Fluid Flashcards
Intracellular
2/3
Extracellular fluid
1/3
Distribution of body fluid: age differences
- Paediatric: at birth 75% to 80% of body weight
- geriatric: decreased percent of total body water (renal decline and diminished thirst perception)
Children and the elderly are more at risk for fluid imbalance due to…
Differences in total body water (TBW) and regulatory mechanisms
Major factors influencing body fluid balances
- water shifts due to hydrostatic, oncotic and osmotic gradients
- where sodium goes, water follows
Major factors influencing body fluid balances is controlled by
ADH, renin-angiotensin- aldosterone, natriuretic peptides, renal function
Normal fluid movement as blood flows from arterioles to capillaries
- “Pressure” forces water into interstitial space
- capillary hydrostatic pressure
Normal fluid movement as blood flow gets closer to veins
- water is pulled back in
- capillary oncotic pressure
Interstitial forces
- interstitial hydrostatic pressure
- interstitial oncotic pressure
Types of fluid imbalances:
- Changes in intravascular volume
- accumulation of fluid in interstitial space
- alteration in fluid movement in and out of cell
Changes in intravascular volume
- fluid volume deficit
- fluid volume overload
Accumulation of fluid in interstitial fluid
Edema
Alteration in fluid movement in and out of cell
Osmosis
Fluid volume deficit
Dehydration
Dehydration
Isotonic loss
Isotonic loss
- water and sodium are lost in proportion
- intravascular space
Dehydration - causes
Bleeding, wound drainage, excess sweating, burn injuries
Dehydration - sign and symptoms
Weight loss, dry skin/mucous membranes, decreased urine output, low bp
Dehydration - treatment
Replace water and solutes/sodium
Fluid volume excess
Volume overload
Volume gain
Isotonic gain
Isotonic gain
- water and sodium are gained in proportion
- intravascular space
Volume overload - cause
Too much IV solution, renal failure, liver failure and heart failure
Volume overload - sign and symptoms
Weight gain, development of edema, veins dilate, strong pulse strength
Volume overload - treatment
Optimize renal, kidney, cardiac function
Edema
- movement of water from capillary (intravascular space) into interstitial space
Edema: causes
- increase in capillary hydrostatic pressure
- decrease in plasma oncotic pressure
- increases in capillary permeability
- lymph obstruction
Manifestations of Edema
- localized Edema
- pitting Edema
- generalized
Alterations in fluid movement in and out of cell because of
- due to changes in osmosis
- strongly linked to sodium imbalances
The most intracellular ion
Potassium
Most extra cellular ion
Sodium
Distribution of body fluid (2)
Interstitial fluid (ICF) Extra cellular fluid (ECF)
an imbalance in one electrolyte often produces an..
imbalance in another electrolyte
hyponatremic (hypotonic) imbalances
concentration of sodium is decreased below normal levels
hyponatremic imbalance - causes
- imbalance in water, not enough sodium or too much water (
hyponatremic and plasma
- plasma will be hypotonic
- cellular edema
hyponatremic imbalances - clinical manifestations
- primarily related to cell swelling
- neurological aches
- muscle cramps, weakness
Hypernatremic (hypertonic) imbalances
concentration of sodium is increased above normal levels
hypernatremic imbalances - causes
too much sodium and not enough water, inability to retain water, excess intake of sodium tablets
hypernatremic and plasma
- plasma will be hypertonic
- cellular dehydration
hypernatremic imbalances - clinical manifestations
- primarily related to cell dehydration
- neurological irritations
- thirst, dry skin
hypernatremic imbalances - intravascular volume
increase (hypertension and bounding pulse)
potassium
- the major systems that show signs and symptoms include CVS and CNS
- a lot of overlap in symptoms with sodium and potassium
- they both interact with acid-base status
hypokalemia - causes
- increased excretion
- diarrhea, vomitting, NG suction, draining wounds
- loop diuretics
- hyperaldosteronism
- decreased replacement
hypokalemia - manifestation
- mostly cardiac (dysrhythmias and cardiac arrest)
- CNS: decreased reflects, lethargy
- GI: decreased peristalsis
hypokalemia - treatment
correct the cause and replace the potassium (either by IV or foods)
hyperkalemia - causes
- decreased excretion (renal disease and hypoaldosteronism)
- burns and crush injuries
- excess replacement
- salt substitutes with K+
hyperkalemia - manifestations
- mostly cardiac (dysrhythmias, cardiac arrest)
- CNS: increased reflects and anxieties
- GI: diarrhea
hyperkalemia - treatment
dialysis and kayexalate (treating the cause)
calcium
- hypocalcemia
- hypercalcemia
hypocalcemia
- chvostek’s sign
- trousseau’s sign
hypercalcemia
weakness, loss of muscle tone and hypertension
H+
- needed to maintain membrane potential
- regulates speed of nerve implies conductions and muscle finer contraction
- maintains speed of enzyme reactions
normal body pH
7.35-7.45
To maintain the body’s normal pH
the H+ must be neutralized by buffers or excreted via the lungs or kidneys
excretion of acids
- Volatile
- nonvolatile
Volatile
- carbonic acid
- eliminated by lungs as CO2
nonvolatile
- sulfuric, phosphoric and other organic acids
- eliminated by the renal tables
renal system controls pH by
- excreting or conserving acid: H+
- conserving or excreting base: bicarbonate (HCO3-)
acid-base imbalances
- caused by respiratory or “metabolic” problems
- categorized as either acidosis or alkalosis
- if one is dysfunctional the other will try to compensate
Respiratory alkalosis
- too little CO2
Respiratory alkalosis - causes
- rapid/deep breathing
Respiration acidosis - causes
- slow/shallow breaking
Respiration acidosis
too much CO2
metabolic acidosis
- not enough bicarbonate ion
- too much acid
metabolic acidosis - causes
- excess production of non-volatile acids
metabolic alkalosis
- too much bicarbonate ion HCO3-
- not enough acid
full compensation
pH will become fully within normal range
partial compensation
pH will move towards normal but not within normal range
