Acute Kidney Injury
Conditions We Treat
Acute Kidney Injury
Acute kidney injury can develop in hours. Prompt nephrology evaluation identifies the cause, guides treatment, and protects long-term kidney function.
What is acute kidney injury?
Acute kidney injury (AKI) is a sudden, rapid decline in kidney function — typically defined as a rise in serum creatinine of 0.3 mg/dL or more within 48 hours, or a 50% increase within 7 days, or a reduction in urine output below 0.5 mL/kg/hour for 6 or more hours. Unlike chronic kidney disease, AKI develops quickly — over hours to days — and may be partially or fully reversible with timely treatment.
AKI is classified into three stages of severity (KDIGO criteria) and into three broad categories by cause: prerenal (reduced blood flow to the kidneys), intrinsic renal (direct damage to kidney tissue), and postrenal (obstruction of urine flow). Identifying which category applies — and which specific cause within that category — is the first and most important step in management.
AKI is not a benign event. Even episodes that appear to resolve fully are associated with an increased risk of developing chronic kidney disease, cardiovascular disease, and recurrent AKI. Patients who experience AKI require follow-up nephrology evaluation to assess recovery and monitor for long-term consequences.
AKI Stages (KDIGO)
How we approach acute kidney injury
Identify the cause
AKI has dozens of causes — dehydration, sepsis, contrast nephropathy, medications (NSAIDs, ACE inhibitors, aminoglycosides), obstruction, and intrinsic kidney diseases such as glomerulonephritis or interstitial nephritis. Accurate diagnosis drives treatment.
Optimize volume status
Prerenal AKI — the most common type — responds to careful fluid resuscitation. Overly aggressive fluid administration can worsen outcomes. We titrate volume replacement based on clinical assessment and hemodynamic monitoring.
Remove nephrotoxins
Many cases of AKI are medication-related. We review the full medication list, hold nephrotoxic agents, and adjust dosing for renally cleared drugs to prevent further injury.
Renal replacement therapy when indicated
Severe AKI with refractory fluid overload, dangerous electrolyte abnormalities, or uremic symptoms may require dialysis. We manage both acute hemodialysis and continuous renal replacement therapy (CRRT) in the inpatient setting.
Post-AKI follow-up
Recovery from AKI requires close monitoring. We follow creatinine trends, assess for residual kidney damage, and screen for the development of CKD — which occurs in a significant proportion of AKI survivors.
Frequently asked questions
What is acute kidney injury?
Acute kidney injury (AKI) is a sudden, rapid decline in kidney function — typically defined as a rise in serum creatinine of 0.3 mg/dL or more within 48 hours, or a 50% increase within 7 days, or reduced urine output. It can range from mild and self-limited to severe, requiring dialysis.
What causes acute kidney injury?
AKI causes fall into three categories: prerenal (reduced blood flow — dehydration, heart failure, sepsis), intrinsic renal (direct kidney damage — glomerulonephritis, acute tubular necrosis, interstitial nephritis, contrast nephropathy), and postrenal (obstruction — kidney stones, enlarged prostate, tumor). Medications — particularly NSAIDs, ACE inhibitors, and certain antibiotics — are a common contributing factor.
Can acute kidney injury be reversed?
AKI is often partially or fully reversible with prompt treatment, depending on the cause and severity. Prerenal AKI typically resolves quickly with volume repletion. Intrinsic AKI may take weeks to recover and may not fully resolve. Even patients who appear to recover fully are at increased risk of CKD and should be followed by a nephrologist.
Does AKI lead to chronic kidney disease?
Yes — AKI is a significant risk factor for CKD. Studies show that patients who experience AKI have a substantially higher risk of developing CKD, even after apparent recovery. The risk is higher with more severe AKI, recurrent episodes, and pre-existing kidney disease.
When should I see a nephrologist after AKI?
Nephrology follow-up is recommended within 3 months of hospital discharge after AKI, and sooner for patients with Stage 2–3 AKI, pre-existing CKD, or incomplete recovery. Early follow-up allows assessment of kidney function recovery and initiation of CKD prevention strategies.
Related conditions
AKI requires prompt nephrology evaluation.
Our nephrologists see patients at our Newport Beach office, affiliated with Hoag Hospital. We are accepting new patients.