Critical Care Medicine Practice Questions

Q: What is the drug of choice for sedation of a patient in the ICU?

Propofol. **Explanation:** The choice of sedative in the Intensive Care Unit (ICU) is governed by the need for rapid onset, easy titration, and quick recovery to allow for daily "sedation holidays" and neurological assessment. **Why Propofol is the Correct Answer:** **Propofol** is currently considered the drug of choice for ICU sedation, particularly for mechanically ventilated patients. Its primary advantage is its **high lipid solubility**, which allows it to cross the blood-brain barrier rapidly (onset <1 minute) and redistribute quickly, leading to a very short duration of action. This "fast-on, fast-off" profile enables clinicians to perform frequent neurological evaluations and shortens the time to weaning from mechanical ventilation compared to benzodiazepines. **Analysis of Incorrect Options:** * **Diazepam (A):** It has a long half-life and active metabolites (desmethyldiazepam) that accumulate, especially in patients with hepatic or renal impairment, leading to prolonged sedation. * **Lorazepam (B):** While used for long-term sedation, it carries a risk of **Propylene Glycol toxicity** when given in high-dose infusions and is associated with a higher incidence of ICU delirium compared to Propofol or Dexmedetomidine. * **Alprazolam (D):** This is primarily an oral anxiolytic and is not used for titratable intravenous sedation in a critical care setting. **NEET-PG High-Yield Pearls:** * **Propofol Infusion Syndrome (PRIS):** A rare but fatal complication of prolonged high-dose infusion (>4mg/kg/hr). Features include metabolic acidosis, rhabdomyolysis, hyperkalemia, and cardiac failure. * **Dexmedetomidine:** An $\alpha_2$-agonist often used as an alternative; it provides "conscious sedation" without respiratory depression. * **Caloric Value:** Propofol is formulated in a 10% lipid emulsion, providing **1.1 kcal/ml**, which must be accounted for in the patient’s nutritional plan.

Q: A patient is in ICU and there is a failed attempt of subclavian catheterization. Shortly after, BP drops and the pulse rises. What is the diagnosis?

Pneumothorax. ***Pneumothorax*** - A failed attempt at **subclavian vein catheterization** carries a high risk of puncturing the **parietal pleura** (due to the proximity of the apex of the lung), leading to a pneumothorax. - The sudden drop in **blood pressure (hypotension)** and rise in **pulse (tachycardia)** indicate acute hemodynamic compromise, often resulting from a **tension pneumothorax** which impedes venous return to the heart. - This is the **most common mechanical complication** of subclavian catheterization. *Displacement of endotracheal tube (ET)* - Displacement means the tube moves from the correct **tracheal position** (e.g., into the esophagus or mainstem bronchus), leading to acute ventilation failure and hypoxia. - While displacement causes hemodynamic instability, it is a complication of **ventilator management or patient movement**, not directly related to a preceding failed attempt at a **central venous line insertion**. *Air embolism* - An air embolism occurs when air enters the venous circulation, usually when the central line tract or needle hub is open to the atmosphere (e.g., during line insertion or removal) and the patient takes a deep breath. - Although it can cause cardiovascular collapse, the presenting feature following a needle stick is classically **pneumothorax**, unless the catheter was successfully placed and air was entrained through the line. - Classic sign: **mill-wheel murmur** on auscultation. *Hemothorax* - Hemothorax results from **vascular injury** (subclavian artery or vein) during catheterization attempts, causing blood accumulation in the pleural space. - While it can occur with subclavian catheterization, it typically presents with **more gradual hemodynamic changes** and signs of blood loss (falling hematocrit), rather than the acute decompensation seen with tension pneumothorax. - Chest X-ray would show pleural fluid rather than air.

Q: According to the American Heart Association (AHA), what is the 6th link added to the chain of survival?

Recovery and rehabilitation. ***Recovery and rehabilitation*** - The American Heart Association (**AHA**) added this as the **6th link** to the chain of survival to emphasize the importance of post-event care for cardiac arrest survivors. - This link focuses on the long-term health outcomes, addressing physical, cognitive, and emotional needs to improve the survivor's **quality of life**. *Rapid defibrillation* - This is the **fourth link** in the chain of survival, often grouped with Advanced Life Support (ALS). - It is a critical intervention for shockable rhythms like **ventricular fibrillation (VF)** and **pulseless ventricular tachycardia (VT)**, but it precedes post-cardiac arrest care and recovery. *High-quality CPR* - This is the **third link** in the chain of survival, immediately following activation of the emergency response system. - Its purpose is to maintain vital organ perfusion until defibrillation or the return of spontaneous circulation is achieved. *Advanced airway management* - This is a component of **Advanced Life Support (ALS)**, which is part of the fourth link in the chain. - While crucial during the resuscitation effort, it is an acute intervention and not the distinct final step focused on long-term patient recovery.

