Week 1 (ch. 2 Fluid, electrolyte, and acid-base imbalances) Flashcards
Hydrostatic pressure
Increases filtration by pushing fluids and solutes out of capillaries
Osmotic pressure
Pressure caused by solution passing through semi-permeable membrane, the pulling force or attracting force
Arteriolar end of capillary (fluid movement through this)
Blood hydrostatic pressure (BP) exceeds the interstitial hydrostatic pressure and plasma colloid osmotic pressure = fluid moves out from capillary into the interstitial space
Fluid movement / capillary exchange: venous end of capillary
Bloods hydrostatic pressure is decreased and osmotic pressure is higher = flui is pulled back (shift) into capillary
Causes of edema - increased capillary hydrostatic pressure
- Increased capillary hydrostatic pressure - pressure prevents the return of fluid from interstitial to venous OR forces amounts out of the capillary. Due to increased blood volume from kidney failure, pregnancy, CHF, or administration of excess fluids
Cause of edema - loss of plasma proteins
Causes a decrease in plasma osmotic pressure allowing more fluid to leave capillary and less fluid to return at the venous end. Due to kidney disease, liver disease, malnutrition/malabsorbtion, burn victims
Cause of edema - obstruction of lymphatic circulation
Fluid and protien can not be returned to general circulation causing local edema. Due to tumor or infection damage of lymph node or lymph node removal
Cause of edema - increased capillary permeability
Chemical mediators released from cells after tissue injury increasing fluid movement into interstitial area typically localized. Due to inflammatory response or infection
third spacing - fluid deficit and fluid excess: what is it?
Fluid shifts from the blood to a body cavity or tissue - causes the fluid that was shifted to no longer be circulating fluid
What does third spacing lead to?
Fluid deficit in the vascular compartment with a fluid excess in the interstitial space
How is third spacing detected?
Lab tests of hematocrit and electrolyte concentrations
When might you see third spacing?
Burn or peritonitis (inflammatory infection of the peritoneal cavity)
What does sodium primarily exist as?
Sodium chloride or sodium bicarbonate
How are sodium levels controlled?
Mostly by kidney through aldosterone
What is Na essential in?
Nerve impulses and muscle contraction
Hyponatremia levels
Less than 135
What is the role of K
Assist in regulation of intracellular fluid volumes
- role in metabolic processes
- nerve conduction and contractions of all muscles
What promotes the movement of k into the cell
Insulin
What shifts k out of the cell and into the extra cellular environment?
Acidosis
What shift k into the cell
Alkalosis
Hyponatremia causes
Direct loss of na or too much water in extra cellular environment
- excess sweating, vomiting, diarrhea
- certain diuretics with low na diet
- hormone imbalance
- early chronic renal failure
- excessive water intake
Hyponaturemia effects
- impairs nerve conduction and results in fluid imbalance
- fatigue, muscle cramps, abd. Discomfort, N/V
- decreased osmotic pressure in ECF leading to fluid shift into cells resulting in hypovolemia
- brain cells swell causing confusing, HA, weakness, seizures
Hypernatremia causes
Too much na Insufficient ADH Loss of thirst mechanism Water diarrhea Hyperventilation
Hypernatremia effect
Fluid shift
Weakness
Agitation
Firm subcutaneous tissue
Increased thirst with dry mucous membranes
Decreases urine d/t ADH secretion/increased urging d/t lack of ADH
Hypokalemia causes
Excessive fluid loss Diuresis from diuretic meds Excessive aldosterone or glucocorticoids Decreased dietary intake Diabetic ketoacidosis
Hypokalemia effects
Cardiac dysthymia Fatigue, muscle weakness Paresthesias (pins and needles) Decreased appetite / nausea - shallow respirations (severe) - polyuria and renal impairment (severe)
Hyperkalemia cause
Renal failure Aldosterone deficit Potassium-sparing diuretics meds Tissue damage causing leaking of extracellular Acidosis
Hyperkalemia effects
Dysthymia
Cardiac arrest
Muscle weakness progressing to paralysis
Fatigue, nausea, and parasthesias
What is Ca controlled by
PTH and calcitonin
How is Ca influenced by vitamin D and Phosphate
Vitamin D is injected from UV rays, activated in kidneys and promotes Ca movement to the blood
Reciprocal relationship with phosphate
Does alkalosis or acidosis lead to hypocalcemia
Alkalosis
Functions of Ca
Structural strength for bones
- stability of nerve membranes
- muscle contractions
- needed for metabolic processes and enzyme reactions (blood clotting)
What is the appropriate lab value for Ca
2.2-5 mmol/ L
Hypocalcemia causes
Hypoparathyroidism (decreased PTH) Malabsorption syndrome Deficient serum albumin Increased pH (alkalosis) Renal failure
Hypocalcemia effects
Skeletal muscle spasms d/t increased irritability of nerves
