Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
74 Cards in this Set
- Front
- Back
|
Percent of body water in ICF
|
66%
|
|
|
Percent of body water in ECF
|
33%
|
|
|
Percent of ECF that's blood
|
25%
|
|
|
Percent of ECF that's ISF
|
75%
|
|
|
What are the three 'third spaces'?
|
- Pericardial cavity
- Pleural cavity - Peritoneal cavity |
|
|
What is TBW primarily controlled by?
|
- Thirst (intake)
- Renal output |
|
|
4 clinical parameters for assessing TBW
|
- Skin elasticity
- MM - BW - Enopthalmia |
|
|
3 laboratory parameters for assessing TBW
|
- PCV
- BUN - Urine SG |
|
|
Clinical manifestation of hypovolemia
|
Dehydration
|
|
|
Clinical manifestation of hypervolemia
|
Edema
|
|
|
Osmolality (define)
|
Measure of the number of particles in a solution (osm/kg)
|
|
|
Tonicity (define)
|
Number of particles that can't diffuse across cell membranes, but are able to generate an osmotic gradient
|
|
|
4 main substances that determine serum osmolality in health
|
- Na
- K - Urea - Glc |
|
|
What is the osmol gap?
|
Difference between measured osmolality and calculated osmolality
|
|
|
Level that the osmol gap should not exceed
|
10 mOsmol/kg
|
|
|
What does an increased osmol gap indicate?
|
Presence of high concentrations of ethylene glycol, methanol, ketones, or lactic acid.
|
|
|
Level of osmol gap that indicates a poor prognosis
|
> 40 mOsmol/kg
|
|
|
Relationship of hypernatremia to hyperosmolality
|
If hypernatremia is present, hyperosmolality will always be present
|
|
|
What does a hyperosmolality occur with?
|
Accumulation of endogenous solutes:
- Glc - Ketones - Urea - Glycols |
|
|
What occurs to water in hyperosmolality?
|
Shifts from ICF to ECF
|
|
|
2 clinical signs of hyperosmolality
|
- Cell shrinkage
- Convulsions |
|
|
Problem with hyperosmolality
|
Can cause cerebral edema if rehydrated too quickly
|
|
|
What is hyposmolality almost always associated with?
|
Hyponatremia
- But not all cases. |
|
|
How does hyposmolality affect water?
|
Shifts water from ECF to ICF
|
|
|
2 problems associated with hyposmolality
|
- Intravascular hemolysis
- Neurological disorders |
|
|
What amplifies a loss of ECF with hypoosmolality?
|
Severe dehydration
|
|
|
What can severe dehydration coupled with hypoosmolality cause? (2)
|
- Circulatory collapse
- Shock |
|
|
4 electrolytes
|
- Na
- K - Cl - tCO2 |
|
|
Two units of measurement for electrolytes
|
mmol/L
mEq/L |
|
|
Two samples that electrolytes can be run off of, and the tubes you do them in.
|
- Serum (red top with nothing in it)
- Plasma (green top with Li Heparin) |
|
|
Major EC cation
|
Na
|
|
|
Which electrolyte is responsible for most of the osmotic force that maintains the ECF?
|
Na
|
|
|
What does serum [Na] reflect?
|
Total body [Na]
|
|
|
What does an increase in Na indicate?
|
ECF expansion (hypervolemia)
|
|
|
What does a decrease in Na indicate?
|
ECF depletion (hypovolemia)
|
|
|
Clinical manifestations of increased Na (4)
|
Those related to hypervolemia
- Edema - Pleural effusion - Pulmonary edema - Ascites |
|
|
Clinical manifestations of decreased Na (5)
|
Those related to hypovolemia
- Loss of skin elasticity - Dry MM - Enopthalmia - Slow CRT - Shock |
|
|
4 systems that work to conserve Na
|
- Receptors in juxtaglomerular cells of kidney
- Volume receptors in veins and atria - Baroreceptors in aorta and carotid sinus - Vasopressin |
|
|
How do receptors in the juxtaglomerular cells regulate Na?
|
Activation of RAAS
|
|
|
Two primary portions of RAAS that control [Na]
|
- Angiotensin II (promotes Na retention and aldosterone release)
- Aldosterone (promotes Na retention) |
|
|
How do volume receptors in the atria affect Na regulation?
|
Sense changes in blood volume
- Causes release of atrial natriuretic factor with hypervolemia - ANF promotes sodium excretion |
|
|
How do pressure receptors affect Na regulation?