Q: Patient in hospital was given IVF and patient develops hyperchloremic metabolic acidosis. Which fluid will cause this?

NS. ***NS*** - **Normal Saline (0.9% NaCl)** contains a **chloride concentration of 154 mEq/L**, which is unphysiologically high (supranormal) compared to plasma (approx. 100 mEq/L). - Rapid infusion leads to the retention of excess chloride and dilution of serum bicarbonate, resulting in a **non-anion gap (hyperchloremic) metabolic acidosis**. *RL* - Ringer's Lactate (RL) is a **buffered solution** because it contains **lactate (28 mEq/L)**, which is metabolized by the liver into bicarbonate. - Because of the bicarbonate precursor (lactate) and a near-physiologic chloride concentration (109 mEq/L), RL tends to **prevent or correct** acidosis, rather than causing it. *DNS* - Dextrose Normal Saline (DNS) still contains the **supranormal chloride concentration** (154 mEq/L) from the normal saline component, posing a similar theoretical risk. - However, it is typically less associated with severe acidosis than pure NS in large volumes, and often the primary differentiating fluid in this context is the **buffered RL**. *5 % dextrose* - **5% Dextrose in Water (D5W)** contains no electrolytes (salt) and is only used to provide free water and small amounts of calories. - Rapid infusion of D5W results in dilution and can cause **hyponatremia** and free water excess, but it cannot precipitate hyperchloremic acidosis.

Q: Which of the following is the correct technique of giving CPR?

. ***Image A*** - This image illustrates the correct body positioning for effective chest compressions during CPR. The rescuer is kneeling beside the patient with straight arms, positioning their shoulders directly over their hands to leverage their body weight for **deeper compressions**. - The hands are placed correctly on the center of the chest, specifically the lower half of the **sternum**, ensuring the force is applied to the appropriate area for maximum cardiac output. *Image B* - This image shows the correct hand placement for chest compressions: one hand over the other, interlocked fingers, with the heel of the bottom hand on the center of the chest. This technique helps to **stabilize the hands** and deliver effective compressions. - However, it does not depict the full-body posture required for proper compression depth and efficiency. *Image C* - This image shows the rescuer with bent elbows and an incorrect body posture, indicating that they are not using their body weight effectively. This would result in **shallow and ineffective chest compressions**, which are not sufficient to maintain blood circulation. - The rescuer's arms should be straight, and their shoulders should be directly over their hands to maximize the force of compressions. *Image D* - This image depicts the anatomy of the upper airway and carotid arteries, likely demonstrating the **head tilt-chin lift maneuver** for opening the airway or checking for a pulse. - While critical for CPR, it is a component of airway management and pulse assessment, not the technique for chest compressions.

Q: A comatose patient after sustaining severe head injury has been admitted to the neurosurgical ICU. Which of the following parameters should ideally be maintained in this patient? 1. pCO2 = 4.5 - 5.0 kPa (33-38 mm Hg) 2. MAP = 80 - 90 mm of Hg 3. pO2 > 11 kPa (> 80 mm Hg) 4. Na+ < 130 meq/L

1, 2 and 3. ***1, 2 and 3*** - Maintaining **pCO2 between 4.5-5.0 kPa (33-38 mmHg)** helps optimize cerebral blood flow; values outside this range can cause vasoconstriction or vasodilation, affecting intracranial pressure (ICP). - A **mean arterial pressure (MAP) of 80-90 mmHg** ensures adequate cerebral perfusion pressure (CPP) and minimizes the risk of secondary brain injury from ischemia. - An **arterial partial pressure of oxygen (pO2) above 11 kPa (>80 mmHg)** is crucial to prevent cerebral hypoxia, which can exacerbate brain damage in severely injured patients. *2, 3 and 4* - This option correctly identifies the importance of maintaining adequate MAP and pO2 but incorrectly suggests a low sodium level. - A low **serum sodium (Na+) below 130 mEq/L (hyponatremia)** should be avoided in severe head injury as it can worsen cerebral edema and increase ICP. *1, 2 and 4* - While maintaining pCO2 and MAP within target ranges is essential, a **sodium level below 130 mEq/L (hyponatremia)** is detrimental and not an ideal parameter to maintain. - Hyponatremia can lead to further **brain swelling** and increased intracranial pressure. *1, 3 and 4* - This combination correctly identifies ideal pCO2 and pO2 targets but incorrectly includes **hyponatremia (Na+ < 130 mEq/L)** as a desirable parameter. - Severe hyponatremia can cause significant neurological complications including **seizures** and worsening cerebral edema.

