AKI & CKD Flashcards
AAFP Board Review lecture: Acute Kidney Disease & Chronic Kidney Disease
1
Q
Name 4 functions of the kidney
A
Hormone secretion
Regulates blood pressure
RBC production- Erythropoietin
Calcium and phosphorous regulation
2
Q
If a UA is positive for blood but no RBCs are present what should you consider?
A
Hemolysis
Rhabdomyolysis
3
Q
What proteins are measured on a UA?
A
Only albumin
4
Q
What UA finding likely indicates UTI?
A
Positive leukocyte esterase (highly sensitive, more likely to be sole indicator of UTI)
Positive nitrite is highly specific
5
Q
What would you consider if UA showed WBCs but no bacteria?
A
Urethritis
Prostatitis
Interstitial nephritis (eosinophils)
6
Q
Which type of casts can be normal and which are always abnormal?
A
Can be normal: hyaline and granular casts
Always abnormal: RBC casts (glomerulonephritis) WBC casts (pyelonephritis)
7
Q
What is the normal range of 24 hour urine protein excretion? pregnant v. non pregnant
What range indicates nephrotic syndrome?
A
<150 mg/24 hours if non-pregnant
<300 mg/24 hours if pregnant
3g/24 hours => nephrotic syndrome
8
Q
What are the ranges for normal microalbumin/creatinine ratio v. microalbuminuria v. macroalbuminuria?
A
Normal: <30 mg/g
Micro: 30-300 mg/g
Macro: > 300 mg/g
9
Q
What are the most common causes of death in patients with renal problems (AKI/CKD)?
A
Infection complications
Cardiopulmonary disease
10
Q
What is the KDIGO criteria for AKI?
A
- Increase in serum Cr of >=0.3 in 48 hours
- Increase in serum Cr of >= 1.5 times baseline within the prior 7 days
- Urine volume <0.5 mL/kg per hour for more than 6 hours
11
Q
What is the most common cause of AKI?
A
Acute tubular necrosis
followed by prerenal causes
12
Q
List some examples of prerenal AKI
A
Dehydration, bleeding
Shock, CHF (cardiorenal), cirrhosis (hepatorenal), thromboembolic disease
13
Q
Name some causes of Acute Tubular Necrosis
A
Hypotension, sepsis Ischemia Surgery, burns Toxins Rhabdo
14
Q
Name some causes of Acute Interstitial Nephritis
A
Drugs
Autoimmune
Infection
Infiltrative diseases
15
Q
What are some clinical signs of Acute Interstitial Nephritis?
A
Fever
Rash
Elevated serum and urine eosinophils
16
Q
How to treat Acute Tubular Necrosis?
A
No therapy available to hasten recovery
17
Q
How to treat Acute Interstitial Nephritis?
A
Remove offending agent if possible
+/- steroids (may be beneficial)
18
Q
Name some drug classes that have increased risk of Acute Interstitial Nephritis
A
PPIs NSAIDs Sulfonamides Allopurinol Thiazides, Furosemide Pheytoin Cephalosporins Ciprofloxacin Penicillin Rifampin Cimetidine
19
Q
Name some causes of Intrarenal AKI
A
Multiple myeloma
Hypercalcemia
Tumor lysis syndrome
Acute phosphate nephropathy (ex: phosphate containing bowel prep for colonoscopy)
Glomerular disease
20
Q
Clinical signs of glomerular intrarenal AKI?
A
Fever, rash, arthritis, edema
RBC casts, hematuria, proteinuria
21
Q
Nephritic v. Nephrotic syndrome clinical findings
A
Nephritic:
RBCs and RBC casts in urine
HTN
mild proteinuria
Nephrotic: Massive proteinuria Edema hypoalbuminemia hyperlipidemia hypercoagulable state
22
Q
Nephritic or nephrotic?
Post infectious glomerulonephritis
A
Nephritic
23
Q
Nephritic or nephrotic?
IgA Nephropathy
A
Nephritic
24
Q
Nephritic or nephrotic?
Minimal change disease
A
Nephrotic
25
Nephritic or nephrotic?
Rapidly progressive glomerulonephritis
Nephritic
26
Nephritic or nephrotic?
Diabetic nephropathy
Nephrotic
27
Nephritic or nephrotic?
Focal segmental glomerulosclerosis
Nephrotic
28
Nephritic or nephrotic?
Mesangial proliferative glomerulonephritis
Nephrotic
29
Nephritic or nephrotic?
Membranoproliferative glomerulonephritis
Nephritic
30
Nephritic or nephrotic?
Membranous glomerulonephritis
Nephrotic
31
Nephritic or nephrotic?
