DAANCE Managing Systemic Diseases 5 — Questions and Answers
Question 1: A patient with severe COPD (FEV1 <35% predicted) presents for sedation. Which supplemental oxygen approach is most appropriate?
- High-flow oxygen at 10 L/min via non-rebreather mask
- Titrated low-flow oxygen at 1–2 L/min via nasal cannula (Correct answer)
- No supplemental oxygen to avoid hypoxic drive suppression
- 100% oxygen via bag-valve mask throughout the procedure
Correct answer: Titrated low-flow oxygen at 1–2 L/min via nasal cannula
Low-flow titrated oxygen (1–2 L/min) maintains adequate SpO2 while minimizing the risk of suppressing the hypoxic ventilatory drive in severe COPD patients.
Question 2: Which electrolyte abnormality most commonly associated with chronic diuretic use can predispose a sedated patient to cardiac dysrhythmias?
- Hypernatremia
- Hypokalemia (Correct answer)
- Hyperphosphatemia
- Hypercalcemia
Correct answer: Hypokalemia
Hypokalemia from chronic diuretic use increases cardiac membrane excitability, predisposing patients to ventricular dysrhythmias during sedation.
Question 3: A patient with Addison's disease is undergoing moderate sedation for a lengthy dental procedure. What supplemental management is required?
- Pre-procedure insulin dose adjustment
- Stress-dose corticosteroid supplementation (Correct answer)
- Prophylactic antibiotic coverage
- Sodium restriction before the procedure
Correct answer: Stress-dose corticosteroid supplementation
Patients with adrenal insufficiency cannot mount a cortisol stress response and require supplemental corticosteroids to prevent an adrenal crisis during stressful procedures.
Question 4: A patient with obstructive sleep apnea (OSA) is sedated with benzodiazepines. What is the PRIMARY concern unique to this population?
- Increased risk of malignant hyperthermia
- Exaggerated upper airway collapse and apnea (Correct answer)
- Paradoxical hypertension
- Prolonged QT interval
Correct answer: Exaggerated upper airway collapse and apnea
OSA patients have anatomically and physiologically compromised upper airways; benzodiazepine-induced muscle relaxation significantly worsens upper airway obstruction and apnea.
Question 5: In a patient with cirrhotic liver disease, which pharmacokinetic change is most clinically significant when dosing sedatives?
- Increased renal clearance of sedatives
- Decreased hepatic first-pass metabolism causing elevated drug levels (Correct answer)
- Enhanced protein binding reducing free drug fraction
- Accelerated glucuronidation of benzodiazepines
Correct answer: Decreased hepatic first-pass metabolism causing elevated drug levels
Cirrhosis significantly reduces hepatic metabolic capacity and decreases plasma proteins, leading to elevated free drug levels and prolonged sedative effects.
Question 6: Which finding in a patient with congestive heart failure (CHF) is a contraindication to elective sedation without medical clearance?
- Bilateral ankle edema controlled on diuretics
- New onset orthopnea and a recent weight gain of 10 lbs (Correct answer)
- Mild exertional dyspnea at 2 METs
- Resting heart rate of 78 bpm on beta-blockers
Correct answer: New onset orthopnea and a recent weight gain of 10 lbs
New orthopnea and rapid weight gain indicate acute decompensated CHF, which is a contraindication to elective sedation until medically stabilized.
Question 7: A hyperthyroid patient not yet rendered euthyroid presents for emergency dental sedation. Which anesthetic complication is most feared?
- Hypothermia and bradycardia
- Thyroid storm triggered by catecholamine release (Correct answer)
- Hyperkalemia from muscle breakdown
- Prolonged neuromuscular blockade
Correct answer: Thyroid storm triggered by catecholamine release
Surgical stress and catecholamine release in an uncontrolled hyperthyroid patient can precipitate thyroid storm, a life-threatening hypermetabolic crisis.
DAANCE Managing Systemic Diseases 5
A patient with severe COPD (FEV1 <35% predicted) presents for sedation.
Which supplemental oxygen approach is most appropriate?