para>GFR normally decreases with age, despite normal creatinine (Cr). Adjust renally cleared drugs for GFR in the elderly. �
Pediatric Considerations
CKD definition is not applicable for children <2 years because of lower GFR even when corrected for body surface area. Calculated GFR based on serum Cr is used in this age group.
�
Pregnancy Considerations
Renal function in CKD may deteriorate during pregnancy. Cr >1.5 and hypertension (HTN) are major risk factors for worsening renal function.
Increased risk of premature labor, preeclampsia, and/or fetal loss
ACE inhibitors and angiotensin receptor blockers (ARBs) are contraindicated due to teratogenicity. Use diuretics with caution.
�
EPIDEMIOLOGY
- Majority of people with CKD in stages 1 to 3
- African Americans are 3.6 times more likely to develop CKD than Caucasians.
- Predominant sex: Similar in both sexes; however, incidence rate of end-stage renal disease (ESRD) is 1.6 times higher in males than females.
Incidence
Estimated annual incidence of 1,700/1 million population �
Prevalence
Overall prevalence of CKD is 14.2%. Unadjusted prevalence/incidence rates of ESRD (stage 5) are 1,752 and 362.4/1 million, respectively. Numbers do not reflect the burden of earlier stages of CKD (stages 1 to 4), which are estimated to affect 13.1% of the population nationwide or 26.3 million in the United States. �
ETIOLOGY AND PATHOPHYSIOLOGY
Progressive destruction of kidney nephrons; GFR will drop gradually, and plasma Cr values will approximately double, with 50% reduction in GFR and 75% loss of functioning nephrons mass. Hyperkalemia usually develops when GFR falls to <20 to 25 mL/min. Anemia develops from decreased renal synthesis of erythropoietin. �
- Renal parenchymal/glomerular
- Nephritic: hematuria, RBC casts, HTN, variable proteinuria
- Focal proliferative: IgA nephropathy, systemic lupus erythematosus (SLE), Henoch-Sch �nlein purpura, Alport syndrome, proliferative glomerulonephritis, crescentic glomerulonephritis
- Diffuse proliferative: membranoproliferative glomerulonephritis, SLE, cryoglobulinemia, rapidly progressive glomerulonephritis (RPGN), Goodpasture syndrome
- Nephrotic: proteinuria (>3.5 g/day), hypoalbuminemia, hyperlipidemia, and edema
- Minimal change disease, membranous nephropathy, focal segmental glomerulosclerosis
- Amyloidosis, diabetic nephropathy
- Vascular: HTN, thrombotic microangiopathies, vasculitis (Wegener), scleroderma
- Interstitial-tubular: infections, obstruction, toxins, allergic interstitial nephritis, multiple myeloma, connective tissue disease, cystic disease
- Postrenal: obstruction (benign prostatic hyperplasia), neoplasm, neurogenic bladder
Genetics
- Alport syndrome, Fabry disease, sickle cell anemia, SLE, and autosomal dominant polycystic kidney disease can lead to CKD.
- Polymorphisms in gene that encodes for podocyte nonmuscle myosin IIA are more common in African Americans than Caucasians and appear to increase risk for nondiabetic ESRD.
RISK FACTORS
- Type 1 or 2 diabetes mellitus (DM); most common
- Age >60 years
- Cardiovascular disease (e.g., HTN [common], renal artery stenosis, atheroemboli)
- Previous kidney transplant
- Urinary tract obstruction (e.g., benign prostatic hyperplasia)
- Autoimmune disease, vasculitis/connective tissue disorder
- Family history of CKD
- Nephrotoxic drugs (lithium, salicylate, high-dose or chronic NSAIDs, sulfa)
- Congenital anomalies, obstructive uropathy, renal aplasia/hypoplasia/dysplasia, reflux nephropathy
- Hyperlipidemia
- Low income/education/ethnic minority status
- Obesity/smoking/heroin use
- Chronic infection (hepatitis B, hepatitis C, HIV)
GENERAL PREVENTION
- Treat reversible causes: hypovolemia, infections, diuretics, drugs (NSAIDs, aminoglycosides, IV contrast).
- Treat risk factors: DM, HTN, hyperlipidemia, smoking, and obesity; adjust medication doses to prevent renal toxicity.
