ABGs - patho 406

Question 1

purpose of ABGs

Answer 1

to assess acid base status and to determine adequacy of oxygenation & ventilation

Question 2

primary event

Answer 2

the problem that initiates the acid base imbalance
(ex: hypovent, hypervent, vomiting, diarrhea)

Question 3

primary disorder

Answer 3

what results from the primary event
(ex: resp acidosis, metabolic alkalosis)

Question 4

compensation mechanisms

Answer 4

physiologic processes that adjust the pH back to the normal range
(ex: lung problem -> kidney will comp)

Question 5

general causes of imbalance: metabolic

Answer 5

-HCO3 level changes secondary to metabolic alterations (kidneys)

Question 6

general causes of imbalance: respiratory

Answer 6

-H2CO3 level changes secondary to respiratory alterations (lungs)

Question 7

respiratory acidosis or alkalosis

Answer 7

increases or decrease in CO2
change in ventilation

Question 8

metabolic acidosis or alkalosis

Answer 8

changes in H+ or bicarb ions

Question 9

acid base mnemonic: ROME

Answer 9

R espiratory
O pposite
inc pH, dec PCO2 = alk; dec pH, inc PCO2 = acid

M etabolic
E qual
inc pH, inc HCO3 = alk; dec pH dec HCO3 = acid

Question 10

metabolic acidosis: what is it & what is our comp

Answer 10

dec HCO3, dec Ph
comp: lungs blow off CO2 to decrease levels (dec pCO2)

Question 11

respiratory alkalosis: what is it & what is our comp

Answer 11

dec CO2, inc pH
comp: kidneys get rid of bicard (HCO3) to decrease levels
(dec HCO3)

Question 12

respiratory acidosis: what is it & what is our comp

Answer 12

inc pCO2, dec pH
comp: kidneys hold on to bicard to increase levels
(inc HCO3)

Question 13

metabolic alkalosis: what is it & what is our comp

Answer 13

inc HCO3, inc pH
comp: lung hold on to CO2 to increase levels
(inc pCO2)

Question 14

metabolic alkalosis: ABG

Answer 14

too much bicard or not enough carbonic acid
pH > 7.48 (B)
PaCO2: 35-45 (N)
HCO3 >29 (B)

Question 15

metabolic alkalosis: causes

Answer 15

-taking excess baking soda, alka-seltzer (H shifts out of the cell & K+ goes in causing hypoK)
-prolonged vomiting
-NG tube suctioning
-diuretics (lose H but bicard stays)

Question 15

metabolic alkalosis: clinical manifestations

Answer 15

CNS over excitability
confusion
tremors
muscle cramps
parethesias
coma
N/V/D
resp depression (to try to hold on to CO2)

Question 16

respiratory alkalosis: ABGs

Answer 16

H2CO3 deficit in extracellular fluid
pH >7.45 (H/basic)
PaCO2 <35 (L)
HCO3-: 24-29 (N)

Question 17

respiratory alkalosis: causes

Answer 17

-hyperventilation (primary event)
kidneys need to comp but can’t work quickly so often time these pts pass out
-fever / sepsis (inc metabolic demand)
-medications
-acute anxiety
-hypoxia
-PE or lung disease
-CNS lesions
-ventilator

Question 18

respiratory alkalosis: clinical manifestations

Answer 18

-CNS over excitability
-tachypnea
-light headedness
-confusion, blurred vision
-paresthesia
-hyperactive reflexes
-coma

Question 19

respiratory acidosis: ABGs

Answer 19

H2CO3 excess in ECF
pH <7.35 (L/acidic)
PaCO2 > 45 (H)
HCO3-: 24-29 (N)
hco3 is wnl w/ acute resp acid bc kidneys don’t have time to comp -> if copd/chronic high bicard and normal pH d/t comp

Question 20

respiratory acidosis: clinical manifestation

Answer 20

-hypoventilation (primary event)
-dyspnea
-respiratory distress
-H/a, restlessness, confusion
-tachycardia, arrhythmias
-dec LOC, stupor, coma

Question 21

when a pt goes into respiratory arrest, they become

Answer 21

acidotic bc they are not breathing

Question 22

respiratory acidosis: causes

Answer 22

not taking good breaths or any
-hypoventilation
-cardiopulmonary arrest
-head injury
-narcotics/sedatives
-anesthesia
-pulmonary disorders
-pain (not taking deep breaths)
-abdominal distension
-airway obstruction
-chest wall deformities
-neuromuscular problems

Question 23

metabolic acidosis: ABGs

Answer 23

HCO3 deficit in the ECF
pH < 7.35 (L/acidic)
PaCO2: 35-45
HCO3- <24 (L)

Question 24

metabolic acidosis: causes

Answer 24

-renal failure
-fistulas
-DKA
-lactic acidosis
-prolonged diarrhea (lose bicarb)
-starvation (ketosis)
-shock & cardiac arrest

Question 25

metabolic acidosis: clinical manifestations

Answer 25

-lethargy, drowsiness, confusion, tremors, muscle cramps, paresthesia
-hypotension
-hyperkalemia
-deep breathing (kussmaul respirations in DKA)

Question 26

summary of respiratory comp

Answer 26

Rate: rapid
Organ: Lungs
activity: hyper/hypo vent
trigger: met acid-base abnorm

Question 27

summary of metabolic comp

Answer 27

Rate: slow
Organ: Kidneys
activity: retention/excretion of H+/HCO3
trigger: resp acid-base abnorm

Question 28

what do we do for pt w/ respiratory acidosis

Answer 28

-give narcan if drug related
-bag mask
-intubate
do not give bicarb bc doesn’t fix respiratory problem

Question 29

what would some w/ respiratory acidosis ABGs look like if they have COPD

Answer 29

they will be fully compensated
pH: normal
PCO2: high
HCO3: high

Question 30

what would we do for a patient with respiratory alkalosis

Answer 30

-calm
-anti anxiety meds
-breathing into paper bag
-rebreather

Question 31

what will someones ABGs look like in respiratory alkalosis who is fully compensated

Answer 31

pH: normal/basic
PCO2: low
HCO3: low

Question 32

what do for someone w/ metabolic acidosis

Answer 32

treat the cause
ex: if DKA, bring down BG

Question 33

what would someones ABGs look like if they have fully compensated metabolic acidosis

Answer 33

pH: normal - acidic
PacCO2: low
HCO3: low

Question 34

with compensation, the arrow will always move….

Answer 34

in the same direction as the disorder

Question 35

what would someones ABGs look like if they have fully compensated metabolic alkalosis

Answer 35

ph: normal
PaCO2: high
HCO3: high

Question 36

treatment for metabolic alkalosis

Answer 36

treat the cause so if vomiting give drugs to reduce gastric hydrochloric acid secretions

Question 37

what is the parameters for the pH to be leaning after compensation has occurred

Answer 37

neutral = 7.4
-leaning toward acidic: <7.4
-leaning toward base: >7.4

Question 38

uncompensated

Answer 38

pH abnormal, acid or base abnormal

Question 39

partially compensated

Answer 39

pH abnormal, acid and base component abnormal

Question 40

compensated

Answer 40

pH normal, acid or base imbalance is neutralized but not corrected -> arrows moving in same direction