Week 3 Flashcards
BP control (neuro-hormonal regulation)
- baroreceptors reflex & sympathetic NS
- RAAS (⇡ BP by ⇡BV, ⇡ vasoconstriction)
- ADH = vasopressin (⇡ BP by ⇡BV, ⇡ vasoconstriction)
- kidneys - long term control of BP thru regulating BV
osmolality
- pulling power of a solution for H2O
- determined by concentration of solutes
which organ has the thirst mechanism?
hypothalamus
ADH = vasopressin
- released by pituitary gland
- function:
1. regulate fluid balance by retaining H20
2. concentrate or dilute urine from collecting ducts
3. vasoconstriction - constrict arteriole smooth muscle
Diabetes (meaning)
large amount of urination
- mellitus - sweet (↓ insulin production)
- insipidus - tastes like water (↓ ADH production)
↓ of ADH (diabetes insipidus)
- ⇡loss of urine –> diluted urine - dehydration
- s/sx = cells shrink – change in mental status
Lab? - hypernatremia
Rx = DDAVP (replace ADH) - fluid replacement, monitor I&O, weight
⇡of ADH (SIADH - syndrome of inappropriate ADH)
- ↓ loss of urine –> concentrated urine - retain H20
- s/sx = cells swell = change in mental status
Rx - Na+ replacement - fluid restriction, weight
Fluid Volume Excess (FVE)
Proportionate ⇡of H20 & Na+
Fluid overload, overhydration, pulmonary edema (drowning), hypervolemia (too much volume in blood), pitting edema
Caused by: HF, CKD, cirrhosis, malnutrition
NI: fluid restriction, Na+ intake, diuretic
Monitor: I/Os, daily wt, TED stockings
Edema
too much fluid w/in interstitial
- pulmonary edema = in lungs/alveoli
- pleural effusion = in pleural space
- ascites = fluid in peritoneal cavity
- periphery = pitting edema
Causes: HF, cirrhosis, renal failure, malnutrition
Rx: diuretic, TED stockings, elevate legs, SCD
Fluid Volume Deficit (FVD)
- dehydration, hypovolemia
- if not treated, can go into hypovolemic shock
causes: proportionate ↓ of Na+ & H20
Rx: anti-diuretic
Labs: keep eye out for hypokalemia (affects heart)
S/Sx of FVD
- flat jugular vein
- change in mental status
- ⇡ pulse, but thready; ↓ BP
- dry mouth, constipation
- tenting of skin; wt loss
Rx: give fluids
isotonic fluids
0.9% normal saline (NS) lactated ringers (LR) - contain Na+, Cl-, K+, Ca++
hypotonic IV solutions
- D5W
- 0.45% NS
hypertonic IV solutions
- 3% NS
- dangerous
Na+ balance
135 - 145 mEq/L