Lecture Exam # 3: Electrolytes Flashcards
Identify the electrolyte most influential in determining circulating blood volume and the hormone which control its concentration in the body.
1) Sodium 2) Aldosterone
RAAS
1) Activated by decreasing blood volume/ decreasing hydrostatic pressure 2) Decreasing BV causes arteries to constrict, stimulating the release of aldosterone 3) Aldosterone causes Na+ retention and water volume retention
Normal Serum Na
135-145 mEq/L
What is sodiums role in thirst?
When Sodium Levels increase, thirst receptors in the hypothalamus stimulate thirst sensations
What do sodium levels tell you/not tell you?
They tell you the level of hydration in the body, however they do not tell you about the possibility of over consumption of sodium
Hypernatremia (levels and hydration analysis)
high levels of sodium in the serum/blood; mimics dehydration, because during dehydration levels of sodium are high.
What level of sodium is indicative of hypernatremia?
levels greater than 145 mEq/L
Symptoms of hypernatremia
Excessive Thirst, Altered mental status, and lethargy/seizures/coma
What are some possible causes of hypernatremia?
Overall loss of water resulting in excess of serum sodium ( water intake, profuse sweating, Diarrhea/vomiting, and high fever)
Treatment of hypernatremia
Adequate fluid intake
Hyponatremia
Excessive loss of sodium
What sodium levels are indicative of hyponatremia?
Serum sodium less than 135 mEq/L
What are symptoms of hyponatremia?
Rapid weight loss, abdominal cramps, and convulsions
What are some causes of hyponatremia?
usage of diuretics; Excessive loss of gastrointestinal fluids from vomiting, diarrhea or fistula drainage; renal disease with sodium wasting states
Treatment of hyponatremia
Administer normal or hypertonic saline
Pseudohyponatremia
Blood contains excess water relative to salt; caused by fluid overload
Sodium levels associated with pseudohyponatremia
Serum sodium levels below 135 mEq/L
Symptoms of pseudohyponatremia
Rapid weight gain, signs of over-hydration; Levels below 130 mEq/L: Nausea/headache, Confusion/agitation, seizures/coma/death
Causes of pseudohyponatremia
Edematous states; Ascites w/cirrhosis of the liver; congestive heart failure
What group of individuals are the most at risk for developing hyponatremia?
The elderly
Treatment of hyponatremia
may require fluid and or sodium restriction
What is the major intracellular electrolyte?
Potassium
Normal Serum Potassium Levels
3.5 - 5.0 mEq/L
What organ is responsible for potassium balance?
The Kidneys
What serum potassium level is associated with hyperkalemia?
serum potassium levels greater than 5.0 mEq/L
Major symptom of hyperkalemia
Cardiac arrhythmias
Causes of hyperkalemia
1) inability to excrete K+ (renal failure) 2) Excessive potassium intake w/renal disease 3) Release of intracellular potassium into the blood stream as a result of tissue injury, malnutrition, or stress
Treatment of hyperkalemia
1) Medication/treatment to enhance cellular uptake of potassium 2) Medications to enhance loss of potassium in the feces or the urine
What Potassium level is associated with hypokalemia?
Serum potassium less than 3.5 mEq/L
Major symptom of hypokalemia?
Cardiac arrhythmias
Factor contributing to hypokalemia
1) Metabolic alkaosis 2) Renal tubular dysfunction 3) Unusual potassium losses due to diuretics, gastric suctioning, or diarrhea
Treatment of hypokalemia
High potassium foods, and K+ Supplements
What foods are high in potassium?
Potatoes, bananas, oranges
Normal pH
7.35 to 7.45
Carbonic Acid, Bicarbonate, and CO2/H2O equation
CO2 + H2O gt H2CO32 gt H+ + HCO3-
Lungs role in Acid/Base balance
Major organ for acid base balance. Converts CO2 and H2O to carbonic acid and vice versa. Regulate acid-base by expelling or retaining CO2
How do the kidneys adjust pH balance
excretion of of H+ through urine and absorption of H+ in the glomerulus
Normal pH of urine
6.0
Serum K and Acid-Base Balance
1) If serum H+ high, H+ uptaken by cells traded with K+ causes hyperkalemia 2) H+ low in serum, H+ leaves the cell and K+ uptaken in the cells leads to hypokalemia
Respiratory Acidosis
Conditions which diminish the lungs ability to exhale carbon dioxide (emphysema, asthma, bronchitis, CHF)
Respiratory Alkalosis
Condition which cause the lungs to exhale larger quantities of carbon dioxide than normal (Hysteria, high altitudes, heart failure w/SOB)
Metabolic acidosis
acid gain - diabetic ketoacidosis
Metabolic alkalosis
loss of acid- Loss of gastric juice/vomiting or diarrhea
Lab values decreased w/hydration status
Over-hydration: decreases serum sodium, osmolality, abumin, BUN, hematocrit/hemoglobin, USP, UO
Lab values increased w/hydration status
Under-hydration: increases serum sodium, osmolality, abumin, BUN, hematocrit/hemoglobin, USP, UO
