Renal Flashcards
_____TBW is water (varies w/ gender, age, body fat %)
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60%
What is ECF? What is it composed of? How much of it is TBW?
- ECF is the fluid outside of cells
- ISF +Plasma
- < 1/2 volume of TBW
- ECF is more immediately altered by kidneys
Slide 3
What are 2 types of homeostasis?
osmolar homeostasis
volume homeostasis
What is osmolar homeostasis mediated by? What does it cause?
- Mediated by osmolality-sensors in anterior hypothalamus
- Stimulate thirst
- Cause Pituitary Release of Vasopressin (ADH)
- Cardiac atria releases ANP→act on kidney to excrete Na+/H20.
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What is volume homeostasis mediated by? what does it cause?
- mediated by juxtaglomerular apparatus
- JGA senses changes in volume
- ↓Vol @ JGA triggers Renin-Angiotensinogen-Aldosterone system (RAAS)→Na+/H20 reabsorption
3
Increased mucles =
increased water
3
What does ADH do?
Helps body ↑H20/Na+ retention
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how do you calculate TBW?
- 60% body weight.
3
What are the categories/cause of hyponatremia?
- Hypovolemia
- Euvolemia
- Hypervolemia
4
Hypovolemia leads to?
- decreased skin turgor
- flat neck vein
- dry mucous membrane
- orthostatic hypotension
- tachycarda
- oliguria.
TOD-FOD (say it like hypovolemia: ta-da!!!)
4
Hypervolemia leads to?
- peripheral edema
- rales
- ascites
Hypervolemia…that’s PAR for the course
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When hypovolemic, if Una ____ it due to renal losses. If Una is ____, its due to extrarenal loses.
- Una >20 [renal loss]
- Una <20 [extrarenal loss]
4
Renal loss due to hypovolemia if Una is > 20 is because of?
- diuretic excess
- mineracorticoid deficiency
- salt losing nephritis
- renal tubular acidosis
- metabolic alkaloss
- ketonuria
- osmotic diuretic
Ren Might Die So Keaton Met Ozzie
Renal loss due to hypovolemia if Una is < 20 is because of?
- Vomiting
- diarrhea
- 3rd space losses
- burns
- pancreatituss
- muscle traume
My 3rd pan burned vomit and diarrhea
4
Hypovolemic hyponatremia is caused by?
- Na/H20 Loss like with diuretics, GI loss, Burns and trauma
Slide 4 comment
Howto treat euvolemia if Una is <20?
Salt restricted diet
4 + comment
What are the causes of euvolemia if Una is >20?
- glucocorticoid deficiency
- hypothyroid
- high sympathetic drive
- drugs
- SIADH
4
When hypervolemic, if Una ____ it due to renal losses. If Una is ____, its due to extrarenal loses.
- Una >20 [renal loses]
- Una < 20 [Avid sodium reabsorption]
4
What are the causes of hypervolemia if Una is >20?
- acute renal failure
- chronic renal failure
4 comment
What are the causes of hypervolemia if Una is <20?
- nephrotic syndrome
- cardiac failure
- cirrhosis
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____ hospitalized pts are hyponatremic. Why?
- 15%
- over fluid-resuscitation
- ↑endogenous vasopressin
4
Normal Na levels?
What levels do you stop surgery?
- 135-145mEq/L
- look at trends, more concerned with acute changes; ≤125 or ≥ 155, want correction prior to elective case
4
S/Sx of hyponatremia: 130-135 (8)
- Asymtomatic
- headache
- nausea
- vomitting
- fatigue
- confusion
- mucle cramp
- depressed reflexes
slide 5
Starts with HA.
S/Sx of hyponatremia: 120 - 130 (8)
- malaise
- unsteadiness
- headache
- nausea
- vomitting
- fatigue
- confusion
- muscle cramps
slide 5
S/Sx of hyponatremia:<120 (7)
- Headache
- Restless
- lethargy
- seizure
- Brainstemp herniation
- respiratory arrest
- death
slide 5
the most severe consequences of hyponatremia
Seizures, coma, death.
slide 5
What is the treatment for mild hyponatremia?
