Critical Care Nursing Advanced Prep:
Master Hemodynamic Monitoring &
Mechanical Ventilation Practice
Questions & Detailed Explanations
Subject: NSG 180 Critical Care Nursing – Hemodynamics, Acid-Base, and
Ventilatory Management
Question 1: A patient in the ICU with cardiogenic shock is being monitored with a pulmonary
artery (PA) catheter. Which of the following hemodynamic profiles most accurately reflects the
transition from compensated cardiogenic shock to worsening left ventricular failure?
A) Elevated Cardiac Index (CI), decreased Systemic Vascular Resistance (SVR), and elevated
Pulmonary Capillary Wedge Pressure (PCWP).
B) Decreased CI, increased SVR, and elevated PCWP.
C) Normal CI, decreased SVR, and normal PCWP.
D) Decreased CI, decreased SVR, and decreased PCWP.
Correct Answer: B) Decreased CI, increased SVR, and elevated PCWP.
Explanation: In cardiogenic shock, the heart’s contractility is impaired, leading to a decreased
Cardiac Index (CI). The body compensates for reduced cardiac output via the sympathetic
nervous system and RAAS activation, causing peripheral vasoconstriction and thus increasing
Systemic Vascular Resistance (SVR). As the left ventricle fails to pump effectively, blood backs
up into the pulmonary circulation, resulting in an elevated Pulmonary Capillary Wedge Pressure
(PCWP). Option A describes a distributive shock pattern; Options C and D are inconsistent with
the classic pathophysiology of cardiogenic shock.
Question 2: You are titrating sedation for a patient on mechanical ventilation using the RASS
(Richmond Agitation-Sedation Scale). The patient is currently at a RASS of +2. What is the
clinical implication of this score?
A) The patient is deeply sedated and unresponsive to voice.
B) The patient is alert and calm.
C) The patient is restless and frequently attempts to remove the endotracheal tube.
,D) The patient has movement or eye opening to sound, but no eye contact.
Correct Answer: C) The patient is restless and frequently attempts to remove the
endotracheal tube.
Explanation: A RASS score of +2 indicates "Agitated"—the patient makes frequent non-
purposeful movements or fights the ventilator. A score of 0 is "alert and calm." A score of -3
indicates "moderate sedation" (movement/eye opening to voice, no eye contact). A score of -5 is
"unarousable." Recognizing +2 is critical to prevent accidental extubation and manage
ventilator dyssynchrony.
Question 3: A patient exhibits an arterial blood gas (ABG) showing pH 7.28, $PaCO_2$ 55
mmHg, and $HCO_3^-$ 26 mEq/L. Which compensatory mechanism is the body expected to
initiate, and what is the nurse's priority assessment?
A) Respiratory compensation; monitor for respiratory fatigue.
B) Metabolic compensation; assess for signs of hyperkalemia.
C) Respiratory alkalosis; administer supplemental oxygen.
D) Renal compensation; monitor hourly urine output.
Correct Answer: B) Metabolic compensation; assess for signs of hyperkalemia.
Explanation: The ABG indicates uncompensated respiratory acidosis. The kidneys (metabolic
system) will respond by retaining bicarbonate ($HCO_3^-$) to buffer the acid, a process that
takes 24–48 hours. During acidotic states, hydrogen ions move into cells in exchange for
potassium ions moving out, often leading to hyperkalemia. Thus, assessing for cardiac
dysrhythmias related to hyperkalemia is a high-priority nursing intervention.
Question 4: Which of the following ventilator settings would most likely exacerbate "auto-
PEEP" (intrinsic PEEP) in a patient with severe COPD?
A) Increasing the tidal volume.
B) Increasing the respiratory rate.
C) Decreasing the inspiratory flow rate.
D) Increasing the inspiratory time.
Correct Answer: B) Increasing the respiratory rate.
