Critical Care — MCQs

Critical Care Indian Medical PG Practice Questions and MCQs

Question 131: A patient presents with the following arterial blood gas (ABG) and electrolyte values: pH: 7.34, Na: 135 mEq/L, Cl: 93 mEq/L, HCO3: 20 mEq/L, Random Blood Sugar (RBS): 420 mg/dl. What is the most likely acid-base disturbance?

A. Normal Anion Gap Metabolic Acidosis (NAGMA)
B. Respiratory Acidosis
C. High Anion Gap Metabolic Acidosis (HAGMA) (Correct Answer)
D. Metabolic Alkalosis

Explanation: ### High Anion Gap Metabolic Acidosis (HAGMA) - The **pH (7.34)** indicates **acidemia**, and the **low bicarbonate (20 mEq/L)** suggests a metabolic acidosis [1], [2]. - Calculation of the anion gap: Na - (Cl + HCO3) = 135 - (93 + 20) = 22 mEq/L. An anion gap > 12 mEq/L is considered high, confirming **High Anion Gap Metabolic Acidosis (HAGMA)** [4]. The **RBS of 420 mg/dl** also points towards a likely cause such as **diabetic ketoacidosis** [3]. *Normal Anion Gap Metabolic Acidosis (NAGMA)* - This would be present if the calculated anion gap were within the normal range (typically 8-12 mEq/L). - Causes of NAGMA (e.g., hyperchloremic acidosis) are typically associated with increased chloride levels to compensate for the bicarbonate loss, which is not the primary finding here [4]. *Respiratory Acidosis* - This condition is characterized by a **low pH** and an **elevated PaCO2**, which is not provided but implied by the **low bicarbonate** not fitting a respiratory picture [2]. - While the pH is low, the primary disturbance given the other values (especially the low bicarbonate) is metabolic, not respiratory. *Metabolic Alkalosis* - Metabolic alkalosis is characterized by an **elevated pH** and an **elevated bicarbonate level**, which contradicts the presented values of low pH and low bicarbonate [2]. - This condition would involve a net gain of bicarbonate or a loss of acids, which is the opposite of the findings in this patient.

Question 132: In the management of septic shock, what is the primary goal of fluid resuscitation?

A. Restore tissue perfusion (Correct Answer)
B. Reduce blood pressure
C. Decrease heart rate
D. Maintain urine output

Explanation: The primary goal of fluid resuscitation in septic shock is to **improve microcirculation** and **deliver oxygen** to tissues, reversing cellular hypoxia [1]. Adequate fluid administration helps to increase cardiac preload, stroke volume, and ultimately, **cardiac output**, which is crucial for **tissue perfusion** [1]. While fluid resuscitation can increase blood pressure, reducing blood pressure is generally not the primary goal, especially if the patient is already **hypotensive**. The focus is on normalizing perfusion, which may involve increasing, not just reducing, blood pressure to adequate levels. Septic shock often presents with **tachycardia** [2] as a compensatory mechanism for hypoperfusion. While an increase in heart rate due to fluid administration may occur initially due to increased preload, decreasing the heart rate is not the primary goal of fluid resuscitation itself. Maintaining urine output is an important **marker of adequate renal perfusion** and overall tissue perfusion [2]. However, it is a *consequence* of successful fluid resuscitation and restoration of tissue perfusion, rather than the primary goal itself.

Question 133: A patient on mechanical ventilation exhibits an abrupt increase in peak airway pressures. What is the most likely cause?

