(see also Ramsey Scale; Riker Sedation-Agitation Scale; Aldrete Scoring System)

Moderate sedation, also known as procedural or conscious sedation, is the second level on a sedation continuum that ranges from mild sedation to general anesthesia. The four levels of the continuum are described as:

• Mild Sedation (Anxiolysis): Patient has normal response to verbal stimulation, airway and spontaneous ventilation are unaffected, and cardiovascular function is maintained.
• Moderate Sedation (Procedural Sedation): Refers to a drug-induced depression of consciousness during which the patient will respond purposefully to verbal commands either alone or accompanied by light tactile stimulation. (Of note, reflex withdrawal from a painful stimulus is not considered a purposeful movement.) No interventions are required to maintain a patent airway, spontaneous ventilation is adequate, and cardiovascular function is maintained.
• Deep Sedation (Analgesia): The patient will show a purposeful response after repeated painful stimulation. Airway intervention may be required and spontaneous ventilation may be inadequate. Cardiovascular function is usually maintained.
• General Anesthesia: The patient is unarousable, even with painful stimulus. Airway intervention is often required and spontaneous ventilation frequently inadequate. Cardiovascular function may be impaired.

Figure 8.9

Most institutions require didactic training and special credentialing before medical staff or other providers are allowed to administer procedural sedation. They must have an in-depth knowledge of the drugs required and be well versed in cardiovascular life support and airway management skills. Evaluation of patient respiratory and circulatory requirements prior to, during, and following the procedure is essential.

The most frequently used drugs for procedural sedation include morphine, fentanyl, dilaudid, versed, and valium. Propofol or ketamine are sometimes used, but usually administered by advanced practice providers only.

The American Society of Anesthesia classification system is used to indicate the level of a patient's physical state prior to surgery. It is often helpful in predicting perioperative risks.

Table 8.21

The Mallampati airway classification system is used prior to moderate sedation to evaluate the patient for a possible difficult intubation by relating tongue size to pharyngeal size. The patient should sit up, open mouth, and fully protrude tongue (phonation is not required). A patient with a Mallampati class III or IV score should have a consult by an anesthesia provider prior to proceeding with procedure.

Figure 8.10