Apex Mock Exams Study Guide
2026/2027 COMPLETE QUESTIONS WITH
VERIFIED CORRECT ANSWERS || 100%
GUARANTEED PASS NEWEST VERSION
Q1. In a circle system, the work of breathing is primarily determined by which
component?
A) The unidirectional valves
B) The CO2 absorbent canister
C) The Y-piece connector
D) The Endotracheal Tube (ETT)
Correct ,,,ANSWER,,,,: D) The Endotracheal Tube (ETT)
Rationale: Work of breathing is primarily determined by resistance. According
to Poiseuille's Law, resistance is inversely proportional to the radius of a tube raised
to the fourth power (𝑅 = 8𝑛𝑙/𝜋𝑟 4 ). The ETT has the narrowest diameter in the entire
circle system, therefore it creates the highest resistance to gas flow, making it the
primary determinant of the work of breathing. The unidirectional valves and CO2
absorbent contribute some resistance, but none as much as the ETT.
Q2. Which of the following are appropriate interventions in the "Can't ventilate,
can't intubate" scenario? (Select 2)
A) Retrograde intubation
B) Percutaneous transtracheal jet ventilation (TTJV)
C) Surgical cricothyrotomy
D) Emergent tracheostomy
,Correct ,,,ANSWER,,,,s: B) Percutaneous transtracheal jet ventilation (TTJV) & C)
Surgical cricothyrotomy
Rationale: TTJV and surgical cricothyrotomy are the two fastest ways to re-establish
an airway in an emergency. TTJV requires a high-pressure oxygen source (jet
ventilator or 50 psi O2 tank). Retrograde intubation takes 5-7 minutes and is too
slow. Formal tracheostomy is an operating room procedure requiring tissue
dissection, and is not considered an emergent "rescue" technique for the "can't
ventilate, can't intubate" situation.
Q3. A neonate with pyloric stenosis is likely to have which of the following
disturbances? (Select 3)
A) Metabolic alkalosis
B) Metabolic acidosis
C) Hyperkalemia
D) Hypokalemia
E) Hyperchloremia
F) Hypochloremia
Correct ,,,ANSWER,,,,s: A) Metabolic alkalosis, D) Hypokalemia, F) Hypochloremia
Rationale: Pyloric stenosis causes persistent vomiting of gastric contents
(hydrochloric acid). The loss of hydrogen ions (𝐻 + ) leads to metabolic alkalosis. The
loss of chloride (𝐶𝑙 − ) leads to hypochloremia. Potassium is also lost in gastric fluid,
and the metabolic alkalosis shifts potassium intracellularly, leading to hypokalemia.
Q4. Which of the following receptors is the primary target for the efferent limb of
the oculocardiac reflex?
A) Beta-1 receptors at the SA node
B) Trigeminal nerve
C) Gasserian ganglion
D) Vagus nerve
,Correct ,,,ANSWER,,,,: D) Vagus nerve
Rationale: The oculocardiac reflex (OCR) is triggered by traction on extraocular
muscles or pressure on the globe. The afferent limb is the trigeminal nerve (CN V)
via the ciliary nerves and gasserian ganglion. The efferent limb is the vagus nerve
(CN X), which directly innervates the SA node. Vagal stimulation results in
bradycardia, and potentially asystole, via muscarinic receptors (not beta-1).
Q5. In a 15 kg pediatric patient in cardiac arrest, what is the correct first
defibrillation shock setting?
A) 15 J (1 J/kg)
B) 30 J (2 J/kg)
C) 45 J (3 J/kg)
D) 60 J (4 J/kg)
Correct ,,,ANSWER,,,,: B) 30 J (2 J/kg)
Rationale: The Pediatric Advanced Life Support (PALS) guidelines recommend an
initial defibrillation dose of 2 J/kg. For a 15 kg patient, this is 15 × 2 = 30 Joules. If
the first shock is unsuccessful, the second attempt is increased to 4 J/kg (60 J for
this patient). Doses above 4 J/kg are not routinely recommended for initial pediatric
shocks.
