Med Phys Unit 4: Renal 3

Urine Specific Gravity

1.005 - 1.030

H20= 1.000

Urine Osmolarity

500-800 mOsm

Why would glucose be in urine?

Glucose above renal threshold

Why would bilirubin be in urine?

Liver disease

Common diuretics

Theophylline

Caffeine

Theobromine

Alcohol

How does nicotine affect ADH?

Raises ADH

Glomerular nephritis

Causes high RBC, WBC, and protein in urine

Renal calculi

Kidney stones can cause blood in urine

Why is [H+] narrowly regulated

Brain f(x)

Enzyme f(x)

Source of [H+]

Metabolism

CO2 + H2O

Acidosis

PH < 7.4

Alkalosis

PH >7.4

Blood buffers are...

1st line of defense but not effective for major pH changes

What is the most important buffer ECF?

HCO3-

Respiratory buffers

Fast, powerful, not 100% compensation

Renal buffers are

Slow, powerful, 100% compensation

How do the kidneys regulate acid-base balance

Conserve HCO3- and acidic/basic urine depending on bodily needs

1 HCO3- molecule for 1 H+

When you save a bicarb you secrete an H+

Metabolic acidosis

Low HCO3-

Respiratory acidosis

High CO2

Metabolic alkalosis

High HCO3-

Respiratory alkalosis

Low CO2

Renal acidosis compensation

High H+ secretion

High HCO3- reabsorption

Renal alkalosis compensation

Low H+ secretion

Low HCO3- reabsorption

What is anion gap?

Difference between cations and anions

3-10 mEq/L

Anion gap formula

Na+ - (Cl- + HCO3-)

Cations - Anions

Anion gap elevators

MUD PILES

Methanol, Uremia, DKA

Polyethylene glycol, Isoniozid, Lactic, Ethanol, Salicylates

Diarrhea

Metabolic Acidosis causes

Aspirin

DKA

Diarrhea

RTA

Carbonic Anhydrase Inhibitors

Respiratory Acidosis causes

TBI

Pneumonia

COPD

Lung dx

Asphyxiation

Metabolic alkalosis

Increase base intake

Vomit stomach acid

Overuse diuretics

Aldosterone excess

Increased renin