NR572 midterm
Rule 1 of oxygenation PaO2 should be 4-5x FiO2
Blood gas = pulse ox
30mmHg = 60%
40 = 70%
50 = 80%
60 = 90%
Rule 2 of oxygenation 90 = 100%
Blood gas reading is best oxygenation it
can be.
Patient with sat of 90% and blood gas is
40 = v/q mismatch = problem
Arterial = delivery/pre-metabolic
Venous = consumption/post metabolic
Arterial v. venous oxygenation
Arterial pO2 about 80mmHg v. Venous
pO2 about 50 mmHg
Will always have a lower oxygen and
higher CO2 (about 5 mmHg) which is an
acid so will have a lower pH than ABG.
VBG values
Amount of CO2 and lungs at end exha-
lation. Will normally be 3 to 5 mmHg less
than arterial CO2.
The 3 to 5 mmHg difference reflects dead
End Title CO2 space and the alveolar-arterial gradient.
CO2 elimination is passive and occurs
down a concentration gradient. So less
CO2 in lungs that in venous blood to
facilitate movement into the lungs for ex-
halation.
,NR572 midterm
CO2 is a metabolic byproduct.
Increased production = hypermetabolic
states
Decreased elimination (breathing slow
and shallow)= poor minute ventilation
(RRxTV) failing to elimination
Reasons for high CO2 "Hypoventilation resultant hypercarbia"
Increased perfusion = ROSC, high car-
diac output
Every 10 of CO2 = about 1L cardiac out-
put
Why AHA wants ET CO2 of at least 10
(25% of low normal CO) during CPR
4L
Every 10 of CO2 = about 1L cardiac out-
Low-normal CO
put
Why AHA wants ET CO2 of at least 10
(25% of low normal CO) during CPR
Decrease production = decreased me-
tabolism
Decrease perfusion= dead, collapsed
lung or blocked blood flow (PE, Tension
Low CO2 causes
PTX, etc)
Increased elimination (breathing fast and
deep) = hyperventilation
V/Q mismatch
Results always listed in this order:
pH/PCO2/PO 2/HCO3-
1. Acid-base status:
PH of less than 7.35 is acidotic, whereas
Blood Gas Analysis one of more than 7.45 indicates blood
as alkolotic. Used to determine degree
of compensation in acidosis or alkalo-
sis (uncompensated, partially compen-
sated, compensated)
2. Oxygen partial pressure (pO2)
,NR572 midterm
PO2 < 60 mmHg may require supple-
mental O2.
3. Carbon dioxide pressure (pCO2)
35-45
4. Bicarbonate levels (HCO3 mmols)
22-26mmols/L
5. Base deficit/excess- +\-3 meq/L
35-45 mmHg
Assessment of ventilation on ABG. Low
pCO2 = hypocapnia = hyperventilation
CO2
(could be respiratory compensation for
academia)
Hi PCO2 = hypercapnia = hypoventila-
tion
22-26mmols/L
Less than 22 = metabolic acidosis (dka
and sepsis toxin, diarrhea, or problem
with kidneys)
HCO3-
Greater than 26 = metabolic alkalosis
Bicarb produced in kidneys, metabolical-
ly used to neutralize acids, and eliminat-
ed primarily in stool.
+\- 3 meq/L
Bicarb produced in kidneys, metabolical-
ly used to neutralize acids, and eliminat-
ed primarily in stool.
Base refers to bicarb.
BE = amount of acid/liter of fully oxy-
genated blood to get pH to 7.4 at 37 de-
Base deficit/excess grees Celsius, CO2 40 mmHg and Hgb
at 5G/DL
< -3 = acidemia (base deficit)
> -3 = alkalemia (base excess)- seen and
metabolic alkalosis. Either overproduced
or under neutralized. Compensation for
respiratory acidosis or vomiting (low HCl)
Pyloric stenosis =nonbilious vomitjng be-
, NR572 midterm
cause it is prebile duct (start IV dextrose)
<= think this in setting of base excess
and/or high bicarbonate
Rules:
.40, 40, 25 = pH, CO2, HCO3- =
first name (compensation), middle name
(cause: respiratory v metabolic), last
name (acidosis v alkalosis)
2 things the body uses to regulate pH=
carbon dioxide/CO2 (lungs) and bicar-
bonate/HCO3- (kidneys)= first thing you
look at.
Look at pH last... it just tells you how
compensated you are.
Arrows:
NAME THE BABY
FIRST NAME-
*If CO2 and HCO3- both moving in same
direction (both up or both down)= body
attempting to compensate
*If CO2 and HCO3- moving in opposite
(one up and one down) directions= un-
compensated.
*pH within 7.35-7.45 range? No- partially
compensated. Yes- fully compensated.
MIDDLE NAME-
*when in ROME: Respiratory = Opposite
arrow direction (ph v CO2), Metabolic =
Equal arrow direction (pH v bicarb).
LAST NAME-
pH- acidosis or alkalosis?