Q6. After releasing a tourniquet on a lower extremity, which of the following
changes would you expect to see first on your monitors?
A) Decreased ETCO2
B) Increased ETCO2
C) Decreased heart rate
D) Decreased blood pressure
Correct ,,,ANSWER,,,,: B) Increased ETCO2
, Rationale: Releasing a tourniquet causes a sudden washout of metabolic
byproducts (lactic acid, CO2) that have accumulated in the ischemic limb. This
bolus of CO2 returns to the lungs via the venous system, causing a transient but
sharp increase in ETCO2. This is followed by metabolic acidosis, potential
hypotension (due to vasodilation), and a transient decrease in body temperature.
Q7. Which local anesthetic has the shortest duration of action?
A) Bupivacaine
B) Lidocaine
C) Chloroprocaine
D) Ropivacaine
Correct ,,,ANSWER,,,,: C) Chloroprocaine
Rationale: Duration of action for local anesthetics is primarily determined by protein
binding (higher binding = longer duration). Chloroprocaine has essentially zero
protein binding and is rapidly metabolized by plasma pseudocholinesterase, giving
it the shortest duration. Bupivacaine and ropivacaine have high protein binding
(longest duration). Lidocaine is intermediate.
Q8. A morbidly obese patient undergoing infected hip hardware removal suddenly
shows: Increased HR, Hypotension, Increased CVP, Drop in ETCO2, and
Increased PIP. What is the most likely diagnosis?
A) Tension pneumothorax
B) Pulmonary Embolism (PE)
C) Malignant hyperthermia
D) Anaphylaxis
Correct ,,,ANSWER,,,,: B) Pulmonary Embolism (PE)
Rationale: This classic presentation (sudden hypotension, increased CVP,
increased PIP, decreased ETCO2) indicates a massive PE. The decrease in ETCO2 is
caused by increased dead space ventilation—blood is blocked from reaching the
2026/2027 COMPLETE QUESTIONS WITH
VERIFIED CORRECT ANSWERS || 100%
GUARANTEED PASS NEWEST VERSION
Q1. In a circle system, the work of breathing is primarily determined by which
component?
A) The unidirectional valves
B) The CO2 absorbent canister
C) The Y-piece connector
D) The Endotracheal Tube (ETT)
Correct ,,,ANSWER,,,,: D) The Endotracheal Tube (ETT)
Rationale: Work of breathing is primarily determined by resistance. According
to Poiseuille's Law, resistance is inversely proportional to the radius of a tube raised
to the fourth power (𝑅 = 8𝑛𝑙/𝜋𝑟 4 ). The ETT has the narrowest diameter in the entire
circle system, therefore it creates the highest resistance to gas flow, making it the
primary determinant of the work of breathing. The unidirectional valves and CO2
absorbent contribute some resistance, but none as much as the ETT.
Q2. Which of the following are appropriate interventions in the "Can't ventilate,
can't intubate" scenario? (Select 2)
A) Retrograde intubation
B) Percutaneous transtracheal jet ventilation (TTJV)
C) Surgical cricothyrotomy
D) Emergent tracheostomy
,Correct ,,,ANSWER,,,,s: B) Percutaneous transtracheal jet ventilation (TTJV) & C)
Surgical cricothyrotomy
Rationale: TTJV and surgical cricothyrotomy are the two fastest ways to re-establish
an airway in an emergency. TTJV requires a high-pressure oxygen source (jet
ventilator or 50 psi O2 tank). Retrograde intubation takes 5-7 minutes and is too
slow. Formal tracheostomy is an operating room procedure requiring tissue
dissection, and is not considered an emergent "rescue" technique for the "can't
ventilate, can't intubate" situation.