A. Pneumothorax
B. Pulmonary embolism
C. Bronchospasm (Correct Answer)
D. Ventilator malfunction

Explanation: Bronchospasm - **Bronchospasm** causes narrowing of the airways, leading to increased resistance to airflow and an abrupt rise in **peak airway pressures**. - This condition can be triggered by various factors, including allergic reactions, aspiration, or underlying respiratory diseases like asthma or COPD. *Pneumothorax* - A **pneumothorax** would cause a sudden increase in peak airway pressures due to lung collapse but would also present with a **decrease in breath sounds** on the affected side and potentially hypoxemia. - This condition typically leads to a **medical emergency** requiring prompt intervention, often involving chest tube insertion. *Pulmonary embolism* - A **pulmonary embolism** primarily affects **gas exchange** and can lead to increased **ventilator demand** or difficulty in oxygenation, but it typically does not directly cause an abrupt increase in peak airway pressures. - This condition is characterized by **thrombotic occlusion** of pulmonary arteries, leading to V/Q mismatch and hypoxemia. *Ventilator malfunction* - While a ventilator malfunction can cause problems, an abrupt increase in peak airway pressures is more commonly indicative of a **patient-related issue** rather than a primary equipment failure [1]. - A **malfunction** could manifest as alarms for high pressure or circuit disconnects, but an isolated increase in peak pressure points to airway obstruction [1].

Question 134: A patient with severe sepsis is hypotensive despite fluid resuscitation. What is the next best step in management?

A. Administer more intravenous fluids
B. Start intravenous dopamine
C. Start intravenous norepinephrine (Correct Answer)
D. Immediate intubation

Explanation: - **Norepinephrine** is the first-line vasopressor recommended for adults with septic shock who remain hypotensive despite adequate fluid resuscitation [1]. - It primarily acts on alpha-1 adrenergic receptors to cause **vasoconstriction**, increasing systemic vascular resistance and mean arterial pressure [1]. *Administer more intravenous fluids* - While initial fluid resuscitation is crucial in sepsis, continued administration beyond initial recommendations in a patient who remains hypotensive can lead to **fluid overload** and worsen outcomes. - The focus shifts from fluid administration to vasopressors once blood pressure fails to improve with initial fluid challenges [1]. *Start intravenous dopamine* - **Dopamine** is not recommended as the first-line vasopressor for septic shock due to its potential for more **arrhythmogenic side effects** compared to norepinephrine. - It can be considered as an alternative in select patients with low risk of tachyarrhythmias or relative bradycardia, but norepinephrine is generally preferred. *Immediate intubation* - **Intubation** is indicated for respiratory failure or airway protection, but it is not the primary next step for hypotension unresponsive to fluids in sepsis. - Addressing the circulatory failure with vasopressors is the immediate priority to restore adequate organ perfusion [1].

Question 135: A 55-year-old man presents to the ICU with septic shock. He is hypotensive despite fluid resuscitation. What is the next best step in management?

A. Initiate vasopressors (Correct Answer)
B. Administer corticosteroids
C. Start broad-spectrum antibiotics
D. Intubate and ventilate

Explanation: ***Initiate vasopressors*** - In **septic shock** with persistent **hypotension** despite adequate **fluid resuscitation**, vasopressors are indicated to maintain mean arterial pressure and ensure organ perfusion [1]. - **Norepinephrine** is typically the first-line vasopressor due to its balanced alpha and beta-adrenergic effects. *Administer corticosteroids* - **Corticosteroids** are generally reserved for refractory septic shock that is unresponsive to fluids and high-dose vasopressors, or for patients with a history of adrenal insufficiency. - Administering corticosteroids as the next step would delay more critical interventions, potentially worsening outcomes. *Start broad-spectrum antibiotics* - While critical in the overall management of **septic shock**, broad-spectrum antibiotics should be initiated as soon as possible after blood cultures are drawn, ideally within the first hour of presentation. - However, the question implies that the patient is already in the ICU and highlights persistent **hypotension** despite fluid resuscitation, meaning that the immediate priority is hemodynamic support. *Intubate and ventilate* - **Intubation and mechanical ventilation** may be necessary if the patient exhibits respiratory distress, hypoxemia, or altered mental status. - However, in the immediate context of **hemodynamic instability** due to refractory **hypotension**, stabilizing blood pressure takes precedence over ventilatory support unless there is an overt respiratory failure event.

