Fluid and Electrolytes/Acid Base Flashcards
movement of fluid through a membrane from an area of higher hydrostatic pressure to a lower pressure
filtration
movement of solutes across a membrane from an area of higher concentration to an area of lower concentration
diffusion
movement of water only through a selectively permeable membrane to achieve an equilibrium of osmolarity
osmosis
normal osmolarity for the body
270-300 mOsm
obligatory urine output
400-600mL/day of urine. any less means toxic waste is retained in the body.
secreted when the plasma sodium levels are low
aldosterone
effect of aldosterone
causes kidneys to reabsorb water and sodium
what happens to potassium when sodium is absorbed?
potassium is excreted
secreted when blood osmolarity rises
Antidiuretic hormone/vasopressin
effect of ADH
causes water to be reabsorbed and retained to lower blood osmolarity
secreted when the heart muscles stretch
natriuretic peptides
effect of natriuretic peptides
excretion of water and sodium- lowering blood osmolarity and volume
actions of angiotensin II
- systemic vasoconstriction
- decreased urinary output
- secretion of aldosterone
what is the goal of the RAAS pathway?
raise blood pressure and increase/maintain organ perfusion
how much fluid should a dehydrated patient get per hour?
60-120 ml/hr
what are the two most important things to monitor during rehydration therapy?
urine output and pulse rate and quality
what is the best indicator of fluid overload and retention?
rapid weight gain
what are the two physiological changes at the cellular level in hyponatremia?
decreased cell membrane depolarization and cellular swelling
what is the normal range of calcium?
9-10.5 mEq/L
what is calcium’s role in the body?
bones, blood, and beats.
bone and dental health, cardiac rhythm, muscle and nerve function, and blood clotting
what is the normal range for magnesium?
1.8- 2.6 mEq/L
What are physical signs of dehydration?
Rapid, weak pulses. Hypotension/orthostatic hypotension. Decreased turgor. Dry mucous membranes. Flat neck veins. Decreased urine output/concentrated urine.
What happens to the labs of a patient with dehydration?
They will be elevated because there is water loss which increases blood concentration
`What is a safety concern for a client with dehydration?
falls due to confusion, muscle weakness, and orthostatic hypotension
What are physical signs of fluid overload?
Rapid, bounding pulse. Elevated BP. Dependent edema. Distended neck veins. Crackles in lungs. Rapid weight gain.
What are important interventions for fluid overload?
Daily weights, strict I and Os, sodium and water restriction. Skin assessments to prevent breakdown.
What are the functions of sodium in the body?
Controls fluid movement, nerve impulse conduction, and muscle contractions
What are some causes of hyponatremia?
Prolonged diuretic use, excessive vomiting, diarrhea, sweating. Kidney disease, NPO.
Signs and symptoms of hyponatremia
Confusion, seizures, decreased DTR, muscle weakness, rapid weak pulse.
What are causes of hypernatremia?
Kidney failure, excessive intake, tube feedings without free water.
Signs and symptoms of hypernatremia
Agitation, risk for seizures, muscle twitching, decreased urine output.
What are functions of potassium in the body?
Nerve impulse conduction and muscle contraction
What are causes of hypokalemia?
Diuretics, diarrhea/vomiting, too much water
Signs and symptoms of hypokalemia
Muscle weakness, heart arrythmias, decreased peristalsis
What are important interventions for a patient with hypokalemia?
Fall precautions due to muscle weakness and respiratory monitoring also due to muscle weakness
What electrolyte can never be given by IV push?
Potassium because it can cause cardiac arrest
What is important to note about administration of potassium?
It is a severe tissue irritant and can cause necrosis of tissues
What are causes of hyperkalemia?
Potassium-sparing diuretics, kidney failure, excessive salt substitute intake, trauma to cells
What does hyperkalemia do at the cellular level?
Increases cell membrane excitability and makes it irritable
Signs and symptoms of hyperkalemia
Cardiac dysrhythmias, muscle twitching, irritability
What is sodium polystyrene sulfonate?
Drug used for hyperkalemia. Binds to K+ in the GI tract
What is the effect of hyperkalemia on the heart?
It decreases cardiac contractility: decreased HR, BP
What are causes of hypocalcemia?
inadequate intake of calcium or vitamin D, parathyroid issues/surgery
What are signs and symptoms of hypocalcemia?
Muscle spasms, tingling, cardiac arrythmias, osteoporosis, Trousseau and Chvostek signs
What is Chvostek’s sign?
Facial muscle response when the side of the face is tapped
What is Trousseau’s sign?
Palmar flexion when a blood pressure cuff is applied to the arm.
Safety considerations for a patient with hypocalcemia?
Fall risk and risk of fractures due to low bone density
What are causes of hypercalcemia?
Thiazide diuretics, kidney failure, excessive intake, hyperparathyroidism
Signs and symptoms of hypercalcemia?
Increased risk of blood clots, decreased BP and HR, muscle weakness, increased risk of kidney stones
What hormone is released when calcium is low?
Parathyroid hormone
What hormone is released when calcium is high?
Thyrocalcitonin
What hormone is typically the opposite of calcium?
Phosphorous
What electrolyte values typically go up and down together?
Magnesium and calcium (Callie and Maggie)
What are the causes of hypomagnesemia?
Loop/thiazide diuretics, malnutrition
Signs and symptoms of hypomagnesemia?
Cardiac dysrhythmias, hypertension, muscle contractions/twitching, confused/agitated, risk of seizures
What are causes of hypermagnesemia?
Renal failure, antacids
Signs and symptoms of hypermagnesemia?
Decreased HR and BP, drowsy/lethargic, muscle weakness/respiratory failure
