ABA Emergency Response Procedures 3 — Questions and Answers
Question 1: During cardiopulmonary bypass weaning, the patient develops ventricular fibrillation. After three defibrillation attempts fail, which pharmacologic agent should be given next?
- Lidocaine 1.5 mg/kg IV
- Amiodarone 300 mg IV bolus (Correct answer)
- Magnesium sulfate 1–2 g IV
- Procainamide 17 mg/kg IV
Correct answer: Amiodarone 300 mg IV bolus
Amiodarone 300 mg IV is the preferred antiarrhythmic after failed defibrillation in shock-refractory ventricular fibrillation per ACLS guidelines.
Question 2: A patient develops sudden bronchospasm during general anesthesia. The anesthesiologist increases the inhaled volatile agent, but airway pressures remain above 50 cmH2O. What is the next best intervention?
- Administer ketamine 1–2 mg/kg IV
- Administer epinephrine 0.1–0.3 mg IV or IM (Correct answer)
- Switch to TIVA with propofol infusion
- Administer dexamethasone 8 mg IV
Correct answer: Administer epinephrine 0.1–0.3 mg IV or IM
Epinephrine is the definitive rescue agent for severe bronchospasm unresponsive to volatiles and beta-agonists, acting on β2 receptors to relieve bronchoconstriction.
Question 3: A term parturient receiving epidural labor analgesia suddenly seizes and becomes unresponsive with a BP of 50/30. The most likely diagnosis is:
- Eclampsia
- Local anesthetic systemic toxicity (LAST) (Correct answer)
- Anaphylaxis to epidural opioid
- Vasovagal syncope
Correct answer: Local anesthetic systemic toxicity (LAST)
Sudden cardiovascular collapse with seizure immediately following epidural bolus is classic for LAST due to intravascular injection of local anesthetic.
Question 4: The treatment for local anesthetic systemic toxicity (LAST) with cardiac arrest includes which unique pharmacologic agent?
- Sodium bicarbonate 1 mEq/kg IV
- 20% Intralipid 1.5 mL/kg IV bolus (Correct answer)
- Calcium gluconate 1 g IV
- Magnesium sulfate 2 g IV
Correct answer: 20% Intralipid 1.5 mL/kg IV bolus
20% lipid emulsion therapy (Intralipid 1.5 mL/kg bolus followed by infusion) is the definitive treatment specific to LAST with cardiovascular collapse.
Question 5: Intraoperatively, a patient on isoflurane develops masseter rigidity, rising ETCO2 of 92 mmHg, and a temperature of 39.8°C. After stopping the triggering agent, which drug is administered first?
- Dantrolene 2.5 mg/kg IV (Correct answer)
- Succinylcholine 1.5 mg/kg IV
- Propofol 2 mg/kg IV
- Sodium bicarbonate 2 mEq/kg IV
Correct answer: Dantrolene 2.5 mg/kg IV
Dantrolene 2.5 mg/kg IV is the specific antidote for malignant hyperthermia and should be administered immediately after stopping triggering agents.
Question 6: During an orthopedic procedure with a tourniquet, the patient develops tachycardia, hypotension, and petechiae on the chest and axillae. SpO2 drops to 90%. The most likely cause is:
- Pulmonary embolism from deep vein thrombosis
- Fat embolism syndrome (Correct answer)
- Anaphylaxis to cement
- Tension pneumothorax
Correct answer: Fat embolism syndrome
The classic triad of hypoxemia, neurologic changes, and petechiae (especially axillary) following long bone manipulation is pathognomonic for fat embolism syndrome.
Question 7: A patient develops stridor and hives 10 minutes after receiving rocuronium induction. BP is 65/40, HR 130. The initial dose of epinephrine for anaphylaxis in an adult is:
- 0.5 mg (1:10,000) IV
- 0.3 mg (1:1,000) IM into lateral thigh
- 1 mg (1:10,000) IV push
- 0.1 mg (1:10,000) IV titratable (Correct answer)
Correct answer: 0.1 mg (1:10,000) IV titratable
In perioperative anaphylaxis with IV access, epinephrine 0.1 mg (1:10,000) IV titrated in boluses is preferred over IM dosing due to reliable absorption.
ABA Emergency Response Procedures 3
During cardiopulmonary bypass weaning, the patient develops ventricular fibrillation.
After three defibrillation attempts fail, which pharmacologic agent should be given next?