Nephrology and Urology 6% Flashcards
Primary d/o
Dec’d HCO3 (met acidosis) -> dec’d PCO2 (resp alk compensation) -> 1.3(change in HCO3) +-2
Inc’d HO3 (met alkalosis) - -> inc’d PCO2 (resp acidosis compensation) -> 40+0.7 (change HCO3)
Inc’d PCO2 (resp acidosis) -> Inc’d HCO3 (met alkalosis compensation)-> Acute 1 HCO3 for 10 PCO2, Chronic 3.5 HCO3 for 10 PCO2
Dec’d PCO2 (resp alkalosis) -> dec’d HCO3 (met acidosis - compensation)-> Acute 2 HCO3 for 10 PCO2, Chronic 5HCO3 for 10 PCO2
Acid/base Method
- Check pH >7.4 alkalotic - met if bicarb inc, resp if CO2 dec
met if bicarb dec, resp if CO2 inc - Check AG - Na+- (Cl+HCO3)
- Compensation
- Met Acidosis with AG - 1:1 rule - change in AG = change bicarb (only if doing AG met acidosis)
Non gap metabolic acidosis causes?
Lower GI losses (diarrhea) /ureteral diversion (like diarrhea)
RTA
Prox: MM, acetazolamide, lead, topamax,
Distal: Sjogrens, lupus, amphote, foscarnet, toluene
RTAs
Proximal RTA (II) - pH=5, urine AG neg (not able to reclaim bicarb) - spills bicarb - UpH alkaline at first but then acidifes in functional distal tubule Distal RTA (I) pH>5.5 - pos Urine AG (inappropriately alkaline urine in setting of systemic acidosis) - a/w CaPO4 kidney stones
Diarrhea - pH=5 - tubules are working - diarrhea gets rid of lots of bicarb in blood - kidneys still get rid of ammonium and hydrogen to compensate - pH of urine still acidic - neg AG urine
Hyporenin hypoaldo (IV) - no aldo, can’t get rid of K -> get hyperkalemia - alkaline pH
Confirm RTA
Urine anion gap = negative (normal) - measure for urine - when can acidify urine/diarrhea ammonium (unmeasured cation)
When AG + -> not dumping ammonium
Proximal RTA vs diarrhea
check products that would be dumping due to prox RTA (AA, glucose, phosphate) - not diarrhea if see these
Anion Gap metabolic acidosis
M ethanol U remia D iabetic ketoacidosis P ropylene glycol, paraldehyde I sonazid (INH) L actate E thylene glycol, ethanol S alicylates - ** also causes respiratory alkalosis
Metabolic gap acidosis with Osmolar gap
AG and Osmolar Gap Methanol Propylene glycol Ethylene glycol, ethanol Osmolar gap=
Ketosis without acidosis in substance AG normal bicarb normal
Isopropyl etoh
Metabolic alkalosis
PCO2 inc’d = 0.6(change in bicarb)
MC acid base abnormality - everyone on diuresis and vomiting (bicarb up, lose hydrogen) - maintained cuz pre-renal - can’t get bicarb out
pH high - high bicarb level
PCO2 inc’d = 0.6(change in bicarb)
Chloride responsive (to saline) - Ucl 20 (hyperaldo)
Mineralocorticoid excess
Diuretic (recent)
Gittleman - like HCTZ dec K, normal BP, UCl>15
Barter’s syndrome - like lasix, normal BP Ucl ?15
Little’s/licorice ingestion - high BP, Ucl>15, dec’d K
Respiratory Acidosis
not breathing - too much PCO2 (chest wall injury, obstruction, CNS resp depression, COPD (chronic)
Acute 1 inc HCO3 for 10 inc PCO2
Chornic 4 inc HCO3 per 10 inc PCO2
Respiratory Alkalosis
Hyperventilating - PE, high altiutde, PNA, sepsis
Acute - dec 2 HCO3 per 10 dec PCO2
Chronic - 5 dec HCO3 per 10 dec PCO2
Glue sniffing
distal RTA (alkalotic urine)
Serum Osm=
2(Na+) + BUN/2.8+Gluc/18
Osm gap=
Ethylene glycol->glycolic acid->CaOx crystals->ATN
