Chapter 38: Renal Disorders

Population

• –Adults and children.

Recommendations

2017 KDIGO CKD-MBD Guidelines

• –Recommends monitoring serum calcium, phosphorus, immunoreactive parathyroid hormone (iPTH), and alkaline phosphatase levels:

  • Beginning with Stage G3a CKD (adults).

  • Beginning with Stage G2 CKD (children).

• –Measure 25-OH vitamin D levels beginning in stage G3a CKD.

• –Recommends treating all vitamin D deficiency with vitamin D supplementation with standard recommended dosing. Decisions to treat should be based on trends of vitamin D levels, not a single level.

• –In Stages G3–5 CKD, consider a bone biopsy before bisphosphonate therapy if a dynamic bone disease is a possibility.

• –In Stages G3–5 CKD, aim to normalize calcium and phosphorus levels.

• –In Stage G5 CKD, seek to maintain a parathyroid hormone (PTH) level of approximately 2–9 times the upper normal limit for the assay.

Source

• –https://kdigo.org/wp-content/uploads/2017/02/KDIGO_CKD_MBD_Guideline_r6.pdf

Comment

1. Options for oral phosphate binders:

   1. Calcium acetate.

   2. Calcium carbonate.

   3. Calcium citrate.

   4. Sevelamer carbonate.

   5. Lanthanum carbonate.

Population

• –Adults.

Recommendations

2012 KDIGO, 2014 NKF-KDOQI

• –Recommends the staging of CKD based on cause, GFR category and albuminuria category with abnormalities being present for at least 3 mo.

  • Cause: Assign cause of CKD based on absence or presence of systemic disease and the location within the kidney of observed or presumed pathologic-anatomic abnormalities.

  • GFR category

    • G1: GFR >90 (mL/min/1.73 m²)

    • G2: GFR 60–89

    • G3a: GFR 45–59

    • G3b: GFR 30–44

    • G4: GFR 15–29

    • G5: GFR <15

  • Albuminuria category

    • A1: ACR (urine albumin-to-creatinine ratio) <3

    • A2: ACR 3–30

    • A3: ACR >30

• –Recommends using creatinine and GFR estimating equation for initial assessment.

• –Evaluation for chronicity.

  • In those with GFR <60 mL/min/1.73 m² (GFR categories G3a–5), evaluate history of prior indicators for kidney disease and prior measurements.

  • If duration is >3 mo then CKD is confirmed. If not >3 mo CKS is not confirmed or is unclear.

• –Assess GFR and albuminuria at least annually for people with CKD. Assess more frequently for those at higher risk for progression. For people with CKD G3a measure serum cystatin C and calculate GFR using a GFR estimating equation and cystatin C if the confirmation of CKD is required.

• –Management of disease progression.

  • Control BP and individualize BP targets based on age, coexisting comorbidities, presence of retinopathy, and tolerance of treatment.

  • Recommend that an ACE-I or ARB be used in diabetic patients with CKD and urine albumin excretion of 30–300 mg/24 h (or equivalent).

  • Suggest lowering protein intake to 0.8 g/kg/d in adults with diabetes and nondiabetics with GFR categories G4–5.

  • Recommend a large hemoglobin A1C of approximately 7% in people with diabetes and CKD.

  • Recommend a salt intake of <2 g/24 h in people with CKD.

• –Recommends at least once a check of serum calcium, phosphate, intact parathyroid hormone, 25-OH vitamin D, and hemoglobin levels for Stages G3a–5 CKD to inform future clinical decisions.

Source

–https://www.ajkd.org/article/S0272-6386(14)00491-0/pdf

Va/DoD 2014

• –Recommends dietary sodium restriction to reduce hypertension and proteinuria.

• –Protein restriction 0.6–0.8 g/kg/d for patients with Stage 3–4 CKD.

• –Recommends administration of vaccinations against influenza, Tdap, 13-valent pneumococcal conjugate vaccine, hepatitis B virus, Zoster, and MMR vaccines.

• –Recommends ACEI or ARB therapy for patients with diabetes, hypertension, or albuminuria.

• –Recommends bicarbonate supplementation in CKD with metabolic acidosis.

• –Recommends oral iron therapy for Stage 3 or worse CKD.

• –Recommends erythropoietic-stimulating agents if hemoglobin <10 g/dL.

Source

• –http://www.guideline.gov/content.aspx?id=48951

Population

• –Children and adults.

Recommendations

NICE 2013

• –Perform a urinalysis in all patients with AKI. Consider checking urine electrolytes (ie, urine sodium, urine creatine, urine urea, and urine osmolarity) to calculate a FENa or FEUrea.

• –Do not routinely obtain a renal ultrasound when the cause of the AKI has been identified.

• –Detect AKI with any of the following criteria:

  • Rise in serum creatinine ≥0.3 mg/dL in 48 h.

  • 50% or more rise in creatinine in last 7 d.

  • Urine output <0.5 mL/kg/h.

• –Refer for renal replacement therapy patients with any of the following refractory to medical management:

  • Hyperkalemia.

  • Metabolic acidosis.

  • Uremia.

  • Fluid overload.

