CRNFA Anesthesia and Patient Safety in the OR 1 — Questions and Answers
Question 1: Which volatile anesthetic agent is most strongly associated with triggering malignant hyperthermia in susceptible patients?
- Propofol
- Succinylcholine and all volatile halogenated agents (e.g., sevoflurane, desflurane) (Correct answer)
- Nitrous oxide
- Ketamine
Correct answer: Succinylcholine and all volatile halogenated agents (e.g., sevoflurane, desflurane)
Malignant hyperthermia is triggered by succinylcholine and all halogenated volatile anesthetic agents; nitrous oxide, propofol, and ketamine are safe in MH-susceptible patients.
Question 2: The CRNFA observes sudden masseter muscle rigidity after succinylcholine administration during intubation. This finding should prompt concern for which emergent condition?
- Laryngospasm
- Malignant hyperthermia (Correct answer)
- Anaphylaxis
- Insufficient neuromuscular blockade
Correct answer: Malignant hyperthermia
Masseter muscle rigidity (jaw rigidity) following succinylcholine is an early and classic warning sign of malignant hyperthermia and requires immediate activation of the MH protocol.
Question 3: Dantrolene sodium is the definitive treatment for malignant hyperthermia. What is the initial recommended IV bolus dose?
- 0.5 mg/kg
- 2.5 mg/kg, repeated up to 10 mg/kg total if needed (Correct answer)
- 5 mg/kg once
- 10 mg/kg as a single bolus
Correct answer: 2.5 mg/kg, repeated up to 10 mg/kg total if needed
The initial dantrolene dose is 2.5 mg/kg IV bolus, repeated every 5 minutes up to 10 mg/kg (or until symptoms resolve) for malignant hyperthermia treatment.
Question 4: During surgery, the anesthesiologist announces end-tidal CO2 of 68 mmHg, temperature of 39.8°C rising, and tachycardia of 148 bpm. The CRNFA's first action should be to:
- Increase IV fluid rate
- Suspend the operation, assist the team to activate the MH protocol, and call for dantrolene (Correct answer)
- Apply ice packs to the patient's neck and axillae only
- Administer a beta-blocker for the tachycardia
Correct answer: Suspend the operation, assist the team to activate the MH protocol, and call for dantrolene
Rising end-tidal CO2, hyperthermia, and tachycardia are cardinal signs of MH; the team must suspend surgery, switch to MH-safe anesthesia, and administer dantrolene immediately.
Question 5: The purpose of pre-oxygenation (denitrogenation) before induction of general anesthesia is to:
- Prevent malignant hyperthermia
- Extend the safe apnea window by maximizing lung oxygen reserves before intubation (Correct answer)
- Prevent laryngospasm
- Reduce anesthetic agent requirements
Correct answer: Extend the safe apnea window by maximizing lung oxygen reserves before intubation
Pre-oxygenation with 100% O2 for 3–5 minutes replaces nitrogen in functional residual capacity with oxygen, extending the safe apneic window from ~1 minute to 3–8 minutes.
Question 6: Which maneuver, performed by the CRNFA or circulating nurse during rapid sequence intubation (RSI), helps prevent aspiration by occluding the esophagus?
- Jaw thrust
- Sellick maneuver (cricoid pressure) (Correct answer)
- Head-tilt chin-lift
- Bimanual laryngoscopy
Correct answer: Sellick maneuver (cricoid pressure)
Cricoid pressure (Sellick maneuver) compresses the cricoid cartilage against the esophagus to occlude it and prevent passive regurgitation during RSI until the cuff is inflated.
CRNFA Anesthesia and Patient Safety in the OR 1
Which volatile anesthetic agent is most strongly associated with triggering malignant hyperthermia in susceptible patients?