CME Questions – Anesthesia
General Anesthesia For Infants Having Surgery and Elective Procedures: Is It Safe?
Which of the following is INCORRECT regarding the basis for concern regarding safety of anesthesia in children?
- In the US, 6 million children on average undergo deep sedation or general anesthesia each year, and 1.5 million of these children are infants.
- Animal models suggest long-term cognitive changes in association with anesthetic exposure.
- Exposure to anesthetic during a “vulnerable window” may lead to neurological damage that is reversible.
- Studies suggest a relationship between anesthetic exposure and an increase in learning disorders and neurocognitive dysfunction.
The correct answer is C.
Explanation: In the presentation, Dr. Castro specifically states that anesthetic delivered during a “vulnerable window” has the potential to lead to irreversible neurologic harm. Choices a, b, and d are clearly stated in the presentation.
Findings from multiple animal studies were presented; which of the following statements is LEAST accurate?
- Benzodiazepines and propofol have been associated with neuroapoptosis in rat and mice models.
- Ketamine has been associated with long-term cognitive dysfunction in rhesus monkey models.
- One of the first animal studies to demonstrate significant neurodegenerative changes associated with anesthesia was published in 1999; this study involved rats exposed to ketamine for 4 hours and demonstrated neurodegenerative changes that were dose- and age-dependent.
- A rat model study in 2003 found no significant increase in neuroapoptosis with midazolam, nitrous oxide, and isoflurane. However, after exposure to all three agents, there were robust findings of neuroapoptosis and profound suppression of long-term potentiation, suggesting impairment of learning and memory formation.
The correct answer is D.
Explanation: Dr. Castro presented the results of the effects of anesthetic agents in multiple animal models. Answers A, B, and C were stated in the presentation. However, she also specifically stated that in the 2003 study isoflurane alone was found to have a dose-dependent increase in neuroapoptosis, as well as in combination with midazolam and nitrous oxide.
Regarding retrospective studies that have analyzed learning disabilities in children exposed to anesthesia, which of the following statements is NOT true?
- Data from Mayo indicates that among children exposed to anesthesia between ages 0-3 years, more had learning disabilities if exposed 2 or more times when compared with children not exposed to anesthesia.
- Brief exposure to anesthesia during cesarean delivery has been associated with an increased incidence of learning disabilities.
- Data from Mayo indicates that the group of children exposed to anesthesia had a higher incidence of attention deficit disorder when compared with children not exposed to anesthesia.
- Data from Western Australia indicates an association between a single anesthesia exposure event and an increased risk of disability in language and abstract reasoning.
The correct answer is B.
Explanation: Dr. Block presented data from multiple studies regarding anesthesia and learning disabilities. In particular, the study by Sprung et al in 2009 did not find an association between learning disabilities and brief exposure to anesthesia during cesarean delivery. The other answer choices were stated in the presentation.
Regarding Dr. Block’s presentation of data involving children who were exposed to anesthesia as infants and their later test scores, which of the following is NOT true?
- The selected group of children that had no known CNS problems/risk factors and exposure to anesthesia in infancy had an average academic performance score lower than the state average.
- Of the selected group of children without CNS problems/risk factors, 14% scored below the 5th percentile, compared to 5% of the population.
- When a larger sample size of children with or without CNS problems/risk factors was evaluated, the average score was shown to be below that of the average score of children in the state.
- A significant correlation was found in the selected group between lower scores and longer duration of exposure to anesthesia.
The correct answer is A.
Explanation: According to Dr. Block, the average score of the selected group of children without known CNS problems/risk factors was not below the state average score. However, when a larger group (including children with and without CNS problems/risk factors) was evaluated, the average score was lower than the state average. It was also stated that 14% of the selected group scored below the 5th percentile, which was statistically significant when compared with the population. Dr. Block also reported a significant correlation between duration of anesthesia and lower scores.