Clinical Context
A typical patient is an adult with suspected or known acute or chronic kidney dysfunction who requires a point-of-care, quantitative measurement of glomerular filtration rate (GFR). The patient presents to an outpatient infusion suite, ambulatory clinic, or hospital setting for functional renal assessment when serum creatinine and estimated GFR are insufficient for clinical decision-making (for example, in patients with rapidly changing renal function, morbid obesity, cachexia, or when precise measured GFR is required for chemotherapy dosing or pre-transplant evaluation). The provider places a proprietary, noninvasive sensor on the patient’s skin and injects a fluorescent pyrazine agent intravenously. A monitor records fluorescence clearance and displays a measured GFR. The code describes administration of more than one dose in a 24‑hour period; this occurs when multiple serial measurements are clinically required (for example, to track rapidly changing renal function during nephrotoxic therapy, immediately postoperatively, or when repeat confirmation is needed for transplant evaluation). Typical workflow: obtain informed consent and IV access, place sensor, administer the agent, monitor clearance on the device, document device placement, agent dosing times and volumes, measured GFR result(s), and any adverse events. Typical sites of service: outpatient infusion center, ambulatory specialty clinic, emergency department, inpatient ward, or preoperative assessment unit. Typical personnel: nephrologist or supervising clinician, trained nurse or technologist to place sensor and administer agent, and device technician or trained staff to operate the monitor. Billing considerations include use of 0603T for each service day when more than one dose is administered within a 24‑hour period and documentation supporting medical necessity for repeat dosing.