# Moderate and Deep Sedation Techniques

## Introduction

Moderate and deep sedation are integral to OMFS practice, enabling the surgeon to perform procedures safely while managing patient anxiety and pain. The OMFS surgeon functions as both the operator and the anesthesia provider, a dual role that demands rigorous training, vigilant monitoring, and a thorough understanding of sedation pharmacology.

## Definitions (ASA Continuum of Sedation)

Minimal sedation (anxiolysis) is a drug-induced state where the patient responds normally to verbal commands; cognitive function may be impaired but ventilatory and cardiovascular functions are unaffected. Moderate sedation (conscious sedation) is a drug-induced depression of consciousness where the patient responds purposefully to verbal commands or light tactile stimulation, no airway intervention is required, and spontaneous ventilation is adequate. Deep sedation is a drug-induced depression of consciousness where the patient cannot be easily aroused but responds purposefully to repeated or painful stimulation; airway intervention may be required and spontaneous ventilation may be impaired. General anesthesia involves loss of consciousness with the patient not arousable and airway intervention often required. The key concept is that sedation is a continuum, and the practitioner must be prepared to rescue a patient from a deeper level than intended.

## Patient Assessment

The medical history focuses on cardiovascular, pulmonary, hepatic, and renal disease, prior anesthesia experiences, and medications. ASA classification guides patient selection, with office-based moderate and deep sedation generally appropriate for ASA I through III. Airway assessment includes Mallampati score, thyromental distance, mouth opening, neck mobility, BMI, and presence of obstructive sleep apnea. NPO status requires clear liquids withheld for 2 hours, light meal for 6 hours, and full meal for 8 hours before sedation. Informed consent documenting risks of sedation, alternatives, and NPO instructions is obtained.

## Monitoring Standards

Pulse oximetry is continuous and mandatory for all levels of sedation. Capnography (ETCO2) is continuous and mandatory for moderate sedation (per the ASA 2018 update) and deep sedation, serving as the earliest indicator of hypoventilation and airway obstruction. ECG is continuous, recommended for moderate sedation and mandatory for deep sedation. Blood pressure is measured non-invasively with automated equipment every 5 minutes at minimum. A precordial or pretracheal stethoscope provides continuous auscultation of breath sounds and heart tones. Clinical observation of chest excursion, skin color, and responsiveness complements instrumental monitoring.

![Photograph of monitoring setup for office-based sedation showing pulse oximetry, capnography, ECG, and automated blood pressure](/images/residency/omfs/sedation-monitoring.jpg)

## Pharmacology of Sedation Agents

| Agent | Class | IV Onset | Duration | Dose (Adult IV) | Reversal Agent | Key Property |
|---|---|---|---|---|---|---|
| Midazolam | Benzodiazepine | 1-2 min | 45-60 min | 0.5-2 mg titrated | Flumazenil 0.2 mg | Anxiolysis, amnesia |
| Fentanyl | Opioid | 1-2 min | 30-45 min | 25-50 mcg titrated | Naloxone 0.04-0.4 mg | Potent analgesia |
| Propofol | Sedative-hypnotic | 30-60 sec | 5-10 min | 0.5-1 mg/kg induction | None | Rapid onset/recovery; no analgesia |
| Ketamine | Dissociative | 1-2 min | 10-20 min | 0.5-1 mg/kg | None | Preserves airway reflexes; analgesic |

### Benzodiazepines

Midazolam (Versed) is the most commonly used benzodiazepine in OMFS sedation. It has an IV onset of 1 to 2 minutes and a duration of 45 to 60 minutes. The dose is 0.5 to 2 mg IV titrated, with a typical total of 2 to 5 mg for adults. It produces anxiolysis, amnesia, and mild sedation. The reversal agent is flumazenil, given as 0.2 mg IV repeated every 60 seconds to a maximum of 1 mg. Diazepam is longer acting and less commonly used intravenously due to venous irritation. Triazolam is used for oral sedation at 0.25 to 0.5 mg sublingually 30 minutes preoperatively.

### Opioids

Fentanyl has an IV onset of 1 to 2 minutes and a duration of 30 to 45 minutes. The dose is 25 to 50 mcg IV, titrated. It is a potent analgesic with minimal cardiovascular depression but carries risk of respiratory depression and chest wall rigidity at high doses. The reversal agent is naloxone at 0.04 to 0.4 mg IV. Meperidine is less commonly used due to risk of seizures from accumulation of the normeperidine metabolite. Morphine is longer acting with more histamine release.

