Activity Fluids & Electrolytes_Exam 4 Flashcards
____________ Fluids (ICF) includes all of the fluid within cells (2/3 of TBW); ________ is the main ion of the intracellular fluid.
Intracellular
potassium
____________ Fluids (ECF) includes all of the fluid outside of the cells (1/3 of TBW); the main ions of the extracellular fluid are * sodium and *chloride, which follows * sodium. The extracellular fluid includes:
– Interstitial fluid, which is the space between cells and outside of the blood vessels
– Intravascular fluid includes the blood plasma
Extracellular
Distribution and movement of water is dependent upon ___________ pressure (pushes water away) and _______ (oncotic) pressure (pulls water).
– _________ hydrostatic pressure (blood pressure) pushes water out of the capillary and into the interstitial space
– _________ oncotic pressure pulls water from the interstitial space into the capillary
– ____________ hydrostatic pressure pushes water into the capillary
– ____________ oncotic pressure pulls water out from the capillary into the interstitial space
hydrostatic
osmotic
Capillary
Capillary
Interstitial
Interstitial
______ the main extracellular ion, is responsible for the extracellular fluid osmotic balance.
Sodium
_________ the main intracellular ion, is responsible for the intracellular fluid osmotic balance.
Potassium
Causes of _____
- Lost or diminished plasma albumin leads to decreased plasma oncotic pressure, which means less fluid flows into the vessel, so fluid remains in the interstitial space > _____
- Capillaries become permeable with inflammation and immune responses so proteins (which are normally too large to cross the membrane) escape from the vascular space and produce _____
- Lymphatic system normally absorbs interstitial fluid and a small amount of proteins, so when lymphatic channels are blocked or surgically removed, proteins and fluids accumulate and produce __________
Edema
lymphedema
Hormones
___________ hormone (ADH) is secreted when plasma osmolality is increased, circulating blood volume is low, or blood pressure is low
– Increased plasma osmolality occurs with water deficit (dehydration) or sodium excess in relation to total body water
– Increased osmolality stimulates osmoreceptors, which cause the posterior pituitary to release ADH (water drinking and water reabsorption)
– Water reabsorption decreases plasma osmolality (returning it to normal) and urine concentration increases
Antidiuretic
Hormones
_____ is released when circulating blood volume is low, blood pressure is reduced, or sodium levels are depressed or potassium levels are increased
– _____ stimulates angiotensin I
– Angiotensin-converting enzyme (ACE) converts angiotensin I to angiotensin II, which stimulates the secretion of aldosterone and causes vasoconstriction
– Aldosterone then promotes excretion of potassium and sodium reabsorption, which draws in water so that blood volume is increased
– Vasoconstriction from the angiotensin II elevates blood pressure and restores renal perfusion – this limits the further release of renin
Renin
Hormones
___________ peptides are hormones that are released when there is an increase in mean arterial pressure; they naturally antagonize the renin-angiotensin-aldosterone system and cause vasodilation and increased sodium and water excretion so that blood pressure is decreased
Natriuretic
What may occur when there is:
– Normal Output but deficient intake of Na+ & H2O
• Lack of access to Na+ & H2O
– Increased output that is not balanced by the intake of Na+ & H2O; this may cause increased osmolality
• Vomiting
• Diarrhea
• Fistula
– Rapid Fluid Shift from extracellular space into a third space
• Acute intestinal obstruction
• Ascites that develops rapidly
• Manifestations of _ _ _ Deficit – Sudden weight loss – Skin tenting – Dry mucous membranes – Rapid, thready pulse – Postural blood pressure drop (orthostatic hypotension) – Oliguria (decreased urine output) – Syncope (fainting)
Extracellular Fluid Volume Deficit
ECF
What may occur when there is:
– Fluid and electrolyte output is less than the intake and absorption of Na+ & H2O; this may cause decreased osmolality
• Excessive IV infusion of Na+ containing isotonic solution (0.9% NaCl)
• High oral intake of salty foods and water with renal retention of Na+ & H2O
• Oliguria (e.g. acute kidney injury)
• Aldosterone excess (e.g. cirrhosis)
• High levels of glucocorticoids (corticosteroid therapy; Cushing’s)
• Manifestations – Sudden weight gain – Dependent edema – Vascular overload – Bounding pulse - Dyspnea
Extracellular Fluid Volume Excess
- ________ means the same concentration of solute as the comparative solution; the osmotic pressure of the solution is the same as the plasma so there is no shifting of water
- Normal saline is an ________ solution, it is 0.9% NaCl
- ________ fluid loss causes ____________ (hemorrhage, excessive sweating)
– ____________ causes:
• Rapid heart rate
• Flattened neck veins
• Normal or decreased blood pressure
– To treat ____________ we would give the patient ________ IV solutions
• ________ fluid excess causes ____________
– ____________ causes weight gain, decreased hematocrit and plasma protein, neck vein distention, and increased blood pressure
– To treat ____________, we would give the patient diuretics to rid the patient of excess fluid
Isotonic
hypovolemia
- __________ means there is a greater concentration of solutes than comparative solution; the solution exerts greater osmatic pressure than and pulls water out of the cells
- 3% or 5% saline would be __________ solutions
- When the extracellular fluid is __________, a person’s osmolality is increased
– _____________ (Na+ >145mEq/L)
• Caused by retention or infusion of Na+, decreased intake of water, or increased loss of H2O
• Often accompanied by _______________
• Movement of H2O to the ECF may cause hypervolemia
• If there is accompanying H2O loss, both ICF and ECF dehydration may occur
• When _____________ is caused by water loss or decreased water intake, it is associated with fever or respiratory tract infections so there is increased respiratory rate and increased water loss from the lungs
• Infants with severe diarrhea and patients with diabetes are at risk for hypernatremia
• Clinical Manifestations of _____________:
• Weight gain
• Bounding pulse
• CNS symptoms (hyperreflexia)
• Treatment – oral fluids or isotonic salt-free fluids (D5W)
Hypertonic
Hypernatremia
hyperchloremia
Hypotonic
• Hypotonic solutions have a lower concentration of solute than the plasma so they extert less osmotic pressure and cause cells to swell
• Hypotonic solutions include 0.45% normal saline, 0.2% normal saline
• Hypotonic imbalances occur when the osmolality is less than normal
• Leads to intracellular overhydration (cellular edema) and cell swelling
– With a Na+ deficit the osmotic pressure of the extracellular fluid decreases and H2O moves into the cell where the osmotic pressure is greater; plasma volume decreases and symptoms of hypovolemia occur
Hypotonic
- ____________ indicates both Na+ and H2O loss (isotonic or isoosmolar dehydration)
- Pure Water deficits – (hyperosmolar or hypertonic dehydration) – rare but can be caused by comatose (inability to consume) or hyperventilation caused by fever
- Clinical Manifestations – headache, thirst, dry skin, elevated temperature, tachycardia, elevated hematocrit and increased sodium concentration
- Treatment – give H2O, stop fluid loss, administer fluid replacement slowly
Dehydration
Water Deficits
