APEX: MOCK EXAM 4 |LATEST UPDATED 2026/2027 (GRADED A+)CORRECT ANSWERS 2026 LATEST UPDATE!!
Which pharmacologic concepts BEST describe the effect of Naloxone at the mu receptor? Select 2
Efficacy
Reversibility
Potentiation
Affinity ✔️Reversibility
Affinity
Competitive antagonist (can be reversed by adding more agonist)
Identify the factors that are MOST likely to increase the gradient between PaCO2 and EtCO2. Select 3
Tracheostomy
Increasing length of tubing in circle system
Face mask
Amniotic fluid embolism
Hypervolemia
Ipratropium ✔️Face mask
Amniotic fluid embolism
Ipratropium
Physiologic dead space = anatomic dead space + alveolar dead space
Anatomic Vd is increased by anything that increases the volume of the airway conduit
Alveolar Vd is increased by anything that reduces pulmonary blood flow.
# of ways this Q could have been asked:
What increases dead space?
What increases zone 1 in the lung?
What increases the PaCO2-EtCO2 gradient?
What increases ventilation in excess of perfusion?
Physiologic dead space is increased by:
Decreased pulm blood flow
Decreased CO
PE
COPD
,old age
Face mask
Positive pressure ventilation
HME
Neck extension
Anticholinergics cause bronchodilation (Ipratropium)
Because Vd begins at the y-piece in the circle system, it is not affected by increasing length of tubing in the circle system
What is the largest ETT that can be passed through a size 3 LMA classic?
A. 6.0
B. 6.5
C. 7.0
D. 7.5 ✔️A. 6.0
LMA 1->3.5ETT
LMA 1.5->4.0 ETT
LMA 2->4.5 ETT
LMA 2.5-> 5.0 ETT
LMA 3-> 6.0 ETT
LMA 4-> 6.0 ETT
LMA 5-> 7.0 ETT
LMA 6-> 7.0 ETT
What is the antidote for central anticholinergic syndrome?
A. Pyridostigmine
B. Glycopyrrolate
C. Physostigmine
D. Atropine ✔️C. Physostigmine
Central anticholinergic syndrome caused by anticholinergics capable of crossing BBB (atropine & scopolamine-NOT glyco)
Signs of toxicity: restlessness, combativeness, confusion, & delerium
The elderly & pts w/ uncontrolled pain are at increased risk of developing central anticholinergic syndrome
Neostigmine, pyridostigmine, & physostigmine are cholinesterase inhibitors (increase Ach in the synaptic cleft), but only physostigmine diffuses
across BBB.
,Select the statement that BEST describes the age related autonomic nervous system changes in the elderly
A. The response to beta stimulation decreases
B. Parasympathetic tone increases
C. Baroreceptor sensitivity is unchanged
D. Sympathetic tone decreases ✔️A. The response to beta stimulation decreases
Key age related ANS changes in elderly include:
SNS tone increases (increased NE in plasma), however the response to beta stimulation is reduced
PNS tone decreases
Baroreceptor sensitivity decreases
CV changes that accompany a normal pregnancy include an increased:
Select 3
SVR
SV
plasma volume
DBP
HR
SBP ✔️SV
plasma volume
HR
Several weeks after conception, SVR decreases with a compensatory rise in CO & RAAS activity (sodium retention—> increased plasma volume)
A reduction in SVR causes the DBP to decline. SBP is unchanged
Key cardiovascular changes during pregnancy:
CO: (Inc 40%)
-SV (Inc 30%)
-HR (Inc 15%)
Peripheral circulation:
-SBP- no change
-DBP- (Dec 15%)
-SVR- (Dec 15%)
, Intravascular fluid volume: (Inc 35%)
-plasma volume (Inc 45%)
-erythrocyte volume (Inc 20%)
A 4 y/o pt who weighs 15kg experiences cardiac arrest. What is energy setting for the first defibrillation attempt? ✔️30J
1st shock: 2 J/kg
2nd shock: 4 J/kg
Subsequent shocks: 4-10 J/kg
Choose the BEST methods to restore CO in heart transplant recipient. Select 2
Atropine
Ephedrine
Isoproterenol
500ml 0.9% NACL bolus ✔️Isoproterenol
500ml 0.9% NACL bolus
CO is the product of SV & HR
The transplanted heart is severed from autonomic influence, so HR is determined by intrinsic rate of phase 4 depolarization of the SA node
(100-120bpm)
Since the HR is fixed, CO becomes dependent on preload. CO adjusts according to the position on the Starling curve—increasing preload
augments CO until a point is reached where the ventricular myocytes become overstretched & cardiac output fails
Anesthetic considerations include maintaining adequate preload to optimize the Frank-Starling mechanism. Isoproterenol and dilute
epinephrine should be available to augment HR
Indirect acting vasopressin's, such as ephedrine, partially rely on endogenous catecholamine stores in the post-synaptic sympathetic neuron &
are therefore less effective
Atropine reduces vagal tone by acting as a competitive antagonist of the cardiac M2 receptor. In the absence of vagal input, atropine has no
effect
Choose the statements that represent an accurate understanding of the flowmeters on the anesthesia machine. Select 2
They are the beginning of the low pressure system
The annular space is the distance b/t the needle valve & the float
The plumb bob float is read in the middle of the float
The internal diameter of the Thorpe tube is narrowest at the base. ✔️They are the beginning of the low pressure system
The internal diameter of the Thorpe tube is narrowest at the base.