Explanation: Auto-PEEP occurs when there is insufficient time for the patient to fully exhale
before the next mechanical breath is delivered. Increasing the respiratory rate decreases the
,expiratory time (T-exp), trapping air in the lungs. While options A, C, and D also affect
ventilation, increasing the frequency of breaths is the most direct cause of shortened expiratory
phases in obstructive disease.
Question 5: A patient with septic shock is receiving norepinephrine. The nurse notes a decrease
in the patient’s ScvO2 (Central Venous Oxygen Saturation) from 75% to 60%. What is the most
likely physiological cause?
A) Increased tissue oxygen extraction due to demand outpacing delivery.
B) Improved cardiac output leading to higher oxygen saturation.
C) Decreased metabolic demand secondary to sedation.
D) An increase in systemic hemoglobin levels.
Correct Answer: A) Increased tissue oxygen extraction due to demand outpacing delivery.
Explanation: ScvO2 represents the balance between oxygen delivery ($DO_2$) and oxygen
consumption ($VO_2$). A drop in ScvO2 indicates that the tissues are extracting more oxygen
than usual from the blood, suggesting that either delivery has decreased (e.g., worsening shock,
anemia) or demand has increased (e.g., fever, shivering, work of breathing). A rising ScvO2
would suggest improved CO or decreased demand.
Question 6: During the assessment of a patient with a tension pneumothorax, which
hemodynamic finding is a hallmark sign?
A) Decreased right atrial pressure (RAP).
B) Pulsus paradoxus.
C) Increased pulse pressure.
D) Elevated systemic vascular resistance (SVR) with normal cardiac output.
Correct Answer: B) Pulsus paradoxus.
Explanation: A tension pneumothorax increases intrathoracic pressure, which impedes venous
return to the heart and can lead to obstructive shock. Pulsus paradoxus—a drop in systolic blood
pressure of >10 mmHg during inspiration—is a classic sign of this mechanical compression of
the heart and great vessels. Options A and C are incorrect because venous pressure typically
rises due to obstruction, and pulse pressure narrows due to decreased stroke volume.
Question 7: A patient in the ICU is being managed for ARDS (Acute Respiratory Distress
Syndrome). The ventilator is set to Pressure Control, and the nurse notes the "High Pressure"
alarm is sounding. What is the most appropriate first action?
, A) Increase the pressure limit on the ventilator.
B) Sedate the patient more deeply to eliminate "fighting" the vent.
C) Disconnect the patient and manually ventilate with a bag-valve mask.
D) Suction the patient's airway to remove potential secretions.
Correct Answer: C) Disconnect the patient and manually ventilate with a bag-valve mask.
Explanation: Safety first: If a high-pressure alarm sounds, the nurse must first rule out life-
threatening causes (e.g., pneumothorax, ETT obstruction/dislodgement). By manually
ventilating, the nurse can assess lung compliance ("feel" the pressure) and verify if the issue is
patient-related or equipment-related. If the patient is stable during manual ventilation, then the
ventilator circuit is the likely culprit.
Question 8: When administering an IV push dose of adenosine for supraventricular tachycardia
(SVT), why is it imperative to flush with a rapid saline bolus immediately after?
A) To ensure the medication reaches the bloodstream before it is metabolized in the peripheral
tissues.
B) To dilute the medication, preventing localized vessel damage.
C) To stimulate the vagus nerve and enhance the medication’s effect.
D) To prevent the medication from crystallizing in the IV tubing.
Correct Answer: A) To ensure the medication reaches the bloodstream before it is
metabolized in the peripheral tissues.
Explanation: Adenosine has an extremely short half-life (<10 seconds). It is metabolized rapidly
by enzymes in the blood and vessel walls. A rapid bolus followed by a rapid saline flush is
required to ensure the drug reaches the AV node in sufficient concentration to transiently block
conduction.
Question 9: A patient with a subarachnoid hemorrhage (SAH) is at risk for vasospasm. Which
medication is the standard of care for preventing secondary ischemic injury, and what is the
primary nursing priority regarding its administration?
A) Nimodipine; monitor for hypotension.
B) Mannitol; monitor for hyperkalemia.
C) Phenytoin; monitor for respiratory depression.
