Continuous renal replacement therapy in neonates and small infants: development and first-in-human use of a miniaturised machine (CARPEDIEM)

Background Peritoneal dialysis is the renal replacement therapy of choice for acute kidney injury in neonates, but in some cases is not feasible or effective. Continuous renal replacement therapy (CRRT) machines are used off label in infants smaller than 15 kg and are not designed specifically for small infants. We aimed to design and create a CRRT machine specifically for neonates and small infants. Methods We prospectively planned a 5-year project to conceive, design, and create a miniaturised Cardio-Renal Pediatric Dialysis Emergency Machine (CARPEDIEM), specifically for neonates and small infants. We created the new device and assessed it with in-vitro laboratory tests, completed its development to meet regulatory requirements, and obtained a licence for human use. Once approved, we used the machine to treat a critically ill neonate Findings The main characteristics of CARPEDIEM are the low priming volume of the circuit (less than 30 mL), miniaturised roller pumps, and accurate ultrafiltration control via calibrated scales with a precision of 1 g. In-vitro tests confirmed that both hardware and software met the specifications. We treated a 2.9 kg neonate with haemorrhagic shock, multiple organ dysfunction, and severe fluid overload for more than 400 h with the CARPEDIEM, using continuous venovenous haemofiltration, single-pass albumin dialysis, blood exchange, and plasma exchange. The patient's 65% fluid overload, raised creatinine and bilirubin concentrations, and severe acidosis were all managed safely and effectively. Despite the severity of the illness, organ function was restored and the neonate survived and was discharged from hospital with only mild renal insufficiency that did not require renal replacement therapy. Interpretation The CARPEDIEM CRRT machine can be used to provide various treatment modalities and support for multiple organ dysfunction in neonates and small infants. The CARPEDIEM could reduce the range of indications for peritoneal dialysis, widen the range of indications for CRRT, make the use of CRRT less traumatic, and expand its use as supportive therapy even when complete renal replacement therapy is not indicated.