ABG

Question 1

purpose of ABG’s

Answer 1

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

Question 2

ABG: pH

Answer 2

balance of H+
7.35-7.45

< = acidic
> = basic

Question 3

PaCO2

Answer 3

35-45 mmHg

respiratory parameter
carbonic acid dissolves into CO2 and H2O
partial pressure of CO2 in ARTERY

Question 4

HCO3

Answer 4

22-26 mEq/L

metabolic parameter
*measured HCO3 is reported as CO2 on a chemistry panel (serum CO2)

Question 5

venous blood gas:
pH
PvCO2

Answer 5

pH: 7.31-7.41
PvCO2: 41-51 (partial pressure of CO2 in VEIN)

Question 6

basic metabolic panel (BMP):
serum CO2 =

Answer 6

HCO3 level
22-26 mmol/L

Question 7

primary EVENT

Answer 7

PROBLEM that initiates imbalance

*hypoventilation
*hyperventilation
*V/D

Question 8

primary DISORDER

Answer 8

what RESULTS from the primary event

*respiratory acidosis (hypovent)
*metabolic acidosis (hypervent)
+ “” alkalosis

Question 9

compensation mechanisms

Answer 9

physiologic processes that adjust the pH back to normal range

*if lungs are problem - kidneys compensate
*if kidneys are problem - lungs compensate

Question 10

metabolic cause

Answer 10

HCO3 (bicarbonate) level changes d/t METABOLIC alterations (KIDNEY)

Question 11

respiratory cause

Answer 11

H2CO3 (carbonic acid) level changes d/t RESPIRATORY alterations (LUNGS)

Question 12

4 types of imbalances are a result of

Answer 12

changes in ventilation
increase/decrease in CO2
changes in H+ or bicarbonate ions

Question 13

ROME

Answer 13

respiratory - opposite

metabolic - equal

Question 14

metabolic acidosis: primary/compensation/pH

Answer 14

decrease HCO3
decrease CO2
decrease pH

Question 15

metabolic alkalosis: primary/compensation/pH

Answer 15

increase HCO3
increase CO2
increase pH

Question 16

respiratory acidosis: primary/compensation/pH

Answer 16

increase CO2
increase HCO3
decrease pH

Question 17

respiratory alkalosis: primary/compensation/pH

Answer 17

decrease CO2
decrease HCO3
increase pH

Question 18

metabolic alkalosis

Answer 18

too much HCO3 OR not enough carbonic acid

pH > 7.45
CO2 35-45
HCO3 > 26

Question 19

causes of metabolic alkalosis

Answer 19

-excess baking soda/sodium bicarb
-prolonged vomiting
-NG tube (GI suctioning)
-diuretics (esp. loop)

Question 20

clinical manifestation of metabolic alkalosis

Answer 20

CNS over excitability –> leads to fatigue
confusion
tremors
muscle cramps
paresthesias
coma
N/V/D
respiratory depression - compensatory hypoventilation
dysrhythmias (tachycardia)
hypokalemia

Question 21

respiratory alkalosis

Answer 21

H2CO3 (carbonic acid) DEFICIT in ECF

pH > 7.45
CO2 < 35
HCO3 22-26

Question 22

cause of respiratory alkalosis

Answer 22

hyperventilation (CO2 blown off)
increased metabolic demands (d/t fever, sepsis)
meds
acute anxiety
hypoxia
PE or lung disease
CNS lesions
ventilator settings

Question 23

clinical manifestations of respiratory alkalosis

Answer 23

CNS over excitability
tachypnea + hyperventilation (deep and rapid)
light headedness
confusion, blurred vision
paresthesia
hyperactive reflexes
seizures
coma
tachycardia
hypokalemia

Question 24

respiratory acidosis

Answer 24

excess carbonic acid/ H2CO3
*hypoventilation – retained CO2

pH < 7.35
CO2 > 45
HCO3 22-26

Question 25

acute respiratory acidosis

Answer 25

HCO3 WNL no time for kidneys to compensate *resp arrest chronic - COPD/oversedation

Question 26

causes of respiratory acidosis

Answer 26

cardiopulmonary arrest head injury narcotics/sedatives anesthesia pulmonary disorders (COPD exacerbation, acute asthma, PNA, resp failure) pain abd distention airway obstruction chest wall deformities neuromuscular problems

Question 27

clinical manifestations of respiratory acidosis

Answer 27

CNS depressing... HYPOventilation dyspnea respiratory distress H/A restlessness confusion tachycardia arrhythmias decreased LOC, stupor, coma

Question 28

metabolic acidosis

Answer 28

HCO3 DEFICIT in ECF excess acids are added or bicarb is lost pH < 7.35 CO2 35-45 HCO3 < 22 IF lungs compensating, respirations increased and CO2 decreased

Question 29

clinical manifestation of metabolic acidosis

Answer 29

CNS... lethargic, drowsy confusion tremors, muscle cramps parasthesias H/A hypotension hyperkalemia warm, flushed skin (vasodilation) *deep breathing (KUSSMAUL RESPIRATIONS [DKA]) *fruity odor breath [DKA]

Question 30

causes of metabolic acidosis

Answer 30

renal failure fistulas T1DM - DKA lactic acidosis prolonged diarrhea starvation (body using fat for energy resulting in ketosis) med overdose (ASA) shock and cardiac arrest (begin to produce lactic acid from lack of oxygen in tissues)

Question 31

respiratory acidosis/alkalosis: compensation

Answer 31

KIDNEYS compensates by: -conserving HCO3 -excreting HCO3 takes kidneys HOURS TO DAYS to compensate

Question 32

metabolic acidosis/alkalosis: compensation

Answer 32

LUNGS compensate by: -conserving CO2 -excreting CO2 (the kidneys also attempts to correct imbalance by retaining/excreting HCO3) takes lungs MINUTES TO HOURS to compensate