ABA Perioperative Patient Management 2 — Questions and Answers
Question 1: A patient with severe aortic stenosis (valve area 0.6 cm²) requires emergent hip fracture repair. Which hemodynamic goal is MOST important intraoperatively?
- Maintain heart rate 80–100 bpm and avoid hypotension (Correct answer)
- Allow heart rate to rise to increase cardiac output
- Aggressively reduce afterload to improve stroke volume
- Target low filling pressures to prevent pulmonary edema
Correct answer: Maintain heart rate 80–100 bpm and avoid hypotension
Severe AS requires maintaining normal-to-slow heart rate and adequate preload/afterload to preserve coronary perfusion pressure across the fixed obstruction.
Question 2: Which of the following best describes the anesthetic consideration for a patient on chronic clonidine therapy undergoing major surgery?
- Continue clonidine perioperatively to prevent rebound hypertension (Correct answer)
- Discontinue clonidine 5 days preoperatively to avoid intraoperative bradycardia
- Switch to a beta-blocker the morning of surgery
- Administer an alpha-2 antagonist if bradycardia occurs intraoperatively
Correct answer: Continue clonidine perioperatively to prevent rebound hypertension
Abrupt clonidine withdrawal can cause severe rebound hypertension; it should be continued perioperatively or a patch applied if oral intake is not possible.
Question 3: During a laparoscopic cholecystectomy, end-tidal CO₂ rises from 38 to 58 mmHg over 20 minutes despite unchanged ventilator settings. The MOST likely cause is:
- Subcutaneous CO₂ absorption from insufflation (Correct answer)
- Endobronchial intubation
- Malignant hyperthermia
- Pulmonary embolism
Correct answer: Subcutaneous CO₂ absorption from insufflation
Peritoneal CO₂ insufflation is rapidly absorbed, and subcutaneous emphysema further increases systemic CO₂ load, raising ETCO₂.
Question 4: A 72-year-old patient undergoing radical prostatectomy develops oliguria (15 mL/hr) despite 2L of crystalloid. CVP is 12 mmHg. The next best step is:
- Assess cardiac output and systemic vascular resistance (Correct answer)
- Administer a fluid bolus of 500 mL NS
- Give furosemide 20 mg IV
- Increase vasopressor infusion
Correct answer: Assess cardiac output and systemic vascular resistance
With adequate filling pressure but persistent oliguria, functional hemodynamic monitoring is needed to distinguish low output from high SVR states before further therapy.
Question 5: Which neuromuscular monitoring pattern indicates adequate reversal with neostigmine before extubation?
- Train-of-four ratio ≥ 0.9 by acceleromyography (Correct answer)
- Absence of fade on double-burst stimulation
- Four equal twitches on TOF by qualitative assessment
- Sustained tetanus at 50 Hz for 5 seconds
Correct answer: Train-of-four ratio ≥ 0.9 by acceleromyography
A quantitative TOF ratio ≥ 0.9 measured by acceleromyography is the accepted threshold for adequate neuromuscular recovery before extubation.
Question 6: A patient with known latex allergy is scheduled for elective surgery. Which material in the operating room is MOST likely to trigger a reaction?
- Standard rubber surgical gloves (Correct answer)
- Polyvinyl chloride (PVC) IV tubing
- Silicone LMA cuff
- Nylon suture
Correct answer: Standard rubber surgical gloves
Natural rubber latex gloves are the highest-risk item; latex-free gloves, IV tubing, and a latex-safe environment must be confirmed before the patient enters the OR.
Question 7: During a thoracotomy with one-lung ventilation, SpO₂ drops to 88%. Which maneuver should be attempted FIRST?
- Apply CPAP (5–10 cmH₂O) to the non-dependent (operative) lung
- Switch to two-lung ventilation immediately
- Increase FiO₂ to 1.0 on the dependent lung (Correct answer)
- Clamp the pulmonary artery on the operative side
Correct answer: Increase FiO₂ to 1.0 on the dependent lung
Increasing FiO₂ to 1.0 on the ventilated dependent lung is the first step before adding CPAP to the operative lung or other maneuvers.
ABA Perioperative Patient Management 2
A patient with severe aortic stenosis (valve area 0.6 cm²) requires emergent hip fracture repair.
Which hemodynamic goal is MOST important intraoperatively?