Measured serum osm-calculated Osm
if osm gap>50 needs HD
if osm gap <50
Non-gap Met acidosis
Loss of bicarb or unable to excrete H+ RTA Diarrhea Ureterosigmoiostomy Early renal failure Post hyperventillation (blowing off PCO2 - kidney dumps bicarb, absorbs Cl-)
Toner fluid/acetone/isopropyl etoh
NOT converted to acid
converts to ketone - not acidic
No AG
inc’d serum osm
Dec’d transportaion defect in ascending loop of henle
Bartter’s syndrome (Lasix), low BP, low K, UCl>15
Dec’d transportationd ef in deistal tubule
Gitelman’s (HCTZ) low BP, low K, UCl>15
INc’d (aldo independent) transport in distal tubule
Liddle’s syndrome (high BP) low K, UCl>15
Pt p/w ingestion unknown substance pH7.18, PCO2 23, Bicarb 8, Na 136, Cl 100 HCO3 10 - Ca Ox crystals
Gap metabolic acidosis
Ethylene glycol
tx: ethanol if Osm Gap 20
HD if osm gap >50
pt brought in with confusion, convulsions and blindness after injesting uknown substance - pH 7.24, PCO2 28, HCO3 14 Na 136, Cl 100 HCO3 15 dx?
Methanol poisoning
formic acid - blindness
Pt to ER depressed/somnolent - friend says was initially excited - injgested unknown substance - smells acetone/ acetone urine +, likely ingested?
Isopropyl etoh
18yo brought to ER with confusion, seizure and ataxia dec’d DTR, fruity odor on breath - dx?
Toluene toxicity (glue sniffing)
Pt with tinnitus, lethargy, tachycardia - pH7.48, Na+140, Cl 100, HCO3 16 - pt has?
ASA tox
Resp alkalosis -> Met acidosis
76yo pt needs to inc’ TV to hear better - c/o ringing in ear mild dizziness - pt with HTN taknig ASA x 10 years - VSS dx?
ASA tox (confusion, fever, hyperventilation, acidosis)
Non AG
Chronic renal failure
HyperK
peaked T wave
Renin problem
Aldo problem - not enough aldo (blocked by ACEi, spironolactone), hyperK, acidosis
Pre-renal state, no distal Na+, can’t dump K into urine (needs K for pump to work)
Insulin def (cellular shifting)
Impaired renin (NSAIDS, BB, cyclosporin, tacrolimus, DM, age)
ACEi
ARB
Impaired aldo metabolism
Aldo rct blockers (spironolactone, epleronone)
Na+ channel blockers (need Na+ into cell to get K out of cell)
Acidosis - Type IV RTA (hypoaldo, hyporenin), CKD
Hypo K
Hyperaldo prim or sec
GI losses - diarrhea/vomiting
Conn’s primary hyperaldo - tumor producing too much aldo - suppresses renin
Acidosis - RTA I/II, diarrhea, toleune
Alkalosis - hyperaldo, loop/thiazinde diuretics, genetic d/o, vomiting
Type IV RTA
no aldo
hyperkalemic
no renin
Osmolarity
2x[Na+]+gluc/18+BUN/2.8
Pre-renal
baro rct’s
No blood to JGA/macula densa
Kicks out renin/angio/aldo secreted
ADH released to hold onto water
Thirst center
hypothalamus releases ADH-> reabsorbs water from urine
CHF/GIB
both high aldo/renin
low urine Na+
SIADH
hyponatremic with high urine osm (inappropriate - should be dilute)
Hypernatremia
Neg free water balance abn thirst mech/no access to wate excessive free water loss (sweat, diarrhea, osm diuresis, DI (no vasopressin or kidney not responsive to vasopressin) kidney should conc for level of hyperosm Excessive hypertonic saline
Diabetes insipidus
hypernatremic and urine osm is low
urine is too dilute - should be concentrated and keeping water to combat high Na in blood
