Procedural sedation and analgesia

Procedural sedation and analgesia
Specialty	{{#statements:P1995}}
MeSH	D016292
MedlinePlus	007409

Procedural sedation and analgesia, previously referred to as conscious sedation, is defined as "a technique of administering sedatives or dissociative agents with or without analgesics to induce a state that allows the patient to tolerate unpleasant procedures while maintaining cardiorespiratory function."

Definitions

The American Society of Anesthesiologists defines the continuum of sedation as follows:

	Minimal Sedation	Moderate Sedation	Deep Sedation	General Anesthesia
Responsiveness	Normal to verbal stimulus	Purposeful response to verbal or tactile stimulus	Purposeful to repeated or painful stimulus	Unarousable, even to painful stimulus
Airway	Unaffected	No intervention required	Intervention may be required	Intervention often required
Ventilation	Unaffected	Adequate	May be inadequate	Frequently inadequate
CardioVasc Function	Unaffected	Usually maintained	Usually maintained	May be impaired

Medical uses

This technique is often used in the emergency department for the performance of painful or uncomfortable procedures. Common purposes include:

• setting fractures
• draining abscesses
• reducing dislocations
• performing endoscopy
• for cardioversion
• during various dental procedures
• during transesophageal echocardiogram
• and certain imaging or minor procedures where the patient is unable (or unwilling) to keep still—especially children

Agents used

Sedatives/dissociative agents

• Propofol
• Ketamine
• Etomidate
• Midazolam

Analgesics

• Fentanyl
• Remifentanyl continue infusion
• Morphine
• Ketamine: Small doses of ketamine have been found to be safer than fentanyl when used in combination with propofol.

Techniques

For most agents the person should have had nothing to eat for at least 6 hours. Clear fluids can be allowed up to two hours before the procedure. An exception to this may be with ketamine in children where fasting may be unnecessary. However, in the emergency room setting, conscious sedation is usually administered without waiting the full 6 hours unless there is clear evidence that the patient may not be able to maintain his/her airway on their own. The most common drug combination used is Versed (midazolam) for sedation (due to its potency and its ability to induce temporary amnesia, which can be beneficial because the unpleasantness of the procedure and any related sights, sounds, or smells) and Fentanyl for analgesia. Despite this being the most frequently used drug combination, variations are not uncommon due to factors such as patient allergies or clinician preference.

Complications

Complications depend on the sedative agent that is used. Many commonly used agents can cause respiratory depression, hypoxia and hemodynamic effects. For some agents antagonists are available that can be used to reverse the effects.

Safety

Procedural sedation can be safely performed in an emergency department if structured sedation protocols are followed.

Electrocardiography, pulse oximetry, capnography and blood pressure monitoring are essential, as is the use of supplementary oxygen.

Controversies

Some resistance to sedation techniques used outside the operating room by non-anesthetists has been voiced.

History

Procedural sedation used to be referred to as conscious sedation. When the patient is adequately sedated this is known as a (+)Ruiz sign.