CKD

Question 1

normal nephron fxn diagram

Answer 1

Question 2

non-urinary renal fxn

Answer 2

• Erythropoietin production
• Vitamin D activation
• BP regulation

Question 3

Evaluating kidney function

Answer 3

• BUN
• Creatinine clearance
• Estimated GFR
• Albumin to creatinine ratio in a spot urine sample

Question 4

BUN

Answer 4

• Urea is formed in liver from protein metabolism
• 85% excreted by kidney

Question 5

Creatinine clearance

Answer 5

• Produced by muscle in relatively steady state, filtered by kidney, some tubular secretion, almost no reabsorption
• ( [creatinine Urine] x Urine flow rate) / [creatinine Plasma]
  
  • urine flow rate (volume/time = ml/min),

Question 6

Estimated GFR

Answer 6

• Nl in adult male is 90-120 ml/min
• https://www.kidney.org/professionals/kdoqi/gfr_calculator

Question 7

Albumin to creatinine ratio in a spot urine sample

Answer 7

• 1st method of preference to detect inc protein
• To calculate, divide [albumin] in mg by [creatinine] in grams
• microalbuminuria = ACR 30-300 mg/g
  
  • Not detectable on dipstick
  • Must check immediately in type 2 DM

Question 8

Screening for CKD

Answer 8

• no generally accepted screening tool for CKD or risk of complications of CKD for asymptomatic adults. DM and HTN are risk factors with strong links to CKD and screening in those population is reasonable
• tests often suggested that are feasible in 1o care include testing the urine for protein and checking serum creatinine to estimate GFR

Question 9

CKD definition

Answer 9

• The Kidney Disease Outcomes Quality Initiative of the National Kidney Foundation definition:
• kidney damage

OR

• ↓ GFR (<60 mL/min/1.73 m2 )*
• for >3 months

•*Nl GFR =120 but with nl aging dec. to ~70 by age 70 yo

Question 10

Stage 1 CKD

Answer 10

• Kidney damage with normal or increased GFR (>90)

Question 11

Stage 2 CKD

Answer 11

• Mild reduction in GFR (60-89)

Question 12

Stage 3 CKD

Answer 12

• Moderate reduction in GFR (30-59)

Question 13

Stage 4 CKD

Answer 13

• severe reduction in GFR (15-29)

Question 14

Stage 5 CKD

Answer 14

• Kidney failure (GFR < 15) [or dialysis]

* some classifications combine Stages 5 and 6

Question 15

Stage 6 CKD

Answer 15

• Dialysis

* some classifications combine Stages 5 and 6

Question 16

Consideration for nephrology consult

Answer 16

Question 17

CKD etiologies

Answer 17

• DM
• HTN
• Cystic kidney ds
• Congenital defects
• Unrecovered AKI (eg prerenal → permanent ischemic damage)
• Urinary tract obstruction or dysfunction
• Vascular ds
• Tubulointerstitial
• Primary Glomerular dz
• Secondary Golmerular dz

Question 18

Urinary tract obstruction or dysfunction CKD causes

Answer 18

• BPH
• kidney stones
• Urethral stricture
• Tumors
• Neurogenic bladder
• Congenital defects of kidney or bladder
• Retroperitoneal fibrosis

Question 19

Vascular dz CKD causes

Answer 19

• RAS
• vasculitides
• atheroemboli
• renal vein thrombosis

Question 20

Tubulointerstitial causes of CKD

Answer 20

• Drugs; sulfonamides, allopurinol
• Infections: viral, bacterial, parasitic
• Sjögren syndrome
• Chronic hypokalemia
• Chronic hypercalcemia
• Sarcoidosis
• Multiple myeloma cast nephropathy
• Heavy metals
• Radiation nephritis
• Polycystic kidneys
• Cystinosis, other inherited ds

Question 21

Primary Glomerular Dz causes

Answer 21

• Membranous nephropathy
• Alport synd
• IgA nephropathy
• Focal and segmental glomerulosclerosis (FSGS)
• Membranoproliferative GN

Question 22

secondary glomerular dz causes

Answer 22

• DM
• SLE & other autoimmune ds
• Wegener granulomatosis
• Hepatitis B and C
• Syphilis
• HIV
• Parasitic infection
• Drugs: Heroin, Gold, Penicillamine
• Light-chain deposition ds, Amyloidosis, MM
• Neoplasia
• TTP, HUS
• Henoch-Schönlein purpura
• Reflux nephropathy

