Chapter 45: Agents Affecting the Volume and Ion Content of Body Fluids Flashcards
volume contraction
decrease in total body water
Volume expansion
- increase in total body water
isotonic contraction
- volume concentration in which sodium and water are lost in isotonic proportions
- decrease in total volume; no change in osmolality
isotonic contractions effect
- vomiting, diarrhea, kidney disease, and misuse of diuretics
isotonic contraction treatments
- fluids that are isotonic to plasma
- 0.9% Normal Saline
hypertonic contraction
- loss of water exceeds loss of sodium
- reduced ECF volume; increase in osmolality
hypertonic contraction causes
- excessive sweating, osmotic diuresis
- secondary to extensive burns or CNS disorders that interfere with thirst
hypertonic contraction treatment
- hypotonic fluids (0.45% sodium chloride or solutions that contain no solutes at all (D5W))
- drinking water
hypotonic contraction
- loss of sodium exceeds loss of water
- both volume and osmolality of extracellular fluid are reduced
hypotonic contraction causes
- excessive loss of sodium through the kidney (diuretic therapy, chronic renal insufficiency, lack of aldosterone)
hypotonic treatment
- mild: infusing isotonic sodium chloride solution
- severe: hypertonic solution (3%) NaCl
volume expansion
- increase in total volume of body fluid
- may be isotonic, hypertonic, or hypotonic
volume expansion causes
- overdose with therapeutic fluids
- disease states (congestive heart failure, nephrotic syndrome, cirrhosis with ascites)
volume expansion treatment
- diuretics
- agents used fro heart failure
acid base balance is maintained by which symptoms
- bicarbonate-carbonic acid buffer system
- respitory system
- kidneys
acid- base disturbances
- respiratory alkalosis
- respiratory acidosis
- metabolic alkalosis
- metabolic acidosis
respiratory alkalosis causes
hyperventilation (decrease in CO2)
respiratory alkalosis treatment
- mild: none
- more severe: rebreathe CO2 (laden expired breath)
respiratory acidosis causes
- retention of CO2 secondary to hypoventilation
respiratory acidosis treatment
- correction of respiratory impairment
- infusion of sodium bicarbonate
metabolic alkalosis causes
- excessive loss of gastric acid
- administration of alkalizing salts
metabolic alkalosis treatment
- solution of sodium chloride plus potassium chloride
metabolic acidosis causes
- chronic renal failure
- loss of bicarbonate during severe diarrhea
- metabolic disorders
- poisoning by methanol and certain medications
metabolic acidosis treatment
- correction of the underlying cause
- alkalinizing salt if severe
what is the most abundant intracellular cation
potassium (K)
potassium has a major roles in
- conducting nerve impulses
- maintaining the electrical excitability of muscle
- regulating acid base balance
potassium is regulated mainly by the
kidneys
hypokalemia
serum potassium levels less than 3.5
what is the most common cause of hypokalemia
treatment with thiazide or loop diuretic
causes of hypokalemia
- treatment with thiazide or loop diuretic
- excessive insulin
- alkalosis
treatment for mild hypokalemia
- oral potassium chloride (KCL)
oral potassium chloride side effects
- abdominal discomfort, nausea and vomiting, diarrhea
oral pottassium chloride should be taken with
meals or a full glass of water
treatment for severe hypokalemia
IV potassium chloride
IV potassium chloride must be
DILUTED (40 or less)
potassium chloride must never be administered by
IV push
hypokalemia treatment must be avoided in patients
who are predisposed to hyperkalemia
- severe renal impairment, use of potassium-sparing diuretics, hypoaldosterone
what is the principle complication of hypokalemia
hyperkalemia
- asses renal function and changes in ECG
hyperkalemia causes
- severe tissue trauma, untreated addisons disease
- acute acidosis
- potassium sparing diuretics or overdose with oral or IV potassium
hyperkalemia conseqeunces (earliest signs)
- disruption of the electrical of the heart
- mild: T wave heightens; PR prolonged
- severe: cardiac arrest
hyperkalemia noncardiac signs
- confusion, anxiety, dyspnea, weakness or haviness of legs, numbness/tingeling of hanfs
hyperkalemia treatment
- withhold foods that contain potassium (potatoes, bananas, raisins, oranges, mushrooms)
- withhold potassium sparing diuretics, potassium supplements
- oral or rectal administration of sodiun polystyrene sulfonate [Kayexalate]
- calcium salt
- infusion of glucose and insulin
hypomagnesemia causes
diarrhea, hemodialysis, kidney disease, prolonged IV feeding, chronic alcoholism, hypermagnesia
hypomagnesemia treatment
- magnesium oxide
- magnesium sulfate
mypomagneseia adverse effects
- respitory paralysis
- cardiac arrest
hypermagnesemia is most common in patients with
renal insufficency
mypermagnesemia effects
- muscle weakness, hypotension, sedation, and ECG changes
- risk of cardiac arrest
