Renal Diseases (Exam III) Flashcards
Which vertebrae are the kidney’s typically situated between?
T12 - L3
Which kidney is slightly more posterior? Why?
Right kidney is more posterior to accommodate the liver.
What stimulates erythropoietin release from the kidneys?
Inadequate O₂ to the kidneys
How much of CO do the kidneys receive?
20 - 25% ( 1-1.25L/min)
What is Azotemia?
What causes it?
- Abnormally high levels of nitrogen containing compounds such as Urea and Creatinine.
- Azotemia is causes by dysfunctional kidneys.
Where are your osmolality sensors located?
What occurs when you have hyperosmolality?
- Anterior Hypothalamus
- Hypothalamus signals pituitary gland to stimulate thirst and secrete ADH.
What degree of hyponatremia would give you pause for surgery?
Less than 125 mg/dL
What are some conditions (discussed in lecture) that can cause hyponatremia?
- Prolonged sweating
- Vomiting/diarrhea
- Insufficient aldosterone
- Excessive H₂O intake
How would hyponatremia be treated?
This is highly dependent on underlying pathology.
- Treatment of underlying disease
- NS
- Hypertonic Saline
- Lasix
- Mannitol
What pathology could occur with rapid over-correction of hyponatremia?
Osmotic Demyelination Syndrome (“Locked-in Syndrome”)
At what degree of hypernatremia would you typically cancel surgery?
155 mg/dL or greater
What is the most common cause of hypernatremia?
Insufficient replacement of water loss
Back home we called this dehydration.
What is the complication from rapid correction of hypernatremia?
There is little evidence of morbidity from rapid hypernatremia correction. 0.5 mmol/L/hr to an absolute change of 10 mmol/L/day would be best to avoid cerebral edema, seizures, and other neurological sequelae.
Severe hyponatremia/hypernatremia both result in what?
Seizures, coma, and death
What are normal levels of serum potassium?
3.5 - 5 mg/dL
Excessive intake of what food is known to cause hypokalemia?
Licorice
When does hypokalemia need to be treated with K⁺ repletion?
Serum K⁺ < 3 mg/dL
What types of symptoms are generally seen with hypokalemia?
Cardiac & neuromuscular
What EKG sign is seen with hypokalemia?
“U”-waves
What other lab(s) needs to be check when replenishing K⁺ ?
Serum Phosphorus and Mg⁺⁺
A patient presents with a gun shot wound to the thorax necessitating exploratory thoracostomy. The patient’s serum K⁺ level is 5.7 mg/dL, what do you do?
- Emergent surgery so proceed and treat the hyperkalemia
If the surgery was not emergent you would treat the K⁺ til it was below 5 mg/dL.
What are hyperkalemia’s effects on on EKG?
What about on the cardiac cellular membrane?
- Peaked “T” Waves
- ↑ Vᵣₘ and ↓ APD (action potential duration)
What is the treatment for hyperkalemia?
“C BIG K”
- Calcium gluconate (1° treatment)
- Bicarbonate
- Insulin
- Glucose
- Kayexelate
What is a normal GFR?
125 - 140 mL/min
What is normal serum creatinine?
0.6 - 1.2 mg/dL
What is better for acute monitoring of renal function, GFR or creatinine?
- Creatinine for acute monitoring
- GFR for chronic/trending
A 100% increase in creatinine is indicative of a _____ decrease in GFR.
50%
What populations would have lower creatinine levels?
Who would have higher?
- ↓ in women and elderly
- ↑ in body builders
What is the normal BUN:Creatinine ratio?
10:1
What is normal urine specific gravity?
1.001 - 1.035
What is normal BUN?
8 - 20 mg/dL
Large amounts of what macromolecule would be suggestive of glomerular injury?
protein
What is the primary metabolite of protein metabolism in the liver?
Urea
Amino acids → ammonia → urea
Which of these two compounds is subject to filtration at the glomerulus?
- Creatinine
- Urea
Trick question. Both are subject to filtration
Which of these two compounds is subject to reabsorption in the nephron?
- Creatinine
- Urea
Urea is reabsorbed unlike creatinine ( and therefore can’t be used to measure GFR)
What would a BUN:Creatinine ratio of greater than 20:1 indicate?
Pre-renal Azotemia