Causes of Edema
-increase hydrostatic pressure
-decrease capillary colloidal pressure
-increase capillary permeability
-lymph obstruction
Increase in hydrostatic pressure
-increase in vascular volume
-venous obstruction
-(PUSH)
Decrease in capillary colloidal pressure
-loss of plasma proteins
-decrease production of plasma proteins
-(PULL)
Increase Lymph Obstruction
-malignant obstruction of lymphatic structures
-surgical removal of lymph nodes
Manifestations of Edema
-local or generalized
-effects determined by location
-edema increases distance for diffusion of nutrients and oxygen
-can compress blood vessels
Fluid Volume Excess Causes
-Increase sodium intake and fluid intakes
-renal insufficiency or failure
-decrease cardiac output
-corticosteroid
Fluid Volume Excess Manifestations
-dependent edema
-generalized edema
-pulmonary edema
-JVD
-Hypertension
-Lab: dilutional hyponatremia and anemia
Fluid Volume Deficit Causes
-inadequate fluid intake
-excess GI losses
-excess renal losses
-excess skin losses
-third space losses
Fluid Volume Deficit Manifestations
-acute weight loss
-increased ADH secretion
-increased serum osmolarity
-decreased vascular volume
-Labs: increased hematocrit, increased BUN, increased specific gravity
Alterations in Electrolyte Balance
**understand concept
The purpose of Na+
-Regulates movement of fluids at cell membrane
-controls extracellular fluid osmolarity
-albumin also contributes to fluid osmolarity
If Na+ changes then what also changes
-H20 volume
-remember water follows salt!!!
What is the most important characteristic of body fluid homeostasis?
-protects circulatory volume
2 mechanisms that protect vascular volume
-alteration in hemodynamic variables
-alterations in Na+ and H20 retention
We need water to do what?
-dissolve and eliminate metabolic wastes
water balance gains:
-oral intake
-absorbed from GI tract
Water balance losses:
-skin, lungs as "insensible losses"
-Basal metabolic rate (BMR) increases with fever-- increase respiratory rate leads to increase in water loss
Most Na+ is in ...
extracellular fluid compartment
Resting cell membrane impermeable to Na+
-Na+ transported out of cell by energy dependent Na+/K+-ATPase pump
Na+ regulates ...
-extracellular fluid and vascular volume
-acid-base balance (NaHCO3)
contributes to what system function
-nervous system function
Mechanisms of Na+ regulation coordinated via RAAS
-kidney is main regulator of Na+
-kidneys monitor BP and retain Na+ when BP decreased
Sodium Balance
-regulation and entrance?
-tightly regulated and enters GI tract
How is Na+ eliminated?
-most: kidneys
-GI tract: vomiting, diarrhea, GI suction
-Skin: sweat, burns
Na+ requirements a day
500 mg
2 Mechanisms of Regulation
-Thirst
-Anti-diuretic Hormone (ADH)
Thirst is regular of ...
-regulator of intake
Thirst
responds
to extracellular change in what
osmolarity and volume
thirst gives us
-conscious sensation
-emergency response
Thirst can happen with
-polydipsia
ADH is regulator of
water reabsorption in the kidney
ADH is .... by extracellular change in osmolarity and volume
regulated
Diabetes Insipidus (DI) is ..
-ADH deficiency
--decrease in ADH synthesis
--inability of kidneys to respond to ADH
Diabetes Insipidus (DI) Manifestations:
-increased urine output
-specific gravity <1.005
-Serum Na+ > 145
-Increased serum osmolarity
-decreased urine osmolarity
-dehydration
-thirst
Syndrome of Inappropriate ADH (SIADH) is ...
