Sevoflurane, sold under the brand name Sevorane, among others, is a sweet-smelling, nonflammable, highly fluorinated methyl isopropyl ether used as an inhalational anaesthetic for induction and maintenance of general anesthesia. After desflurane, it is the volatile anesthetic with the fastest onset. While its offset may be faster than agents other than desflurane in a few circumstances, its offset is more often similar to that of the much older agent isoflurane. While sevoflurane is only half as soluble as isoflurane in blood, the tissue blood partition coefficients of isoflurane and sevoflurane are quite similar. For example, in the muscle group: isoflurane 2.62 vs. sevoflurane 2.57. In the fat group: isoflurane 52 vs. sevoflurane 50. As a result, the longer the case, the more similar will be the emergence times for sevoflurane and isoflurane.
General anaesthesia (UK) or general anesthesia (US) is a method of medically inducing loss of consciousness that renders a patient unarousable even with painful stimuli. This effect is achieved by administering either intravenous or inhalational general anaesthetic medications, which often act in combination with an analgesic and neuromuscular blocking agent. Spontaneous ventilation is often inadequate during the procedure and intervention is often necessary to protect the airway. General anaesthesia is generally performed in an operating theater to allow surgical procedures that would otherwise be intolerably painful for a patient, or in an intensive care unit or emergency department to facilitate endotracheal intubation and mechanical ventilation in critically ill patients.
Propofol is the active component of an intravenous anesthetic formulation used for induction and maintenance of general anesthesia. It is chemically termed 2,6-diisopropylphenol. The formulation was originally approved under the brand name Diprivan. Numerous generic offerings of this formulation now exist. Intravenous administration is used to induce unconsciousness after which anesthesia may be maintained using a combination of medications. It is manufactured as part of a sterile injectable emulsion formulation using soybean oil and lecithin, giving it a white milky coloration.
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 induces sleepiness, decreases anxiety, and causes anterograde amnesia.
An anesthetic or anaesthetic is a drug used to induce anesthesia — in other words, to result in a temporary loss of sensation or awareness. They may be divided into two broad classes: general anesthetics, which result in a reversible loss of consciousness, and local anesthetics, which cause a reversible loss of sensation for a limited region of the body without necessarily affecting consciousness.
Premedication is using medication before some other therapy to prepare for that forthcoming therapy. Typical examples include premedicating with a sedative or analgesic before surgery; using prophylactic (preventive) antibiotics before surgery; and using antiemetics or antihistamines before chemotherapy.
Remifentanil, marketed under the brand name Ultiva is a potent, short-acting synthetic opioid analgesic drug. It is given to patients during surgery to relieve pain and as an adjunct to an anaesthetic. Remifentanil is used for sedation as well as combined with other medications for use in general anesthesia. The use of remifentanil has made possible the use of high-dose opioid and low-dose hypnotic anesthesia, due to synergism between remifentanil and various hypnotic drugs and volatile anesthetics.
Brotizolam is a sedative-hypnotic thienotriazolodiazepine drug which is a benzodiazepine analog. It possesses anxiolytic, anticonvulsant, hypnotic, sedative and skeletal muscle relaxant properties, and is considered to be similar in effect to other short-acting hypnotic benzodiazepines such as triazolam or midazolam. It is used in the short-term treatment of severe insomnia. Brotizolam is a highly potent and short-acting hypnotic, with a typical dose ranging from 0.125 to 0.25 milligrams, which is rapidly eliminated with an average half-life of 4.4 hours.
Etomidate is a short-acting intravenous anaesthetic agent used for the induction of general anaesthesia and sedation for short procedures such as reduction of dislocated joints, tracheal intubation, cardioversion and electroconvulsive therapy. It was developed at Janssen Pharmaceutica in 1964 and was introduced as an intravenous agent in 1972 in Europe and in 1983 in the United States.
Dexmedetomidine, sold under the trade name Precedex among others, is a drug used in humans for sedation. Veterinarians use dexmedetomidine for similar purposes in treating cats, dogs, and horses. It is also used in humans to treat acute agitation associated with schizophrenia or bipolar I or II disorder.