Question 136: A 70-year-old female with hypertension and chronic kidney disease stage 3 presents with a hypertensive crisis. Which medication should be avoided?

A. Labetalol
B. Furosemide
C. Nitroprusside (Correct Answer)
D. Captopril

Explanation: ***Nitroprusside*** - This medication should be avoided in patients with **chronic kidney disease (CKD)** due to the risk of **cyanide toxicity**. - Its metabolism produces **thiocyanate**, which accumulates in renal impairment and can lead to severe adverse effects. *Labetalol* - This **beta-blocker** is often a preferred agent for hypertensive crisis, even in patients with CKD, as it generally does not worsen renal function. - It provides both alpha and beta blockade, leading to rapid blood pressure reduction without significantly increasing heart rate. *Furosemide* - As a **loop diuretic**, furosemide is frequently used in hypertensive emergencies, especially when there is evidence of **volume overload** or pulmonary edema. - It helps reduce blood pressure by decreasing plasma volume, and its efficacy is generally maintained even in CKD, though higher doses may be required. *Captopril* - While ACE inhibitors like captopril can be used cautiously in CKD, they are generally **not the first-line choice for acute hypertensive crisis**. [1] - In an acute setting, they may cause a precipitous drop in blood pressure and potentially worsen renal function, especially in patients with **renal artery stenosis**. [1]

Question 137: A 70-year-old man presents with hypotension, tachycardia, and altered mental status following a severe infection. What is the initial management for septic shock?

A. Start vasopressors
B. Administer broad-spectrum antibiotics and fluids (Correct Answer)
C. Perform intubation
D. Administer corticosteroids

Explanation: ***Administer broad-spectrum antibiotics and fluids*** - The **initial management** for septic shock involves prompt administration of **broad-spectrum antibiotics** [1], [2] to target the underlying infection and aggressive **intravenous fluid resuscitation** [3] to restore circulating volume and improve perfusion. - This approach addresses both the infectious cause and the hemodynamic instability seen in septic shock, forming the cornerstone of early resuscitation [1], [3]. *Start vasopressors* - **Vasopressors** are indicated if **hypotension persists** despite adequate fluid resuscitation, not as the very first step [3]. - While critical for maintaining mean arterial pressure (MAP), they are typically initiated after initial fluid challenges have failed to improve hemodynamics [3]. *Perform intubation* - **Intubation** is indicated for **respiratory failure** or **airway protection**, which may occur in severe sepsis but is not the universal initial management for all septic shock patients. - The immediate priority is to stabilize hemodynamics and control the infection [3]. *Administer corticosteroids* - **Corticosteroids** are generally reserved for patients with **refractory septic shock** who remain hypotensive despite adequate fluids and high-dose vasopressors. - Their routine use as initial management is not recommended due to potential side effects and limited evidence of benefit in all cases.

Question 138: A 75-year-old man presents with fever, hypotension, and confusion. He has a history of a recent urinary tract infection. What is the most appropriate initial management?

A. Obtain blood cultures
B. Monitor closely
C. Start broad-spectrum antibiotics (Correct Answer)
D. Administer IV fluids

Explanation: ***Start broad-spectrum antibiotics*** - The patient presents with classic signs of **sepsis** (fever, hypotension, confusion) following a recent **urinary tract infection**, making immediate empiric broad-spectrum antibiotics crucial [1]. - Delay in antibiotic administration in sepsis dramatically increases **mortality**, so this is the most appropriate first therapeutic step after initial stabilization efforts [1], [2]. *Obtain blood cultures* - While essential for guiding definitive antibiotic therapy and identifying the causative organism, obtaining **blood cultures** should not delay the initiation of antibiotics in a septic patient [2]. - Cultures can be drawn quickly, but treating the suspected infection is time-sensitive. *Monitor closely* - Close monitoring is always necessary, but it is **insufficient as the sole initial management** for a patient presenting with suspected sepsis. - This patient requires urgent medical intervention to prevent further deterioration and organ damage. *Administer IV fluids* - **Intravenous fluids** are critical for managing **hypotension** in sepsis and should be initiated promptly to restore tissue perfusion [2], [3]. - However, fluids alone do not treat the underlying infection, and combining them with immediate antibiotics is the standard of care for septic shock [2].