COMMONLY ASSOCIATED CONDITIONS
HTN, DM, cardiovascular disease �
DIAGNOSIS
HISTORY
Patients with CKD stages 1 to 3 are usually asymptomatic; can present with �
- Oliguria, nocturia, polyuria, hematuria, change in urinary frequency
- Bone disease
- Edema, HTN, dyspnea
- Fatigue, depression, weakness
- Pruritus, ecchymosis
- Metallic taste in mouth, anorexia, nausea, vomiting
- Hyperlipidemia, claudication, restless legs
- Erectile dysfunction, decrease libido, amenorrhea
PHYSICAL EXAM
- Volume status (pallor, BP/orthostatic; edema; jugular venous distention; weight)
- Skin: sallow complexion, uremic frost
- Ammonia-like odor (uremic fetor)
- Cardiovascular: Assess for murmurs, bruits, pericarditis.
- Chest: pleural effusion
- Rectal: enlarged prostate
- CNS: asterixis, confusion, seizures, coma, peripheral neuropathy
DIAGNOSTIC TESTS & INTERPRETATION
Initial Tests (lab, imaging)
- GFR can be estimated by multiple equations (freely available in medical calculators), including MDRD equation:
- GFR (mL/min/1.73 m2) = 175 � [(serum Cr μmol/1/88.4)-1.154] � [age (years)-0.203] � 0.742 for females or 1.21 for African American
- Often used as estimate in electronic health records
- Cr clearance (CrCl) can be calculated using Cockroft-Gault formula
- CrCl (male) = ([140 - age] � weight (kg)/(serum Cr � 72)]
- CrCl (female) = CrCl (male) � 0.85
- Formula used for determining cut points for renally adjusted medications
- Urine analysis
- Urine microscopy: WBC casts in pyelonephritis, RBC casts in glomerulonephritis/vasculitis, dysmorphic RBCs
- Urine electrolytes: sodium, Cr, urea (if on loop diuretics)
- Proteinuria/albuminuria
- 24-hour urine collection: >30 to 300 mg/24 hr (20 to 200 μg/min) is microalbuminuria and >300 mg/24 hr (>200 μg/min) is macroalbuminuria.
- Albumin/Cr ratio (ACR): See "Description."�
- Hematology: normochromic, normocytic anemia; increased bleeding time
- Chemistry
- Elevated BUN, Cr, hyperkalemia, metabolic acidosis
- Increased parathyroid hormone, decreased 25-(OH) vitamin D, hypocalcemia, hyperphosphatemia
- Hyperlipidemia, decreased albumin
ALERT
Drugs that may alter lab result:
Cimetidine: inhibits Cr tubular secretion
Trimethoprim: inhibits Cr and K+ secretion and may cause/worsen hyperkalemia
Cefoxitin and flucytosine: increases serum Cr
Diltiazem and verapamil (like ACE/ARBs) have significant antiproteinuric effects in patients with CKD.
Ultrasound (initial test of choice): Small, echogenic kidneys; may see obstruction (e.g., hydronephrosis); cysts; kidneys may be enlarged with HIV and diabetic nephropathy.
Doppler ultrasound to assess for renovascular disease, thrombosis
Noncontrast CT scan: obstruction, calculi, cysts, neoplasm, renal artery stenosis
MRI/MRA: Avoid gadolinium because of the risk of nephrogenic systemic fibrosis.
Renal arteriogram for renal artery stenosis can be therapeutic (angioplasty or stenting).
Renal scan to screen for differential function between kidneys
Retrograde pyelogram: if strong suspicion for obstruction despite negative finding on ultrasound
�
Follow-Up Tests & Special Considerations
- Serology: antinuclear antibody (ANA); double-stranded DNA, antineutrophil cytoplasmic antibody; complements (C3, C4, CH50); anti-glomerular basement membrane (GBM) antibodies; hepatitis B, C; and HIV screening
- Serum and urine immunoelectrophoresis
Diagnostic Procedures/Other
Biopsy: hematuria, proteinuria, acute/progressive renal failure, nephritic or nephrotic syndrome �
TREATMENT
GENERAL MEASURES
- Lowering salt intake to <2 g/day of sodium in adults, unless contraindicated (1)[C]
- Minimize radiocontrast exposure; prehydrate; N-acetylcysteine use is controversial. Avoid nephrotoxins (NSAIDs, aminoglycosides, etc.).
- Renal replacement: Prepare for dialysis or transplant when GFR <30 mL/min/1.73 m2.
