Sedation is the reduction of

irritability Irritability is the excitatory ability that living organisms have to respond to changes in their environment. The term is used for both the physiological reaction to stimuli and for the pathological, abnormal or excessive sensitivity to stimul ...

or agitation by administration of

sedative A sedative or tranquilliser is a substance that induces sedation by reducing irritability or Psychomotor agitation, excitement. They are central nervous system (CNS) Depressant, depressants and interact with brain activity, causing its decelera ...

drugs, generally to facilitate a

medical procedure A medical procedure is a course of action intended to achieve a result in the delivery of healthcare. A medical procedure with the intention of determining, measuring, or diagnosis, diagnosing a patient condition or parameter is also called a medi ...

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 halogenated ether used as a general anesthetic. It can be used to start or maintain anesthesia; however, other medications are often used to start anesthesia, due to airway irritat ...

diethyl ether Diethyl ether, or simply ether, is an organic compound with the chemical formula , sometimes abbreviated as . It is a colourless, highly Volatility (chemistry), volatile, sweet-smelling ("ethereal odour"), extremely flammable liquid. It belongs ...

, propofol,

etomidate Etomidate (United States Adopted Name, USAN, International Nonproprietary Name, INN, British Approved Name, BAN; marketed as Amidate) is a short-acting intravenous anaesthetic agent used for the induction of general anaesthesia and sedation for ...

ketamine Ketamine is a cyclohexanone-derived general anesthetic and NMDA receptor antagonist with analgesic and hallucinogenic properties, used medically for anesthesia, depression, and pain management. Ketamine exists as its S- (esketamine) a ...

pentobarbital Pentobarbital (US) or pentobarbitone (British and Australian) 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 of insomnia but ...

lorazepam Lorazepam, sold under the brand name Ativan, Tavor among others, is a benzodiazepine medication. It is used to treat anxiety (including anxiety disorders), insomnia, severe agitation, active seizures including status epilepticus, alcoh ...

and

midazolam Midazolam, sold under the brand name Versed among others, is a benzodiazepine medication used for anesthesia, premedication before surgical anesthesia, and procedural sedation, and to treat psychomotor agitation, severe agitation. It induces ...

Medical uses

Sedation is typically used in minor surgical procedures such as

endoscopy An endoscopy is a procedure used in medicine to look inside the body. The endoscopy procedure uses an endoscope to examine the interior of a hollow organ or cavity of the body. Unlike many other medical imaging techniques, endoscopes are insert ...

vasectomy Vasectomy is an elective surgical procedure that results in male sterilization, often as a means of permanent contraception. During the procedure, the male vasa deferentia are cut and tied or sealed so as to prevent sperm from entering into ...

, or

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

and for reconstructive surgery, some cosmetic surgeries, removal of

wisdom teeth The third molar, commonly called wisdom tooth, is the most posterior of the three molars in each quadrant of the human dentition. The age at which wisdom teeth come through ( erupt) is variable, but this generally occurs between late teens a ...

, 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 factitious air, among others, is a chemical compound, an Nitrogen oxide, oxide of nitrogen with the Chemical formula, formula . At room te ...

), 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 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 intensive care medicine. An inten ...

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

trachea The trachea (: tracheae or tracheas), 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 animals' lungs. The trachea extends from ...

. 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 Airway obstruction is a blockage of respiration in the airway that hinders the free flow of air. Airway obstructions can occur either in the upper airway or lower airway. The upper airway consists of the nose, throat, and larynx. The lower ai ...

apnea Apnea (also spelled apnoea in British English) is the temporary 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 ...

, and

hypotension Hypotension, also known as low blood pressure, is a cardiovascular condition characterized by abnormally reduced blood pressure. Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps out blood and is ...

are not uncommon during sedation and require the presence of

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

s who are suitably trained to detect and manage these problems. Aside from the respiratory depression, risks also include unintended levels of sedation, postoperative

somnolence Somnolence (alternatively sleepiness or drowsiness) is a state of strong desire for sleep, or sleeping for unusually long periods (compare hypersomnia). It has distinct meanings and causes. It can refer to the usual state preceding falling aslee ...

, 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 an airway obstruction. This ensures an open pathway for gas exchange between a patient's lungs and the atmosphere. This is accomplished by either ...

. 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 Praxis (process), practice of caring for patients, managing the Medical diagnosis, diagnosis, prognosis, Preventive medicine, prevention, therapy, treatment, Palliative care, palliation of their injury or disease, ...

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 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 General anaesthesia (UK) or general anesthesia (US) is medically induced loss of consciousness that renders a patient unarousable even by painful stimuli. It is achieved through medications, which can be injected or inhaled, often with an analgesi ...

, 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 Osteoporosis is a systemic skeletal disorder characterized by low bone mass, micro-architectural deterioration of bone tissue leading to more porous bone, and consequent increase in Bone fracture, fracture risk. It is the most common reason f ...

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, premedication before surgical anesthesia, and procedural sedation, and to treat psychomotor agitation, severe agitation. It induces ...

. Indications: * Reduced dental anxiety and

phobia A phobia is an anxiety disorder, defined by an irrational, unrealistic, persistent and excessive fear of an object or situation. Phobias typically result in a rapid onset of fear and are usually present for more than six months. Those affected ...

* 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

Sedation for pediatric patients

Present drugs commonly used to sedate children:

Methohexital Methohexital or methohexitone (marketed under the brand names Brevital and Brietal) is a drug which is a barbiturate derivative. It is classified as short-acting, and has a rapid onset of action. It is similar in its effects to sodium thiopental ...

; Thiopental;

Benzodiazepine Benzodiazepines (BZD, BDZ, BZs), colloquially known as "benzos", are a class of central nervous system (CNS) depressant, depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed t ...

Diazepam Diazepam, sold under the brand name Valium among others, is a medicine of the benzodiazepine family that acts as an anxiolytic. It is used to treat a range of conditions, including anxiety disorder, anxiety, seizures, alcohol withdrawal syndr ...

;

Ketamine Ketamine is a cyclohexanone-derived general anesthetic and NMDA receptor antagonist with analgesic and hallucinogenic properties, used medically for anesthesia, depression, and pain management. Ketamine exists as its S- (esketamine) a ...

;

Opioid Opioids are a class of Drug, drugs that derive from, or mimic, natural substances found in the Papaver somniferum, opium poppy plant. Opioids work on opioid receptors in the brain and other organs to produce a variety of morphine-like effects, ...

Morphine Morphine, formerly also called morphia, is an opiate that is found naturally in opium, a dark brown resin produced by drying the latex of opium poppies (''Papaver somniferum''). It is mainly used as an analgesic (pain medication). There are ...

; Meperidine;

Fentanyl Fentanyl is a highly potent synthetic piperidine opioid primarily used as an analgesic (pain medication). It is 30 to 50 times more Potency (pharmacology), potent than heroin and 50 to 100 times more potent than morphine. Its primary Medici ...

. Whenever it is necessary to sedate a child, one must consider the type of procedure planned (painful or nonpainful), the duration of the procedure (important in choosing the appropriate sedative), the underlying medical condition of the patient (proper fasting, contracted blood volume, interaction with other medications, and intact mechanisms of drug elimination), the need for anxiolysis or narcosis, and experience with alternative techniques or routes of administration. A child undergoing a procedure that is nonpainful (e.g., CT scan or small laceration infiltrated with local anesthetic) does not require a narcotic. Conversely, a child undergoing a painful procedure may require an opioid.

References

External links

{{Authority control Anesthesia