MAC Pediatric & Obstetric Anesthesia 1 — Questions and Answers
Question 1: What is the most common cause of cardiac arrest in pediatric patients under general anesthesia?
- Malignant hyperthermia
- Laryngospasm leading to hypoxia (Correct answer)
- Induction drug overdose
- Air embolism
Correct answer: Laryngospasm leading to hypoxia
Laryngospasm causing hypoxia is the leading cause of cardiac arrest in pediatric anesthesia, emphasizing the critical importance of airway management.
Question 2: What formula is used to estimate uncuffed endotracheal tube size (internal diameter) in pediatric patients?
- Age/4 + 3.5
- Age/4 + 4 (Correct answer)
- Weight/10 + 2
- Age/3 + 3
Correct answer: Age/4 + 4
The formula (Age/4 + 4) estimates uncuffed ETT internal diameter in millimeters for pediatric patients.
Question 3: At what gestational age are nociceptive pathways sufficiently developed for fetal pain response?
- 12 weeks
- 18 weeks
- 24 weeks (Correct answer)
- 30 weeks
Correct answer: 24 weeks
Nociceptive pathways are sufficiently developed by approximately 24 weeks gestation for a fetal response to pain.
Question 4: Which induction method is preferred for a pediatric patient with a full stomach requiring emergency surgery?
- Propofol slow titration induction
- Rapid sequence induction with succinylcholine (Correct answer)
- Inhalational induction with sevoflurane
- Ketamine IM injection
Correct answer: Rapid sequence induction with succinylcholine
Rapid sequence induction minimizes time to securing the airway and reduces aspiration risk in pediatric patients with full stomachs.
Question 5: Which anatomical difference in infant airways compared to adults most affects laryngoscopy?
- The infant trachea is wider in proportion
- The infant larynx is positioned more anteriorly and cephalad (Correct answer)
- Infants have larger vocal cords
- The infant epiglottis is shorter and less floppy
Correct answer: The infant larynx is positioned more anteriorly and cephalad
The infant larynx is positioned more anteriorly and cephalad (C3-C4 vs. C4-C5 in adults), requiring adjustments in laryngoscopy technique.
Question 6: What reduction in MAC occurs in pregnant patients compared to non-pregnant patients?
- 10%
- 20%
- 30-40% (Correct answer)
- 50%
Correct answer: 30-40%
Pregnancy reduces MAC by approximately 30-40% due to elevated progesterone levels, which have CNS sedative properties.
MAC Pediatric & Obstetric Anesthesia 1
What is the most common cause of cardiac arrest in pediatric patients under general anesthesia?