### Propofol

Propofol is an ultra-short-acting sedative-hypnotic with rapid onset (30-60 seconds) and rapid recovery. It has no analgesic properties. The dose is 0.5 to 1 mg/kg for induction with a 25 to 75 mcg/kg/min infusion for sedation. It carries significant respiratory depression and apnea risk, requiring advanced airway skills. Pain on injection is mitigated by lidocaine co-administration. It is used for deep sedation and general anesthesia by OMFS surgeons with appropriate training.

### Ketamine

Ketamine is a dissociative anesthetic with analgesic and amnestic properties. The dose is 0.5 to 1 mg/kg IV for sedation or 4 to 6 mg/kg IM. It preserves airway reflexes and respiratory drive, which is a relative advantage. It may cause emergence reactions (delirium, hallucinations), which are mitigated by co-administration of midazolam. It increases secretions, so glycopyrrolate should be considered. It is a useful adjunct in pediatric sedation.

## Common Sedation Protocols in OMFS

### Moderate Sedation Protocol (typical adult)

A typical moderate sedation protocol uses midazolam 2 to 4 mg IV plus fentanyl 50 to 100 mcg IV, titrated incrementally and supplemented with local anesthesia. The patient maintains verbal responsiveness and spontaneous ventilation.

### Deep Sedation Protocol

Deep sedation typically combines midazolam plus fentanyl with a propofol infusion or intermittent boluses, or alternatively midazolam plus fentanyl with ketamine. The patient may lose purposeful response, requiring advanced airway management capability. The practitioner must be prepared to provide general anesthesia if sedation deepens beyond the intended level.

## Airway Management During Sedation

A nasal hood or nasal cannula with ETCO2 monitoring is used. Head positioning in slight extension (the "sniffing position") maintains airway patency. Jaw thrust and chin lift maneuvers address obstruction. A nasopharyngeal airway is well tolerated in sedated patients and serves as a valuable adjunct. An oropharyngeal airway may be used if the patient tolerates it at deeper sedation levels. Suction must be immediately available. A throat pack prevents aspiration of blood and debris during surgical procedures.

![Illustration demonstrating proper patient positioning and nasal cannula placement with capnography sampling during moderate sedation](/images/residency/omfs/sedation-airway-positioning.jpg)

## Complications and Management

Oversedation and respiratory depression are managed by stopping sedation, stimulating the patient, supporting ventilation, and administering reversal agents. Airway obstruction is addressed with repositioning, jaw thrust, nasal or oral airway, and suction. Laryngospasm is treated with positive-pressure ventilation and deepening anesthesia, with succinylcholine as a last resort. Hypotension is managed with an IV fluid bolus, Trendelenburg positioning, and vasopressors if needed. Nausea and vomiting are treated with ondansetron 4 mg IV and dexamethasone, with suction and lateral positioning to protect the airway. Paradoxical reactions to benzodiazepines, which are more common in elderly and pediatric patients, may respond to a small dose of propofol.

## Discharge Criteria

The patient must be alert, oriented, and hemodynamically stable with a Modified Aldrete score of 9 or above. Nausea should be minimal and pain controlled. A responsible adult escort must accompany the patient. Written postoperative instructions are provided and reviewed, and 24-hour contact information is given.

![Discharge assessment checklist including Modified Aldrete scoring criteria for post-sedation patients](/images/residency/omfs/discharge-criteria-checklist.jpg)

## Clinical Pearls

Sedation is a continuum, and the practitioner should always be prepared to manage a patient one level deeper than intended. Capnography is the earliest warning of hypoventilation and is mandatory for moderate and deep sedation. Drugs should be titrated incrementally, as it is easier to add more than to reverse an overdose. The combination of a benzodiazepine and an opioid produces synergistic respiratory depression, so careful titration is essential. A sedated patient should never be discharged without a responsible adult escort and written instructions.

## References

1. American Society of Anesthesiologists. Practice Guidelines for Moderate Procedural Sedation and Analgesia 2018. *Anesthesiology*. 2018;128(3):437-479.
2. Dionne RA, Yagiela JA, Moore PA, et al. Comparing efficacy and safety of four intravenous sedation regimens in dental outpatients. *J Am Dent Assoc*. 2001;132(6):740-751.
3. Bennett JD, Kramer KJ, Bosack RC. *Sedation and Anesthesia for the Ambulatory Oral Surgeon*. Oral Maxillofac Surg Clin North Am. 2013;25(3).
4. Becker DE, Haas DA. Management of complications during moderate and deep sedation: respiratory and cardiovascular considerations. *Anesth Prog*. 2007;54(2):59-69.