Question 23

CKD Epidemiology

Answer 23

• 1/10 American adults has some level of CKD
• 9th leading cause of death in the US
• prevalence ↑ with age
• 4% at age 29-39 yo
• 47% at age >70 yo
• ESRD ~350 per 1 million population

Question 24

Uremia

Answer 24

• encompassing the signs and symptoms of renal failure often used a synonym for chronic renal failure
• Usually occurs when creatinine clearance is <20/ml/min (Stage 4 or 5)

Question 25

Signs and symptoms of uremia

Answer 25

• Metabolic acidosis
  
  • dec. lean body mass
  • muscle weakness
  • inc. RR (Kussmaul respirations)
• Abn salt and water balance
  
  • peripheral edema
  • pulmonary edema
  • HTN
• Electrolyte imbalances
  
  • Arrhythmias
  • Hyperkalemia
  • Peaked T-wave
• Pericarditis
  
  • Uremic pericarditis
• Anemia
  
  • normochromic normocytic
  • due to dec. erythropoietin
  • fatigue
• Encephalopathy
• Peripheral neuropathy
• Restless leg syndrome
• Depression
• Malnutrition
• Bone disease
  
  • Vit D deficiency
  • dec. Ca++, inc. PO4-
  • secondary hyperparathryoidism
• Sexual dysfunction
  
  • ED
  • dec. libido
  • amenorrhea
• Platelet dysfunction
  
  • with NORMAL platelet count (thrombocytopathy)
    
    • Thrombocytopathyà renal failure causes
    • Thrombocytopeniaà renal failure does NOT cause
• GI symptoms
  
  • anorexia
  • N&V
  • diarrhea
• Skin manifestations
  
  • dry skin
  • pruritus
  • ecchymosis
  • uremic frost in feet picture

​

Question 26

Uremia Labs

Answer 26

• Chemistry
  
  • inc. K+, Mg++, PO4-, BUN, creatinine
  • dec. HCO3- (inc. AG metabolic acidosis), Ca++
• ABGs
  
  • metabolic acidosis dec. pH, dec. HCO3-
• CBC
  
  • dec. Hgb, Hct; nl MCV, MCH, MCHC
• Other labs
  
  • vary depending on the cause

Question 27

Delay Progression of CKD

Answer 27

Question 28

management of anemia in CKD

Answer 28

• treat with erythropoiesis-stimulating agents (ESAs), e.g. epoetin alfa and darbepoetin alfa If Hgb <10, after Fe sat and ferritin are at acceptable levels

Question 29

management of Hyperphosphatemia in CKD

Answer 29

• treat with dietary phosphate binders and dietary phosphate restriction

Question 30

management of hypocalcemia in CKD

Answer 30

• treat with calcium supplements + calcitriol (vit D)

Question 31

management of Hyperparathryoidism in CKD

Answer 31

• treat with vit D or calcimimetics
  
  • Cinacalcet is only FDA-approved drug of this class. It mimics Ca++ at the PTH receptor. This will inc. sensitivity of Ca++-sensing receptors on the parathyroid gland. As a result of the receptor “thinking” there is sufficient Ca++-, PTH secretion will dec.

Question 32

Management of volume overload in CKD

Answer 32

• treat with loop diuretics (e.g. furosemide/Lasix, bumetanide/Bumex, torsemide/demadex)

Question 33

management of metabolic acidosis in CKD

Answer 33

• treat with oral alkali supplementation

Question 34

management of Uremic manifestations in CKD

Answer 34

• treat with long-term renal replacement therapy (hemodialysis, peritoneal dialysis, or renal transplantation)

Question 35

Dialysis

Answer 35

• separation of substances in solution by means of their unequal diffusion through semipermeable membranes normally passing from the side of higher concentration to that of lower

Question 36

Hemodialysis

Answer 36

• Intermittent (IHD)
• Continuous renal replacement therapies (CRRT)

Question 37

Peritoneal dialysis (PD)

Answer 37

• Continuous ambulatory peritoneal dialysis
• Automated peritoneal dialysis

Question 38

Intermittent hemodialysis

Answer 38

• Most commonly used for CKD
• Total amount of solute transported per unit of time (clearance), depends on the MW of the molecule, membrane characteristics (dialysance), dialysate flow, and blood flow
• Usually, 3–6 h per treatment 3x/wk

