ABA Safety Protocols & Risk Management 3 — Questions and Answers
Question 1: When using a pulse oximeter, which hemoglobin species causes falsely HIGH SpO2 readings in cases of carbon monoxide poisoning?
- Methemoglobin
- Carboxyhemoglobin (Correct answer)
- Deoxyhemoglobin
- Sulfhemoglobin
Correct answer: Carboxyhemoglobin
Carboxyhemoglobin (COHb) absorbs light similarly to oxyhemoglobin at 660 nm, causing pulse oximetry to overestimate true SaO2.
Question 2: A 45-year-old patient receives 3 g of bupivacaine IV in error. Which treatment is most specific to reverse cardiac toxicity?
- Sodium bicarbonate 1–2 mEq/kg IV
- Magnesium sulfate 2 g IV
- Intralipid 20% 1.5 mL/kg IV bolus (Correct answer)
- Amiodarone 300 mg IV
Correct answer: Intralipid 20% 1.5 mL/kg IV bolus
Intralipid (lipid emulsion therapy) is the specific antidote for local anesthetic systemic toxicity (LAST) cardiac arrest.
Question 3: Correct sequencing of the five steps in a pre-use anesthesia machine checkout (per FDA 1993) begins with:
- Low-pressure system leak test
- Verification of backup ventilation equipment (Correct answer)
- Calibration of the O2 analyzer
- Pipeline pressure check
Correct answer: Verification of backup ventilation equipment
The FDA checkout recommends verifying that backup ventilation (e.g., self-inflating bag) is available and functional as the first step.
Question 4: Which monitoring modality is most appropriate to guide goal-directed fluid therapy and detect occult hypovolemia intraoperatively?
- Central venous pressure (CVP)
- Pulse pressure variation (PPV) (Correct answer)
- Mixed venous oxygen saturation (SvO2)
- Urine output alone
Correct answer: Pulse pressure variation (PPV)
PPV >13% in mechanically ventilated patients with sinus rhythm reliably predicts fluid responsiveness for goal-directed therapy.
Question 5: Under which condition is cricoid pressure (Sellick maneuver) CONTRAINDICATED?
- Rapid sequence induction in a trauma patient
- Suspected active regurgitation
- Patients with known cervical spine instability (Correct answer)
- Pregnant patients at term
Correct answer: Patients with known cervical spine instability
Cricoid pressure is contraindicated in patients with cervical spine instability because it can displace the spine and worsen neurological injury.
Question 6: The Joint Commission's National Patient Safety Goal regarding medication labeling requires that all medications in the sterile field be labeled:
- Only if more than one medication is on the field
- Immediately upon being drawn up, even if the syringe will be used right away (Correct answer)
- After the case begins, once the scrub tech confirms the drug name
- Only for high-alert medications such as neuromuscular blockers
Correct answer: Immediately upon being drawn up, even if the syringe will be used right away
NPSG 03.04.01 requires that all medications and solutions on and off the sterile field be labeled immediately when prepared.
Question 7: Which action BEST mitigates the risk of awareness under general anesthesia during rapid sequence induction?
- Administer a defasciculating dose of rocuronium before succinylcholine
- Use BIS monitoring and target BIS 40–60 throughout induction
- Ensure adequate induction agent dose BEFORE applying cricoid pressure (Correct answer)
- Increase the inspired volatile agent concentration above 2 MAC
Correct answer: Ensure adequate induction agent dose BEFORE applying cricoid pressure
Administering a full induction dose of the hypnotic before intubation ensures unconsciousness is established prior to laryngoscopy.
ABA Safety Protocols & Risk Management 3
When using a pulse oximeter, which hemoglobin species causes falsely HIGH SpO2 readings in cases of carbon monoxide poisoning?