Alfaxalone, also known as alphaxalone or alphaxolone and sold under the brand name Alfaxan, is a neuroactive steroid and general anesthetic which is used currently in veterinary practice as an induction agent for anesthesia and as an injectable anesthetic. Though it is more expensive than other induction agents, it often preferred due to the lack of depressive effects on the cardiovascular system. The most common side effect seen in current veterinary practice is respiratory depression when Alfaxan is administered concurrently with other sedative and anesthetic drugs; when premedications aren't given, veterinary patients also become agitated and hypersensitive when waking up.
Procedural sedation and analgesia (PSA) is a technique in which a sedating/dissociative medication is given, usually along with an analgesic medication, in order to perform non-surgical procedures on a patient. The overall goal is to induce a decreased level of consciousness while maintaining the patient's ability to breathe on their own. Airway protective reflexes are not compromised by this process and therefore endotracheal intubation is not required. PSA is commonly used in the emergency department, in addition to the operating room.
Twilight anesthesia is an anesthetic technique where a mild dose of sedation is applied to induce anxiolysis, hypnosis, and anterograde amnesia. The patient is not unconscious, but sedated. During surgery or other medical procedures, the patient is under what is known as a "twilight state", where the patient is relaxed and "sleepy", able to follow simple directions by the doctor, and is responsive. Generally, twilight anesthesia causes the patient to forget the surgery and the time right after. It is used for a variety of surgical procedures and for various reasons. Just like regular anesthesia, twilight anesthesia is designed to help a patient feel more comfortable and to minimize pain associated with the procedure being performed and to allow the medical practitioner to practice without interruptions.
Ro48-8684 is a water-soluble benzodiazepine derivative developed by Hoffman-LaRoche in the 1990s, which was designed along with Ro48-6791 as an improved replacement for midazolam, but ultimately proved to have little advantages over the parent drug and has not been introduced into clinical practice.
Lirequinil (Ro41-3696) is a nonbenzodiazepine hypnotic drug which binds to benzodiazepine sites on the GABAA receptor. In human clinical trials, lirequinil was found to have similar efficacy to zolpidem, with less side effects such as clumsiness and memory impairment. However it was also much slower acting than zolpidem, with peak plasma concentrations not reached until 2.5 hours after oral administration, and its O-desethyl metabolite Ro41-3290 is also active with a half-life of 8 hours. This meant that while effective as a hypnotic, lirequinil failed to prove superior to zolpidem due to producing more next-day sedation, and it has not been adopted for clinical use. It was developed by a team at Hoffmann-La Roche in the 1990s.
Remimazolam, sold under the brand name Byfavo, is a medication for the induction and maintenance of procedural sedation in adults for invasive diagnostic or surgical procedures lasting 30 minutes or less. It is a benzodiazepine drug, developed by PAION AG in collaboration with several regional licensees as an alternative to the short-acting imidazobenzodiazepine midazolam, for use in the induction of anesthesia and conscious sedation for minor invasive procedures. Remimazolam was found to have both a more rapid onset and a shorter duration than midazolam, and human clinical trials showed a faster recovery time and predictable, consistent pharmacokinetics, suggesting some advantages over existing drugs for these applications.
Coinduction in anesthesia is a pharmacological tool whereby a combination of sedative drugs may be used to greater effect than a single agent, achieving a smoother onset of general anesthesia. The use of coinduction allows lower doses of the same anesthetic agents to be used which provides enhanced safety, faster recovery, fewer side-effects, and more predictable pharmacodynamics. Coinduction is used in human medicine and veterinary medicine as standard practice to provide optimum anesthetic induction. The onset or induction phase of anesthesia is a critical period involving the loss of consciousness and reactivity in the patient, and is arguably the most dangerous period of a general anesthetic. A great variety of coinduction combinations are in use and selection is dependent on the patient's age and health, the specific situation, and the indication for anesthesia. As with all forms of anesthesia the resources available in the environment are a key factor.
Total intravenous anesthesia (TIVA) refers to the intravenous administration of anesthetic agents to induce a temporary loss of sensation or awareness. The first study of TIVA was done in 1872 using chloral hydrate, and the common anesthetic agent propofol was licensed in 1986. TIVA is currently employed in various procedures as an alternative technique of general anesthesia in order to improve post-operative recovery.
Ciprofol is a novel 2,6-disubstituted phenol derivative that is used for the intravenous induction of general anesthesia. A short-acting and highly selective γ-aminobutyric acid agonist, ciprofol is 4–6 times more potent than other phenol derivatives such as propofol or fospropofol.