Central vs nephrogenic DM
Give DDAVP - better? Central DI
not better? nephrogenic DI
Hyperosmolar hyponatremia
Glucose - sugar 1000 - all in blood - osm high because of glucose - water rushes into blood from cells - sodium goes down - hyponatremia
Correction factor gluc >300, for every inc 100, dec Na 2.5
Hypoosmolar hyponatremia
serum osm low, sodium low - too much water in blood - urine should be dilute
If Uosm high - kidneys not working or too much ADH
Example:
Hypovolemic - cerebral salt wasting, diarrhea, beer potomania
Isovolemic - SIADH, exstacy
Hypervolemic - CHF
Primary polydipsia
Serum osm low, urine osm low
Too much ADH (SIADH)
Etio
Renin-angio system elev
Urine Na low - pre-renal - has CHF/GIB/sepsis - stimulating ADH release
If not pre-renal (Urine Na+ high)
HCTZ/salt losing nephropathy
Inc’d ADH from non-volume, non-osmotic source (tumor)
SIADH
Inapprop conc urine in setting of watery blood normal effective circulating volume (no renin-aldo issue) Causes CNS Pulm - PNA Oat cell carinoma Post op Drugs - NSAID, SSRI,
Tx: restrict water Vaptan (block adh) Diuretic - lasix If MS changes - hypertonic saline
SIADH vs HCTZ hyponatremic hyponatremia
SIADH - all blood numbers look dilute (BUN, Cr Uric acid)
HCTZ - BUN Cr is high, bicarb high ish
Primary polydipsia vs
Central DI vs
Nephrogenic DI
Baseline Serum Na 140, Uosm 100, UOP 8
Water deprivation Serum Na 147, Uosm 110, UOP 7.8 (not primary polydipsia - without water input, still peeing a lot, still dilute urine, Na going up)
DDAVP Serum Na 149, UOsm 115, UOP 7.5 - (Not central DI, if it was DDAVP would cause UOP to go down, urine osm would go up significantly) -> Nephrogenic DI
Central DI
after DDAVP - urine OSM goes up, UOP goes down, serum Na goes down
Primary polydipsia
after water deprivation, Uosm goes up, UOP goes down, Serum Na goes down (not diluted)
28yo M DM pt with anusea, BS 310 - Na 135, K 5.6, Cl 94, HCO3 20
AG=21 - DKA (BS 310)
28yo M DM p/w nausea, BS 310 Na 135, K 5.6, Cl 104, HCO3 20
AG = 11 (no gap) - non- gap -> Type IV RTA?
80yo taking NSAID and tylenol for OA - Na 138, Cl 100, bicarb 16, ABG pH 7.3, PCO2 32
Met Acidosis AG=22 - > Gap Compensation - 1.3 (8) about 10 - pCO2 is 37 should be 30 -> concominant respiratory acidosis Tylenol toxicity (salicylate)
Na 135, Cl 80, HCO3 24, BUN cr 110/11, pH 7.4, pCO2 37, HCO3 22 pt has?
pH normal 2. Compensation - 3. change in AG - 31-12=19 if bicarb serum > change in AG (19) then met alkalosis if delta gap/delta bicarb>2 then met alk + metabolic acidosis
change in anion gap from normal should equal change in bicarb from usual level - if not then indicates other process - so there is concurrent metabolic acidosis
Chronic renal failure with vomiting
Na 142 K 3.3, Cl 95, HO3 38 BP 150/100, Renin level low Ucl >20 most likely has?
Licorice ingestion (high BP, low K) or could be little’s defect (not gittleman or barrters - low/normal BP low K)
Pt with exacerbation of COPD PCO2 70 pH 7.45, pedal edema intubated/vent -> PCO2 now 50, furesemide gien -> extubated and d/cd on tiotropium albuterol steroids and lasix - 1 week later pH 7.46, PO2 55, PCO2 60, bicarb 40 - most likely cuase - ?
