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
Rarely caused by excessive Na⁺ intake
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 needs to be check when replenishing K⁺ ?
Serum Phosphorus
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
What is normal urine output in adults?
1 mL/kg/hr
Your pre-operative patient has had less than 500 mLs of urine output in the past 24 hours. How would you classify this patient?
Oliguric