Tulane (HIGH YIELD) Flashcards
What does para aminohippurate (PAH) measure and why?
Renal plasma flow; it is freely filtered and secreted, but not reabsorbed (nearly 100% excretion)
5 most common causes of HTN?
Sleep apnea (most important), drug-induced, CKD, primary aldosteronism, renovascular disease
4 biologic effects of 1, 25 vitamin D
- Incr. Ca++ and PO4 reabsorption from gut
- Feedback inhibition of itself
- Feedback inhibit PTH
- Bone mineralization and turnover
What causes intracellular potassium movement?
Insulin, epinephrine (into muscles; important for fight-or-flight), alkalosis, incr. plasma K+
What causes extracellular potassium movement?
Lack of insulin, beta blockers, acidosis, decr. plasma K+
What are the most common causes of sustained hypokalemia?
Potassium losses (renal or GI, e.g. vomiting or diarrhea)
Most common causes of abnormal potassium distribution
Lack of insulin, beta blockers, hyperosmolarity
Anion gap formula
Na - (HCO3 + Cl)
Winter’s formula (with interpretation)
pCO2 = (1.5 x HCO3 + 8) +/- 2
If actual pCO2 > predicted, it’s combined acidosis
If actual pCO2 = predicted, it’s just metabolic acidosis
If actual pCO2 < predicted, it’s compensated metabolic acidosis
Formula for Net Acid Excretion
NAE = Urinary titratable acid + NH4 - HCO3
Define uremia
Azotemia + symptoms (nausea, vomiting)
High anion gap metabolic acidosis causes
GOLDMARK: Glycols: ethyl glycol or propyl glycol from moonshine, hand Sani, antifreeze 5-Oxoproline: classically Tylenol consumption in LOLs L-lactate D-lactate Methanol Aspirin (i.e. salicylates) Renal failure (incl. uremia) Ketones (incl. DKA)
Normal anion gap metabolic acidosis causes
HARDASS: Hyperalimentation Acetazolamide – CA inhibitor incr. “flushing” of bicarb RTA Diarrhea Addison’s disease = lack of aldosterone Saline infusion (RAAS not needed low Ang II loss of bicarb) Spironolactone (hypothetical)
Under what particular circumstances would you see high anion gap acidosis with compensatory resp. alkalosis?
Ingestion of aspirin
Describe the appearance of gonorrhea on gram stain
Gram negative intracellular diplococci
Full syphilis presentation
Stage 1 – painless chancre 1 wk post-sex
Stage 2 – maculopapular rash on hands + trunk
Stage 3 – end organ damage, neuro + cardio problems (recall aneurysm), dementia
Characteristic syphilis labs
VLDR+, darkfield microscopy
Describe 2 ways by which the sympathetic nervous system responds to decr. ECV?
o Vasoconstriction (decr. RBF and GFR) o alpha receptors in PCT incr. Na+ resorption
Describe the pathophysiology of edema in heart failure
Decr. CO –> decr. RBF –> RAAS activation –> incr. Na+ (and water) resorption AND vasoconstriction –> incr. capillary hydrostatic pressure –> fluid loss to interstitial space (perpetuates the cycle)
What part of the nephron is referred to as the “diluting segment” and why?
Thick ascending limb, DCT, and collecting duct; in the absence of ADH, reabsorption of solute (but not water) occurs here
Hypovolemic hyponatremia clinical presentation
Hypotension, lightheadedness, orthostatic hypotension, vomiting, diarrhea, GI losses, etc.
Most common cause of hypernatremia d/t low ADH
Diabetes insipidus
Diabetes insipidus presentation
Polyuria (most important), polydipsia, normal to elevated sodium, dilute urine
Hypernatremia treatment
Water!!!! water water water water