- Treat underlying cause (look at volume status)
- Electrolyte drinks
- Normal saline
- Diuretics
Mildhyponatremia TENDs to be treated by…
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What is the treamtent for extreme hyponatremia [<120?]
- Hypertonic Saline/3% NaCl
sllide 6
Hypertonic saline is adminsitered for hyponatremia. What is the dose and consideration?
- 80ml/hr over 15h
- Na+ correction should not exceed 1.5 mEq/L/hr
slide 6
What happens if you correct hyponatremia fast? What is considered fast?
Rapid correction (>6 mEq/L in 24 h) can cause Osmotic Demyelination Syndrome (often permanent neuro damage)
slide 6
With low sodium levels, what is a medical emergency?
How do you treat it?
- Hyponatremic seizures=medical emergency (neurological damage)
- 3-5ml/kg of 3% over 20 min, until seizures resolve
slide 6
Common causes of Hypernatremia
- Excessive evaporation
- Poor oral intake (very young, very old, altered mental status)
- Overcorrection of hyponatremia
- Diabetes insipidus
- GI losses
- Excessive sodium bicarb (treating acidosis)
PODGEE
slide 7
What are the s/sx of hypernatremia?
- Orthostasis
- Restlessness
- Lethargy
- Tremor/Muscle twitching/spasticity
- Seizures
- Death
slide 9
hypernatremia sx mirror hyponatremia sx
What is the treatment for hypernatremia?
- Route cause, Assess volume status (VS, UOP, Turgor, CVP)
- Hypovolemic: normal saline
- Euvolemic: water replacement (po or D5W)
- Hypervolemic: diuretics
What should be the sodium reduction rate for hypernatremia and why?
- Want Na+ reduction rate ≤0.5 mmol/L/hr, and ≤ 10 mmol/L per day
- to avoid cerebral edema, seizures, and neurologic damage
slide 9
Normal K+ levels?
% in the ECF?
- 3.5-5 mmol/L
- < 1.5% in ECF
slide 10
______ reflects transmembrane K+ regulation more than total body K+
Serum K+
slide 10
_____ causes the distal nephron to secrete K+ (and reabsorb Na+)
Aldosterone
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____ is inversly related to K.
Aldosterone
slide 10
In renal failure, what happens to K excretion>
K+ excretion declines.
Excretions shifts towards GI system
slide 10
What are the 3 major categories for the cause of hypokalemia?
- Renal loss
- GI loss
- Transcellular loss
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Causes of hypokalemia due to renal loss include?
- Diuretics
- hyperaldosteronism
- Mineralcorticoids
- high-dose glucocorticoids
- abx (penicillin, nafcillin, ampicillin)
- Drugs associated with magnesium depletion
- Surgical Trauma
- Hyperglycemia
slide 11
Causes of hypokalemia due to GI loss include?
- N/V/D
- Malabsorption
- Zollinger-Ellison Syndrome
- Jejunoileal bypass
- Chemo
- Nasogastric suction
slide 11
Causes of hypokalemia due to transceullar shift include?
- Akalosis
- Beta-agonist
- Insulin
- Tocolytic drugs
- alkalosis
- Hypercalcemia
- Hypomagnesemia
slide 11
Common cause of hypokalemia
- Low PO Intake
- Renal loss- Diuretics, Hyperaldosteronism
- GI loss – N/V/D, malabsorption
- Intracellular shift- Alkalosis, β-Ag’s, Insulin
- DKA (osmotic diuresis)
- HCTZ (in BP meds)
- Excessive licorice
slide 11
List the s/sx of hypokalemia
- Generally cardiac and neuromuscular
- Muscle weakness/Cramps
- Ileus
- Dysrhythmias, U wave
s;ode 12
Tx for hypokalemia?
- Underlying cause
- 10-20meq/L/hr IV [Potassium PO > IV ]
slide 12
____ meq of IV K+ increases serum K by ____
- 10 meq
- 0.1 mmol/L
slide 12
To prevent hypokalemia what needs to be avoided?
