Lecture 2 Notes Flashcards
Fluids and Electrolytes: Crystalloids
- Supply water and sodium
- Normal saline
- Hypertonic saline
- Lactated Ringers
- D5W
- Plasmalyte
Fluids and Electrolytes: Colloids
- Increase colloid oncotic pressure
- Dextran 70
- Dextran 40
- Hetastarch
- 5% albumin
- 25% albumin
Potassium (K+)
- 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
Causes of hyperkalemia (>5 mEq)
- Renal failure
- Burns
- Hyperaldosteronism
- Trauma
- Infections
- Potassium supplements
- Potassium-sparing diuretics
Causes of hypokalemia (<3.5 mEq/L)
- Malabsorption
- Vomiting, diarrhea
- Burns
- Loop diuretics
- Thiazide diuretics
- Corticosteroids
- Crash diets
- Licorice (large amounts)
Symptoms of hypokalemia
Early: -Anorexia -Hypotension -Lethargy -Mental confusion -Muscle weakness -Nausea Late: -Cardiac dysrythmias -Neuropathy -Paralytic ileus -Secondary alkalosis
Potassium Replacement Therapy
*Causes pain when goes into patient. No more than 10 mEq/h into peripheral IV.
Sodium (Na+)
- 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
Hyponatremia (<135 mEq/L)
- Inadequate intake
- Excessive losses (vomiting, diarrhea)
- Excessive dilution of body fluids with water
Hypernatremia (>145 mEq/L)
- Deficiency of water in relation to Na
- Excessive intake of sodium
- Hyperaldosteronism
Magnesium (Mg++)
- 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)
Catecholamines
Active amines (e.g. epinephrine, norepinephrine, dopamine) that have an effect on the CV system
Decompensation
The inability of the heart to adequately circulate oxygenated blood to the body’s vital organs
Diastolic dysfunction
Impaired relaxation and filling of the ventricles during diastole
Digitalis toxicity
An accumulation of digitalis in the body that leads to nausea, vomiting, and atrial tachycardia
Digitalization
The adminstration of a loading dose of digoxin (Lanoxin) to achieve a therapeutic blood level of the medication more rapidly.
Endothelin
A peptide that raises BP, constricts blood vessels, and contributes to the onset of heart failure
Inotropic
Related to or influencing the force of myocardial contractility. Cardiac glycosides that act to influence the contractility of the heart muscle.
Renin
An enzyme produced by the kidney that divides angiotensinogen to form angiotensin I, which is then changed to angiotensin II to produce vasoconstriction
Systolic dysfunction
Impaired myocardial contraction during systole
Therapeutic Index
Blood level of a medication that will produce therapeutic effects
Ventricular remodeling
Dilation and hypertrophy of the ventricles in the initial phases of heart failure, causing the ventricle to assume a spherical shape
Thiazide diuretics
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.
HCTZ
Hydrochlorothiazide (Hydrodiuril) - Ideal agent for hyptertension, chronic edema, idiopathic hypercalcuria. Inhibits sodium and chloride reabsorption in the distal tubule.