Master Hemodynamic Monitoring &
Mechanical Ventilation Practice
Questions & Detailed Explanations
Subject: NSG 180 Critical Care Nursing – Hemodynamics, Acid-Base, and
Ventilatory Management
Question 1: A patient in the ICU with cardiogenic shock is being monitored with a pulmonary
artery (PA) catheter. Which of the following hemodynamic profiles most accurately reflects the
transition from compensated cardiogenic shock to worsening left ventricular failure?
A) Elevated Cardiac Index (CI), decreased Systemic Vascular Resistance (SVR), and elevated
Pulmonary Capillary Wedge Pressure (PCWP).
B) Decreased CI, increased SVR, and elevated PCWP.
C) Normal CI, decreased SVR, and normal PCWP.
D) Decreased CI, decreased SVR, and decreased PCWP.
Correct Answer: B) Decreased CI, increased SVR, and elevated PCWP.
Explanation: In cardiogenic shock, the heart’s contractility is impaired, leading to a decreased
Cardiac Index (CI). The body compensates for reduced cardiac output via the sympathetic
nervous system and RAAS activation, causing peripheral vasoconstriction and thus increasing
Systemic Vascular Resistance (SVR). As the left ventricle fails to pump effectively, blood backs
up into the pulmonary circulation, resulting in an elevated Pulmonary Capillary Wedge Pressure
(PCWP). Option A describes a distributive shock pattern; Options C and D are inconsistent with
the classic pathophysiology of cardiogenic shock.
Question 2: You are titrating sedation for a patient on mechanical ventilation using the RASS
(Richmond Agitation-Sedation Scale). The patient is currently at a RASS of +2. What is the
clinical implication of this score?
A) The patient is deeply sedated and unresponsive to voice.
B) The patient is alert and calm.
C) The patient is restless and frequently attempts to remove the endotracheal tube.
,D) The patient has movement or eye opening to sound, but no eye contact.
Correct Answer: C) The patient is restless and frequently attempts to remove the
endotracheal tube.
Explanation: A RASS score of +2 indicates "Agitated"—the patient makes frequent non-
purposeful movements or fights the ventilator. A score of 0 is "alert and calm." A score of -3
indicates "moderate sedation" (movement/eye opening to voice, no eye contact). A score of -5 is
"unarousable." Recognizing +2 is critical to prevent accidental extubation and manage
ventilator dyssynchrony.
Question 3: A patient exhibits an arterial blood gas (ABG) showing pH 7.28, $PaCO_2$ 55
mmHg, and $HCO_3^-$ 26 mEq/L. Which compensatory mechanism is the body expected to
initiate, and what is the nurse's priority assessment?
A) Respiratory compensation; monitor for respiratory fatigue.
B) Metabolic compensation; assess for signs of hyperkalemia.
C) Respiratory alkalosis; administer supplemental oxygen.
D) Renal compensation; monitor hourly urine output.
Correct Answer: B) Metabolic compensation; assess for signs of hyperkalemia.
Explanation: The ABG indicates uncompensated respiratory acidosis. The kidneys (metabolic
system) will respond by retaining bicarbonate ($HCO_3^-$) to buffer the acid, a process that
takes 24–48 hours. During acidotic states, hydrogen ions move into cells in exchange for
potassium ions moving out, often leading to hyperkalemia. Thus, assessing for cardiac
dysrhythmias related to hyperkalemia is a high-priority nursing intervention.
Question 4: Which of the following ventilator settings would most likely exacerbate "auto-
PEEP" (intrinsic PEEP) in a patient with severe COPD?
A) Increasing the tidal volume.
B) Increasing the respiratory rate.
C) Decreasing the inspiratory flow rate.
D) Increasing the inspiratory time.
Correct Answer: B) Increasing the respiratory rate.
Explanation: Auto-PEEP occurs when there is insufficient time for the patient to fully exhale
before the next mechanical breath is delivered. Increasing the respiratory rate decreases the
,expiratory time (T-exp), trapping air in the lungs. While options A, C, and D also affect
ventilation, increasing the frequency of breaths is the most direct cause of shortened expiratory
phases in obstructive disease.