Sources

• –https://doi.org/10.1016/0002-9343(84)90368-1

• –http://www.guideline.gov/content.aspx?id=47080

Population

• –Adults and children with kidney stone disease.

Recommendations

EAU 2010, AUA 2014

• –Recommended imaging study for patients with acute flank pain is a noncontrast CT urogram.

• –Recommended evaluation for renal colic:

  • Urinalysis

  • Serum CBC, creatinine, uric acid, calcium, and albumin +/– intact parathyroid hormone.

  • Stone analysis by x-ray crystallography or infrared spectroscopy.

• –Recommends 24-h urine analysis for complicated calcium stone disease: calcium; oxalate; citrate; creatinine; urate; magnesium; phosphate; sodium; and potassium.

• –Recommends a thiazide diuretic for patients with hypercalciuria.

• –Recommends treatment with an alkaline citrate for hypocitraturia, type 1 renal tubular acidosis (RTA), hypercalciuria, and hyperoxaluria.

• –Recommends that adults with a history of urinary stones drink sufficient water to maintain a urine output >2.5 L/d.

• –Consider use of an α-receptor blocker to facilitate spontaneous passage of ureteral stones <10 mm.

• –Consider active ureteral stone removal for persistent obstruction, failure of spontaneous passage, or the presence of severe, unremitting colic.

  • Options include shockwave lithotripsy or ureteroscopy.

• –For calcium stones and hypercalciuria

  • Limit sodium intake and consume 1–2 g/d of dietary calcium.

  • Thiazide diuretic.

• –For calcium oxalate stones

  • If high urinary oxalate, limit intake of oxalate-rich foods and maintain normal calcium consumption.

  • If hyperuricosuria, treat with allopurinol.

• –For uric acid stones and high urinary uric acid, limit intake of non-dairy animal protein.

• –For struvite stones refractory to surgical management, consider acetohydroxamic acid therapy.

• –For uric acid or cystine stones, consider potassium citrate therapy to raise urinary pH to optimal level.

Sources

• –http://www.uroweb.org/gls/pdf/18_Urolithiasis.pdf

• –http://www.guideline.gov/content.aspx?id=48229

Comment

1. Patients at high risk for recurrent stone formation:

   1. ≥3 stones in 3 y.

   2. Infection stones.

   3. Urate stones.

   4. Children and adolescents with stones.

   5. Cystinuria.

   6. Primary hyperoxaluria.

   7. Type 1 RTA.

   8. Cystic fibrosis.

   9. Hyperparathyroidism.

   10. Crohn’s disease.

   11. Malabsorption syndromes.

   12. Nephrocalcinosis.

   13. Family history of kidney stone disease.

Population

• –Adults with kidney stone disease.

Recommendations

EAU 2013

• –Recommended evaluation for renal colic:

  • Sodium, potassium.

  • CRP.

  • PT, PTT (if intervention is likely).

• –Contrast-enhanced CT scan recommended if stone removal is planned and the renal anatomy needs to be assessed.

• –Hyperoxaluria.

  • Oxalate restriction.

  • Pyridoxine.

• –Renal colic analgesia.

  • NSAIDs.

  • Opiates.

  • Alpha-blockers.

• –Management of sepsis with obstructed kidney.

  • Requires urgent decompression with a ureteral stent or percutaneous nephrostomy tubes.

  • Start antibiotics immediately.

• –Indications for active kidney stone treatment:

  • Stone growth.

  • Acute or chronic pain.

  • Kidney infection.

  • Kidney obstruction.

EAU 2013

• –Stop antiplatelets and anticoagulation before stone removal.

• –Goal is to drink water to maintain a urine output >2.5 L/d.

• –Struvite and infection stones:

  • Surgical removal of stones.

  • Antibiotics.

  • Urinary acidification.

  • Urease inhibition.

• –Cystine stones.

  • Potassium citrate.

• –Tiopronin.

Source

• –http://www.guideline.gov/content.aspx?id=45324

Population

• –Children with kidney stone disease.

Recommendations

EAU 2013

• –Recommends a complete metabolic workup based on stone analysis.

• –Ultrasound is the preferred imaging method in children.

• –Percutaneous nephrolithotripsy is recommended for treatment of renal pelvic or calyceal stones with a diameter >20 mm.

Source

• –http://www.guideline.gov/content.aspx?id=45324

Recommendations

NCCN 2016

• –Stage I—Follow-up after a partial or radical nephrectomy

  • History and physical (H&P) every 6 mo for 2 y then annually up to 5 y after surgery.

  • Comprehensive metabolic panel or other blood tests as indicated every 6 mo for 2 y then annually until 5 y.

• –Abdominal imaging after partial nephrectomy

  • Baseline abdominal CT, MRI, or US within 3–9 mo of surgery. If initial scan-negative abdominal imaging may be considered annually for 3 y based on overall risk factors.

• –After radical nephrectomy

  • Abdominal CT, MRI, or US within 3–12 mo of surgery.

  • If initial post-op imaging is negative, abdominal imaging beyond 12 mo may be done at the discretion of the physician.

