Sedation is the reduction of irritability or agitation by administration of

sedative A sedative or tranquilliser is a substance that induces sedation by reducing irritability or excitement. They are CNS depressants and interact with brain activity causing its deceleration. Various kinds of sedatives can be distinguished, but ...

drugs, generally to facilitate a medical procedure or diagnostic procedure. Examples of drugs which can be used for sedation include

isoflurane Isoflurane, sold under the brand name Forane among others, is a general anesthetic. It can be used to start or maintain anesthesia; however, other medications are often used to start anesthesia rather than isoflurane, due to airway irritation w ...

, diethyl ether,

propofol Propofol, marketed as Diprivan, among other names, is a short-acting medication that results in a decreased level of consciousness and a lack of memory for events. Its uses include the starting and maintenance of general anesthesia, sedation ...

, etomidate,

ketamine Ketamine is a dissociative anesthetic used medically for induction and maintenance of anesthesia. It is also used as a recreational drug. It is one of the safest anesthetics, as, in contrast with opiates, ether, and propofol, it suppresses ...

pentobarbital Pentobarbital (previously known as pentobarbitone in Britain and Australia) is a short-acting barbiturate typically used as a sedative, a preanesthetic, and to control convulsions in emergencies. It can also be used for short-term treatment o ...

lorazepam Lorazepam, sold under the brand name Ativan among others, is a benzodiazepine medication. It is used to treat anxiety disorders, insomnia, trouble sleeping, Psychomotor agitation, severe agitation, active Epileptic seizure, seizures including ...

and

midazolam Midazolam, sold under the brand name Versed among others, is a benzodiazepine medication used for anesthesia and procedural sedation, and to treat severe agitation. It works by inducing sleepiness, decreasing anxiety, and causing a loss of ...

Medical uses

Sedation is typically used in minor surgical procedures such as endoscopy,

vasectomy Vasectomy, or vasoligation, is an elective surgical procedure for male Sterilization (medicine), sterilization or permanent contraception. During the procedure, the male vas deferens, vasa deferentia are cut and tied or sealed so as to prevent sp ...

, or

dentistry Dentistry, also known as dental medicine and oral medicine, is the branch of medicine focused on the teeth, gums, and mouth. It consists of the study, diagnosis, prevention, management, and treatment of diseases, disorders, and conditions ...

and for reconstructive surgery, some cosmetic surgeries, removal of wisdom teeth, or for high-anxiety patients. Sedation methods in

include inhalation sedation (using

nitrous oxide Nitrous oxide (dinitrogen oxide or dinitrogen monoxide), commonly known as laughing gas, nitrous, or nos, is a chemical compound, an oxide of nitrogen with the formula . At room temperature, it is a colourless non-flammable gas, and has ...

), oral sedation, and intravenous (IV) sedation. Inhalation sedation is also sometimes referred to as ''relative analgesia''. Sedation is also used extensively in the

intensive care unit 220px, Intensive care unit An intensive care unit (ICU), also known as an intensive therapy unit or intensive treatment unit (ITU) or critical care unit (CCU), is a special department of a hospital or health care facility that provides intensi ...

so that patients who are being ventilated tolerate having an endotracheal tube in their

trachea The trachea, also known as the windpipe, is a cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all air-breathing animals with lungs. The trachea extends from th ...

. It can also be used during a long term brain EEG to help patient relax.

