Body fluids, Edema and IV fluids Flashcards
Isotonic Loss
Body Osmolality, ECF volume, ICF volume, RAAS response, ADH response
- No change
- Decrease
- No change
- Increase
- Increase
Isotonic Gain
Body Osmolality, ECF volume, ICF volume, RAAS response, ADH response
- No change
- Increase
- No change
- Decrease
- Decrease
Hypotonic Loss
Body Osmolality, ECF volume, ICF volume, RAAS response, ADH response
- Increase
- Decrease
- Decrease
- Increase
- Increase
Hypotonic Gain
Body Osmolality, ECF volume, ICF volume, RAAS response, ADH response
- Decrease
- Increase
- Increase
- Decrease
- Decrease
Hypertonic Loss
Body Osmolality, ECF volume, ICF volume, RAAS response, ADH response
- Decrease
- Decrease
- Increase
- Increase
- No change (???)
Hypertonic Gain
Body Osmolality, ECF volume, ICF volume, RAAS response, ADH response
- Increase
- Increase
- Decrease
- Decrease
- No change (???)
Isotonic Loss
Causes
- Hemorrhage
- Diarrhea
- Vomiting
- Isotonic urine
Isotonic Gain
Causes
- Isotonic saline
- Hyperaldosteronism
Hypotonic Loss
Causes
- Dehydration
- Alcoholism
- DI
Hypertonic Loss
Causes
Adrenal insufficiency
Hypertonic Gain
Causes
- Salt ingestion
- Hypertonic saline
- Mannitol
Hypotonic Gain
Causes
- Hypotonic saline
- Water intoxication
- SIADH
Aldosterone
Regulators
- Plasma angiotensin II (stimulate release)
- Plasma K+ (stimulate release)
ADH
Regulators
- Plasma osmolality (directly related)
- Blood pressure/volume (inversely related)
Renin
Regulators
- Perfusion pressure to the kidneys (inversely related)
- Sympathetic stimulation to the kidneys (direct effect via beta-1 receptors)
- Na+ delivery to macula densa (inversely related)
Starling Equation
- Qf = k [(Pc + Oif) - (Pif + Oc)]
- Qf is fluid movement
- k is filtration coefficient
- P is hydrostatic pressure
- O is oncotic pressure
- c is capillary
- if is interstitium
Capillary hydrostatic pressure
Regulators
- Blood flow (regulated by arteriole)
- Venous pressure
- Blood volume
Interstitial oncotic pressure
Regulators
Interstitial protein concentration (regulated by lymphatics)
Capillary oncotic pressure
Regulators
Capillary protein concentration
Interstitial hydrostatic pressure
Regulators
Lymphatic flow
Filtration Coefficient
Regulators
Capillary permeability
Peripheral Edema
Primary Causes
- Increased capillary hydrostatic pressure (Pc)
- Increased interstitial oncotic pressure (Oif)
- Decreased capillary oncotic pressure (Oc)
- Increased capillary permeability (k)
- Lymphatic obstruction/removal (lymphedema)
Increased capillary hydrostatic pressure (Pc)
Causes
- Marked increase in blood flow like vasodilation in a given vascular bed
- Increasing venous pressure like venous obstruction or HF
- Elevated blood volume (Na+ retention) like in HF
Increased interstitial oncotic pressure (Oif)
Causes
- Thyroid dysfunction (elevated mucopolysaccharides in the interstitium that act as osmotic agents resulting in fluid accumulation)
- Lymphedema
Decreased capillary oncotic pressure (Oc)
Causes
- Liver failure
- Nephrotic syndrome
Increased capillary permeability (k)
Causes
- Circulating agents like tumor necrosis factor-alpha (TNF-alpha), bradykinin, and histamine
- Cytokines related to burn trauma
Lymphatic obstruction/removal (lymphedema)
Causes
- Filarial (W. bancrofti [elephantiasis])
- Bacterial lymphangitis (streptococci)
- Trauma
- Surgery
- Tumors
Pulmonary Edema
Causes
- Cardiogenic (elevated Pc) associated with increased pulmonary wedge pressure
- Non-cardiogenic (adult respiratory distress syndrome [ARDS] due to increased permeability) that can be due to sepsis, bacterial pneumonia, trauma and gastric aspirations. Pulmonary wedge pressure is normal or low
Volume of Distribution
- V = A / C
- V: volume of compartment to be measured
- A: amount of tracer
- C: concentration of tracer in the compartment to be measured
Tracers used to measure Plasma
Characteristics, Examples
- It should not cross the capillary membranes
- Albumin
Tracers used to measure ECF
Characteristics, Examples
- It should cross the capillary membranes but not the cell membranes
- Inulin, mannitol, sodium and sucrose
Tracers used to measure Total body water
Characteristics, Examples
- It should cross both the capillary and cell membranes
- Tritiated water and urea
Blood volume
Calculation
- Blood volume = plasma volume / (1 - hematocrit)
- 7% of body weight in kgs
Angiotensin II
Effects
- Direct vasoconstrictive effect
- Increases aldosterone secretion
- Increases ADH release from posterior pituitary
- Increases thirst
- Increases Na+ reabsorption in the proximal tubule
Cortisol
Factoids
- Zona fasciculata/reticularis
- Steroid
- Catabolic
- Immunosuppression
- Increase appetite
Cortisol
Effects on Metabolism
- Increases lipolysis
- Increases protein degradation
- Increases gluconeogenesis
Cortisol
Permissive effects
- Enhances catecholamines effect on alpha receptors (vasculature) and beta receptors (especially in lung and liver)
- Enhances effects of glucagon
Cortisol
Other effects
- Anti-inflammatory effect by stimulating Lipocortin synthesis which is a phospholipase A2 inhibitor
- Increases bone breakdown by increasing RANK-L and decreasing OPG
- Binds to mineralocorticoids receptors (Aldosterone-like)