Question 39

Intermittent hemodialysis acutely used for OD Tx of…

BLISTMEDO

Answer 39

• Barbiturates
• Lithium
• Isoniazid
• Salicylates (aspirin)
• Theophylline/caffeine (methylxanthines)
• Methanol
• Ethylene glycol
• Depakote
• Others - carbamazepine

Question 40

CRRT

Answer 40

• Applied for 24 h per day most commonly in an ICU for AKI
• Solute removal achieved by convection (hemofiltration), diffusion (hemodialysis), or combo(hemodiafiltration)
• Hemodialysis most efficiently removes small MW substances such as urea, creatinine, and K
• Middle and larger MW substances more efficiently removed by hemofiltration

Question 41

CRRT vs IHD

Answer 41

• CRRT has theoretical advantages
  
  • better fluid mgmt
  • less hypotension
  • better control of middle and large MW substances
  • ??? beneficial immunomodulatory effect in sepsis
• But these have not been demonstrated in RCTs to improve mortality or recovery of kidney function
• CRRT is more expensive

Question 42

Peritoneal dialysis

Answer 42

• Uses the peritoneum as a natural semi-permeable membrane for diffusive removal of solutes
• Very effective treatment modality in CKD, and pt outcomes are at least equivalent to hemodialysis
• Valuable in peds critical care
  
  • vascular access is challenging
  • peritoneal surface area is relatively larger than in adults
• Two methods
  
  • Continuous Ambulatory Peritoneal Dialysis (CAPD)
  • Automated peritoneal dialysis

Question 43

Continuous Ambulatory Peritoneal Dialysis (CAPD)

Answer 43

• Done while pt does nl activities. Pt places ~2L of fluid into abdomen by hooking a plastic bag of dialysis fluid to the tube in the belly. Raising the bag to shoulder level causes gravity to pull fluid into the belly. When empty, bag is removed and discarded.
• When exchange is finished, the fluid (which now has wastes removed from the blood) is drained from the belly and thrown away.
• Usually done 3-5x/day while pt is awake. Takes ~30 to 40 min. Some pts do exchanges at mealtimes and bedtime.

Question 44

Automated Peritoneal Dialysis (APD)

Answer 44

• A machine (cycler) delivers then drains dialysis fluid. Treatment usually done at night while pt sleeps.

Question 45

Indications for dialysis

Answer 45

• diuretic-resistant pulmonary edema
• hyperkalemia (refractory)
• met acidosis (refractory)
• uremic sx (pericarditis, encephalopathy, bleeding, etc.)
• dialyzable intoxications (eg, lithium, salicylates)

Question 46

Transplantation: recipient with ESRD gets a functioning kidney from a donor

Answer 46

• Donation may be from a living person, usually a relative
  
  • Best option in terms of success
  • May create a “chain” whereby a living donor who is incompatible with a relative gives their kidney to a stranger who also has a living relative who is willing to donate but incompatible. Then that person donates to another stranger continuing the chain.

OR

• Donation may be from a deceased person (formerly called cadaveric donation)
  
  • brain dead (heart still pumping) or
  • cardiac death given no chance of survival, mechanical ventilation is stopped, death is pronounced, body rushed to OR, organs removed and flushed with storage solution and anticoagulants – important to follow strict ethical guidelines!

Question 47

transplant recipients must…?

Answer 47

• Must take life-long immunosuppressives
  
  • Most commonly tacrolimus, prednisolone, mycophenolate
  • Also may use cyclosporine, sirilomus, azathioprine
  • Must avoid grapefruit, pomegranate, green tea bc of interactions with these meds

Question 48

transplant complications

Answer 48

• Rejection
  
  • Hyperacute within minutes
    
    • kidney must be removed immediately to prevent patient’s death
  • Acute 1 week - 3 months
    
    • 10-25% in initial 30 days but does not mean kidney is lost
    • Only 7% have failed within a year
  • Chronic ongoing over years
• Bleeding
• Thrombosis

Question 49

transplant : Drug-related complications

Answer 49

• Immunosuppressive drugs
  
  • infection/sepsis
    
    • CMV, HSV, HZ
    • bacterial, esp pneumonia
    • fungal , parasitic
  • post-transplant lymphoproliferative disorder (form of lymphoma)
• Cyclosporine
  
  • hirsutism
• Tacrolimus
  
  • Alopecia
• Steroids
  
  • UGI bleeding
  • Cushings synd
  • DM
  • osteoporosis
  • acne
  • dyslipidemia