Sedation is a procedure in which a person's level of consciousness is diminished or depressed by sedative drugs. Sedation encompasses a range in the level of consciousness--from minimal sedation, during which a person is slightly sedated, to general anesthesia, during which the person is completely unconscious and may need mechanical support for his airway.
Types
Minimal sedation is sometimes called anxiolysis. At this level, the patient is awake or can be somnolent, but the level of anxiety is decreased. The next level is moderate sedation, in which the patient's level of consciousness is depressed but is easily aroused. During deep sedation, the patient is unconscious but can be aroused by pain. The deepest level of sedation is general anesthesia, in which the person does not respond to pain.
Features
Another difference in the levels of sedation pertains to the ability of the patient to maintain her airway and cardiopulmonary system. In other words, the deeper the level of sedation, the harder it is for the patient to maintain a patent airway and for her heart and lungs to function without the help of mechanical ventilation and the support of drugs to maintain heart rate and blood pressure at a steady level.
Medications
There are several types of medicines used for sedation. For example, benzodiazepines, such as Valium, help decrease anxiety. Hypnotics, such as ketamine, depress the level of consciousness in a way that the patient hallucinates, while tolerating painful procedures. Drugs such as propofol are useful for long, painless procedures, including MRI.
Considerations
Patients undergoing sedation go through a series of steps to prepare them for the procedure. The patient's medical history is reviewed to assess risk factors for sedation and previous allergies to medicines and sedatives. Also, patients must have an empty stomach before the procedure to decrease the risk of aspiration of stomach contents. According to the American Society of Anesthesiologists, you need at least two hours after ingesting clear fluids and six hours after a light meal for a safe sedation.
Warning
There are several risks involved in sedating a person. The doses of drugs must be titrated slowly to assess their effect, as each person may react differently to the same dose of a particular drug. Also, providers must be prepared to resuscitate the patient from a deeper level of sedation than originally intended.