-excessive release of ADH (vasopressin)= increased water retentions = fluid and electrolyte imbalance
Syndrome of Inappropriate ADH (SIADH) Causes:
-malignancies
-pulmonary disorders
-CNS Disorders (trauma, stroke)
-drugs
Syndrome of Inappropriate ADH (SIADH) Manifestations:
-decreased urine output
-specific gravity >1.020
-serum Na+ < 130 mEq/L
-weight gain
-decreased serum osmolality
-increased urine osmolality
-increased urine Na+
-GI changes (N&V)
-changes in level of consciousness
-headache
Hyponatremia
Na+ <135 mEq/L
-decrease serum Na+
-increase H20 ("dilutional")
Hyponatremia: decrease Serum Na+
-excessive losses: diaphoresis, GI losses, Addison's disease, diuretics, wounds
-decreased intake (IV/PO)
Hyponatremia: increase H20
-H20 retention: increase ADH levels
-CHF, acute renal failure cirrhosis
-H20 shifts from EC fluid to cells- hyperglycemia
-IVF/po intake with H20
Hyponatremia: Manifestations
-cramps, weakness
-brain and CNS most affected --> headache, lethargy, seizures, coma
Hyponatremia Treatment:
-restore normal serum Na+ levels: small volume hypertonic IVF saline
-treat cause: decrease loop diuretics
-nutrition: increase oral ingestion Na+, NaCl tablets
Hypernatremia:
-Na+ >145 mEq/L, Serum Osmo > 295 mOsm/kg
-increase serum Na+
-decrease H20
Hypernatremia: increase serum Na+
-increased Na+ intake (IV or PO)
-Meds
-Increased retention: cushing, hyperaldosteronism, renal failure
Hypernatremia: decrease H20
-losses: diarrhea, burns, diaphoresis, fever/infection (increased RR), DI
-decreased intake: dehydration, NPO, unconsciousness
Hypernatremia: Manifestations
-due to water loss and cellular dehydration (as water is pulled out of cells)
-thirst increases
-urine output decreases
-urine osmolarity increases
-dry mucous membranes
-water pulled from CNS cells--> decrease reflexes, agitation, headache, restlessness,
Hypernatremia: Treatment
-restore normal serum Na+ levels- hypotonic IVF
-treat cause
-drug therapy- lasix (hypernatremia due to poor KF)
-nutrition- Na+ restriction
Potassium is mainly intracellular or extracellular?
-intracellular
Potassium intake and mechanism of loss
-intake- dietary sources
-loss- kidneys (90%), urine sweat, stool
Potassium function:
regulates electrical membrane potentials controlling excitability of skeletal, cardiac, and smooth muscle tissue
Potassium regulation:
-renal
-intracellular-extracellular shifts
Intracellular-extracellular shifts of K+
**
come back to this important
***
Hypokalemia:
-K+ < 3.5 MEq/L
-decrease intake dietary
-increase loss of GI: vomiting, etc.; burns, sweat, kidneys: diuretics, RAAS
-redistricution: EC--> IC- alkalosis
Hypokalemia: Manifestations
-nausea/vomiting/diarrhea (N/V/D)
-decrease bowel sounds
-decrease neuromuscular excitability
-weakness, fatigue, crampls
-confusion
-depression
Hyperkalemia
-K+ >5.0mEq/L
-increased intake- dietary K+ supplements, salt subs, IVF
-decreased elimination: renal failure, K+ sparing diuretics, ACE inhibitors, ARBs
-Redistribution: IC --> EC
-acidosis; cell trauma/death, burns, injuries, extreme exercise, seizure
Hyperkalemia Manifestations:
Neuromuscular excitability and EKG changes
Major life threatening complications of changes in K+ =
cardiac
Major life threatening complications of changes in Na+ =
Neuro
Hyperkalemia Treatment:
-calcium gluconate/ calcium chloride
-D50 + insulin IV
-Albuterol
-kayexelate
-Diuretics
-Dialysis
Hypokalemia Treatment:
-increase serum K+
-prevent K+ loss
-patient safety
-nutrition
-COME BACK FOR DETAILS!!!