation and inadequate oxygen delivery at the cellular level occurs. Prior studies have attempted to characterize the microcirculation by imaging the sublingual and buccal mucosa, but these techniques are limited by the need for deep sedation or patient cooperation. We propose that visualization of finger nailfold capillary networks may serve as a feasible and novel approach to understanding the microvascular disturbance in pediatric patients who undergo CPB.

Methods: A single center, feasibility study of patients < 18 years of age requiring CPB in the Cardiac Intensive Care Unit (CICU) of Ann & Robert H. Lurie Children’s Hospital of Chicago between November 2023 and June 2024. Nailfold capillary images were obtained for each patient at three time points: pre-operatively (T0), within 12 hours of CPB completion (T1), and 24-72 hours post-operatively (T2). The pediatric sequential organ failure assessment (pSOFA) score was also collected at each imaging time point.

Results: 31 patients were enrolled (consent rate of 100%) and nailfold imaging was completed in 84% of participants (26/31). 2 patients were unable to cooperate, and 3 patients had their operation cancelled after study enrollment. Median patient age was 5.5 months. 46% (12/26) participants were male. Average CPB time was 140 minutes. 42% (11/26) of patients had cyanotic cardiac lesions. Participants also represented a wide range of surgical complexity and mortality risk; patients with each Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery Congenital Heart Surgery (STAT) Mortality Score (range 1-5) were represented.

Conclusions: Nailfold capillaroscopy is a feasible method of evaluating the microcirculation in pediatric patients who undergo CPB. Future work will analyze these nailfold capillary metrics to detect whether a decline in microvascular density is associated with worse post-operative organ dysfunction, defined by pSOFA score.