Diuretics
COPD pt with PCO2, PO2 60, bicarb 28, pedal edema - tx’d wit htiotropium and diuretics - 1 week later PCO2 60, bicarb 40 - pt on O2 and pedal edema decreased - wtd?
KCl runs - fixes hypo K, decreases bicarb
pH 7.6, PCO2 30, PO2 70, bicarb 32
Respiratory alkalosis (CO2 low) Metabolic alkalosis (HCO3 high)
pCO2 reduced despite high bicarb - when pCO2 and HCO3 move in different directions from reference values there are at least 2 acid base problems present - low PCO2 indicates resp alkalosis, high HCO3 shows metabolic alkalosis
Scenario - pre-existing metabolic alkalosis from thiazide therapy - develops PNA with hyperventilation causing respiratory alkalosis
pH 7.3 PCO2 50, HCO3 22, Na135, HCO3 24, Cl 82
Resp acidosis (low pH, high PCO2) compensated - HCO3 should be 22-26 AG=29 - > AG metabolic acidosis Delta delta - 17/0= infinity (>2) so AG met acidosis+met alkalosis
pH7.5, PCO2 30, HCO3 24, Na 144, Cl 80
Resp alkalosis (high pH, low PCO2) compensated - HCO3 should be 20-24 AG=40 - AG metabolic acidosis delta delta - 28/0 = infinity - AG met acidosis + metabolic alkalosis
pH 7.48, PCO2 32, PO2 90, HCO3 24, Na 135, Cl 84, HCO3 24
Resp alk alkalosis (high pH, low PCO2)
compensated (HCO3 should be 20-24)
AG=27 - AG metabolic acidosis
delta delta - 15/0 >2 -> AG met acidosis + met alkalosis
RTA
Prox RTA (II) Defect - reabsorbtion of HCO3 -> temporarily alk urine then acidifies in functional distal tubule Dz: Fanconi's MM Acetazolamide Topiratmate Osteomalcia \+- stones hypoK+ UpH 5.5
Fanconi’s
RTA II
Osteomalaica
RTA II
Hypokalemia
RTA I&II
Nephorlitiasis
RTA I&II
Urine pH>5.5
RTA I
HyperK+
RTA IV
DM
RTA IV
MM/Acetazolamide
RTA II
Dry mouth, enlarged partid, arthralgia
Sjogrens -> RTA I
Hyponatremia problems
Normal - Serum Na 135-145, UNa>20, UOsm 600, post water dep Ur Osm inc’d, post DDAVP UOsm inc’d
Central DI Serum Na inc’d, UNa dec’d, UOsm Dec’d, Post water depriv UOsm no change, Post DDAVP U OSm inc’d
Nephorgenic DM Ser Na inc’d, UNa dec’d, UOsm dec’d, Post water UOsm no change, Post DDAVP UOsm no change
Psychogenic polydypsia Ser Na dec’d, UNa dec’d, UOsm dec’s, post water dep UOsm inc’d, Post DDAVP UOsm inc’d
SIADH Ser Na dec’d, UNa inc’d, Ur Osm inc’d
Ser Na 146, UNa 10 UOsm 73 post H20 depriv UOsm 76 post DDAVP UOsm 600
Central DI
Ser Na 148 UNa12 UOsm 71 Post H20 restric UOsm 75 Post DDAVP UOSm 77
Nephrogenic DI
Ser Na 131 UNa 12 UOsm 65 Post H20 restriction UOsm 500 Post DDAVP UOsm 600
Psychogenic polydypsia
Ser Na 132 UNa 45 UOsm 600 Young female rec Sx or Lung Ca
SIADH
NH Pt Ser Na 160 UNa 10 UOsm 800
Hypernatremic dehydration
Ser Na 130 UNa 5 H/o Liver dz
Hepatorenal syndrome
Best long term management SIADH
Demecyclocine
Hypertonic hyponatremia
DKA
Isotonic hyponatremia
Pseduohyponatremia TG>1000
Acute sx hyponatremia (MS change - lethargy/sz)
Aggressive tx with 3% saline >1mEq/hr for several hours - 12mEq/hr x 24 hrs
If Chronic hyponatremia do not correct >0.5mEq/hr
Central Pontine myelinolysis
Pt is chronic hyponatremic - then sudden correction with hypertonic saline causes fluid shift out of neurons causing shrinkage of cells and myelin sheaths -> paralysis
Conivaptan
V1/V2 rct antagonist - causes iatrogenic nephrogenic DI - free water diuresis
Pt undergoes CTS - started on D5W alternating with 1/2 NS - day one Na 142, UNa 42, Day 6 Serum Na 118, UNa 20 wtd?