Q: Patient of pneumonia on ventilator with wt. 50 kg. RR 14/min, bicarbonate - 18, pH 7.3, pCO2 48 mmHg, pO2 110 mmHg, PEEP 12 cm H2O, tidal volume 420 mL, SpO2 - 100% with FiO2 90%. What is next step in management?

Decrease fio2. **Decrease FiO2** - The patient has an **SpO2 of 100% with a FiO2 of 90%**, indicating **hyperoxia** induced by excessive oxygen delivery. - Decreasing FiO2 is the appropriate next step to prevent **oxygen toxicity** (e.g., absorption atelectasis, free radical damage) while maintaining adequate oxygenation. *Increase PEEP* - The patient's **PaO2 of 110 mmHg** is already well within the normal to high range, suggesting that oxygenation is adequate. - Increasing PEEP would be considered if the patient had **refractory hypoxemia**, not hyperoxia. *Increase tidal volume* - The current tidal volume of **420 mL for a 50 kg patient (8.4 mL/kg)** is already at the higher end of lung-protective ventilation (typically 6-8 mL/kg). - Increasing tidal volume further could lead to **ventilator-induced lung injury** (VILI) due to volutrauma, especially in a patient with pneumonia. *Decrease RR* - The patient has a **pCO2 of 48 mmHg** and a **pH of 7.3**, indicating **respiratory acidosis** (hypoventilation). - Decreasing the respiratory rate would further exacerbate the acidosis by reducing minute ventilation and increasing pCO2, which is inappropriate.

Question 1

In CPR, where are chest compressions performed?

Accepted Answer

On the middle of the lower part of the sternum

Answer

On the upper part of the sternum

Answer

On the xiphoid process

Answer

On the left side of the chest

Question 2

A 74-year-old man with a history of myocardial infarction 3 years prior underwent elective repair of an abdominal aortic aneurysm. On the first postoperative day in the ICU, he is hypotensive and receiving dobutamine. What is the best method of physiologic monitoring necessary for this patient?

Accepted Answer

Pulmonary artery catheterization

Answer

Central venous catheterization

Answer

Blood-gas monitoring

Answer

Intracranial pressure monitoring

Question 3

What is the drug of choice for sedation of a patient in the ICU?

Accepted Answer

Propofol

Answer

Diazepam

Answer

Lorazepam

Answer

Alprazolam

Question 4

A patient is in ICU and there is a failed attempt of subclavian catheterization. Shortly after, BP drops and the pulse rises. What is the diagnosis?

Accepted Answer

Pneumothorax

Answer

Air embolism

Answer

Displacement of endotracheal tube (ET)

Answer

Hemothorax

Question 5

According to the American Heart Association (AHA), what is the 6th link added to the chain of survival?

Accepted Answer

Recovery and rehabilitation

Answer

Advanced airway management

Answer

High-quality CPR

Answer

Rapid defibrillation

Question 6

Patient in hospital was given IVF and patient develops hyperchloremic metabolic acidosis. Which fluid will cause this?

Accepted Answer

NS

Answer

RL

Answer

5 % dextrose

Answer

DNS

Question 7

A 65-year-old patient is on mechanical ventilation for acute respiratory distress syndrome (ARDS). Suddenly, the patient becomes hypotensive, tachycardic, and shows absent breath sounds on the left side with tracheal deviation to the right. What is the most common cause of this in patients receiving mechanical ventilation?

Accepted Answer

Barotrauma due to high airway pressure

Answer

Endotracheal tube malposition

Answer

Oxygen toxicity

Answer

High tidal volume

Question 8

Which of the following is the correct technique of giving CPR?

Accepted Answer

Question 9

A comatose patient after sustaining severe head injury has been admitted to the neurosurgical ICU. Which of the following parameters should ideally be maintained in this patient?

1. pCO2 = 4.5 - 5.0 kPa (33-38 mm Hg)

2. MAP = 80 - 90 mm of Hg

3. pO2 > 11 kPa (> 80 mm Hg)

4. Na+ < 130 meq/L

Accepted Answer

1, 2 and 3

Answer

2, 3 and 4

Answer

1, 2 and 4

Answer

1, 3 and 4

Question 10

Patient of pneumonia on ventilator with wt. 50 kg. RR 14/min, bicarbonate - 18, pH 7.3, pCO2 48 mmHg, pO2 110 mmHg, PEEP 12 cm H2O, tidal volume 420 mL, SpO2 - 100% with FiO2 90%. What is next step in management?

Accepted Answer

Decrease fio2

Answer

Increase PEEP

Answer

Increase tidal volume

Answer

Decrease RR

Critical Care Medicine — MCQs

Critical Care Medicine — MCQs

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