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Acids are
substances that release hydrogen when disolved in water
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Acid base balances can alter
- respiration
- metabolism
- function of the CNS
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Acidosis
excess of hydrogen ions
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acidosis ph
arterial pH less than 7.35
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bases are
substances that nind hydrogen ions when in water
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alkalosis
excess of base (bicarbonate)
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alkalosis pH
greater than 7.45
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acidosis seen in pts with
- pneumonia
- dehydration
- infection
- renal disease
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alkalosis seen in pts with
- overhydration
- heart failure
- thazide and loop diuretics
- digoxin insulin
- chemotherapy
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respiratory rate increase will cause a drop in
CO2 and pH
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decrease in respiration rate will cause a decrease in
CO2 and pH
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Kidney's movement of HCO2
- when pH is high, HCO2 is excreted in urine
- when pH is low, HCO2 is reabsorbed
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When HCO2 is reabsorbed it binds with
phosphate in the urine to make acid (H2PO4)
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Ammonium is formed by
the kidneys when amino acids bind with H to form ammonium and is excreted in urine
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alkalosis is a excess of
bicarbonate
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Acidic means
- more acid than base
- more hydrogen ions
- lower pH
- (kicking Down the pH) AciDosis
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Alkaline means
- more acid than base
- fewer hydrogen ions
- higher pH
- (Kicking Up the pH) Alkalosis
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pH greater than 7.8
death
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ph lowers if
- hydrogen level concentration increases
- bicarbonate level decreases
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3 physiologic systems act interdependently to maintain a normal serum pH
- buffering of excess acid or base by blood buffer systems
- excretion of acid by the lungs
- excretion of acid or regeneration of base by the kidneys
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chemical buffers
- act immediately to protect tissues and cells
- combinds with acids or bases immediately to neutralize
- located in ICF and ECF
- control H ions by either absorbing them to make an acid or releasing them to make a base
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compensations
- only works for respiratory acidiosis
- resp system changes hydrogen ions concentration by changing respiratory rate and depth
- more carbonic acid is formed with decrease respiration
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respirations will increase if
more CO2 needs to be breathed off
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Buffers are found in
- blood
- ICF
- interstitial fluid
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main buffers
- bicarbonate
- phosphate
- protien
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bicarbonate buffers use a week
acid or week base as carbonic acid or bicarb with a strong base or strong acid as HCL to make less strong base or acid
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protien buffers
- most abundant in the body
- hemoglobin and other protiens
- neutralizes acid and base
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in RBCs hemoglobin will bind with what to act as a buffer
Hions
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PaCO2 is
- measures dissolved carbon dioxide
- regulate to amount produce in cells
- regulate by lungs
- related to alvolar ventilation
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an increase in ventilation will cause what in PaCO2
decrease
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a decrease in ventilation will cause a what in PaCO2
increase
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CO2 combinds with what to make carbonic acid
water
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increased levels of carbonic acid will cause a what in pH
decrease
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what area of the brain has chemoreceptors that regulate rate and depth of breathing to control CO2
medulla
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the more CO2 that is lost the more
carbonic acid is made
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alveoli hypoventilation occurs
either from decreaseed respiration of inadequate gas exchange
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respiratory acidosis
- caused by the under elimination of hyddrogen ions causing retention of carbon dioxide in the body
- resulting in increased production of carbonic acid
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four causes of respiratiory acidosis
- airway onbstruction
- interference with capillary diffusion
- poor chest expansion
- respiratory depression
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In cronic respiratory acidosis as with COPD the kidneys have had time to compensate so the pH may be
within normal range
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Respiratory depression
- anesthesis
- narcotic
- head trauma
- cardiac arrest
- injury to chest, airway, lungs
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As brain cells become acidotic mental stauts
- changes are noticed
- disorientation
- depression
- weakness
- stupor
- warm and moist mucus membranes
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Respirtory acidosis oxygen and ECG changes
- dyspnea
- tachycardia
- dysrhythmia
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Respiratory acidosis cases chemical changes
- decrease in pH
- increase in PaCO2
- increase in HCO2
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Respiratory acidiosis casues
- headache
- mental status change
- decreased level of conciousness
- muscle twitching
- electrolyte change
- K and Ca
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interventions of respiratory acidosis
- safety measures
- assist with positioning
- monitor IandO
- admisister fluids as orderd
- administer oxygen and medication as orderd
- monitor ABGs
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Respiratory alkalidosis
