Diagnostic approach to the patient with subacute kidney injury in an outpatient setting
- Pedram Fatehi, MD, MPH
Pedram Fatehi, MD, MPH
- Assistant Clinical Professor of Medicine
- Stanford University School of Medicine
- Chi-yuan Hsu, MD, MSc
Chi-yuan Hsu, MD, MSc
- Professor of Medicine
- University of California, San Francisco
Patients with kidney disease may have a variety of different clinical presentations. Some have symptoms or signs that are directly referable to the kidney (such as hematuria) or to associated extrarenal manifestations (edema, hypertension, signs of uremia). Many patients are asymptomatic and are incidentally found to have an elevated serum creatinine concentration, abnormal urine studies (such as proteinuria or microscopic hematuria), or abnormal radiologic imaging of the kidneys.
Specific disorders generally cause acute, subacute, or chronic kidney injury. Acute kidney injury (AKI) develops over hours to days and is usually diagnosed in hospitalized patients or following a procedure. Subacute kidney injury defines a presentation that develops more slowly than AKI but generally results in an increased creatinine in less than three months. Chronic kidney disease (CKD) is defined by an elevated creatinine, or other evidence of kidney damage, that is relatively stable for greater than three months.
Although not all presentations fit within these narrowly defined categories, knowledge of the duration and acuity of onset of disease often narrows the differential diagnosis among patients who may present similar clinical findings related to the kidney.
This topic reviews the evaluation of patients who present with subacute kidney injury . Most patients are evaluated as outpatients. The evaluation of patients (generally hospitalized patients) who develop an increase in creatinine within hours to days is discussed elsewhere . (See "Evaluation of acute kidney injury (acute renal failure) among hospitalized patients".)
The evaluation of patients with newly identified CKD is discussed elsewhere . (See "Diagnostic approach to the patient with newly identified chronic kidney disease".)
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- MAJOR CAUSES AND PATHOGENESIS OF KIDNEY DISEASE
- Prerenal disease
- Intrinsic renal vascular disease
- Intrinsic glomerular disease
- Intrinsic tubular and interstitial disease
- Obstructive nephropathy
- CLINICAL MANIFESTATIONS
- Initial testing
- Estimation of glomerular filtration rate
- Urine volume
- Radiologic studies
- Serologic testing and role of renal biopsy
- INFORMATION FOR PATIENTS
- SUMMARY AND RECOMMENDATIONS