Normal saline + lasix (isovolemic hyponatremia)
70yo pt with PNA - Na at presentation 135 started on NS 1100cc/hr - 3 days later pt no fever, WBC dec’s pt confused and has seizure Na is 110 - UNa is 80 dx?
SIADH (similar presentation pt with small ll lung Ca, post in young woman)
Tx: Stop NS IVF, start 3% saline and Diuretics
35yo man found in bathroom brought to ER - gluc 90, pulse ox 96% on room air h/o schizophrenia BP 130/84 Serum Na110, BUN/Cr 8/0.7, Cl 88, CO2 18, Ur Na 10, UOsm 40 - dx?
Psychogenic polydypsia
tx: fluid restriction, 3% Saline/diuretics (MS change)
45yo long h/o bipolar d/o ON LITHIUM found in coma - Na 169 dx?
Hypernatremia 2/2 lithium thrapy
Water deficit - replace half in 24 hour - use D5w with 1/4 NS
If hypotensive NS until stable
24yo F body buidling competition c/o wk and cramps - admits to polyuri and slightly dizzy when gets up - Serum Na 148, K 2.7, bicarb 28 UOsm 80, spot lyte K>25 dx?
Diuretic abuse
Pt with HEAD injury p/w urinary incontinence UOsm 42, plasma OSm 310 (nl 280) Na 150, BUN/Cr 50/1.8 etiology?
Diabetes insipidus
wtd?
Give DDAVP check for dec in UOP and inc’d UOsm
Pt pw polyuria - severe polydipsia - Uosm 60 blood sugar 120 - after water dep UOsm to 72, after DDAVP to 82 - dx?
DDAVP not working so nephrogenic DI
Hyperkalemia
Causes
Factitious (leading cause)
Cell bkdn (hemolysis, rhabdo)
Adrenal hypofunction (decreased excretion of K)
-hyporeninemic hypoaldo (Type IV RTA)
-Addition’s dz
Acidosis
-DKA
-Renal failure
EKG changes - peaked twaves -> flattened p waves-> sine wave, -> vfib
Tx: stabilze cardiac memb - calcium gluconate (1st)
Push K back in cells - insulin/albuterol, HCO3
Excretion - sodium polystyrene sulfonate resin or HD
Hypophophatemia
Renal wasting -hyperPTH -Fanconi (prox RTA) Dec'd absorbtion -vit D def (inc'd alk phos) -malabsorption -etoh abuse -phosphate binder INc'd cellular uptake -tx of DKA -carb repletion in etoh abuse - refeeding syndrome
Hypomagnesemia
Dec'd intake -starvation -eto abuse -NGT aspiration Renal loss -Diuretics -anminoglycosides -ampho B Pancreatits - precipitate as Mg Soap PTH ectomy - deposit in bone "hungry bone syndrome - p/w lethargy anorexia, nausea, tetany convulsions **Can't correc tK or Ca+ until you correct Mg!!!***
Pt p/w weakness, anorexia, leethargy
Na 136, K 3, Cl 105, Ca 6, phos 1.3 - started on IVF, 40 Meq K - next day K and Ca not corrected - etio?
