From the ICU Essentials 2025 Webinar Series – Barbara McLean, MN, RN, CCRN
“Kidney angina” is a clinically useful metaphor for early, reversible kidney stress caused by inadequate perfusion. Just as cardiac angina signals a heart under strain before infarction, early pre-renal AKI indicates a window for intervention, before permanent structural damage occurs.
Sepsis-induced AKI carries a high burden, increasing mortality by six to eight times and tripling the risk of long-term kidney disease. Nearly 50% of septic patients already have undiagnosed AKI when they arrive in the emergency department, underscoring the urgent need for earlier detection and more responsive monitoring.
Serum creatinine (SCr), though widely used, often fails to detect early kidney injury. Its levels rise only after significant damage has occurred, typically with a 24–48 hour delay. In patients with low muscle mass or altered fluid status, SCr may give a misleading impression of renal function. Because it reflects filtration capacity—not structural injury—it can underrepresent subclinical AKI and delay critical interventions.
Continuous urine output (UO) monitoring offers a more sensitive and immediate view of kidney function. Declining UO often precedes a rise in SCr, making it a valuable frontline indicator for early renal stress.
Kinetic estimated GFR (KeGFR) adds another layer of insight. Unlike static eGFR, which provides only a snapshot, KeGFR calculates the rate of change in creatinine over time. A drop of more than 10% from baseline KeGFR has been shown to predict AKI development up to 24 hours earlier than traditional markers, allowing for more proactive care.
Manual UO tracking, however, remains error-prone—up to 35% of fluid balance charts contain inaccuracies. These errors can delay recognition of declining renal perfusion and compromise outcomes. Accurate, hourly monitoring is critical to identifying early changes and initiating timely treatment.
At the core of AKI prevention is empowered, well-informed nursing care. With the right tools and data in hand, bedside clinicians are uniquely positioned to detect early signs of kidney injury, respond rapidly, and prevent progression to irreversible damage.