Primary Amyloidosis
Nephrotic
32
Nephritic or nephrotic?
Henoch-Schonlein purpura
Nephritic
33
Nephritic or nephrotic?
Preeclampsia
Nephrotic
34
Nephritic or nephrotic?
Vaculitis
Nephritic
35
How to evaluate for postrenal AKI?
Renal US
*recovery is directly proportional to duration of obstruction
36
Signs to get a renal biopsy in patient with AKI?
```
Oliguria
Rapidly worsening GFR
Ruled out pre and post renal causes
No clear intrinsic cause
May need confirmation of diagnosis before starting treatment (immunosuppressants)
```
37
Signs of contrast induced nephropathy?
Increase in serum creatinine >= 0.5 or 25% above baseline
38
Treatment of contrast induced nephropathy?
Usually reversible (1% -> dialysis)
Begins to improve in 3-7 days
39
Name some ways to prevent contrast induced nephropathy
Stop metformin 48 hours before
Isotonic IV hydration
Inconsistent evidence for urine alkalization, Acetylcysteine
40
How to interpret FENa?
<1% prerenal
1-2% intrinsic
>2-3% ATN
41
What should you use instead of FENa if a patient is on diuretics and why?
FeUrea: <35% prerenal, >50% ATN
diuretics induce Na excretion, looks like intrinsic renal
42
How can obstruction affect FENa?
early obstruction: <1%
| chronic obstruction: >1%
43
What electrolyte disturbances can AKI cause?
```
Metabolic acidosis
Hyperphosphatemia
Hyperkalemia
Hyper or hypo calcemia
Azotemia
```
44
How to calculate MAP and what is the goal?
(systolic + 2x diastolic)/ 3
Goal > 65
45
In patients with AKI and decreased or no urine output should diuretics be used to stimulate urine output?
No
Increased mortality, does not promote renal recovery
46
In patients with AKI and volume overload should diuretics be used to stimulate urine output?
Yes
Lasix 20-100 IV q6 as initial treatment
47
What is the treatment of hyperkalemia?
1. Calcium gluconate 10%, 10 ml IV - cardioprotection
2. Insulin 10 u IV and glucose 25 g- shift K intracellular
3. Inhaled beta agonists
4. Patiromer (Veltassa) 8.4 - 25.2 g daily
5. Sodium Bicarb 3 amps in 1L 5% dextrose
48
When should bicarb be given in acidosis?
if serum bicarb <15 or pH <7.2
49
What are the indications for dialysis in AKI?
Metabolic acidosis pH <7.1
Uremia- altered, pericarditis/pleuritis, neuropathy
Fluid overload refractory to diuretics
Hyperkalemia >6.5
Toxins- ethylene glycol, lithium
50
Name some general principles of AKI prevention
Maintain hydration, avoid hypotension
Avoid nephrotoxic medications
Avoid unnecessary exposure to contrast
51
Patients who have had an AKI are at higher risk for what 3 problems?
Developing CKD
Higher risk of ESRD
Higher risk of premature death
52
What two cardiac conditions are patients with CKD at higher risk of?
Atherosclerotic CVD
Heart failure
*CVD is the cause of up to 50% of the deaths in pts with renal failure
53
Where and why is renin released?
Released by the juxtaglomerular apparatus
```
Due to:
Fall in BP
Dec blood volume
Dec [Na] in distal tubule
Sympathetic stimulation
```
54
What effects does Angiotensin 2 have?
Direct arterial vasoconstriction (efferent arterioles)
Aldosterone secretion from adrenal gland (Na retention)
Vasopressin release from post. pituitary (water retention at distal tubule)
55
What effects do ACE inhibitors have?
Block conversion of angiotensin I to II
Increase levels of angiotensin I, renin and bradykinin
Lower arteriolar resistance
Increase venous capacity
Increase Na excretion
Enhance parasympathetic activity
56
How do ACE inhibitors benefit CHF patients?
Reduce plasma norepinephrine levels:
- reduce prevalence of cardiac arrhythmias
- reduce sudden death
- reduce cardiac remodeling that worsens CHF
57
How may ACEi/ARBs change renal funtion?
Dilate efferent arteriole
- Inc flow through glomerulus
- Dec Cr excretion (increased serum Cr)
58
How can you tell if an increase in Cr after starting and ACEi/ARB is a hemodynamic change v. structural change?
hemodynamic: If Cr increased 20-30% then stabilizes
Structural: >30% in Cr (d/c medication, work up causes of renal dysfunction)
59
If Cr increases >30% after starting an ACEi/ARB, what causes might you think of?
