(1278) Corrected Carotid Flow Time Does Not Correlate With Volume Status in Pediatric Patients With DKA

Introduction: Point of Care Ultrasound (POCUS) is a valuable tool and can answer many clinical questions. In pediatrics, a reliable POCUS measure of volume status has yet to be demonstrated. Carotid artery flow time, corrected for heart rate (cCFT) has been proposed as one such measure, with values below 0.360 seconds suggesting dehydration, and values above suggesting hydration. We sought to evaluate the performance of cCFT in assessing the volume status of pediatric diabetic ketoacidosis (DKA) patients during treatment.

Methods: Single center prospective observational pilot study. Patients aged < 21 and undergoing treatment for DKA were enrolled. Exclusion criteria: significant fluid therapy before enrollment, pregnancy, congenital heart disease, previously diagnosed arrhythmia, and presence of any indwelling catheter. cCFT was measured by pulse-wave doppler of the carotid artery in a procedure similar to that described by Blehar and colleagues (PMID 24930363). Values were measured before fluid administration (T0), after an initial fluid bolus (T1), and after the resolution of DKA (T2). Additionally, healthy control patients were enrolled in pediatrics clinic and a cCFT value was measured. Data were expressed as means with standard deviation (SD), or percentages. Comparisons made using paired and 2-sample T-tests.

Results: 14 DKA patients were enrolled; 8 had complete data. Mean age was 17 years, mean pH at diagnosis was 7.12. Overall, patients showed a 25-point reduction in heart rate from T0 to T2. Patients had a cCFT value of 0.338 seconds at T0 (SD 0.011), 0.332 seconds at T1 (SD 0.007), and 0.344 seconds at T2 (SD 0.020). There was no significant difference between cCFT values across the 3 time points. 20 healthy control patients were enrolled; mean age was 11.75 years and average cCFT was 0.323 seconds (SD 0.016). We found that patients < 12 years had a significantly higher cCFT than those >12 (0.332 seconds [SD 0.013] vs. 0.311 seconds [SD 0.010]; p< 0.001).

Conclusions: In this pilot study, we found that cCFT did not increase during treatment of pediatric DKA, despite a reduction in heart rate suggesting that rehydration occurred. Additionally, we found some suggestion that cCFT may vary with age. Our findings suggest that cCFT is a poor measure of pediatric hydration status.