PaCO2 goes down and pH up
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respiratory alkalidosis causes hyperventilation resulting in
- retain oxygen blow off CO2
- fever
- sailcylate intoxication (early ASA OD)
- CNS trauma
- excess mechanical ventilation with O2>CO2
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Respiratory alkalosis skin, oxygen, ecg problems
- warm flush mucous membranes
- sweating and diaphoresis
- RAPID, SHALLOW BREATHING (compensating)
- palpitations
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Respiratory alkaladosis biochemical effects
- increase in pH
- decrease in PaCO2
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Respiratory Alkalidosis causes these problems
- anorexia (to rid acid) N/V
- abd pain
- weakness
- altered mental staus
- decreased LOC
- dysthrythmia
- bradycardia
- tetany convulsions
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Respiratory alkalosis cognitive and sensory
- hyperactive reflexes
- tetany
- positive chvostek's sign
- positve trousseau sign
- vertigo
- unconciousness
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causes of respiratory alkalosis
- hyperventlation
- early PE
- fever
- anxitey (blows of CO2)
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Metabolic alkalosis causes
- loss of gastric juice
- potassium wasting diuretic (loss of H)
- misuse of antacids
- too much bicard or loose acid
- high carb diet
- hyperkalemia hypercalcemia
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metabolic alkalosis
hypokalemia occurs as K is exchanged for H ions in the cell
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Lungs will begin to retain CO2 to lower pH when
- metabolic alkalosis
- clinical manifestation
- hypotension
- tachycardia
- confusion
- decreased LOC
- hyperreflexia
- tetany
- dysthrhymia
- seizures
- respiratory failure
- as pH increases , respiratry failure dysthrhythmia, seizure coma occur
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Acidosis caused by
- respiratory hypoventilation
- pulmonary edema
- drug overdose
- airway obstruction
- chest trauma
- COPD
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Metabolic acidosis causes
- asprin overdose
- sepsis
- diarrhea
- Renal Failure (K increase)
- fasting, DKA, Salicylates poisoning, diarrhea, interstiatl suction, Pancreatic damage, renal impairment, saline infusions, bicarb is lost
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hyperventilation is a cardinal sign of
metabolic acidosis
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fluid is lost>
acidity increases>lowering pH
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to correct metabolic acidosis the lungs blow off
CO2 to increase pH (promoting alkaline HCO3)
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metabolic acidosis regulaters do what
- meausres bicarbonate ion
- regulated by kidneys
- acts as buffer in acid base system
- kidneys have slower response to adjust pH than lungs
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if blood has more base and less acid then
kidneys hold hydrogen and excrete bicarb
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respiratory helps to regulate metabolic imbalances; lack of bicarb causes acidosis
lungs will increase rate of breathing and blow off CO2, thus raising pH
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An excess of bicarb causes alkalosis; lungs will decrease rate of breathing and retain CO2
thus lowering the pH
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acid base balance exists when
- the body produces acids or bases equal to the rate they are excreted
- metabolic processes maintain a steady balance between acids and bases for optimal functioning of cells
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ratio of acids to base
20 base to 1part acid
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if acids increase or base decreases then
scale tips toward acidic side lowering pH
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if acid decreases or base increases then
tips to base side and pH increases
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Volatile acid is in what system
respiratory, can be excreted as a gas
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Nonvolatile acid
renal, must be metabolized or excreted from the body in a water form
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things that will alter the result of ABGs
- air bubble in syrnge may alter level
- venous blood will alter results
- cup of ice immediately
- hold pressure for 5 min
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increase or decrease in PaCO2 levels shows that what has occured
- decrease, hyperventilation (blows off)
- increase, hypoventilation (retained)
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ROME
- Respiratory (PaCO2 and pH)
- Oposite
- Metabolic (HCO3 and pH)
- Equal
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is there a normal decline in older adults
yes of PaCO2
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hypoxemia may cause
hyperventilation resulting in resiratory alkalosis
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oxygen saturation
the point at which hemoglobin is saturated by oxygen
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oxygen saturation can be effected by
- changes in temperature
- changes in pH
- changes in PaCO2
- when PaCO2 falls below 60 there is a large drop in saturation
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serum bicarbonate HCO3
the major renal componet of acid base balance is excreted and reproduced by the kidneys to maintain a normal acid base environment
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bicarbonate reflects the renal systems ability to
- compensate for changes in the pH
- pH is high (basic) HCO3 is excreted by the kidney
- pH is low (acid) HCO2 is reabsorbed by kidneys, H, ammonia, and protien excreted by diney
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How to read ABGs
- evaluate PaO2 and SaO2
- evaluate pH
- evaluate PaCO2
- evaluate HCO3
- evaluate in respiratory or metabolic
- evaluate compensation
- pull it all together
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high PaCO2
- hypercapnia
- breathing slowly/shallow/poor expiratory effort and not blowing off CO2
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Compensation
- body's attempt to maintain normal pH
- respiratory system controls PaCO2
- renal system controls HCO3
if one system changes: other system changes to compensate
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if compensation is metabolic then all go
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