HypoMg
tx: correct Mg
Urinalysis
Proteinuria 1. Overflow proteins - MM, MGUS 2. INc'd filtratio nof protein - -glomerular dz -Nephortic protein >3g/day Nephritic protein < 2g/day 4. Transient -fever -Excercise -Upright position -Seizure Normal < 100mg protein exxr/day 5g - check protein electrophoresis r/o MM, MGUS
Pt with fever, UTI, U+ for protein wtd?
Repeat U/A after fever/UTI resolved
Pt on NSAIs fo rpain - U/A + protein
repeat after d/c NSAID x 2 weeks
Pt with protein + in uprigh tposition wtd?
Check first void AM urine specimen - if neg then no further w/u
Pt with proteinuria on dipstick post excercise - wtd?
repeat U/A after stopping excercise x 2 weeks
Hematuria
Nephronal
w/ RBC casts & proteinuria -> Glomerular dz’s
w/o RBC casts -> renal cysts, SCDz, intersitial dz
Non-nephronal w/o RBC casts or proteinuria Renal pelvis -> tumors -nephrolithiasis UTI/Hemorrhagic cystitis Coaguloapthy Post extreme excercise
Pt with urine diptick + blood, RBC neg - cauesed by?
Rhabdo High vit C Paroxysmal nocturnal hemoglobinuria Contamination with Povidine (NOT BY NEPHROLITIASIS)
20yo p/w asx hematuria - U/a 20-30 RBC, WBC neg, protein 1+ no casts h/o run marathon day after dx?
Excreme exc indued hematuria
repeat UA in few weeks
22yo asx man with persistent asx hematuria - US nromal kidneys BUN/Cr 6/0.7 wtd?
f/u rneal eval in 1 year (Age<25)
50yo M routine phsyical, U/A >5RBC no casts wtd?
Repeat U/A - repeat with persisten microhematuria - Renal US needed
Pt with SCDz p/w sudden onset flank pain, fever, passage dark tissue in urine - U/A RBC no casts, BUN/Cr inc’d wtd?
CT Scan r/o PAPILLARY NECROSIS (high incidence in sickle cell dz)
All can cause papillary necrosis
Analgesics Sickle Cell trait Sickle Cell dz DM Pyelonephritis (NOT Aminoglycoside -> cuases ATN)
30yo Sickle cell trait with microhematuria BUN/CR 14/0.8, U/A with RBC>20, no casts no protein 24 hr protein 300mg/day wtd?
IVP
if neg then cystoscopy
22yo college student p/w hematuria and dysuria x 3 days, UA >30 RBCs WBC 10-15, no casts dx?
Hemmorragic cystitis
tx: 3 days bactrim/cipro/nitrofurantoin
21yo M pt with recurrent UTI - sexually active with one partner x 1 year - 3rd episode in last 6 months - each episode resolved with tx with quinolone - no h/o urethral d/c - no d/c on exam - best way to establish cause?
Urine chlamydia and gonococcal test
20yo with cola colored urine - athlete - had sore throat 4 days ago UA RBC 10-20, RBC cast +, protein 1+, complement in serum normal likely has?
IgA nephropathy
(normal complement - time table within days of sore throat)
If was post strep GN then would be weeks later, decreased complement
60yo M p/w dull ache in L flank region, 9lb involuntary wt loss - BP 14090, UA RBC 15, no casts or WBC dx?
Renal cell CA (older, dull ache L flank, wt loss)
Pt with flank pain, hematuria HTN h/o UTI in past - Renal US stone - fhx stones and Renal faiure dx?
ADPKD - Autosomal dom poly cystic kidney dz
h/o parents/relatives with renal failure
a/w hepatic cysts and berry aneurysms
tx: Tolvaptan->
Mother wants to donate kidney to son with poly cystic kdney dz with renal failure wtd?