Avoid excessive insulin, β-agonists, bicarb, hyperventilation, diuretics
slide 12
List the causes of hyperkalemia (8).
- Renal failure
- Hypoaldosteronism
- Drugs that inhibit RAAS
- Drugs that inhibit K+ excretion
- Depolarizing NMB (Succs)
- Acidosis (Respiratory/Metabolic)
- Cell death (trauma, tourniquet)
- Massive blood transfusion
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What are the s/sx of hyperkalemia
- Chronic may be minimally symptomatic (malaise, GI upset)
- Skeletal muscle paralysis,↓fine motor
- Cardiac dysrhythmias
slide 13
What EKG changes can be seen with hyperkalemia?
- peaked T wave
- P wave disappearance
- prolonged QRS complex
- sine waves
- asystole
slide 13
_____ causes K+ secretion & excretion
Aldosterone
slide 13
How much does Succinylcholine increases serum K+ by ?
0.5-1 mEq/L
slide 13
Hyperkalemia treament includes (7)? And what do avoid (3)
- Dialyze within 24h prior to surgery
- Calcium- 1st initial treatment (quickly stabilize cell membrane)
- Hyperventilation
- Insulin +/- glucose
- Bicarb
- Loop Diuretics
- Kayexalate (hrs to days)
- Avoid Succs, hypoventilation, LR & K+ containing IV fluids
slide 14
How much does hyperventilation decrease K levels?
↑pH by 0.1 →↓K+ by 0.4-1.5 mmol/L
slide 14
What dose is insulin and glucose adminsterd at for hyperkalemia?
How long does it take to work?
- 10u IV: 25g D50
- works in 10-20 min
slide 14
How much % of calcium is stored in the ECF vs bone?
How much plasma calcium is protein bound?
- ECF: 1%
- Bone: 99%
- 60% and its mainly to albumin. this is inactive.
slide 15
What types of calcium is physiologically active? Normal values?
- Only ionized plasma Ca++ is physiologically active (Not PB Ca++)
- Normal iCa++: 1.2-1.38 mmol/L
slide 15
What is calcium level effected by?
- albumin levels and pH
- ↑pH/Alkalosis→↑Ca++ binding to albumin (therefore ↓iCa++)
slide 15
What are the hormones that regulate Ca++ and how?
- Parathyroid hormone: ↑’s GI absorption, renal reabsorption and pulls from bone
- Vitamin D: augments intestinal Ca++ absorption
- Calcitonin: promotesbone reabsorption (decreases plasma Ca++)
slide 15
Causes of Hypocalcemia include?
- ↓Parathyroid hormone (PTH) secretion
- Magnesium deficiency [required for PTH production]
- Low Vit D or disorder of Vit D metabolism [aids in absorption]
- Renal failure (kidneys not responding to PTH)
- Massive blood transfusion (citrate preservative binds Ca++)
Maggie D. Rents Paragliders and Bikes
slide 16
PH acts where to increase calcium absorption?
bones, kidneys, GI system
slide 16
After __ units of PRBCs, __ is checked to see if it needs to be replaced.
- 4+
- iCa++
Slide 16
Causes of hypercalcemia include?
- Hyper-parathyroid or cancer [majority]
- Vit D intoxication
- Milk-alkali syndrome (excessive GI Ca++ absorption)
- Granulomatous diseases (sarcoidosis)
Scar Hypes VitD Milk
slide 17
Hyperparathyroid serum Ca++?
Cancer serum Ca++?
- Hyperparathyroid serum Ca++ <11
- Cancer serum Ca++ >13
slide 17
With parathyroidectomy, what is the biggest complication?
- Hypocalcemia-induced laryngospasm (life threatening complication)
- caution when extubating parathyroidectomy
slide 18
Hypercalcemia s/sx
- Confusion, lethargy
- Hypotonia/↓DTR
- Abd pain
- N/V
- Short QT-I
Slide 18
What does a chronic ↑Ca++ causes ?
Hypercalciuria & nephrolithiasis
slide 18