Which pharmacologic concepts BEST describe the effect of Naloxone at the mu receptor? Select 2
Efficacy
Reversibility
Potentiation
Affinity ✔️Reversibility
Affinity
Competitive antagonist (can be reversed by adding more agonist)
Identify the factors that are MOST likely to increase the gradient between PaCO2 and EtCO2. Select 3
Tracheostomy
Increasing length of tubing in circle system
Face mask
Amniotic fluid embolism
Hypervolemia
Ipratropium ✔️Face mask
Amniotic fluid embolism
Ipratropium
Physiologic dead space = anatomic dead space + alveolar dead space
Anatomic Vd is increased by anything that increases the volume of the airway conduit
Alveolar Vd is increased by anything that reduces pulmonary blood flow.
# of ways this Q could have been asked:
What increases dead space?
What increases zone 1 in the lung?
What increases the PaCO2-EtCO2 gradient?
What increases ventilation in excess of perfusion?
Physiologic dead space is increased by:
Decreased pulm blood flow
Decreased CO
PE
COPD
,old age
Face mask
Positive pressure ventilation
HME
Neck extension
Anticholinergics cause bronchodilation (Ipratropium)
Because Vd begins at the y-piece in the circle system, it is not affected by increasing length of tubing in the circle system
What is the largest ETT that can be passed through a size 3 LMA classic?
A. 6.0
B. 6.5
C. 7.0
D. 7.5 ✔️A. 6.0
LMA 1->3.5ETT
LMA 1.5->4.0 ETT
LMA 2->4.5 ETT
LMA 2.5-> 5.0 ETT
LMA 3-> 6.0 ETT
LMA 4-> 6.0 ETT
LMA 5-> 7.0 ETT
LMA 6-> 7.0 ETT
What is the antidote for central anticholinergic syndrome?
A. Pyridostigmine
B. Glycopyrrolate
C. Physostigmine
D. Atropine ✔️C. Physostigmine
Central anticholinergic syndrome caused by anticholinergics capable of crossing BBB (atropine & scopolamine-NOT glyco)
Signs of toxicity: restlessness, combativeness, confusion, & delerium
The elderly & pts w/ uncontrolled pain are at increased risk of developing central anticholinergic syndrome
Neostigmine, pyridostigmine, & physostigmine are cholinesterase inhibitors (increase Ach in the synaptic cleft), but only physostigmine diffuses
across BBB.
,Select the statement that BEST describes the age related autonomic nervous system changes in the elderly
A. The response to beta stimulation decreases
B. Parasympathetic tone increases
C. Baroreceptor sensitivity is unchanged
D. Sympathetic tone decreases ✔️A. The response to beta stimulation decreases
Key age related ANS changes in elderly include:
SNS tone increases (increased NE in plasma), however the response to beta stimulation is reduced
PNS tone decreases
Baroreceptor sensitivity decreases
CV changes that accompany a normal pregnancy include an increased:
Select 3
SVR
SV
plasma volume
DBP
HR
SBP ✔️SV
plasma volume
HR
Several weeks after conception, SVR decreases with a compensatory rise in CO & RAAS activity (sodium retention—> increased plasma volume)
A reduction in SVR causes the DBP to decline. SBP is unchanged
Key cardiovascular changes during pregnancy:
CO: (Inc 40%)
-SV (Inc 30%)
-HR (Inc 15%)
Peripheral circulation:
-SBP- no change
-DBP- (Dec 15%)
-SVR- (Dec 15%)
, Intravascular fluid volume: (Inc 35%)
-plasma volume (Inc 45%)
-erythrocyte volume (Inc 20%)
A 4 y/o pt who weighs 15kg experiences cardiac arrest. What is energy setting for the first defibrillation attempt? ✔️30J
1st shock: 2 J/kg
2nd shock: 4 J/kg
Subsequent shocks: 4-10 J/kg
Choose the BEST methods to restore CO in heart transplant recipient. Select 2
Atropine
Ephedrine
Isoproterenol
500ml 0.9% NACL bolus ✔️Isoproterenol
500ml 0.9% NACL bolus
CO is the product of SV & HR
The transplanted heart is severed from autonomic influence, so HR is determined by intrinsic rate of phase 4 depolarization of the SA node
(100-120bpm)
Since the HR is fixed, CO becomes dependent on preload. CO adjusts according to the position on the Starling curve—increasing preload
augments CO until a point is reached where the ventricular myocytes become overstretched & cardiac output fails
Anesthetic considerations include maintaining adequate preload to optimize the Frank-Starling mechanism. Isoproterenol and dilute
epinephrine should be available to augment HR
Indirect acting vasopressin's, such as ephedrine, partially rely on endogenous catecholamine stores in the post-synaptic sympathetic neuron &
are therefore less effective
Atropine reduces vagal tone by acting as a competitive antagonist of the cardiac M2 receptor. In the absence of vagal input, atropine has no
effect
Choose the statements that represent an accurate understanding of the flowmeters on the anesthesia machine. Select 2
They are the beginning of the low pressure system
The annular space is the distance b/t the needle valve & the float
The plumb bob float is read in the middle of the float
The internal diameter of the Thorpe tube is narrowest at the base. ✔️They are the beginning of the low pressure system
The internal diameter of the Thorpe tube is narrowest at the base.
