Renal Part 2: Schoenwald Flashcards
Electrolyte Panel: (includes)
Na K CL CO2
Kidney is the main regulator of water and _____
sodium
Sodium: normal range
Normal 136-145 mEq/L
Sodium is the primary circulating _____
cation (extracellular space)
Sodium is needed for?
neuromuscular function
Sodium: -how are serum levels balanced?
Serum levels are the balance between dietary intake and renal excretion
Sodium: -indicator of ____
*free body water -If free water increased, Na diluted and levels decrease -If free water decreased, Na concentrated and levels increased
Sodium is a major contributor to _____
plasma osmolality
Osmolality: normal serum
280-295 mOsm/kg H20
Osmolality is useful in which settings?
hyponatremia, evaluating ADH (antidiuertic hormone) related illnesses
Osmolality: -measures?
concentration of dissolved particles in blood
As amount of free water increases, amount of particles decreases= osmolality ______
osmolality decreases
As amount of free water decreases, amount of particles increases=osmolality
increases
Therefore, osmolality decreases with _____
overhydration, and increases with dehydration
Antidiuretic Hormone(ADH): -regulates?
body water and osmolality
ADH is stimulated by (3 things)
Increased osmolality Hypovolemia Thirst
ADH acts on the ______ ______ to increase permeability=increase water reabsorption=more concentrated urine
collecting tubule
Osmolality-Serum: -Is increased in:
-Hypernatremia -Hyperglycemia -Ketosis -Dehydration -Diabetes insipidus
Osmolality-Serum: -is decreased in:
-Overhydration -Syndrome of inappropriate ADH
Syndrome of inappropriate ADH=
=Abnormally high amount of ADH present –Increased water reabsorption leading to decreased serum sodium levels —Lose sodium in urine
Syndrome of inappropriate ADH: -What is a common cause of this syndrome?
drugs (commonly after anesthesia type drugs ie post surgery)
Diabetes insipidus= inadequate amount of ____ present
ADH
Diabetes Insipidus: -Sx? -Labs?
Sx: increased thirst and passage of large volumes of dilute urine -Hypernatremia present
Urine Osmolality: normal range
50-1200 mOsm/kg H20
Urine Osmolality: -measures? -Is more accurate than?
-Measures dissolved particles in urine -More accurate than specific gravity
T/F: Urine Osmolality Evaluates ability of kidney to concentrate urine
True
Urine Osmolality: -Is Increased in which conditions?
-SIADH -CHF
Urine Osmolality: -Is decreased in which conditions?
-Diabetes insipidus -Excess fluid intake
Hyponatremia is defined as:
Serum sodium <136mEq/L
Hyponatremia: 2 types
-Sodium depletion-free water loss -Dilutional-water intake greater than water output-(renal failure)
Hyponatremia: -most asymptomatic until ____
level<120 mEq/L
Hyponatremia: Sx?
-lethargy, nausea, mm cramps -**Cerebral edema (this can be lethal!!)
Hypernatremia is defined as
>145 mEq/L
Hypernatremia: -etiology
-Impaired thirst mechanism (ie stroke) or water loss without sodium loss (ie burns, or high fever) -dehydration
Which is more lethal, hyper or hyponatremia?
hyponatremia
Urine Sodium: -tests? -normal range?
-Spot testing or 24 hour urine –Normal values vary -Spot normal generally >20mEq/L
Urine sodium: -used for?
Helpful for distinguishing between renal and nonrenal causes of hyponatremia
Urine Sodium: -Is increased in which conditions?
-Dehydration -Diuretic therapy -Adrenocortical insufficiency -SIADH -Chronic renal failure
Urine Sodium: -is DECREASED in which conditions?
-CHF -Diarrhea
Hyponatremia initial eval
Slide 16
Eval of Hyponatremia: starting with osmolality
Hypotonic Hyponatremia (eval)
slide 18
Potassium:
- normal range:
- Is a primaru intracellular ______
- Function
- Norm 3.5-5.5 mEq/L
- Primary intracellular cation
- Function of cardiac muscle depends on K
Potassium:
-minor changes in concentration have ________
**significant consequences
T/F: Potassium is not reabsorbed from the kidneys, it’s excreted
True
(important when we prescribe lasix (diuretic therapy) because they get K+ depleted. For life long Pts on this med they MUST have K+ monitored and taking K+ supplements
Potassium:
-For Pts who are unable to eat and they are not yet on TPN (total parenteral nutrition), what is necessary to add to their treatment regimen?
**Necessary to supplement by IV in those that can’t eat
As sodium is reabsorbed, ______ is lost
Potassium
hypokalemia:
- range?
- Sx?
- EKG findings?
- K < 3.5 mmol/L
- Malaise, skeletal mm weakness, arrythmias
- EKG flattened or inverted T waves
Hypokalemia: causes?
Causes:
- Deficient dietary intake
- Diuretic usage (ie lasix!!!**)
- Burns
- Glucose administration
- Licorice ingestion
- Aldosterone excess-enhances potassium excretion
Hyperkalemia:
- K+ range ?
- Associated complications?
- K > 5.5 mmol/L
- Associated with renal failure and acidosis-K driven out of cell
Hyperkalemia:
- Sx?
- Associated EKG findings?
- Sx include arrythmias and cardiac arrest, numbness, tingling, weakness
- EKG: **peaked T waves
Hyperkalemia:
-Causes? (list 4)
- Excessive dietary intake
- ACE inhibitors
- Acute or chronic renal failure
- hemolysis
Chloride:
- normal range?