Question 139: Which of the following is the most appropriate treatment for a patient with severe sepsis or septic shock?

A. Broad-spectrum antibiotics and fluid resuscitation (Correct Answer)
B. Corticosteroids alone
C. Vasopressors alone
D. Mechanical ventilation alone

Explanation: Broad-spectrum antibiotics and fluid resuscitation - **Broad-spectrum antibiotics** are critical to target the likely causative pathogen swiftly, as delays in administration increase mortality in **sepsis** [1]. - **Fluid resuscitation** is essential for restoring tissue perfusion and maintaining organ function, especially in the context of **hypotension** associated with septic shock [2]. *Corticosteroids alone* - While corticosteroids may be used in specific cases of **septic shock** refractory to fluids and vasopressors, they are not the primary or sole treatment and can have significant side effects. - Using corticosteroids alone without addressing the underlying infection and hypovolemia would be detrimental and lead to poor outcomes. *Vasopressors alone* - **Vasopressors** are primarily used to maintain mean arterial pressure after initial **fluid resuscitation** has failed to restore adequate perfusion, not as a standalone treatment [2]. - Administering vasopressors without adequate fluid resuscitation can worsen tissue perfusion and lead to organ damage due to widespread vasoconstriction. *Mechanical ventilation alone* - **Mechanical ventilation** is indicated for respiratory failure or to reduce the work of breathing in severe sepsis, but it does not address the underlying infection or circulatory collapse. - It is a supportive measure, not a definitive treatment for the systemic issues of **sepsis** and **septic shock**.

Question 140: A patient with COVID-19 develops severe ARDS despite receiving dexamethasone. What additional treatment option could target the underlying inflammatory process?

A. Tocilizumab (Correct Answer)
B. Remdesivir
C. Ivermectin
D. Azithromycin

Explanation: ***Tocilizumab*** - **Tocilizumab** is an **IL-6 receptor blocker** that can be considered in severe COVID-19 with ARDS, especially when there's evidence of a cytokine storm despite corticosteroids. - It works by inhibiting the pro-inflammatory effects of **interleukin-6 (IL-6)**, a key mediator in severe COVID-19 inflammation. *Remdesivir* - **Remdesivir** is an **antiviral medication** that directly inhibits viral replication, but it does not directly target the inflammatory process leading to ARDS. - Its benefit is primarily seen in reducing recovery time and preventing progression to severe disease, not in managing established severe inflammation or ARDS. *Ivermectin* - **Ivermectin** is an **antiparasitic drug** that has been investigated for COVID-19, but there is no strong evidence from large, well-designed clinical trials to support its use for treating or preventing COVID-19, especially not for ARDS related to inflammation. - Its mechanism of action is not related to modulating the inflammatory pathways involved in severe COVID-19 ARDS. *Azithromycin* - **Azithromycin** is an **antibiotic** with some anti-inflammatory properties, but its efficacy in directly treating severe COVID-19 or ARDS has not been consistently demonstrated. - It's mainly used to treat bacterial co-infections and doesn't target the primary immunological drivers of severe COVID-19 ARDS like IL-6.

Practice by Chapter

Shock Syndromes and Management

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Acute Respiratory Distress Syndrome

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Mechanical Ventilation Principles

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Hemodynamic Monitoring

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Nutrition in Critical Illness

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Sedation and Analgesia in ICU

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Multi-organ Dysfunction Syndrome

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Acid-Base and Electrolyte Disturbances

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Toxicologic Emergencies

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Neurological Emergencies in ICU

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Renal Replacement Therapy

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End-of-Life Care in ICU

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