Renal Flashcards
What is the prevalence of kidney stones?
Approx. 1% of US Adults9% lifetime risk
What is the Epi of ESRD by race?
AA 3.5 X more than whitesLatinos 1.5X more than whitesAA 19x lower chance of receiving a kidney transplant
What is the Epi of CKD?
1 in 3 adults with DM1 in 5 adults with HTN1 in 2 adults aged 30-64 lifetime
What are the typical locations of pain with KD?
flank and abdominaldysuria
what are the typical general signs and sx of KD?
feverfatigue
What are the typical GI signs and sx of KD?
nauseavomiting
What are some common causes of pre-renal KD?
hypovolemiaCHFRAS
What are some common causes of post-renal KD?
prostate enlargementobstructing tumornephrolithiasis
What are some common intrarenal causes of KD?
ATNRenal vascular diseasetubulointerstitial diseaseglomerular disease
How do you define acedemia?
Low serum pH (less than 7.35)
low serum bicarbonate
(compensation causes compensatory alveolar hyperventilation and a resulting fall in PaCO2
How is H+ secreted by the kidney?
combined with NH3 to become NH4+
or HPO42- becomes H2PO4-
What are some common reasons for increased acid load?
lactic acid
ketoacids (DM, alcohol, starvation)
inorganic acid addition (HCL, NH4Cl)
What are two circumstances where NH4+ production in response to an increased acid load cannot occur?
- renal failure
- distal renal tubular acidosis (Type I)
There are only two routes of bicarbonate loss from the body. What are they?
- diarrhea
- urethra - tubular dysfunction
How do you calculate anion gap?
AG = Na - (Cl + HCO3-)
Figge correction = AG + [(4.4-Albumin) x 2.5]
What is a normal anion gap?
10-12
What does it mean if anion gap is high?
AG metabolic acidosis
What is the differential diagnosis for anion gap metabolic acidosis?
CUTE DIMPLES
Citrate
Uremia
Toluene
Ethanol
Diabetic ketoacidosis
Iron
Methanol
Paraldehyde
Lactate
Ethylene glycol
Salicylate
Which three causes of anion gap metabolic acidosis are NOT ingestion related?
- uremia
- ketoacidosis
- lactic acidosis
What stages of CKD are likely to be anion gap metabolic acidosis?
Stages 4-5
retention of hydrogen ion and sulfate anion due to marked reduction in nephrons and GFR
DKA causes anion gap acidosis how?
- insulin deficiency causes low glucose levels in the cell, leads to free fatty acid breakdown, which leads to acetone production
- glucagon excess causes free fatty acid conversion to ketoacids
What are the steps to diagnosing acid-base disorders?
- Is the patient acidemic or alkalemic?
- is the primary disorder respiratory or metabolic?
- For respiratory, process acute or chronic?
- for metabolic acidosis, is an anion gap present?
- Is it a mixed disorder?
- Is there appropriate compensation for the disturbance?
What’s a normal arterial pCO2?
36-44
What’s a normal aterial bicarb?
22-26
What is Winter’s formula used for?
Provides a measure of the expected respiratory compensation to a metabolic acidosis
Expected pCO2 = [1.5 x (HCO3)] +8 +/-2
metabolic acidosis ONLY
how do you interpret the results of Winter’s formula?
If the pCO2 is below expected, then respiratory alkalosis is present also
If the pCO2 is higher than the expected, respiratory acidosis is present also
citrate anion gap metabolic acidosis is usually due to one or more of these three things?
transfusion
trauma
anticoagulation
What is Type 1 Renal Tubular Acidosis?
Defect in tubule causing altered secretion of H+ as NH4+ with GFR usually preserved
Impaired apical H+-ATPAse
decreased carbonic anhydrase activity
increased permeability to H+
Overall, less net acid excretion
When bicarbonate is lost to diarrhea, sodium levels ____ and Cl- ____
Stay the same
Cl- in the serum increase
What is proximal renal tubule acidosis (Type 2)?
An inabilty to reabsorb HCO3- in the proximal tubule, leading to loss of bicarbonate in the urine unless distal can compensate
What are the major clinical manifestations of metabolic acidosis?
