Quiz 4 Flashcards
what percentage body weight is Total Body water
60% total body weight
what percentage body weight is Intracellular volume
40% total body weight
what percentage body weight is Extracellular volume
20% total body weight
what is extracellular fluid made up of? percentage?
Interstitial fluid volume (75% of ECV)
Plasma (intravascular) volume (25% of ECV)
TBW is _____ of a man’s weight
55%
TBW is _____ of a woman’s weight
45%
TBW is _____ of an infant’s weight
80%
__________ pump maintains the high concentration of K+ in ICF
Sodium-potassium
High concentration of what lytes intracellularly?
Potassium (primary cation)
Phosphate (primary anion)
Magnesium
High concentration of what lytes extracellularly?
Sodium (primary cation)
Chloride(primary anion)
What is main determinant of osmotic pressures?
Albumin
An expression of the number of osmoles of a solute in a liter of solution
Osmolarity
An expression of the number of osmoles of a solute in a kilogram of solvent
Osmolality
How a solution affects cell volume
For example – isotonic, hypertonic, hypotonic
Tonicity
Concentration disorder, Insufficient water present in relation to sodium levels
Dehydration
might have too much salt, or not enough water – fluid replacement specific too disorder
Loss of extracellular fluid
Absolute loss of fluid from the body
Reduced circulating volume
Hypovolemia
____ is the most abundant electrolyte in the ECF.
Na+
Most common electrolyte abnormality in hospitalized patients
hyponatremia
Clinical Manifestations of Hyponatremia
Headache Weakness Coma Confusion Cerebral edema Cramps Agitation Malaise Anorexia Nausea/vomiting
Treatment of Hyponatremia
Fluid restriction
Administration of hypertonic saline and an osmotic or loop diuretic
!!!Correction of serum sodium levels too rapidly can result in neurologic damage and myelinolysis!!! Breaks down nerves and axons
Most common cause is water deficiency d/t:
Excessive loss
Inadequate intake
Clinical Manifestations of Hypernatremia
Thirst Hallucinations Irritability Renal insufficiency Disorientation Seizure Hypervolemia Intracranial bleeding Polyuria or oliguria Coma Weakness
Treatment of Hypernatremia
Plasma sodium should be decreased by 1-2mEq/hr until the patient is clinically stable.
Correction of serum sodium to normal should gradually progress over a 24 hour time frame.
K+ Largely responsible for
resting membrane potential
The most common electrolyte abnormality encountered during clinical practice.
Hypokalemia
Hypokalemia causes
Gastrointestinal losses Poor dietary intake Systemic alkalosis Diabetic ketoacidosis Diuretic therapy Sympathetic nervous system stimulation
Clinical Manifestations of Hypokalemia
ST-segment depression Presence of U wave Flattened or inverted T waves Ventricular ectopy Weakness ( respiratory muscle) Decreased reflexes Confusion
how fast can you run K+ in?
40 mEqs/hour
Clinical Manifestations of Hyperkalemia
Tall, peaked and elevated T waves Widened QRS complex Prolonged PR interval Flattened or absent P wave ST segment depression Cardiac arrest
Treatment of Hyperkalemia
- Avoid adverse cardiac effects
- Insulin and glucose to shift K+ into cells
- IV calcium to antagonize cardiac effects of hyperkalemia
- hyperventilate
(3 goals: 1. Stabilize cardiac membrane; 2. driving K from ECV to ICV; 3. remove K from body)
what is upper limit of potassium level for elective procedures?
5.5 mEq/L
Clinical Manifestations of Hypomagnesemia
Flat T-waves U-waves Prolonged QT interval Widened QRS Atrial and Ventricular PVCs
Low Mag has inhibitory effect on ________ which alters the _______________.
NA-K-ATPase
resting membrane potential
Treatment of Hypomagnesemia
- 1-2g over 5 minutes with EKG monitored
- Followed by continuous IV infusion 1-2g/hr
What moves Ca into bones?
Calcitonin
What moves Ca out of bones?
Parathyroid hormone
Clinical Manifestations of Hypercalcemia
Hypertension Heart block Shortened QT interval Dysrhythmias Muscle weakness Decreased deep tendon reflexes Sedation