Risks

There are studies claiming that sedation accounts for 40 percent to 50 percent procedure-related complications. Airway obstruction,

apnea Apnea, BrE: apnoea, is the temporal cessation of breathing. During apnea, there is no movement of the muscles of inhalation, and the volume of the lungs initially remains unchanged. Depending on how blocked the airways are (patency), there may ...

and

hypotension Hypotension is low blood pressure. Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps out blood. Blood pressure is indicated by two numbers, the systolic blood pressure (the top number) and the dia ...

are not uncommon during sedation and require the presence of

health professional A health professional, healthcare professional, or healthcare worker (sometimes abbreviated HCW) is a provider of health care treatment and advice based on formal training and experience. The field includes those who work as a nurse, physician (suc ...

s who are suitably trained to detect and manage these problems. Aside from the suppression of respiration, risks also include unintended levels of sedation, postoperative somnolence, aspiration, and adverse reactions to sedation medications. Complications could also include perforation, bleeding, and the stimulation of vasovagal reflexes. To avoid sedation risks, care providers conduct a thorough pre-sedation evaluation and this process includes pre-sedation history and physicals with emphasis on the determining characteristics that indicate potential risks to the patient and potential difficult

airway management Airway management includes a set of maneuvers and medical procedures performed to prevent and relieve airway obstruction. This ensures an open pathway for gas exchange between a patient's lungs and the atmosphere. This is accomplished by either c ...

. This process can also reveal if the sedation period needs to be prolonged or additional therapeutic procedures are required.

Levels of sedation

Sedation scales are used in

medical Medicine is the science and practice of caring for a patient, managing the diagnosis, prognosis, prevention, treatment, palliation of their injury or disease, and promoting their health. Medicine encompasses a variety of health care practi ...

situations in conjunction with a medical history in assessing the applicable degree of sedation in patients in order to avoid under-sedation (the patient risks experiencing pain or distress) and over-sedation (the patient risks side effects such as suppression of breathing, which might lead to death). Examples of sedation scales include MSAT (Minnesota Sedation Assessment Tool), UMSS (University of Michigan Sedation Scale), the Ramsay Scale (Ramsay, et al. 1974) and the RASS ( Richmond Agitation-Sedation Scale). The

American Society of Anesthesiologists The American Society of Anesthesiologists (ASA) is an educational, research and scientific association of physicians organized to raise the standards of the medical practice of anesthesiology and to improve patient care. As of 2021, the organiza ...

defines the continuum of sedation as follows: * Minimal sedation – normal response to verbal stimuli. * Moderate sedation – purposeful response to verbal/tactile stimulation. (This is usually referred to as "conscious sedation") * Deep sedation – purposeful response to repeated or painful stimulation. * General anesthesia – unarousable even with painful stimulus. In the United Kingdom, deep sedation is considered to be a part of the spectrum of general anesthesia, as opposed to conscious sedation. In addition to the aforementioned precautions, patients should be interviewed to determine if they have any other condition that may lead to complications while undergoing treatment. Any head, neck, or spinal cord injuries should be noted as well as any diagnosis of osteoporosis.

Intravenous sedation

The most common standard conscious sedation technique for adults is intravenous sedation using

Midazolam Midazolam, sold under the brand name Versed among others, is a benzodiazepine medication used for anesthesia and procedural sedation, and to treat severe agitation. It works by inducing sleepiness, decreasing anxiety, and causing a loss of ...

. This requires a needle to be put into a vein to deliver the medication; this is known as an IV cannula. Indications: * Reduced dental anxiety and phobia * Traumatic or prolonged dental procedures * Patients with gag reflex * Medical conditions potentially aggravated by the stress of dental treatment * Special care (mild intellectual or physical disability) * Some disorders involving its spasticity due to its muscle relaxant properties Contraindications: * Uncooperative patient * Psychologically immature individuals * Patients unable to provide a suitable escort * Difficult oral surgery or prolonged surgical procedure * Muscle diseases or diseases which cause muscle wastage * ASA III or above * Allergy or hypersensitivity to benzodiazepines * Pregnancy and breast feeding * History of psychiatric disorders * Kidney or liver dysfunction * Acute pulmonary insufficiency * Preexisting respiratory conditions as patients are susceptible to respiratory depression * Alcohol or drug addiction * Lack of visible superficial veins * CNS depressant medications which can alter reaction to sedation

References

{{Authority control Anesthesia

Medical uses

Risks

Levels of sedation

Intravenous sedation

See also

References