Critical Care Medicine Practice Questions

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 NOT considered as an indicator of adequate fluid resuscitation?

Respiratory rate. ***Respiratory rate*** - While an *elevated respiratory rate* can indicate *hypovolemia* or other systemic stress, it is a **less specific** and less direct indicator of the adequacy of *fluid resuscitation* compared to *perfusion parameters*. - Changes in *respiratory rate* can be influenced by many factors such as *pain*, *anxiety*, *metabolic acidosis*, and primary *pulmonary issues*, making it less reliable for guiding *fluid therapy*. *Pulse* - A *decreasing pulse rate* and *improving pulse quality* (becoming stronger and less thready) are good indicators of **improved cardiac output** and *volume status* during *fluid resuscitation*. - A *persistently high* or *weak pulse* suggests ongoing *hypovolemia* or inadequate *fluid replacement*. *Urine output* - *Adequate urine output* (typically >0.5 mL/kg/hr in adults) is a critical indicator of **sufficient renal perfusion** and overall *systemic hydration*. - A *rising urine output* after *fluid administration* signifies that organs are receiving adequate blood flow and *fluid balance* is improving. *Blood pressure* - An *increasing blood pressure*, particularly improvement in *mean arterial pressure*, directly reflects **better systemic perfusion** and resolution of *hypotension* caused by *hypovolemia*. - Normalization of *blood pressure* indicates that the *circulatory volume* is adequate to maintain vital organ function.

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.

Q: Which of the following statements given below is incorrect regarding CPR?

Ventilation 22-25/ min. ***Ventilation 22-25/ min*** - A ventilation rate of 22-25 breaths/min is **too high** for CPR, which typically recommends 10-12 breaths/min, corresponding to 2 breaths after every 30 compressions. - Excessive ventilation can lead to **hyperventilation**, increasing intrathoracic pressure and reducing venous return, thus decreasing cardiac output. *Chest compression rate 100-120/min* - The recommended chest compression rate for adults in CPR is **100-120 compressions per minute**, ensuring adequate blood flow to vital organs. - Maintaining this rate is crucial for maximizing the effectiveness of chest compressions by providing sufficient circulation. *Depth of chest compression up to 5-6 cm* - The recommended depth for adult chest compressions is at least 5 cm (2 inches), but no more than **6 cm (2.4 inches)** to prevent injury. - This depth ensures that enough pressure is exerted to circulate blood effectively without causing excessive trauma. *Allow adequate chest recoil* - Complete chest recoil is essential to allow the heart to **fully refill with blood** between compressions. - Leaning on the chest between compressions prevents adequate recoil, which can reduce pulmonary and coronary perfusion and **decrease the effectiveness of CPR**.

Q: In CPR, number of chest compressions per minute in an adult:

100-120 per minute. ***100-120 per minute*** - The **American Heart Association (AHA)** and other international resuscitation guidelines recommend a compression rate of **100 to 120 beats per minute** for adults. - This rate ensures adequate blood flow to vital organs while minimizing rescuer fatigue. *30-50 per minute* - This rate is **too low** and would be ineffective in maintaining adequate cerebral and coronary perfusion during cardiac arrest. - Insufficient compressions per minute significantly **reduce the chances of survival** and positive neurological outcomes. *50-72 per minute* - While better than 30-50, this rate is still **below the recommended range** for effective CPR in adults. - It would likely result in **inadequate blood flow** to the brain and heart, diminishing the effectiveness of resuscitation. *120-200 per minute* - While aiming for higher compression rates might seem beneficial, rates **above 120 per minute** can be counterproductive. - Excessively fast compressions can **reduce chest recoil** and ventricular filling time, actually decreasing cardiac output and perfusion.

Q: A patient in shock requires rapid fluid resuscitation. If intravenous (IV) cannulation is not possible, within what time frame should an intraosseous (IO) line be placed?

1.5 minutes. ***1.5 minutes*** - The goal for intraosseous (IO) line placement in a patient in shock when IV access is difficult is within **90 seconds** (1.5 minutes) to ensure rapid fluid resuscitation and drug delivery. - This timeframe is crucial for minimizing the duration of inadequate perfusion and improving patient outcomes in critical situations. *2.5 minutes* - This timeframe is generally considered too long for establishing emergency vascular access in a patient in shock. - Delays beyond **90 seconds** can lead to significant morbidity and mortality due to prolonged hypoperfusion. *1 minute* - While a faster placement time is always desirable, **1 minute** may be a challenging target to consistently achieve, especially for less experienced operators or in difficult situations. - The established guideline aims for a balance between speed and realistic attainability. *2 minutes* - This timeframe is still longer than the recommended maximum for IO access in shock. - Every additional second of delay can negatively impact the patient's condition, making **2 minutes** less ideal than the recommended 1.5 minutes.

Q: A 55-year-old woman was admitted to the intensive care unit with severe lobar pneumonia and septic shock. She remained hypoxemic despite intubation, a high fraction of inspired oxygen, and positive end-expiratory pressure (PEEP). When PEEP was increased further, she paradoxically became more hypoxemic and her blood pressure and central venous hemoglobin saturation fell. What would be your approach?