- it’s the most abundant ________ cation
- Norm 96-106 mEq/L
- Most abundant extracellular anion
Chloride:
- Is directly regulated by:
- Indirectly regulated by?
- Regulated by renal proximal tubules and exchanged for bicarb ions
- Indirectly regulated by Na and H20
T/F: Chloride test by itself does not provide much info
True
Chloride:
-increased levels? (causes)
- Dehydration
- Metabolic acidosis
Chloride:
-decreased levels? (causes)
- Overhydration
- SIADH
- Vomiting
Why do you need to know all these labs?
- Acute Renal Failure
- Chronic Renal Failure
- Fluid Therapies
Acute renal failure:
- definition?
- Accumulation of ______
- Rapid deterioration of kidney function
- ** nitrogenous wastes
Acute Renal failure:
- MC cause=
- Prerenal causes=
- MC caused by nephrotoxins-medications. (ABX are big culprits)
- Prerenal causes-hypoperfusion
(prerenal causes- ie CHF leading to decreased blood flow to the kidney,
T/F: acute renal failure is reversible in most cases
TRUE
Acute Renal failure:
-Sx?
Symptoms-nausea, vomiting, change in mental status, edema
ARF Causes:
-Prerenal?
- Hypovolemia
- Hypotension
- CHF
- Renal artery stenosis (RAS)
ARF:
-Renal causes?
- Nephrotoxins
- Autoimmune diseases
ARF:
-Postrenal causes?
obstruction
Acute kidney injury aka ____
=Acute renal failure (previous terminology)
Define an acute kidney injury (aka acute renal failure)
-hint: serum creatinine=
-
=Acute increase in serum creatinine ≥ 0.5 mg/dl or more than 50% over baseline levels
Acute Kidney Injury is classified by:
-Classified as prerenal, intrinsic renal, or postrenal
Acute kidney Injury:
-what is the KEY parameter for renal function management?
- **GFR(glomerular filtration rate)
- BUN and Creatinine less reliable than GFR but easily measured
Acute kidney injury:
-Criteria (RIFLE classification)
Acute Kidney Injury:
-Diagnostic la findings for **prerenal causes:
- Urine Na <20mEq/L
- Fractional Excretion of Na(Fena)<1%
- Urine osmolality 500 mOsm
- ^BUN/Creat ration (20:1)
Acute kidney injury:
-Diagnostic lab findings associated with Intrinsic renal causes:
- Urine Na >40mEq?l
- Fena>1-2%
- Urine osm 250-300
- Decreased BuN/Cr ration (<15:1)
Acute kidney injury:
-diagnostic lab findings assoc. with Postrenal causes?
-Postrenal-results vary due to length of time of obstruction
Acute kidney injury= (defined using the RIFLE criteria)
-Injury=. increased creatinine 2x of GFR >50% decrease from baseline
Chronic kidney disease:
- definition?
- Stages?
- Progressive and ongoing loss of kidney function
- Staged: 1-5
CKD:
-Stage 1=
Stage 1: kidney damage with normal GFR >90 mls/min
CKD: Stage 2
Stage 2: kidney damage with mild decrease in GFR 60-89 mls/min
CKD: stage 3
Stage 3:moderate decrease GFR 30-59 mls/min
CKD: Stage 4
Stage 4: severe disease GFR 15-29 mls/min
CKD: stage 5
Stage 5:kidney failure with GFR <15mls/min
Summary of lab Results in ARF/AKI:
KNOW!!
- BUN/Creat elevated, BUN/Creat ratio <15:1 =renal cause; BUN/Creat ratio >20:1=prerenal cause
- Decreased creat clearance
- Hyperkalemia
- Urinalysis (UA) positive for protein and blood
Chronic Renal Failure:
- reversible or irreversible?
- defined as?
- Irreversible
- Mild to moderate decrease in glomerular filtration rate over time without presence of uremic symptoms
Chronic Renal Failure:
- 2 MC causes?
- Sx?
- Hypertension and diabetes most common causes
- At first asymptomatic, but progress to fatigue, malaise, vomiting
Summary of labs/Results in CRF:
- BUN and Creat elevated
- UA and serum electrolytes generally normal until advanced stage
Carbonic acid/bicarbonate system:
-Describe this system?
**=Primary buffer system of body
- CO2=acid-regulated by lungs
- Bicarb = base-regulated by kidneys
- These parameters easily measured in lab
Equation of Life =
HCO3¯+H+«—-»H2CO3«—-»CO2+H2O
Equation of Life:
-is controlled by which organ systems?
- Controlled by lungs and kidneys
- Pathology in these organs associated with acid/base disorders
- Lungs excrete CO2
- Kidneys regulate HCO3 (bicarb)
Increase in blood CO2 levels=
(lungs regulate CO2=respiratory)
=**respiratory acidosis
Decrease in blood CO2 levels=
respiratory alkalosis
Increase in blood bicarb=
(kidneys regulate HCO3 (bicarb))
=metabolic alkalosis
Decrease in blood bicarb=
(remember kidneys regulate bicarb (metabolic disorders)
=metabolic acidosis
Recommend review of Acid/Base arterial blood gas interpretation
- Especially metabolic acidosis/alkalosis
- Anion gap
- MUDPILES acronym for metabolic acidosis –>M-methanol, U-urea, D-DKA, P-paraldehyde, isoniozid/or iron overload, L=lactic acidosis, E-Ethanol, S-salicyclate
Go over!!
(no test questions, but will help your understanding of kidneys)
