A wonderful discussion with my friend michael.civitello inspired this conversation.
Michael pointed out that moderate sedation is permitted in both NFPA 99 2015 and 2018 Category 2 and 3 medical gas systems. Meanwhile, in the new Chapter 15 Dental Gas and Vacuum Systems of NFPA 99 2018, Category 3 systems allow only minimal sedation and anxiolysis. Why the discrepancy?
In addition, I had learned and spoken with numerous medical gas verifiers (ASSE 6030) and engineers that stated that under NFPA 99 2015 that a Category 1 system was required for general anesthesia and deep sedation, a Category 2 system for moderate sedation, and a Category 3 system for minimal sedation / anxiolysis. However, a quick read of Chapter 5 suggests that Moderate Sedation is permissible in either a Category 2 or Category 3 system. This is not the case in Chapter 15 of NFPA 99 2018. Why the difference?
Perhaps the Devil is in the details. A thorough, almost legal-like, dissection of the standard in Chapter 5 leaves me with the following interpretation. As a disclaimer though, I am a clinician and not a building official or AHJ.
- Category 1 - Any of the following apply: 1) Deep Sedation or General Anesthesia. 2) failure of the system may result in major injury or death. 3) or the patient care space is intended for Category 1 ( See 18.104.22.168)
- Category 2 - All the following apply: 1) Only moderate sedation; minimal sedation; or no sedation; Deep sedation and general anesthesia shall not be permitted. 2) failure of the system may result in minor injury. 3) the patient care space is intended for Category 2 ( See 22.214.171.124)
- Category 3 - All the following apply: 1) Only moderate sedation; minimal sedation; or no sedation; Deep sedation and general anesthesia shall not be permitted. 2) failure of the system is not likely to cause injury, but may cause discomfort 3) the patient care space is intended for Category 3 or Category 4 ( See 126.96.36.199)
Category 1 seems to be fairly obvious, this is deep sedation and general anesthesia. Although as a clinician I could see the argument that deaths that have occurred during moderate sedation constitutes major injury or death. Others might argue that this happens when moderate sedation unintentionally goes to deep sedation. Nevertheless, the continuum of sedation and anesthesia is not distinct and does not depend on the route of drug administration.
Category 2 seems to be moderate sedation in my humble opinion. Why? Moderate sedation definitely can cause injury if the medical gas system fails. I am fairly certain that failure of suction or positive gas pressure could result in much more than simply discomfort. However, playing devil's advocate, I can see where by permitting moderate sedation in Category 3, this category may be unnecessary.
Category 3 seems to be nitrous anxiolysis and minimal sedation. A patient is never incapacitated with nitrous only. Minimal sedation doses are allowed to be given unmonitored, thus failure is unlikely to cause injury, but might cause discomfort.
So why do we put moderate sedation in both Category 2 and Category 3? Why the difference between dental offices and medical facilities? I am sure the authors had a perfectly good reason for the above, and thought it might be worth discussing.