Question 5: A patient with septic shock is receiving norepinephrine. The nurse notes a decrease
in the patient’s ScvO2 (Central Venous Oxygen Saturation) from 75% to 60%. What is the most
likely physiological cause?
A) Increased tissue oxygen extraction due to demand outpacing delivery.
B) Improved cardiac output leading to higher oxygen saturation.
C) Decreased metabolic demand secondary to sedation.
D) An increase in systemic hemoglobin levels.
Correct Answer: A) Increased tissue oxygen extraction due to demand outpacing delivery.
Explanation: ScvO2 represents the balance between oxygen delivery ($DO_2$) and oxygen
consumption ($VO_2$). A drop in ScvO2 indicates that the tissues are extracting more oxygen
than usual from the blood, suggesting that either delivery has decreased (e.g., worsening shock,
anemia) or demand has increased (e.g., fever, shivering, work of breathing). A rising ScvO2
would suggest improved CO or decreased demand.
Question 6: During the assessment of a patient with a tension pneumothorax, which
hemodynamic finding is a hallmark sign?
A) Decreased right atrial pressure (RAP).
B) Pulsus paradoxus.
C) Increased pulse pressure.
D) Elevated systemic vascular resistance (SVR) with normal cardiac output.
Correct Answer: B) Pulsus paradoxus.
Explanation: A tension pneumothorax increases intrathoracic pressure, which impedes venous
return to the heart and can lead to obstructive shock. Pulsus paradoxus—a drop in systolic blood
pressure of >10 mmHg during inspiration—is a classic sign of this mechanical compression of
the heart and great vessels. Options A and C are incorrect because venous pressure typically
rises due to obstruction, and pulse pressure narrows due to decreased stroke volume.
Question 7: A patient in the ICU is being managed for ARDS (Acute Respiratory Distress
Syndrome). The ventilator is set to Pressure Control, and the nurse notes the "High Pressure"
alarm is sounding. What is the most appropriate first action?
, A) Increase the pressure limit on the ventilator.
B) Sedate the patient more deeply to eliminate "fighting" the vent.
C) Disconnect the patient and manually ventilate with a bag-valve mask.
D) Suction the patient's airway to remove potential secretions.
Correct Answer: C) Disconnect the patient and manually ventilate with a bag-valve mask.
Explanation: Safety first: If a high-pressure alarm sounds, the nurse must first rule out life-
threatening causes (e.g., pneumothorax, ETT obstruction/dislodgement). By manually
ventilating, the nurse can assess lung compliance ("feel" the pressure) and verify if the issue is
patient-related or equipment-related. If the patient is stable during manual ventilation, then the
ventilator circuit is the likely culprit.
Question 8: When administering an IV push dose of adenosine for supraventricular tachycardia
(SVT), why is it imperative to flush with a rapid saline bolus immediately after?
A) To ensure the medication reaches the bloodstream before it is metabolized in the peripheral
tissues.
B) To dilute the medication, preventing localized vessel damage.
C) To stimulate the vagus nerve and enhance the medication’s effect.
D) To prevent the medication from crystallizing in the IV tubing.
Correct Answer: A) To ensure the medication reaches the bloodstream before it is
metabolized in the peripheral tissues.
Explanation: Adenosine has an extremely short half-life (<10 seconds). It is metabolized rapidly
by enzymes in the blood and vessel walls. A rapid bolus followed by a rapid saline flush is
required to ensure the drug reaches the AV node in sufficient concentration to transiently block
conduction.
Question 9: A patient with a subarachnoid hemorrhage (SAH) is at risk for vasospasm. Which
medication is the standard of care for preventing secondary ischemic injury, and what is the
primary nursing priority regarding its administration?
A) Nimodipine; monitor for hypotension.
B) Mannitol; monitor for hyperkalemia.
C) Phenytoin; monitor for respiratory depression.