US, HLA matching
Autosomal dominant poly cystic kidney dz a/w the following
Cerebral aneurysm - need to screen pts Hepatic/Pancreatic cyt elev Hematocrit CV Conduction issues MVP (NOT AS)
Medulllary sponge dz
hematuria
hyperCalciuria->stones
DOES NOT cause renal failure
IVP-> outpouching of renal papillary ducts
Alport’s syndrome
Xlinked - in males Hemturia proteinuria Renal failure in 2nd or 3rd decade Problem in colagen IV/V synthesis a/w deafness
Urine Analysis
WBC in urine (pyuria) -tubular injury Interstitial nephritis UTI Pyelonephritis
Pt pw polyuria and nocturia, no c/o dysuria or flank pain, no uretheral d/c, UA 10 WBC/hpf - no casts, pt tx’d with abx - repeat UA 2 wk later still WBCs - renal US one kidney smaller than other, IVP multiple strictures wtd?
Urine for AFB
Place PPD r/o TB
AKI
ischemic hit to kidney - ATN - do not apply Cr clearance in ARF
Non-oliguric UOP>400cc/24hr
Oliguric <100cc/24hrs
obstruction, vascular even, severe ATN, cortical necrosis
Post renal
Pre-renal
Renal
Post Renal Etiology AKI
intrinsic or extrinsic obstruction
b/l obstruction - prostate,
unilateral stone, fibrosis, aortic anursym, papillary necrosis, clot, RCC
Hydronephrosis - dilated calyx/ureter
Pre-renal
Volume depletion
senses volume depletion
senses CHF (low flow to kidney but body is overloaded)
and sepsis - true low volume as same (both reduced effective arterial blood volume)
kidney inc’d renin, angiotensin, aldo
If continues kidney dies -> ATN -> starts to spill Na (can’t reabsorb)
Typical U/A - bland - kidney still reabsorbs Na UNa20:1 - BUN more easily reabsorbed than Cr
Hepatorenal
perpetually vasodilated - renin/aldo always elevated
BP low
Only thing that works is spironolactone
FENA
UNaxPCr/PNaxUCr *100
If pre-renal - 99% filtered sodium is reabsorbed
If FENA <1% - pre-renal
ATN
UA - abnormal - hematuria, proteinuria, RBC casts
Does not respond to volume
Casts to remember
RBC casts - glomerular nephritis
WBC casts - pyelonephritis/acute interstitial nephritis
Granular/Muddy brown casts - ATN - casts of tubular death
Intrinsic Renal Disease
Tubular -> ATN
Interstitial -> AIN
Glomerular
Vascular -> afferent (atherembolic dz,
ATN
Ischemic - hypotension, sepsis, needs CVVH,
Nephrotoxic - aminoglycosides
Urine Na>20 (to distinguish from pre-renal) -> FENA 3% - can’t just tx with normal saline - only time will heal and remove offending agent or solve hypotension
Brush border sloughing off - granular casts
Pre-renal -> ATN
Normal
GIB - dec’d perfusion - autoregulation prostoglandins dilate afferent - renin-angio-aldo constrict efferent
NSAID prevent prostoglandin induced dilation of afferent, ACE inhibitor prevents efferent constriction
Triple threat - Pre-renal on NSAID and ACEi
Contrast Nephropathy ATN
10% of all hospital ARF, MCC ATN
Usually 48hrs later Cr peak** (vs 2-3 weeks for atheroembolic)
initial low urine Na looks like pre-renal
then becomes ATN
risk factor CKDz
also DM, MI, CHF, dec vol, lots o fcontrast
Prevent - alt imaging, isotonic IVF
Mucomyst doesn’t work but doesn’t help necessarily
Intersitial Nephritis - allergy in kidney
drug rash, fever, maculpapular rash, eosinophilia
NSAIDs
U/A - sterild pyuria, eosinpiluria (hansel/wright stain)
glomeruli surround by lymphocytes
Vascular dz
atheroembolic dz
cholesterol emboli (2-3 weeks after cath**)
a/w abd pain, lividoreticularis, holererst plaques (eyes)
TTP, HUS, DIC, sleroderma, microangiopathy
TTP - vasc dz in arterioles - less blood to kidney
Glomerular dz
Active sediment, RBC casts, RBC, oval fat bodies
>3gm protein
Albumin (fenestrated epithelial, GBM, podocyte)
Edema
Low albumen
Lipiduria
HLD