Renal Lecture Flashcards
Acute kidney injuy (AKI) complicates _____% of hospital admissions
15-20%
Increased nitrogen containing compounds (urea, creatinine)
Azotemia
(can have preenal, renal, postrenal)
RIFLE
AKIN
KDIGO
ways to stage AKI
Rise in creatinine > 0.3
Decreased urine output to < 3 mL over 6 hours
AKI
Severe azotemia
Symptomatic
Metabolic acidosis
Electrolyte disturbances
Uremia
Often no visual signs or noticeable sxs
Edema
HTN
Decreased urine output
Labs: albuminuria, increased BUN, hyperK, hypoNa
AKI
Causes:
Inadequate perfusion
Hypovolemia
Inadequate PO intake
GI losses
Diuretics
Blood loss
Cardiac or hepatic failure
Sepsis
AKI pre-renal azotemia
MC cause of acute renal failure
*excess nitrogen compounds due to lack of blood flow to each kidney
Pre renal azotemia
Prolonged renal ischemia from prerenal azotemia can cause..
Acute tubular necrosis (ATN)
Which type of renal tubular acidosis..?
Decreased H+ excretion
Hypokalemic
Herditary vs acquired (hyperPTH)
Type I (distal)
Which type of renal tubular acidosis..?
Decreased proximal bicarb reabsorption
Hypokalemic
Hereditary vs acquired (multiple myeloma, chem exposures)
Type II (proximal)
Which type of renal tubular acidosis..?
Impaired hydrogen and potassium excretion
Aldosterone deficiency or tubular unresponsiveness to aldosterone
Hyperkalemia
ie..Addison’s dz, DM
Type IV
Glomerulonephritis vs nephorsis
Caused by nephrotoxic things:
Ischemia
Radiocontrast
Toxins
DIC
Intrinsic arterial or venous obstruction
Intrarenal precipitation
Nephritis
Minimal change Disease
Renal azotemia (intrinsic)
Urinary obstruction
Prostratism
Bladder, pelvic, retroperitoneal tumors
Calculi
Urethral obstruction
Postrenal Azotemia
Causes:
AKI
HTN
DM
Vascular disease
CKD
30-300 mg/day albumin
microalbuminuria
17-250 mg/g for men
25-355 mg/g for women
Spot Ur albumin:creatinine ratio
What stage CKD:
GFR>90
Stage 1
What stage CKD:
GFR 60-89
Stage 2 (mild)
What stage CKD:
GFR 45-59
3A (moderate)
What stage CKD:
GFR 30-44
3B (moderate)
What stage CKD:
GFR 15-29
stage 4 (severe)
What stage CKD:
GFR <15
stage 5 (end stage)
Low sodium, protein, potassium, phosphate
CKD diet
Diet (low Na, protein, potassium, phosphate) Avoid nephrotoxins (NSAIDs, radiocontrast) H20 management (THINK about IVF)
CKD management in-patient
What is the goal for hospital management of CKD?
prevent acute on chronic kidney disease/injury
What is the primary intracellular cation?
Potassium!
What is the only way to measure potassium?
Extracellular (ECFV)
*there are very small quantities extracellularly
Causes:
AKI or CKD
Adrenal insufficiency
Dietary intake (bananas, potatoes)
Hemolysis (blood draw, clotting, leukocytosis)
Metabolic acidosis
Beta blockers
Insulin deficiency
Aldosterone antagonists
Hyperkalemia
Weakness
Paralysis
Cardiac arrhythmias: peaked T waves, widened PR, QRS, eventual PEA
HyperKalemia
Tx:
tx the cause
IVF
Kayexelate
Limit intake
Insulin + dextrose
Beta adrenergics
Hyperkalemia
Causes:
Decreased intake
Increased GI loss: vomit, diarrhea, laxatives, tube drainage
Increased renal loss: diuretics, hypoMg, non reabsorbable anions
Increased entry into cells: insulin, beta agonists or stress hypothermia, alkalosis
HYPOkalemia
Manifestatios:
Weakness/rhabdomyolysis
Glucose intolerance
Cardiac arrhythmias- increased U wave amplitude
HYPOkalemia
Tx:
PO or IV replacement
Mg replacement
Consideration in hyperglycemia and DKA
HYPOkalemia
What is the main extracellular ion?