Bilateral renal artery obstruction (also think about stenosis)
Low intravascular volume (dehydration, CHF)
Renal vasoconstriction (NSAIDS)
60
True or False?
Patients with CKD are more likely to die of cardiovascular disease than to require dialysis
True
61
What are the two main risk factors for CKD?
Diabetes
Hypertension
*Autoimmune, glomerular disease, cystic disease, toxins, family hx, lower urinary tract obstruction, infections, AKI, etc.
62
What causes of CKD have the highest risk of developing ESRD and needing a transplant?
Diabetic kidney disease
HTN nephropathy
Chronic glomerulonephritis
Polycystic kidney disease
Chronic pyelonephritis
Renal calculi
63
What is the KDOQI definition of CKD?
```
Kidney damage for >3 months
-structural or functional
+/- dec GFR
-abnormal testing, persistent albuminuria
-Pathological abnormalities
```
or
GFR <60
+/- kidney damage
64
GFR in CKD1
GFR >90 (normal) with kidney damage
65
GFR in CKD2
GFR 60-89 (normal) but with other evidence of kidney damage
66
GFR in CKD3a
GFR 45-59
67
GFR in CKD3b
GFR 30-44
68
GFR in CKD4
GFR 15-29
69
GFR in CKD5 (ESRD)
GFR <15
70
Albuminuria in CKD, stages?
A1 <30 mg/g
A2 30-300 mg/g (microalbuminuria)
A3 300 mg/g (macroalbuminuria)
71
What are the baseline labs for CKD evaluation?
UA with microscopic
Random (or 24 hour) urine Cr/GFR
Random (or 24 hour) urine protein
CBC, CMP, Ca, Phosphorous
Uric acid
72
What tests might you order in addition to the baseline labs for CKD evaluation?
Serum protein electrophoresis
Hep B and C, HIV
ANA
C3/C4
ANCA
Anti-GBM antibody
73
What imaging may be helpful in CKD evaluation?
Renal US
CT kidneys and liver
MRI
Renal angiogram
Voiding cystourethrogram
74
What are the indications to get a biopsy in CKD?
Persistent hematuria with low GFR or proteinuria
Nephrotic range proteinuria
CKD of unknown cause
75
Who is at risk of developing Nephrogenic Systemic Fibrosis?
Patients with CKD4/5 (GFR <30), on dialysis, or with AKI who receive gadolinium contrast (MRI)
*gadolinium forms insoluble salts with anions and deposits in tissues leading to fibrosis
76
What are some symptoms of Nephrogenic Systemic Fibrosis?
Skin plaques (itchy, painful, discolored)
Joint contractures
Fibrosis of organs
77
What is the treatment of Nephrogenic Systemic Fibrosis?
None
Dialysis does not help
Avoid gadolinium if GFR <15
78
Management of CKD 1 and 2?
Diagnose and treat comorbid conditions
Slow progression
CV risk reduction
Encourage patient self management
79
Management of CKD 3?
Evaluate and treat complications
Slow progression
CV risk reduction
Encourage patient self management
80
Management of CKD 4?
Refer to nephrology
Prepare for kidney transplant
Continue measure to slow progression and eval and treat comorbid conditions
81
Management of CKD 5?
Transplant or dialysis
82
How often should GFR be monitored in CKD?
At least yearly
More often if GFR <60 or fast progression
83
Name some complications of CKD?
HTN
Anemia
Acidosis
Hyperkalemia
Metabolic bone disease
Cardiovascular disease
84
What should be reviewed at all visits in patients with CKD?
Medications
- renal dosing as GFR changes
- Monitor side effects
- D/c meds with adverse renal effects
85
KDOQI HTN guidelines for CKD
BP goal?
If albumin/Cr ratio <30: BP <140/90
If alb/Cr ration >30: BP <130/80
86
KDOQI HTN guidelines for CKD
Medication selection?
- ACEi/ARB if DM or proteinuria
- Include diuretics for most patients
- Additional agents should be selected based on CVD indications
87
KDOQI HTN guidelines for CKD
Use ACEi/ARB if?
Patients with DM kidney disease:
-Alb/Cr ratio >30 or GFR <60, +/- HTN
Patients with NON dm kidney disease:
-Alb/Cr ratio > 300 or urine alb >300 in 24 hours, +/- HTN
*ACEi/ARB can be used safely in most patients with CKD
88
KDOQI HTN guidelines for CKD
Diuretic use?
Use thiazides if GFR >30
Use loops if GFR < 30
*Caution in K sparing diuretics due if GFR <30, taking ACEi/ARB, HyperK risk factors
89
KDOQI HTN guidelines for CKD
Dietary Na goal?