Initiate dobutamine and reduce PEEP to 5cm H2O. ***Initiate dobutamine and reduce PEEP to 5cm H2O*** - The patient is experiencing negative hemodynamic effects from **excessive PEEP**, indicated by falling blood pressure and central venous hemoglobin saturation. Reducing PEEP will improve **venous return** and **cardiac output**. - **Dobutamine** is a positive inotrope that will help support cardiac output and improve oxygen delivery to tissues, addressing the shock state. *Increase PEEP further* - Increasing PEEP would worsen the patient's **hemodynamic compromise** by further increasing intrathoracic pressure, reducing venous return, and potentially decreasing cardiac output, leading to more profound shock. *Keep PEEP at the highest and give adrenaline* - Maintaining high PEEP would continue to suppress cardiac output. While **adrenaline** is a potent vasopressor and inotrope, it would be treating the symptoms (hypotension) without addressing the root cause of the hemodynamic instability (excessive PEEP-induced reduced venous return and cardiac output). *Increase FiO2* - The patient is already on a **high fraction of inspired oxygen** and remains hypoxemic, suggesting that the primary problem is not lack of oxygen in the inspired air but rather impaired oxygen delivery due to hemodynamic compromise or significant intrapulmonary shunting. Increasing FiO2 further is unlikely to resolve the issue and may expose the patient to **oxygen toxicity**.

Q: A 22-year-old street vendor was found in the park having a seizure. Cops brought him to ER, unaware of any background medical history. He is continuously having seizures for 13 minutes and paramedics are not able to gain intravenous access. You ensure the airway is secure and administer oxygen, however, you are unable to gain intravenous access after two attempts. Blood glucose levels are 80mg%. Which medication would be most suitable to administer at this stage to treat patient's seizure?

Midazolam. .***Midazolam*** - **Midazolam** is a benzodiazepine that can be given via **intramuscular (IM)**, buccal, or intranasal routes, making it ideal when IV access is difficult or impossible. - Its rapid onset of action and efficacy in acute seizure management, particularly in **status epilepticus**, make it the most appropriate choice in this scenario. *Sodium Valproate* - While an effective anticonvulsant, **sodium valproate** is primarily administered **intravenously** in acute settings, which is not feasible here due to lack of IV access. - It also has a slower onset of action compared to benzodiazepines for immediate seizure cessation. *Lorazepam* - **Lorazepam** is a first-line benzodiazepine for status epilepticus but is typically given **intravenously (IV)**. - Although it can be given IM, its absorption is slower and less predictable than IM midazolam, and the question specifies difficulty in gaining IV access after two attempts. *Levetiracetam* - **Levetiracetam** is an effective anticonvulsant for status epilepticus but is generally administered **intravenously**, requiring reliable IV access. - It works more slowly than benzodiazepines and is often used as a second-line agent or adjunct once immediate seizure control is achieved.

Question 1

According to the Muir-Barclay formula, which of the following is considered the best colloid for volume replacement?

Accepted Answer

Albumin

Answer

Fresh Frozen Plasma (FFP)

Answer

Packed Red Blood Cells (PRBC)

Answer

Dextran 40

Question 2

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 3

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 4

Which of the following is NOT considered as an indicator of adequate fluid resuscitation?

Accepted Answer

Respiratory rate

Answer

Pulse

Answer

Urine output

Answer

Blood pressure

Question 5

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

Question 6

Which of the following statements given below is incorrect regarding CPR?

Accepted Answer

Ventilation 22-25/ min

Answer

Chest compression rate 100-120/min

Answer

Depth of chest compression up to 5-6 cm

Answer

Allow adequate chest recoil

Question 7

In CPR, number of chest compressions per minute in an adult:

Accepted Answer

100-120 per minute

Answer

30-50 per minute

Answer

50-72 per minute

Answer

120-200 per minute

Question 8

A patient in shock requires rapid fluid resuscitation. If intravenous (IV) cannulation is not possible, within what time frame should an intraosseous (IO) line be placed?

Accepted Answer

1.5 minutes

Answer

2.5 minutes

Answer

1 minute

Answer

2 minutes

Question 9

A 55-year-old woman was admitted to the intensive care unit with severe lobar pneumonia and septic shock. She remained hypoxemic despite intubation, a high fraction of inspired oxygen, and positive end-expiratory pressure (PEEP). When PEEP was increased further, she paradoxically became more hypoxemic and her blood pressure and central venous hemoglobin saturation fell. What would be your approach?

Accepted Answer

Initiate dobutamine and reduce PEEP to 5cm H2O

Answer

Increase PEEP further

Answer

Keep PEEP at the highest and give adrenaline

Answer

Increase FiO2

Question 10

A 22-year-old street vendor was found in the park having a seizure. Cops brought him to ER, unaware of any background medical history. He is continuously having seizures for 13 minutes and paramedics are not able to gain intravenous access. You ensure the airway is secure and administer oxygen, however, you are unable to gain intravenous access after two attempts. Blood glucose levels are 80mg%. Which medication would be most suitable to administer at this stage to treat patient's seizure?

Accepted Answer

Midazolam

Answer

Sodium Valproate

Answer

Lorazepam

Answer

Levetiracetam

Critical Care Medicine — MCQs

Critical Care Medicine — MCQs

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