Faculty Bibliography

INTRODUCTION/BACKGROUND:Neonatal acute kidney injury disproportionately affects extremely low birthweight (ELBW) infants (<1,000 g), who are especially vulnerable to fluid imbalance and its consequences. Current renal replacement therapy options are not optimized for patients under 2.5 kg. The Brophy Kit™, a cost-conscious, manual single-lumen dialysis device, may address this gap. METHODS:A preclinical feasibility study was conducted using eight healthy male Sprague Dawley rats (600-800 g), approximating the weight and blood volume of ELBW neonates. Each rat underwent 3-French catheter placement and sequential ultrafiltration (UF) cycles with the Brophy Kit™, targeting 5% and 10% blood volume removal. Respiratory rate was monitored as a surrogate for procedural tolerance. RESULTS:All eight animals tolerated the procedure and survived to UF completion. One rat was excluded due to catheter clotting before UF initiation. Respiratory rates remained stable throughout. Observed UF volumes deviated from prescribed volumes at the end of each experiment day by 11-12%. CONCLUSION/CONCLUSIONS:This proof-of-concept study demonstrates the feasibility of using the Brophy Kit™ for manual UF in a preclinical model approximating ELBW neonates. The device shows potential as an accessible solution for fluid management in resource-limited settings.

INTRODUCTION/UNASSIGNED:clearance and ultrafiltration (UF) performance. METHODS/UNASSIGNED:We diluted packed red blood cells to a normal hematocrit (Hct: 31.1%-36.8%) and conducted 12 clearance and 3 UF experiments. A cycle consisted of aspirating 10 ml of blood from the blood bag, passing it through a hemofilter, and returning it in a circular path. For clearance experiments, we tested 4 configurations, with varied timing and volume of saline flushes to refresh the dialysis compartment, then measured blood urea nitrogen (BUN) and potassium concentrations every 5 cycles. For each UF cycle, 1 ml of ultrafiltrate was removed, and Hct was measured every 10 cycles. RESULTS/UNASSIGNED:Median BUN and potassium reduction were 31.0% (interquartile range [IQR]: 17.6-37.9) and 35.0% (IQR: 26.9-41.7), respectively, after 30 clearance cycles. Median Hct increased to 52.6% (IQR: 52.5-53.8) after 60 UF cycles, more than the expected Hct (47.7%). CONCLUSION/UNASSIGNED:clearance efficiently and UF consistently. The Brophy Kit may address a technological KRT gap for small neonates because of its minimal extracorporeal volume and ability to function with single lumen access.

BACKGROUND:Access to pediatric dialysis is challenged in low-resource settings due to high costs, scarcity of equipment, and the lack of qualified personnel availability. We demonstrated the manual single lumen alternating micro-batch (mSLAMB) device can remove small solutes in vitro without the need for electricity, batteries, or pumps. We developed a new version (Kirpa Kit™) to address some of the technical limitations of mSLAMB. Here, we compare the in vitro clearance performance and ease of use of the Kirpa Kit™ with that of prior mSLAMB configurations. METHODS:A mixture of expired packed red blood cells, 0.9% NaCl, urea, and heparin was used to test the efficiency of two mSLAMB configurations and the Kirpa Kit™ in removing potassium and urea. Clearance was evaluated by measuring percent reduction after 25-min sessions with each device. A survey was used to evaluate the ease of use of each configuration. RESULTS:The Kirpa Kit™ achieved a median urea reduction of 82.4% and potassium reduction of 82.1%, which were higher than those achieved with the best-performing mSLAMB configuration (urea 71.9%, potassium 75.4%). The Kirpa Kit™ was easier to use with a shorter perceived time of use than the mSLAMB. CONCLUSIONS:The Kirpa Kit™, evolution of mSLAMB, is easy to use and may have improved efficacy, making it an optimal candidate for in vivo testing.

INTRODUCTION: The pathological manifestations of vascular air embolism (VAE) depend on the volume and rapidity of gas entry, and result from mechanical obstruction, leading to ischemia and inflammatory reactions to air as a foreign body. Physiologic effects on the cardiovascular, neurologic, or pulmonary systems may be trivial or catastrophic.
METHOD(S): A 17-year-old boy with anti-MOG syndrome was admitted for plasmapheresis for optic neuritis. Minutes after removal of his internal jugular central venous catheter (CVC), he developed paresthesias, chest discomfort, and sudden onset cough, progressing to unresponsiveness. Noncontrast head CT was negative for acute intracranial process. Upon transfer to the PICU, the patient decompensated further, requiring intubation and initiation of vasoactives for refractory shock. CT angiogram of the head and neck was unremarkable. Initial brain MRI showed diffuse leptomeningeal enhancement concerning for infection, however extensive infectious workup was negative. Repeat MRI revealed numerous scattered foci of acute and lateacute infarcts consistent with an embolic event. Cardiac workup was significant for an EKG with anterolateral ST elevation, elevated serum troponin, and TEE demonstrating left ventricular hypokinesia and a trivial PFO. Cardiac MRI confirmed an intraventricular septal infarct. The sudden onset of signs of neurologic and cardiopulmonary compromise with temporal relation to CVC manipulation led to the clinical diagnosis of VAE.
RESULT(S): We describe a rare case of CVC-associated VAE in a pediatric patient resulting in neurologic injury and cardiopulmonary collapse. When air enters the vasculature, it can migrate along three major pathways: via pulmonary circulation, paradoxically via intra-cardiac shunt, or to the cerebral venous system via retrograde ascension. In most described cases, emboli migrate along only one or two of these pathways. In this case, the patient developed ARDS, cardiogenic shock, and multiple ischemic strokes, suggesting embolic migration along all three pathways. There is inadequate awareness of VAE as a potentially fatal complication of CVC use. Though a rare complication, the vast majority of catheter-associated VAE are largely preventable with focused instruction and reinforcement through enhanced supervision