EDAIC - European Diploma in Anesthesiology and Intensive Care Respiratory and Thoracic Anesthesia Questions and Answers — Questions and Answers
Question 1: Which of the following anesthetic agents is known to most significantly inhibit hypoxic pulmonary vasoconstriction (HPV), potentially worsening oxygenation during one-lung ventilation?
- Desflurane
- Propofol
- Nitroglycerin (Correct answer)
- Fentanyl
Correct answer: Nitroglycerin
Nitroglycerin, a potent vasodilator and nitric oxide donor, is a significant inhibitor of hypoxic pulmonary vasoconstriction (HPV). By attenuating the HPV response in the non-ventilated lung, it can increase intrapulmonary shunt and worsen hypoxemia during one-lung ventilation. While volatile anesthetics like desflurane can also inhibit HPV, this effect is dose-dependent and generally less profound than that of direct vasodilators. Propofol and opioids such as fentanyl have minimal to no clinically significant effect on HPV.
Question 2: A 68-year-old male with a history of COPD is scheduled for a right upper lobectomy for a lung mass. His preoperative FEV1 is 1.6 L (55% predicted). A quantitative V/Q scan shows the right upper lobe contributes 20% to total lung function. What is the best estimate of his predicted postoperative FEV1 (ppoFEV1)?
- 1.44 L
- 1.28 L (Correct answer)
- 0.88 L
- 1.06 L
Correct answer: 1.28 L
The predicted postoperative FEV1 (ppoFEV1) is calculated by the formula: ppoFEV1 = Preoperative FEV1 × (1 − fraction of functional lung tissue to be removed). In this case, the V/Q scan indicates the lobe to be resected contributes 20% (0.20) of function. Therefore, ppoFEV1 = 1.6 L × (1 - 0.20) = 1.6 L × 0.8 = 1.28 L. This calculation is crucial for assessing postoperative risk.
Question 3: Which of the following is considered the most serious, albeit infrequent, major complication associated with mediastinoscopy?
- Pneumothorax
- Recurrent laryngeal nerve injury
- Major hemorrhage (Correct answer)
- Tracheal compression
Correct answer: Major hemorrhage
While all the options are known complications of mediastinoscopy, major hemorrhage is the most serious and potentially fatal. It can occur from injury to the great vessels, such as the innominate artery, superior vena cava, or pulmonary artery, and may require immediate sternotomy for control. Although its incidence is low (around 0.4%), its severity makes it the most feared major complication.
Question 4: During a left thoracotomy with one-lung ventilation (OLV), a patient's SpO2 drops to 85% despite an FiO2 of 1.0. The double-lumen tube's position has just been confirmed as correct with a fiberoptic bronchoscope. According to standard management algorithms, what is the most appropriate next step?
- Apply Continuous Positive Airway Pressure (CPAP) to the non-dependent lung.
- Briefly re-inflate the non-dependent lung.
- Increase the tidal volume to the dependent lung.
- Apply Positive End-Expiratory Pressure (PEEP) to the dependent (ventilated) lung. (Correct answer)
Correct answer: Apply Positive End-Expiratory Pressure (PEEP) to the dependent (ventilated) lung.
After confirming correct tube placement and ensuring an FiO2 of 1.0, the next step in managing hypoxemia during OLV is to optimize the ventilation of the dependent lung. Applying PEEP (e.g., 5-10 cmH2O) to the dependent lung can help recruit atelectatic alveoli, improve its functional residual capacity, and enhance V/Q matching. Applying CPAP to the non-dependent lung is a subsequent step if PEEP is not effective. Increasing tidal volume is generally avoided due to the risk of ventilator-induced lung injury.
Question 5: For postoperative pain management following a posterolateral thoracotomy, which regional anesthesia technique is considered to provide analgesia of similar efficacy to a thoracic epidural but with a more favorable side-effect profile?
- Intercostal nerve block
- Serratus anterior plane block
- Paravertebral block (Correct answer)
- Erector spinae plane block
Correct answer: Paravertebral block
The thoracic paravertebral block (TPVB) is considered a first-line regional technique for thoracotomy pain. It provides dense unilateral somatic and sympathetic blockade, effectively covering both incisional and visceral pain. Multiple studies and meta-analyses have shown TPVB to have analgesic efficacy comparable to thoracic epidural analgesia (TEA) but with fewer side effects, such as hypotension, urinary retention, and bilateral motor blockade.
Question 6: Which of the following is a primary anesthetic goal during induction for a patient with a large, high-flow bronchopleural fistula (BPF) requiring surgical repair?
- Administer a high-dose opioid bolus to blunt the stress response.
- Maximize positive pressure ventilation to ensure oxygenation.
- Place the patient in the Trendelenburg position to improve pre-oxygenation.
- Maintain spontaneous ventilation until the affected lung is isolated. (Correct answer)
Correct answer: Maintain spontaneous ventilation until the affected lung is isolated.
The primary anesthetic goal during induction for a BPF is to avoid positive pressure ventilation (PPV) before the airway is secured and the affected lung is isolated. PPV can force gas through the fistula, leading to a tension pneumothorax if a chest drain is not functioning, and can soil the contralateral 'good' lung with pleural fluid or pus. Therefore, maintaining spontaneous ventilation until a double-lumen tube or bronchial blocker is correctly placed is a critical safety measure.
EDAIC - European Diploma in Anesthesiology and Intensive Care Respiratory and Thoracic Anesthesia Questions and Answers
Which of the following anesthetic agents is known to most significantly inhibit hypoxic pulmonary vasoconstriction (HPV), potentially worsening oxygenation during one-lung ventilation?