Review of Concept: Anesthesia as a Spectrum

There are various methods to managing patients and optimizing dental treatment for pediatric patients and/or patients with anxiety. When behavioral management techniques do not achieve a satisfactory result, advanced techniques can be utilized. Sedation and anesthesia support safe and compassionate care.¹

Dentists who provide sedation or anesthesia to dental patients are urged to be current in their knowledge of pharmacology. They must recognize indications and contraindications to the delivery of sedation and anesthesia medications including epinephrine-containing localanesthetics. All decisions should be made based on risk and benefit. The provider must meet the national and state specific guidelines.¹
Sedation and anesthesia occur along a spectrum.² Figure 1 shows the spectrum of “pain and anxiety control.” At the left there is no sedation or anesthesia. Moving right, there are levels of conscious sedation up to the vertical bar. The bar represents loss of consciousness. To the right of the bar is deep sedation/general anesthesia. Although an experienced provider may not need a graphic representation to help determine level of sedation or anesthesia, a classification system is necessary. The dentist must understand where they are on the spectrum and its relationship to where they want to be.²

The goal should be to use the lowest level possible to achieve the desired outcome. Complications increase as you move to deeper levels and additional training by the provider is required.²

“Rescue” is an essential concept for safe sedation. Because sedation and anesthesia are a continuum, a provider must be able to recover a patient from unintended entry to a more profound level of CNS depression. To reduce morbidity and mortality, the ASA guidelines include and stress the concept of rescue during the administration of sedation by “non-anesthesiologists.”^2,3,4,5,6,7

The stages of sedation do not reflect a definitive on/off switch, but instead reflect a continuum along which the state of consciousness is gradually depressed. Minimal sedation with solely nitrous oxide or oral anxiolytics, such as Triazolam, achieves a relaxed state during which the patient is awake, able to respond to commands, and still converse with the provider. The airway, respiratory drive, and cardiovascular function is unaffected at this stage. Moderate sedation is an attenuation of consciousness in which the patient is able to purposefully respond to commands. The patient may become amnestic during moderate sedation depending on the drugs administered, and the airway, respiratory drive and cardiovascular function are minimally affected. The medications utilized in moderate sedation are typically opioids such as Fentanyl, benzodiazepines such as Midazolam, and alpha-2 agonists such as Dexmedetomidine. Deep sedation achieves loss of consciousness during which the patient is only arousable following repeated painful stimulation. While cardiovascular function is usually maintained in deep sedation, respiratory drive may be inadequate, and airway patency may require intervention. The deepest state is general anesthesia which is beyond the scope of this discussion.^3,6

Patient selection and sedation modality is paramount in achieving the desired goal. A proper and thorough review of your patient’s health history via a medical consultation and/or preoperative phone call can provide valuable information to provide safer and more predictable anesthetic results. Given the patient’s medical history, ASA status, and anesthetic requirements, a balanced anesthesia technique should be utilized to achieve anxiolysis, amnesia, and analgesia by pairing decreased dosages of concurrent medications. These medications are outlined below:²

References

1. Malamed, SF (2017) Sedation: A Guide to Patient Management. 6th edition Mosby Elsevier, St. Louis Missouri.
2. Cooke MR, Tanbonliong TS. “Sedation and Anesthesia for the Adolescent Dental Patient.” 2021 Dental Clinics of North America Volume 65(4) P 753-773.
3. Excerpted from Continuum of Depth of Sedation: Definition of General Anesthesia and Levels of Sedation/Analgesia, 2014, of the American Society of Anesthesiologists. A copy of the full text can be obtained from ASA, 1061 American Lane Schaumburg, IL 60173-4973 or online at www.asahq.org.
4. American Society of Anesthesiologists Task Force on Sedation and Analgesia by Non-Anesthesiologists: Practice guidelines for sedation and analgesia by non-anesthesiologists (2002), Anesthesiology 96:1004-1017.
5. American Academy of Pediatric Dentistry “Guidelines for Monitoring and Management of Pediatric Patients During and After Sedation for Diagnostic and Therapeutic Procedures.” (2019) Reference Manual: Volume 41 (4): E26-E52.
6. American Dental Association, Council on Dental Education and Licensure: Guidelines for teaching pediatric pain control and sedation to dentists and dental students. As adopted by the January 2021 ADA House of Delegates, Chicago, 2021 The Association.
7. American Dental Association, Council on Dental Education: Guidelines for the use of sedation and general anesthesia by dentists. As adopted by the Oct. 2016 ADA House of Delegates, Chicago, 2016 The Association.