- Vaccines: pneumococcal, influenza
- Encourage smoking cessation, encourage weight loss (if applicable), and limit alcohol consumption.
MEDICATION
ISSUES FOR REFERRAL
- Nephrology consult: GFR <15: immediate
- GFR 15 to 29: urgent
- GFR 30 to 59: nonurgent referral
- GFR 60 to 89: not required unless with comorbidities
SURGERY/OTHER PROCEDURES
Placement of dialysis access or transplantation �
INPATIENT CONSIDERATIONS
Admission Criteria/Initial Stabilization
Uremia: nausea/vomiting, fluid overload, pericarditis, uremic encephalopathy, resistant HTN, hyperkalemia, metabolic acidosis, hyperphosphatemia �
ONGOING CARE
DIET
Nutrition consult for CKD diet: Protein restriction in early CKD is controversial but may be beneficial in ESRD; restricted intake of phosphates; sodium and water restriction to avoid volume overload; potassium restriction if hyperkalemic �
PATIENT EDUCATION
National Kidney Federation patient Web site at: http://www.kidney.org/patients �
PROGNOSIS
Patients with CKD gradually progress to ESRD, with bad prognoses. 5-year survival rate for U.S. patients on dialysis is ~35%. �
COMPLICATIONS
HTN, anemia, secondary hyperparathyroidism, renal osteodystrophy, sleep disturbances, infections, malnutrition, electrolyte imbalances, platelet dysfunction/bleeding, pseudogout, gout, metabolic calcification, sexual dysfunction �
REFERENCES
11 Mancia �G, Fagard �R, Narkiewicz �K, et al. 2013 ESH/ESC guidelines for the management of arterial hypertension: the Task Force for the Management of Arterial Hypertension of the European Society of Hypertension (ESH) and of the European Society of Cardiology (ESC). J Hypertens. 2013;31(7):1281-1357.22 Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2012 clinical practice guideline for the evaluation and management of chronic kidney disease. Kidney Inter Suppl. 2013;3:1-150. www.kdigo.org/clinical_practice_guidelines/pdf/CKD/KDIGO_2012_CKD_GL.pdf
SEE ALSO
- Hydronephrosis; Nephrotic Syndrome; Polycystic Kidney Disease; Proteinuria
- Algorithm: Anuria or Oliguria
CODES
ICD10
- N18.9 Chronic kidney disease, unspecified
- Q63.9 Congenital malformation of kidney, unspecified
- N18.3 Chronic kidney disease, stage 3 (moderate)
- Q61.4 Renal dysplasia
- Q61.8 Other cystic kidney diseases
- Q61.5 Medullary cystic kidney
- N18.5 Chronic kidney disease, stage 5
- N18.4 Chronic kidney disease, stage 4 (severe)
- N18.1 Chronic kidney disease, stage 1
- N18.6 End stage renal disease
- N18.2 Chronic kidney disease, stage 2 (mild)
ICD9
- 585.9 Chronic kidney disease, unspecified
- 753.3 Other specified anomalies of kidney
- 585.3 Chronic kidney disease, Stage III (moderate)
- 753.15 Renal dysplasia
- 753.10 Cystic kidney disease, unspecified
- 585.6 End stage renal disease
- 585.4 Chronic kidney disease, Stage IV (severe)
- 585.2 Chronic kidney disease, Stage II (mild)
- 585.1 Chronic kidney disease, Stage I
- 753.16 Medullary cystic kidney
- 585.5 Chronic kidney disease, Stage V
SNOMED
- 709044004 Chronic kidney disease (disorder)
- 44513007 Congenital anomaly of the kidney (disorder)
- 433144002 Chronic kidney disease stage 3 (disorder)
- 204949001 Renal dysplasia (disorder)
- 82525005 Congenital cystic kidney disease (disorder)
- 46177005 End stage renal disease (disorder)
- 433146000 Chronic kidney disease stage 5 (disorder)
- 431857002 Chronic kidney disease stage 4 (disorder)
- 431856006 Chronic kidney disease stage 2 (disorder)
- 431855005 Chronic kidney disease stage 1 (disorder)
- 204958008 Nephronophthisis (disorder)
CLINICAL PEARLS
- Maintaining BP <140/90 mm Hg is imperative (in patients not on dialysis).
- Avoid nephrotoxins including ACE/ARB in acute kidney injury (AKI) with or without CKD.
- CKD is a CHD risk equivalent.