|
Hypovolemia stimulates SNS
- SNS activity increases Na retention |
|
|
6 causes of hyponatremia
|
- Diarrhea/vomiting
- Renal failure - Diabetes Mellitus (osmotic diuresis) - Ruptured or obstructed urinary tract - Hypoadrenocorticism (due to loss of aldosterone production) - Treatment with diuretics |
|
|
3 causes of hypernatremia
|
- Volume depletion with no intake of water
- Pure water loss - Increased salt intake without water intake |
|
|
Two causes of pure water loss
|
- Pituitary diabetes insipidus
- Insensible water loss without replacement (heat stroke, high temperature) |
|
|
Two causes of increased salt intake without adequate water intake
|
- Iatrogenic administration
- Salt poisoning |
|
|
What is the major IC cation?
|
K+
|
|
|
Two ways that K+ is regulated
|
- Renal excretion
- Movement from ECF to ICF |
|
|
What hormone enhances renal excretion of K+?
|
Aldosterone
|
|
|
What hormone drives K+ from ECF to ICF?
|
Insulin
|
|
|
How can pH affect movement of K+ from ECF to ICF?
|
An acidosis that's not due to increased organic acids moves K+ from ICF to ECF (so a metabolic acidosis with a normal anion gap)
An alkalosis causes K+ to move from ECF to ICF |
|
|
Pseudohyperkalemia (define)
|
Spurious increase in K+
|
|
|
4 causes of a pseudohyperkalemia
|
- Leaked from RBCs
- Extremely high leukocyte count - Extremely high platelet count - Use of EDTA |
|
|
3 GI causes of hypokalemia
|
- Diarrhea
- Vomiting - Anorexia |
|
|
2 polyuric causes of hypokalemia
|
- Renal failure
- Osmotic diuresis |
|
|
2 iatrogenic causes of hypokalemia
|
- Insulin therapy
- Diuretics |
|
|
5 causes of hyperkalemia
|
- Decreased renal excretion
- Hypoadrenocorticism (lack of aldosterone causes K+ retention) - Massive tissue injury - Metabolic acidosis with normal anion gap - Hyperkalemic periodic paralysis (inherited disorder) |
|
|
Major ECF anion
|
Cl-
|
|
|
Cause of a Cl- change that does not parallel sodium change
|
Obstruction of gastric or abomasal outflow
|
|
|
2 causes of a Cl- decrease that is paralleled with sodium change
|
- GI loss (vomiting, diarrhea)
- Kidney failure |
|
|
What is tCO2 equivalent to?
|
Measurement of HCO3-
|
|
|
2 NaHCO3 rich bodily fluids
|
- Intestinal secretions
- Urine |
|
|
What do changes in tCO2 cause?
|
Metabolic acidosis or alkalosis (or both)
|
|
|
Formula for anion gap
|
AG = Na + K - Cl - tCO2
|
|
|
What is the anion gap due to?
|
Unmeasured anions
|
|
|
3 unmeasured cations
|
- Ca
- Mg - Gamma globulins |
|
|
7 unmeasured anions
|
- Lactate
- Ketones - Uremic acid (PO4 + SO4) - PO4 - SO4 - Metabolites of poisons - Albumin |
|
|
Anion gap in a loss of HCO3 where there's also a loss of water
|
Normal
|
|
|
Anion gap in a loss of HCO3 due to consumption from titration of acids
|
Increased
|
|
|
Anion gap in a loss of HCO3 where there's both loss and consumption
|
Increased
|
|
|
3 causes of a loss of HCO3 with loss of water as well
|
- Loss of ISF through vomiting/diarrhea
- Sequestration in gut lumen - Loss of saliva through inability to swallow (cattle only) |
|
|
5 causes of consumption of HCO3 due to titration of acids
|
- Decreased tissue perfusion with buildup of lactic acid
- Grain overload in large animals producing lactic acid - Renail failure with accumulation of uremic acids - Unregulated diabetes mellitus with accumulation of ketones - Ethylene glycol poisoning |
|
|
3 abnormalities of a mixed metabolic alkalosis and acidosis
|
- High tCO2
- Low Cl- - High anion gap |
|
|
Pathogenesis of a metabolic alkalosis and acidosis
|
Metabolic alkalosis accompanied by a severe hypovolemia with decreased tissue perfusion
- Leads to a concurrent buildup of lactic acid, causing a metabolic acidosis |