- muscle twitching, hyperactive reflexes
- Chvostek sign, tetany, laryngospasm, abdominal cramps
Weaker muscle contraction of the heart
- arrythmias, lower BP
Hypercalcemia causes
Uncontrolled release of calcium ion-neoplasms
Hyperthyroidism (increased PTH)
Immobility (demineralization of bones)
Increased intake
Milk-alkali syndrome
Hypercalcemia effects
Decrease neuromuscular activity
- muscle weakness, loss of tone, lethargy, personality change
Interferes with ADH in kidneys
- polyuria
Cardiac contractions increase — dysthymia
Effect on bone — decreased density leading to fractures OR bone strength maintained
Kidney stone formation
Magnesium serum level
1.6 - 2 mg / dL
Causes of hypomagnesemia
Diuretics, diabetic ketoacidosis, hyeraldosteronism
Hypomagnesemia effects
Neuromuscular hyperirritability Tremors Chorea Insomnia Personality changes Increase HR
Hypermagnesemia causes
Renal failure Administering magnesium (maternity)
Hypermagnesemia effects
Depressed neuromuscular function, decreased reflexes, lethargy, cardiac arrythmias
Hypophosphatemia causes
Malabsorption syndrome, diarrhea, excessive use of anti-acids, alkalosis, hyperparathyroidism
Hypophosphatemia effects
Tremors, weak reflexes, paresthesias, confusion, anorexia, dysphagia, blood cell functions
Hyperphosphatemia causes
Renal failure
Tissue damage
Chemo
Hyperphosphatemia effects
Muscle twitching, hyperactive reflexes, arrhythmia
Hypochloremia causes
Excessive sweating
Associated with alkalosis
Hypochloremia effects
N/v, diarrhea, muscle twitching, confusion, sleepiness
Hyperchloremia cause
Too much intake of sodium chloride
Hypernatremia
Hyperchloremia effects
Edema
Weight gain
What is the bodies normal pH
7.35 - 7.45
At what levels will death occur for the pH values
Less than 6.8
Higher than 7.8
What controls the serum pH
Buffer pairs - respond immediately
Respiratory system - alter carbon dioxide (carbon acid) by changing respiratory rate
Kidneys - slowest but most effective
Control of serum pH: Buffer system
Several present in blood
- combination of weak acid and its alkaline salt
- reaction to acids/alkali added to blood to neutralize - maintaining constant pH
What are the 4 major pairs of the buffer system
Sodium bicarbonate - carbonic acid system
Phosphate system
Hemoglobin system
Protein system
Control of serum pH: respiratory system
If carbon dioxide or hydrogen levels increase, then the respiratory control system is stimulated to increase the respiratory rate which rids more acid from the body. If the body is alkalotic, the respiratory decreased the respiratory rate, increase acid levels.
Control of serum pH: renal system
- may reduce body’s acid by exchanging hydrogen for sodium through aldosterone, removes the hydrogen by combining with ammonia
- provides bicarbonate ion
- kidneys compensate for metabolic conditions and dietary intake
Acidosis
Decrease in pH, increase in H ion
Alkalosis
Increase in pH, decrease in H ions
What are the 4 basic types of acid-base imbalance?
- respiratory acidosis
- respiratory alkalosis
- metabolic acidosis
- metabolic alkalosis
Acid-base imbalance: compensation
When the serum pH is normal
- one system compensation to fix the imbalance because caused by the other system
Ex. Respiratory disorder causes acidosis so the kidneys compensate to rid more acid
- time limited, patient must be monitored closely
Acid-base imbalance: decompensation
When the serum pH is abnormal
- this means the respiratory or renal system can buffer to maintain balance
- intervention is essential to maintain homeostasis
Explain acidosis: value, effects
PH < 7.35
Impair nervous system, headache, lethargy, weakness, confusion leads to coma and death
Deep rapid breathing
Respiratory acidosis: what happens and what are the causes
Increase in CO2
Pneumonia, aspiration, chest injury, meds that depress resp. Control center (opiates)
COPD
Metabolic acidosis: what is it and what are the causes
Decrease in bicarbonate
Excessive loss (diarrhea)
Increased use to buffer increased acids
Renal failure/disease
Alkalosis: what is the value and what are the effects
< 7.45
Increased irritability of nervous system, restlessness, muscle twitching, tingling, numbness, eventually leads to tetany, seizures, and coma
Respiratory alkalosis: what is it and what are its causes
Results from hyperventilation
- anxiety, fear, overdose aspirin, head injury, brain stem tumor causing hyperventilation
Metabolic alkalosis: what is it and what are its causes
Increase in bicarbonate
Follows loss of hydrochloric acid from stomach
- early states of vomiting, drainage of stomach
- hypokalemia
- excessive ingestion of antacids
Treatments of acid-base imbalances
A. Deficits are reversed by adding fluid/electrolyte that has the deficit
B. Excess is removed though diuretics to increase excretion through kidneys
C. Levels are monitored closely
D. Some cases, diet changes can accomplish the correction