Q3. A neonate with pyloric stenosis is likely to have which of the following
disturbances? (Select 3)
A) Metabolic alkalosis
B) Metabolic acidosis
C) Hyperkalemia
D) Hypokalemia
E) Hyperchloremia
F) Hypochloremia
Correct ,,,ANSWER,,,,s: A) Metabolic alkalosis, D) Hypokalemia, F) Hypochloremia
Rationale: Pyloric stenosis causes persistent vomiting of gastric contents
(hydrochloric acid). The loss of hydrogen ions (𝐻 + ) leads to metabolic alkalosis. The
loss of chloride (𝐶𝑙 − ) leads to hypochloremia. Potassium is also lost in gastric fluid,
and the metabolic alkalosis shifts potassium intracellularly, leading to hypokalemia.
Q4. Which of the following receptors is the primary target for the efferent limb of
the oculocardiac reflex?
A) Beta-1 receptors at the SA node
B) Trigeminal nerve
C) Gasserian ganglion
D) Vagus nerve
,Correct ,,,ANSWER,,,,: D) Vagus nerve
Rationale: The oculocardiac reflex (OCR) is triggered by traction on extraocular
muscles or pressure on the globe. The afferent limb is the trigeminal nerve (CN V)
via the ciliary nerves and gasserian ganglion. The efferent limb is the vagus nerve
(CN X), which directly innervates the SA node. Vagal stimulation results in
bradycardia, and potentially asystole, via muscarinic receptors (not beta-1).
Q5. In a 15 kg pediatric patient in cardiac arrest, what is the correct first
defibrillation shock setting?
A) 15 J (1 J/kg)
B) 30 J (2 J/kg)
C) 45 J (3 J/kg)
D) 60 J (4 J/kg)
Correct ,,,ANSWER,,,,: B) 30 J (2 J/kg)
Rationale: The Pediatric Advanced Life Support (PALS) guidelines recommend an
initial defibrillation dose of 2 J/kg. For a 15 kg patient, this is 15 × 2 = 30 Joules. If
the first shock is unsuccessful, the second attempt is increased to 4 J/kg (60 J for
this patient). Doses above 4 J/kg are not routinely recommended for initial pediatric
shocks.
Q6. After releasing a tourniquet on a lower extremity, which of the following
changes would you expect to see first on your monitors?
A) Decreased ETCO2
B) Increased ETCO2
C) Decreased heart rate
D) Decreased blood pressure
Correct ,,,ANSWER,,,,: B) Increased ETCO2
, Rationale: Releasing a tourniquet causes a sudden washout of metabolic
byproducts (lactic acid, CO2) that have accumulated in the ischemic limb. This
bolus of CO2 returns to the lungs via the venous system, causing a transient but
sharp increase in ETCO2. This is followed by metabolic acidosis, potential
hypotension (due to vasodilation), and a transient decrease in body temperature.
Q7. Which local anesthetic has the shortest duration of action?
A) Bupivacaine
B) Lidocaine
C) Chloroprocaine
D) Ropivacaine
Correct ,,,ANSWER,,,,: C) Chloroprocaine
Rationale: Duration of action for local anesthetics is primarily determined by protein
binding (higher binding = longer duration). Chloroprocaine has essentially zero
protein binding and is rapidly metabolized by plasma pseudocholinesterase, giving
it the shortest duration. Bupivacaine and ropivacaine have high protein binding
(longest duration). Lidocaine is intermediate.
Q8. A morbidly obese patient undergoing infected hip hardware removal suddenly
shows: Increased HR, Hypotension, Increased CVP, Drop in ETCO2, and
Increased PIP. What is the most likely diagnosis?
A) Tension pneumothorax
B) Pulmonary Embolism (PE)
C) Malignant hyperthermia
D) Anaphylaxis
Correct ,,,ANSWER,,,,: B) Pulmonary Embolism (PE)
Rationale: This classic presentation (sudden hypotension, increased CVP,
increased PIP, decreased ETCO2) indicates a massive PE. The decrease in ETCO2 is
caused by increased dead space ventilation—blood is blocked from reaching the
