April 13 Lectures

Scariano

40-80 mg/day = normal protein in urine 
<300 mg.dL = microproteinuria        >300 mg/dL = macroproteinuria

"foot strike hemolysis" in long distance runners = urine findings

ketones = acetoacetate and hydroxybutyrate  (conjugate bases of their acids) (contribute to anion gap of metabolic acidosis)

specific gravity - normal range 1.003 - 1.035  (distilled water = 1.000)

pH  minimum pH of urine about 4.5  ([H] = 0.03 mEq/L)

oval fat bodies - hyperlipidemia associated with nephrosis.  low albumin levels stimulate hepatocytes to produce lipoproteins = hyperlipedemia.

red blood cells - dysmorphic erythrocytes = acanthocytes - acanthocyte is derived from the Greek word "acantha" meaning "thorn." imbalance in membrane lipids causes cells to stiffen, wrinkle, pucker, and form spicules.

Rohrscheib

60:40:20 rule   Intracellular volume is 2x extracellular.  therefore, K is major cation of the body.

Ins and Outs:   GI loss is normally 10% vs. renal at 90%. 
GI loss increases with diarrhea; K =30-40 mEq/L in diarrhea fluid.  can lose 5L or more (e.g., cholera) per day.


a good review of K and ECG.  ECG findings can be understood from high K effects on cardiac myocytes and nodal cells (decreased slope of phase 4 = bradycardia). 

Myocyte

solid line = normal; dashed line = hyperkalemia.  decreased slope of phase 0 causes slowed cell to cell conduction time (long PR interval; widening of QRS). Increased rate of repolarization (higher conductance of K channels) causes peaked T wave.

Practice question: Predict effect of Bartter and Gitelman syndromes on plasma Na and K.