Lecture 2 Notes

Question 1

Fluids and Electrolytes: Crystalloids

Answer 1

• Supply water and sodium
• Normal saline
• Hypertonic saline
• Lactated Ringers
• D5W
• Plasmalyte

Question 2

Fluids and Electrolytes: Colloids

Answer 2

• Increase colloid oncotic pressure
• Dextran 70
• Dextran 40
• Hetastarch
• 5% albumin
• 25% albumin

Question 3

Potassium (K+)

Answer 3

• Major INTRACELLULAR cation
• 95% of body potassium is INTRACELLULAR
• INTRACELLULAR concentration is 150 mEq/L
• PLASMA concentrations: 3.5-5.0 mEq/L
• Many critical functions:
  
  • Muscle contraction
  • Transmission of nerve impulses
  • Regulation of heart beat
  • Acid-base balance
  • Gastric secretion
  • Renal function
  • Carbohydrate metabolism

Question 4

Causes of hyperkalemia (>5 mEq)

Answer 4

• Renal failure
• Burns
• Hyperaldosteronism
• Trauma
• Infections
• Potassium supplements
• Potassium-sparing diuretics

Question 5

Causes of hypokalemia (<3.5 mEq/L)

Answer 5

• Malabsorption
• Vomiting, diarrhea
• Burns
• Loop diuretics
• Thiazide diuretics
• Corticosteroids
• Crash diets
• Licorice (large amounts)

Question 6

Symptoms of hypokalemia

Answer 6

Early:
-Anorexia
-Hypotension
-Lethargy
-Mental confusion
-Muscle weakness
-Nausea
Late:
-Cardiac dysrythmias
-Neuropathy
-Paralytic ileus
-Secondary alkalosis

Question 7

Potassium Replacement Therapy

Answer 7

*Causes pain when goes into patient. No more than 10 mEq/h into peripheral IV.

Question 8

Sodium (Na+)

Answer 8

• Major EXTRACELLULAR cation
• Normal PLASMA concentration is 135-145 mEq/L.
• Maintaining fluid distribution/where Na goes, water goes
• Major cation in EXTRACELLULAR FLUID
• Major functions:
  
  • Control of water distribution
  • Fluid and electrolyte balance
  • Osmotic pressure of body fluids
  • Acid base balance

Question 9

Hyponatremia (<135 mEq/L)

Answer 9

• Inadequate intake
• Excessive losses (vomiting, diarrhea)
• Excessive dilution of body fluids with water

Question 10

Hypernatremia (>145 mEq/L)

Answer 10

• Deficiency of water in relation to Na
• Excessive intake of sodium
• Hyperaldosteronism

Question 11

Magnesium (Mg++)

Answer 11

• Cation occuring primarily in the intracellular fluid (concentrated there predominantly)
• Required for conduction of nerve impulses and contraction of muscle
• Required component of many enzymes involved in carb and protein metabolism (as a cofactor)
• Normal serum concentration (1.5-2.5 mEq/L)

Question 12

Catecholamines

Answer 12

Active amines (e.g. epinephrine, norepinephrine, dopamine) that have an effect on the CV system

Question 13

Decompensation

Answer 13

The inability of the heart to adequately circulate oxygenated blood to the body’s vital organs

Question 14

Diastolic dysfunction

Answer 14

Impaired relaxation and filling of the ventricles during diastole

Question 15

Digitalis toxicity

Answer 15

An accumulation of digitalis in the body that leads to nausea, vomiting, and atrial tachycardia

Question 16

Digitalization

Answer 16

The adminstration of a loading dose of digoxin (Lanoxin) to achieve a therapeutic blood level of the medication more rapidly.

Question 17

Endothelin

Answer 17

A peptide that raises BP, constricts blood vessels, and contributes to the onset of heart failure

Question 18

Inotropic

Answer 18

Related to or influencing the force of myocardial contractility. Cardiac glycosides that act to influence the contractility of the heart muscle.

Question 19

Renin

Answer 19

An enzyme produced by the kidney that divides angiotensinogen to form angiotensin I, which is then changed to angiotensin II to produce vasoconstriction

Question 20

Systolic dysfunction

Answer 20

Impaired myocardial contraction during systole

Question 21

Therapeutic Index

Answer 21

Blood level of a medication that will produce therapeutic effects

Question 22

Ventricular remodeling

Answer 22

Dilation and hypertrophy of the ventricles in the initial phases of heart failure, causing the ventricle to assume a spherical shape

Question 23

Thiazide diuretics

Answer 23

Blocks reabsorption of NaCl; Decreased Na, Decreased filtration rate of kidney, Decreased volume in blood stream equals decreased BP. Good for chronic edema. Well absorbed.

• Contraindicated in individuals with SULFONAMIDE allergies.
• Can cause hypokalemia. Causes K to be excreted, but not absorbed.

Question 24

HCTZ

Answer 24

Hydrochlorothiazide (Hydrodiuril) - Ideal agent for hyptertension, chronic edema, idiopathic hypercalcuria. Inhibits sodium and chloride reabsorption in the distal tubule.

Question 25

Potassium sparing diuretics

Answer 25

Weak diuretics, but don’t cause K wasting symptoms like thiazide and loop diuretics.

• Amiloride (Midamor)
• Spironolactone (Aldactone)
• Triamterene (Dyrenium)

Question 26

Combination diuretic products

Answer 26

Enhanced diuretic effect with minimal K loss.

• Aldactazide 25/25 and 50/50
  
  • Spironolactone and HCTZ
• Dyazide, Maxzide
  
  • Triamterene and HCTZ
• Moduretic
  
  • Amiloride and HCTZ

Question 27

Loop Diuretics

Answer 27

• Most potent diuretic - 10 x more saluretic than thiazide diuretics.
• Inhibits reabsorption of Na and Cl in the descending limb of the loop of Henle.