Sodium
Causes:
- *Extra renal water loss** (fever, sweating, diarrhea, mechanical ventilation)
- *Renal water loss** (osmotic diruresis, iatrogenic)
HYPERnatremia
DKA, hyperalimentation, mannitol, sodium
diabetes insipidus
all examples of _____ water loss, which can lead to hypernatremia
Renal
For diabetes insipidus…
which is LOW ADH and which is UNRESPONSIVE TO ADH
(options= central, nephrogenic)
Central= low ADH
Nephrogenic= unresponsive to ADH
1 amp NaHCO3 has ____x’s the concentration of 3% saline
2x’s
(NaHCO3 can be an iatrogenic cause of renal water loss)
urine output is >3L/day
Polyuric
>300 mOsm/L =?
Osmotic diuresis
<150 mOsm/L= ?
Diabetes insipidus
Give NS inititally if volume depleted
Transition to 1/2 NS vs. D5W
(avoid correction faster than 0.5 mEq/L/hr to avoid cerebral edema)
Tx for hypernatremia
When giving hyperNa pt NS, avoid correction faster than 0.5 mEq/L/hr to avoid..?
Cerebral edema
ADH elevation
Increased serum osmolality
Decreased circulating volume
Inappropriate elevation
Hypoosmolar HypoNatremia
Increased levels of another osmolyte
- glucose
- mannitol
- proteins
- lipids
Hyperosmolar HypoNatremia
“too much salt”
Seen with:
CHF
Cirrhosis
Nephrotic syndrome
***increased ADH due to decreased effective circulating volume
kidneys retain both Na and H20
Hypervolemic HypoNatremia
Urine Na < 30 mmol/L indicates _______ (renal/extrarenal) losses
Extra renal
Urine Na > 30 mmol/L indicates ______ (renal/extrarenal) losses
Renal
Hypovolemic Hyponatremia (too little salt)
can be divided into…
Renal (>30 mmol/L Na in urine)
Extra-renal (<30 mmol/L Na in urine)
Urine Na >30
RAA NOT engaged
Na is being released
Euvolemic HypoNa
Psychogenic polydipsia
Beer potomania
Tea and toast diet
cause euvolemic hyponatremia with urine osmol ……
less than 100
SIADH
Reset osmostat
Renal insufficiency
Hypothyroidism
TZDs
SSRIs
Secondary adrenal insufficiency
cause euvolemic hyponatremia with urine osmol _______
greater than 100
this is an excess of water but we treat it like its a deficiency of Na
Hyponatremia
Tx:
Saline.. normal (0.9%) vs 3%
Loop diuretic
Serum Na and urine osmol monitored every 1-2 hours
Acute Hyponatremia
For hyponatremia…
Aim for 1-2 mEq/hr the first few hours then no more than 10mEq/L in the first 24 hours.
No more than 18mEq/L in ___ hours
48
Pain
Volume depletion (followed by LR or hypotonic fluids
Trauma
Meds (SSRIs, TZDs)
Neoplasm
Severe nausea
Neuropsychiatric meds
common causes of increased ADH in hospitalized patients
May briefly use 3% saline
Stop NaCl when serum Na starts to rise, urine osm decreases or symptoms resolve
Chronic symptomatic HypoNatremia Tx
True or False..
There is a risk of osmotic demyelination syndrome if correction of chronic hyponatremia happens too rapidly
True
154 mOsm/L
77 mEq/L
..which saline?
1/2 NS
308 mOsm/L
308 mEq/L
which saline?
NS
1026 mOsm/L
513 mEq/L
which saline?
3% saline
130 mEq/L
which saline?
LR
Fluid restrict
Safest initial approach
Increase solute intake
Discontinue offending agents
ADH receptor antagonist
tx for?
Chronic asymptomatic hyponatremia
Usually asymptomatic
NaCl
Maintain ≤ 10mEq/24 hours correction
Hypovolemic Hyponatremia
