week 7 Flashcards
pH
scale used to specify the acidity or basicity of an aqueous solution
pCO2
partial pressure of carbon dioxide, reflecs amount of carbon dioxide dissolved in the blood
HCO3
bicarbonate, deprotonated form of carbonic acid
pO2
partial pressure of oxygen, reflects amount of oxygen dissolved in blood
Respiratory buffer system
controls how much carbon dioxide produced -increase in CO2 causes decrease in pH -decrease in CO2 causes increase pH
Renal buffer system
controls how much bicarbonate is made -increase in bicarbonate causes increase in pH -decrease in bicarbonate causes decrease in pH
Metabolic Acidosis with respiratory compensation
-Decrease in bicarbonate with is compensated with decrease in CO2
Physical presentation of ethylene glycol overdose
confusion, ataxia, hallucinations, slurred speech, and coma
Metabolism of ethylene glycol
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How does ethylene glycol cause an increase in anion gap?
metabolites of ethylene glycol (acids) accumulate in blood
How does ethylene glycol increase osmolar gap
osmolar gap=measured gap-estimated gap measured gap: derived directly from osmometer estimated gap: 2[Na}+(glucose/18)+(BUN/2.8)
How is sodium bicarbonate used as a buffer for metabolic acidosis?
sodium bicarbonate raises pH by supplying hydroide ions to the solution. Causes H+ to drop as they bind to hydroxide to form water
four primary acid base disorders
- Metabolic acidosis: decrease in bicarbonate 2. Metabolic alkalosis: increase in bicarbonate 3. Respiratory acidosis: increase in CO2 4. Respiratory alkalosis: decrease in CO2
Hyponatremia signs and symptoms
- Nausea and vomiting
- Headache
- Confusion
- Loss of energy, drowsiness and fatigue
- Restlessness and irritability
- Muscle weakness, spasms or cramps
- Seizures
- Coma
Intracellular Fluid Composition
consists mostly of water, dissolved ions, small molecules, and large, water-soluble molecules (such as proteins).
Extracellular Fluid Composition
mainly cations and anions
- cations include: sodium (Na+ = 136-145 mEq/L), potassium (K+ = 3.5-5.5 mEq/L) and calcium (Ca2+ = 8.4-10.5 mEq/L).
- Anions include: chloride ( mEq/L) and hydrogen carbonate (HCO3- 22-26 mM).
hyperosmotic fluid contraction
decrease in ECF volume; causes decreased blood volume and decreased blood pressure.
hypoosmotic fluid expansion
gain of fluid into ECF; causing increase of fluid into ECF and increased blood pressure
physiological consequences of hypernatremia
increase of Na in blood, causing fluid to leave cell. If these occurs too quickly, cell will shrink, can die or lose function. When this occurs in neurons will cause demylenation
3% saline
Hypertonic solution; meaning high solute concentration, will cause water to be shifted into ECF when given
Normal saline
Isotonic solution; allows for fluids to be given without a shift in fluid balance across ECF and ICF
Lactated ringers
Isotonic solution that contains mixture of sodium chloride, sodium lactate, potassium chloride, and calcium chloride in water. It is used for replacing fluids and electrolytes in those who have low blood volume or low blood pressure and can also be used to treat metabolic acidosis in cases other than those caused by lactic acidosis
Central Pontine Mylenolysis
This is caused by hypernatremia, where fluid will flow from ICF to ECF to dilute high Na concentration. When this occurs too quickly it will shrink the cells. When glial cells, which form the myelin sheaths on the axon of neurons, begin to shrink they fall off of axon thus causing myelin loss from the neuron and making impulses travel slower