Less than 2.4 grams/day of Na
90
KDOQI Anemia guidelines for CKD
Definition of anemia?
Males: Hb <13.5
Females Hb <12
91
KDOQI Anemia guidelines for CKD
Initial labs?
CBC (annually)
Absolute reticulocyte count
Ferritin
transferrin saturation
Iron
TIBC
92
Serum iron, TIBC and Fe/TIBC in Anemia of chronic disease v. Iron deficiency anemia?
Anemia of chronic disease: Low Fe, TIBC low, Fe/TIBC normal (>15%)
Iron def: Low Fe, TIBC high, Fe/TIBC low (<15%)
93
Treatment of anemia of chronic disease?
Treat underlying cause
Erythropoiesis- stimulating agents
Transfusion
94
When to use erythropoiesis- stimulating agents?
Symptomatic anemia not improved by treating underlying cause
Hb <11 or <10 (if dialysis)
95
What are some risks of Erythropoiesis- stimulating agents?
Increased mortality and risk of CV events (MI, CVA, CHF) in CKD patients
Increased mortality and risk of tumor progression in cancer patients
Increased thromboembolic events in surgery patients
Contraindicated in uncontrolled HTN
96
KDOQI Anemia guidelines for CKD
Transfusion principles
- Use transfusion judiciously (sensitivity affects future transplant ability)
- No specific Hb trigger
- EPO target Hb is not a transfusion trigger
97
Causes of anion gap metabolic acidosis?
MUDPILES
```
Methanol
Uremia
DKA
Propylene Glycol
Iron and INH
Lactic acidosis
Ethylene Glycol
Salicylates
```
98
What causes metabolic acidosis in CKD?
Decreased H+ excretion
Bicarb <22 associated with increased CKD progression and inc mortality
99
Treatment of acidosis in CKD?
Goal: serum CO2 >=22
-Na bicarb (0.5-1 mEq/kg/day)
-Na citrate
-Ca acetate
Ca carbonate
100
Pattern of Ca, PO4 and PTH in CKD?
Ca low
PO4 high
PTH high
*Secondary hyperparathyroidism
101
What causes Secondary hyperparathyroidism in CKD?
Dec GFR -> phosphate retention
Decreased free Ca
Decreased 1,25 Vit D
102
KDOQI dietary phosphorous guideline?
Less than 800-1000 mg/day if PO4 is elevated
Use PO4 binders if phosphate is uncontrolled despite diet
103
Name 3 PO4 binders
Non Calcium containing:
Sevelamer (Renleva) 800- 1600 mg TID
Lanthanum (Fosrenol) 1500-3000 mg/day
```
Calcium containing:
Ca acetate (PhosLo) 1300-2600mg with meals
```
*non-calcium containing binders, better per KDOQI
104
What is calciphylaxis?
Calcific uremic arteriolopathy
-Ca deposits in small vessels, skin, fat
CKD5 on dialysis patients most at risk
105
What are the symptoms of calciphylaxis and treatment?
Extremity pain, non healing ulcers, infection
Tx: Na thiosulfate
*high 1 year mortality
106
Explain screening for albuminuria, who? how often?
T1 DM: 1-5 years from initial diagnosis
T2DM: At diagnosis
If normal, screen annually
If positive, confirm with samples over 3-6 months (confirmed if 2/3 samples positive)
107
What is the preferred test for albumin screening?
Random spot albumin/Cr ratio
Normal <30 mg/g
Microalbuminuria 30-299 mg/g
Macroalbuminuria >300 mg/g
108
What are some ways to prevent progression of albuminuria?
Intensive blood glucose and blood pressure control
ACEi/ARB therapy
109
If a patient has diabetes, normal blood pressure and alb/Cr ration is less than 30, should they be started on an ACEi/ARB to prevent CKD?
NO
If a patient has diabetes and normal blood pressure only start ACEi/ARB if they have an alb/Cr ratio >30 or GFR <60
110
When should a patient with NON diabetic CKD get an ACEi/ARB?
If they have HTN or alb/Cr >300
111
What is the dietary protein goal for CKD patients?
0. 8- 1.0 g/kg/day in early stages
| 0. 8 g/kg/day in later stages
112
When should CKD patients be referred to nephrology?
If they develop:
Complex, severe CVD
Anemia
Bone mineral disorder
Hyperkalemia (K >5.5 despite treatment)
Alb/Cr > 300 mg/g
Resistant HTN (on 3+ medications)
CKD stage 4 (GFR <30)
Unexplained decrease in GFR (>30%)
113
What is the goal Hb for a patient on erythropoiesis- stimulating agents?
Hb goal should not exceed 11