Deep, rapid breathing; usually the result
of an accumulation of certain acids when
Kussmaul respirations
insulin is not available in the body seen
in DKA (metabolic acidosis)
Rule 1 of oxygenation PaO2 should be 4-5x FiO2
Blood gas = pulse ox
30mmHg = 60%
40 = 70%
50 = 80%
60 = 90%
Rule 2 of oxygenation 90 = 100%
Blood gas reading is best oxygenation it
can be.
Patient with sat of 90% and blood gas is
40 = v/q mismatch = problem
Arterial = delivery/pre-metabolic
Venous = consumption/post metabolic
Arterial v. venous oxygenation
Arterial pO2 about 80mmHg v. Venous
pO2 about 50 mmHg
Will always have a lower oxygen and
higher CO2 (about 5 mmHg) which is an
acid so will have a lower pH than ABG.
VBG values
Amount of CO2 and lungs at end exha-
lation. Will normally be 3 to 5 mmHg less
than arterial CO2.
The 3 to 5 mmHg difference reflects dead
End Title CO2 space and the alveolar-arterial gradient.
CO2 elimination is passive and occurs
down a concentration gradient. So less
CO2 in lungs that in venous blood to
facilitate movement into the lungs for ex-
halation.
,NR572 midterm
CO2 is a metabolic byproduct.
Increased production = hypermetabolic
states
Decreased elimination (breathing slow
and shallow)= poor minute ventilation
(RRxTV) failing to elimination
Reasons for high CO2 "Hypoventilation resultant hypercarbia"
Increased perfusion = ROSC, high car-
diac output
Every 10 of CO2 = about 1L cardiac out-
put
Why AHA wants ET CO2 of at least 10
(25% of low normal CO) during CPR
4L
Every 10 of CO2 = about 1L cardiac out-
Low-normal CO
put
Why AHA wants ET CO2 of at least 10
(25% of low normal CO) during CPR
Decrease production = decreased me-
tabolism
Decrease perfusion= dead, collapsed
lung or blocked blood flow (PE, Tension
Low CO2 causes
PTX, etc)
Increased elimination (breathing fast and
deep) = hyperventilation
V/Q mismatch
Results always listed in this order:
pH/PCO2/PO 2/HCO3-
1. Acid-base status:
PH of less than 7.35 is acidotic, whereas
Blood Gas Analysis one of more than 7.45 indicates blood
as alkolotic. Used to determine degree
of compensation in acidosis or alkalo-
sis (uncompensated, partially compen-
sated, compensated)
2. Oxygen partial pressure (pO2)
,NR572 midterm
PO2 < 60 mmHg may require supple-
mental O2.
3. Carbon dioxide pressure (pCO2)
35-45
4. Bicarbonate levels (HCO3 mmols)
22-26mmols/L
5. Base deficit/excess- +\-3 meq/L
35-45 mmHg
Assessment of ventilation on ABG. Low
pCO2 = hypocapnia = hyperventilation
CO2
(could be respiratory compensation for
academia)
Hi PCO2 = hypercapnia = hypoventila-
tion
22-26mmols/L
Less than 22 = metabolic acidosis (dka
and sepsis toxin, diarrhea, or problem
with kidneys)
HCO3-
Greater than 26 = metabolic alkalosis
Bicarb produced in kidneys, metabolical-
ly used to neutralize acids, and eliminat-
ed primarily in stool.
+\- 3 meq/L
Bicarb produced in kidneys, metabolical-
ly used to neutralize acids, and eliminat-
ed primarily in stool.
Base refers to bicarb.
BE = amount of acid/liter of fully oxy-
genated blood to get pH to 7.4 at 37 de-
Base deficit/excess grees Celsius, CO2 40 mmHg and Hgb
at 5G/DL
< -3 = acidemia (base deficit)
> -3 = alkalemia (base excess)- seen and
metabolic alkalosis. Either overproduced
or under neutralized. Compensation for
respiratory acidosis or vomiting (low HCl)
Pyloric stenosis =nonbilious vomitjng be-
, NR572 midterm
cause it is prebile duct (start IV dextrose)
<= think this in setting of base excess
and/or high bicarbonate
Rules:
.40, 40, 25 = pH, CO2, HCO3- =
first name (compensation), middle name
(cause: respiratory v metabolic), last
name (acidosis v alkalosis)
2 things the body uses to regulate pH=
carbon dioxide/CO2 (lungs) and bicar-
bonate/HCO3- (kidneys)= first thing you
look at.
Look at pH last... it just tells you how
compensated you are.
Arrows:
NAME THE BABY
FIRST NAME-
*If CO2 and HCO3- both moving in same
direction (both up or both down)= body
attempting to compensate
*If CO2 and HCO3- moving in opposite
(one up and one down) directions= un-
compensated.
*pH within 7.35-7.45 range? No- partially
compensated. Yes- fully compensated.
MIDDLE NAME-
*when in ROME: Respiratory = Opposite
arrow direction (ph v CO2), Metabolic =
Equal arrow direction (pH v bicarb).
LAST NAME-
pH- acidosis or alkalosis?
Deep, rapid breathing; usually the result
of an accumulation of certain acids when
Kussmaul respirations
insulin is not available in the body seen
in DKA (metabolic acidosis)