- Respiratory - increased ventilation
- CV - decreased contractility, arrhythmias
- GI - nausea/vomiting, abdominal pain, diarrhea
- MSK - weakness, osteomalacia, osteopenia, hypercalcuria
- CNS - lethargy, coma
- Kids - impaired bone growth, anorexia, listlessness
What causes metabolic alkalosis?
progessive loss of acids
(H+ with increased HCO3- generation)
What are some common caues of metabolic alkalosis?
GI
- vomiting
- nasogastric suction
- villous adenoma
Renal
- diuretics
- inherited transport defects
- mineralcorticoid excess
- posthypercapnia
What is contraction alkalosis?
when fluid loss creates alkalosis by increasing bicarbonate in the serum.
What are the common mimics of hematuria?
menstruationdrugspigmenturiabeets
What are the general categories of things that could cause hematuria?
infectionmalignancymetabolicglomerulartubulointerstitialtraumaother
What is a benign cause of transient gross hematuria in adults?
vigorous exercise
How is microscopic hematuria defined?
>3 RBCs/High Power Field in 2 or more specimens
Does a positive dipstick confirm hematuria?
No - myoglobin and hemoglobin also will cause a positive result
What are the major risk factors for bladder cancer?
smokingoccupational exposuregross hematuria>40 years oldcyclophosphamide (?)
What are the most common causes of hematuria in a person who is 0-20?
glomerulonephritisUTIcongenital
What are the most common causes of hematuria in a person who is 20-40?
UTI Calculibladder and renal cancer
What is the most common pathogen in UTI?
E. coli
What is the total mortality rate (direct and indirect) for hospital acquired infections?
About 30%
How much more common are UTIs in women than in men?
10-30x
What is the second most common pathogen in community acquired UTI?
Staph
What is the third most common pathogen in community acquired UTI?
Proteus
What are two common pathogens seen in hospital acquired UTI?
KlebsiellaPseudomonas
Who gets Staph saprophytic UTIs?
95% female16-35>20% incidencevast majority have symptomsdrug resistance unusualrelapse rare
Do patients with immune deficiencies get UTIs more often?
NO.
What is the GFR in a fully working kidneys?
200 ml/minute
What is the definition of CKD?
- kidney damage > or equal to 3 months, as defined by structural or functional abnormalities of the kidney, with/without reduced GFR manifested by either:
a. pathological abnml; or
b. markers of kidney damage, which is abnormal urine or imaging studies - GFR < 60 ml/min. for greater or equal to 3 months with or without kidney damage
why do we look at proteinuria or albuminuria in the urine?
Presence indicates a poor prognosis
How do people with CKD present?
No symptoms until eGFR less than 30 ml/min
- elevated serum creatinine
- microscopic or gross hematuria
- proteinuria (foamy urine)
- abnormal imaging study (incidential finding)
How do you work up CKD?
Follow the same path as for AKI,
but time course determines whether it is acute or chronic
How do you reduce hyperfiltration in the kidney?
Low protein diet
aldosterone antagonists or ACE-I/ARBs
What is the definition of metabolic acidosis?
Lowered serum bicarbonate and low pH
Bicarb less than 24
pH less than 7.35
What is a consequence of prolonged metabolic acidosis?
osteopenia or osteoporosis
What are the conditions for dialysis?
AEIOU
acid/base disturbance
electrolyte abnormalities
remove posions (intoxication)
volume overload
uremia (creatinine clearance < 15 ml/mn)
What is renal replacement therapy?
hemodialysis
peritoneal dialysis
kidney transplant
What are the indications for acute RRT?
AEIOU
- Acidosis, metabolic
- Electrolyte abnormalities (esp. hyperk or hypercal)
- Intoxications (think poisoning)
- Overload of fluid that is refractory
- Uremia - encephalopathy, pericarditis
What are the ways to obtain vasular access for hemodialysis?
Arteriovenous fistula is best!
arteriovenous graft
permcath (tunneled catheter)
quinton (non-tunneled) catheter - hospital only
Where are most tumors of the urinary tract located?
bladder
Are urinary tract cancers more common in men or women?
Men
bladder cancer is what percentage of total cancer?
7%
what is the male to female predominance of bladder cancer?
3:1
What is the most common tumor type in bladder cancer?
urothelial (transitional) tumors - 90%
What is the most important risk for bladder cancer?
cigarette smoking
What are some other exposure risk factors for bladder cancer besides smoking?
exposure to aryl amines (industrial)long term analgesic useheavy cyclophosphamide exposureschistosoma haematobium irradiation
What is the clinical presentation of bladder cancer?
