ABA Critical Care & Pain Medicine 2 — Questions and Answers
Question 1: A patient in the ICU develops acute respiratory distress syndrome (ARDS). Which ventilator strategy has been shown to reduce mortality?
- High tidal volume ventilation at 10-12 mL/kg IBW
- Low tidal volume ventilation at 6 mL/kg IBW with plateau pressure <30 cmH2O (Correct answer)
- Pressure-controlled ventilation with high PEEP >20 cmH2O
- High-frequency oscillatory ventilation as first-line therapy
Correct answer: Low tidal volume ventilation at 6 mL/kg IBW with plateau pressure <30 cmH2O
The ARDSNet trial demonstrated that lung-protective ventilation with 6 mL/kg IBW and plateau pressure <30 cmH2O significantly reduces mortality in ARDS.
Question 2: Which opioid is preferred for continuous infusion in critically ill patients with renal failure due to its lack of active metabolite accumulation?
- Morphine
- Hydromorphone
- Fentanyl (Correct answer)
- Meperidine
Correct answer: Fentanyl
Fentanyl is preferred in renal failure because it has no clinically significant active metabolites that accumulate, unlike morphine (morphine-6-glucuronide) or meperidine (normeperidine).
Question 3: In the management of septic shock, what is the recommended initial fluid resuscitation volume within the first 3 hours according to Surviving Sepsis Campaign guidelines?
- 10 mL/kg IV crystalloid
- 20 mL/kg IV crystalloid
- 30 mL/kg IV crystalloid (Correct answer)
- 40 mL/kg IV crystalloid
Correct answer: 30 mL/kg IV crystalloid
The Surviving Sepsis Campaign recommends at least 30 mL/kg of intravenous crystalloid within the first 3 hours of sepsis-induced hypoperfusion.
Question 4: A patient on chronic opioid therapy presents with hyperalgesia (increased sensitivity to pain with lower opioid doses). The BEST initial management strategy is:
- Increase the opioid dose to overcome tolerance
- Add a benzodiazepine for adjunct analgesia
- Rotate to a different opioid at a reduced equianalgesic dose
- Add an NMDA receptor antagonist and consider opioid rotation (Correct answer)
Correct answer: Add an NMDA receptor antagonist and consider opioid rotation
Opioid-induced hyperalgesia is best managed by opioid rotation with dose reduction combined with NMDA antagonists (e.g., ketamine) to address central sensitization.
Question 5: Which of the following is the MOST reliable indicator of adequate fluid resuscitation in a mechanically ventilated patient with septic shock?
- Central venous pressure (CVP) of 8-12 mmHg
- Urine output >0.5 mL/kg/hr
- Pulse pressure variation (PPV) <13% after fluid challenge (Correct answer)
- Mean arterial pressure >65 mmHg
Correct answer: Pulse pressure variation (PPV) <13% after fluid challenge
Pulse pressure variation <13% during mechanical ventilation reliably predicts fluid responsiveness and indicates adequate preload, whereas CVP is poorly predictive.
Question 6: A patient with complex regional pain syndrome (CRPS) type I fails to respond to NSAIDs and physical therapy. Which intervention has the STRONGEST evidence as a next step?
- Surgical sympathectomy
- Spinal cord stimulation (Correct answer)
- Long-term high-dose opioids
- Oral corticosteroids as sole therapy
Correct answer: Spinal cord stimulation
Spinal cord stimulation has the strongest level of evidence for refractory CRPS type I, demonstrating significant pain reduction and improved function in randomized controlled trials.
Question 7: During prone positioning for ARDS, which complication requires immediate return to supine position?
- Transient decrease in SpO2 during the turn
- Endotracheal tube displacement or obstruction (Correct answer)
- Mild facial edema after 4 hours of prone ventilation
- Increase in peak airway pressure by 5 cmH2O
Correct answer: Endotracheal tube displacement or obstruction
Endotracheal tube displacement or obstruction during prone positioning is a life-threatening emergency requiring immediate return to supine position to secure the airway.
ABA Critical Care & Pain Medicine 2
A patient in the ICU develops acute respiratory distress syndrome (ARDS).
Which ventilator strategy has been shown to reduce mortality?