  • Chest x-ray or CT annually for 3 y then as indicated clinically.

• –Stage II or III—follow-up after radical nephrectomy

  • H&P every 3–6 mo for 3 y then annually up to 5 y after radical nephrectomy, then as clinically indicated.

  • Comprehensive metabolic panel, LDH, and C-reactive protein every 6 mo for 2 y then annually up to 5 y.

• –Abdominal imaging after radical nephrectomy

  • Baseline abdominal CT or MRI within 3–6 mo then CT, MRI, or US every 3–6 mo for 3 y then annually up to 5 y.

  • Chest imaging—baseline chest CT within 3–6 mo.

  • Pelvic, brain, or spinal imaging as clinically indicated. Nuclear bone scan as clinically indicated.

Source

• –J Clin Oncol. 2014; j32:4059.

Comments

1. RCC staging

   1. Stage I—Tumor <7 cm N0M0.

   2. Stage II—Tumor >7 cm limited to kidney N0M0.

   3. Stage III—Any tumor size with regional node metastasis.

   4. Stage IV—T4 (spread beyond Gerota’s fascia—any T, any N, M [systemic metastases]).

2. Features of high risk for relapse

   1. Stage III, size of tumor, high grade (Fuhrman 3 or 4), coagulative tumor necrosis (5 times increase in risk of death). (Br J Urol. 2009; 103:165)

3. Paraneoplastic syndromes in RCC and clinical caveats

   1. Anemia, hepatic dysfunction, fever, hypercalcemia, cachexia, erythrocytosis, thrombocytosis, polymyalgia rheumatica. (Lancet. 1998; 352:1691)

   2. Chemotherapy no longer used in treatment of RCC. Multi-targeted tyrosine kinase inhibitors and checkpoint immune blockade are treatments of choice. High-dose interleukin-2 is used occasionally in young, fit patients. (NEJM. 2015;373:1803) (NEJM. 2013;369:722)

   3. In patients with small-volume metastasis a nephrectomy to remove the primary mass has resulted in a prolongation of survival. (N Engl J Med. 2001;345:1655)

   4. In selected patients with low-volume, limited, resectable metastatic disease, surgical removal of the metastasis increases overall survival with occasional long-term remission. (Cancer. 2011;117:2873)

   5. The use of adjuvant therapy with multi-targeted tyrosine kinase inhibitors does not extend progression-free or overall survival in a placebo-controlled trial. (Lancet. 2016; published online March 14, 2016). A second trial in higher risk patients did show a survival benefit with adjuvant TKI inhibitors. (N Engl J Med. 2016; 375:2246)

Population

• –Adults with small renal masses SRM (<4 cm).

Recommendations

ASCO Guidelines (J Clin Oncol. 2017;35:668-680)

• –Based on tumor-specific findings and competing risks of mortality, all patients with an SRM (<4 cm in size) should be considered for renal tumor biopsy (RTB) when the results may alter management (strength of recommendation: strong).

• –Active surveillance should be an initial management option for patients who have significant comorbidities and limited life expectancy (end-stage renal disease, SRM <1 cm, life expectancy <5 y).

• –Partial nephrectomy (PN) for SRM is the standard treatment that should be offered to all patients for whom an intervention is indicated and who possess a tumor that is amenable to this approach (recommendation: strong).

• –Percutaneous thermal ablation should be considered an option for patients who possess tumors such that complete ablation will be achieved. A biopsy should be obtained before or at the time of ablation (recommendation: moderate).

• –Radical nephrectomy for SRM should be reserved only for patients who possess a tumor of significant complexity that is not amenable to PN or where PN may result in unacceptable morbidity even when performed at centers of excellence. Referral to experienced surgeon and a center with experience should be considered (recommendation: strong).

• –Referral to a nephrologist should be considered if CKD (GFR<45 mL/min) or progressive CKD develops after treatment, especially if associated with proteinuria (recommendation: moderate).

Sources

• –N Engl J Med. 2010;362:624.

• –Eur Urol. 2016;69:116.

• –JAMA. 2015;150:664.

• –Eur Urol. 2015;67.

Comments

1. SRM are commonly discovered incidentally during diagnostic evaluation for other medical conditions. A significant number of SRM are benign. As the size increases (especially >4 cm), the likelihood of malignancy increases. Imaging with MRI, CT scans, and ultrasound cannot make an absolute diagnosis of malignancy, necessitating a core biopsy if possible. About 10%–15% of patients will have a nondiagnostic biopsy and must be followed closely and rebiopsied if the mass is growing. Radiofrequency ablation (RFA) is commonly used to ablate small cancers but should have a biopsy done first to document malignancy.

2. Decision regarding therapy in patients with significant comorbidities is difficult. The Charleston Comorbidity Index (CCI) is a tool that can predict 1-y mortality. In patients with a short life expectancy, surveillance and supportive care are the best approach for this population. Partial nephrectomy is the treatment of choice for SRM that are amenable to nephron-sparing surgery. Radical nephrectomy in the past has been the procedure of choice in managing small RCC. Today partial nephrectomy is preferred and radical nephrectomy now is the treatment of choice in <30% of patients with SRM.