- painless hematuria (but also sign in non-tumor lesions of the bladder)
- irritative symptoms (frequency, urgency, dysuria)
- hydronephrosis (when ureteral orifice involved)
How is bladder cance diagnosed?
- urine examination
- microsocpic exam
- FISH analysis
- cystoscopy
- washings/tissue biopsy
what is another name for urothelium?
transitional epithelium
What are the two precusor lesions to bladder cancer?
- noninvasive papillary tumors (mc)
- may progress to invasive carcinoma (different histologic grades)
- cauliflower-like
- fibrocascular core with cells coming off of it
- noninvasive flat carcinomas (carcinoma in situ)
- always severe atypia/high grade
- almost always progress to invasive carcinoma
What is the standard treatment for bladder cancer that invades the muscle wall?
cystectomy
(surgical removal of bladder)
What is the grading system for bladder tumors?
T1-T4
T1 - lamina propria invasion
T2 - muscularis propria invasion
T3 - extravesical fat invasion
T4 - invasion into adjacent structures/organs
Renal cell carcinoma are ____ of all newly diagnosed cancers in the U.S.
3%
(85% of adult renal cancers)
What is the male:female ratio of renal cell carcinoma?
2:1
What percentage of renal carcinoma is clear cell carcinoma?
70-80%
What is the most common mutation in renal cell carcinomas?
Von Hipple Lindau gene deletion on chromosome 3p
What does clear cell renal carcinoma look like pathologically?
- round cells with abundant clear cytoplasm (fat and glycogen)
- delicate branching vasculature (chicken-wire)
what is the cure rate for wilms tumor?
approximately 90%
What effect does the RAAS have on the glomeruli?
constricts the efferent arteriole
serum sodium concentration DOES NOT tell you __________
what is the patient’s TOTAL BODY SODIUM.
what’s normal serum sodium?
135-145 mEq/L
What are the CNS symptoms of hyponatremia?
Mild - apathy, headache, lethargy
Moderate - agitation, ataxia, confusion, psychosis
Severe - stupor, coma, tentorial herniation, cheyne-stokes
DEATH
What are the GI symptoms of hyponatremia?
VAN
vomiting, anorexia, nausea
What are MSK signs of hyponatremia?
muscle cramps
dimished deep tendon reflexes
What are CNS signs and symptoms of hypernatremia?
mild - restlessness, lethargy, irritability
moderate - disorientation, confusion
severe - stupor, coma, seizures
DEATH
What are the non-CNS signs and symptoms of hypernatremia?
Respiratory - labored breathing
GI - intense thirst, nausea, vomiting
MSK - muscle twitching, spasticity, hyperreflexia
What’s normal daily water intake?
1-1.5L/day
What’s typical insensible daily water loss?
0.5 L/day
What makes the collecting duct permeable to water so that it can be reabsorbed?
ADH
The ascending limb of the loop of Henle is also known as the ____________segment of the nephron
diluting
because it is pulling Na+ and other electrolytes OUT of the tubular fluid and reabsorbing them
what senses the osmolality of your plasma?
osmoreceptors in the hypothalamus
will release/supress ADH at the anterior pituitary
what’s normal plasma osmolality?
280-290 mOsm/Kg H20
What is the disorder of urine concentration
diabetes insipidus
How do you treat hypovolemic hyponatremia?
volume restoration with isotonic saline
identify and correct cause of water and sodium loss
(cholera and gastroenteritis)
How do you treat hypervolemic hyponatremia?
water restriction
sodium restriction
loop diuretics
treatment of underlying condition
ADH (V2) receptor antagonist (vaptans)
How do you treat euvolemic hyponatremia?
Is it SIADH? - Is the plasma level of ADH inappropriately elevated relative to plasma osmolality (in other words, low osmolality and salty pee?)
acute (less than 48 hours)
increase serum sodium at rate up to 2 meq/hour until asymptomatic
chronic (greater than 48 hours)
rate of correction should not exceed 1 meq/hour (no more than 18 in 24 hours)
measure serum and urine electrolytes every 2 hours
perform frequent neuro evals
What happens in the CNS in hyponatremia?
At first, K+, Na+ and osmolytes leave
later, H2O moves in
what should you suspect when you see hypernatremia in a patient who has access to water?
Diabetes insipidus
