Twilight anesthesia
Encyclopedia
Twilight anesthesia is a type of anesthetic technique where a mild dose of general anesthesia is applied that affects the brain as well as the entire body. 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."
is used to control pain by using medicines that reversibly block nerve conduction near the site of administration, therefore, generating a loss of sensation at the area administered. Close monitoring by the anesthesiologist
will sometimes be provided, to help keep the patient comfortable during a medical procedure, along with other drugs to help relax the body. It can also help control breathing, blood pressure
, blood flow
, and heart rate and rhythm, when needed.
There are four levels of sedation by anesthesia which include the following:
and coordination of the patient are impaired, cardiovascular and ventilatory functions remain unaffected.
of consciousness during which the patient responds purposefully to verbal commands, either alone or accompanied with light physical stimulation. Breathing tubes
are not required for this type of anesthesia
. This is Twilight Anesthesia.
of consciousness during which the patient cannot be easily aroused, but respond purposefully following repeated or painful stimulation. Ventilatory functions may be impaired, breathing tubes are required. Cardiovascular functions are usually sustained.
. Ventilatory function is often impaired and cardiovascular functions may be impaired.
is used under which type of medical procedures. Along with the factors determined, there are different types of anesthesia medications used depending on the medical procedure being done. While the patient is under level two (2) of sedation by anesthesia
, depending on the type and dose administered, they are in a state that is known as a “twilight” state, thus attaining the name "twilight anesthesia."
(laughing gas), or intravenously, with drugs such as Ketamine
(Pediatrics primarily, and infrequently in adults), propofol
, and midazolam
. They provide a light sleep, anxiety relief, and amnesia (loss of any memories of surgery). It's important to remember that twilight anesthesia alone is not used to provide relief from surgical pain, therefore, it is always given in conjunction with a local or regional anesthetic. Additionally, IV sedation is frequently administered as a cocktail of several agents including those previously mentioned for induction and maintenance of anesthesia, as well as a Benzodiazepine
(usually midazolam
, but temazepam
or flunitrazepam
are also used via the oral route) and a narcotic/systemic analgesic such as demerol or fentanyl. As discussed in the levels of sedation by anesthesia, assistance with breathing tubes (ETT or LMA
) are not generally used for this type of anesthesia.
regimes that measure the quality of recovery period and health-related quality of life. Factors other than degree of analgesia and presence of analgesic agent-related side effects (e.g., fatigue, physical functioning, and mental health) may potentially influence these outcomes. Twilight anesthesia offers a limited recovery period after procedures, and is usually associated with less nausea and vomiting than general anesthesia which makes it a popular choice among doctors who are performing procedures such as minor plastic surgeries.
Anesthesia
Anesthesia, or anaesthesia , traditionally meant the condition of having sensation blocked or temporarily taken away...
, "twilight anesthesia is designed to help a patient feel more comfortable and to minimize pain associated with the procedure being performed."
Overview
Twilight anesthesia is commonly known as I.V. sedation and calls for an easy awakening and speedy recovery time by the patient. AnesthesiaAnesthesia
Anesthesia, or anaesthesia , traditionally meant the condition of having sensation blocked or temporarily taken away...
is used to control pain by using medicines that reversibly block nerve conduction near the site of administration, therefore, generating a loss of sensation at the area administered. Close monitoring by the anesthesiologist
Anesthesiologist
An anesthesiologist or anaesthetist is a physician trained in anesthesia and peri-operative medicine....
will sometimes be provided, to help keep the patient comfortable during a medical procedure, along with other drugs to help relax the body. It can also help control breathing, blood pressure
Blood pressure
Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...
, blood flow
Blood flow
Blood flow is the continuous running of blood in the cardiovascular system.The human body is made up of several processes all carrying out various functions. We have the gastrointestinal system which aids the digestion and the absorption of food...
, and heart rate and rhythm, when needed.
There are four levels of sedation by anesthesia which include the following:
Level One
Minimal sedation (anxiolysis) – a drug induced state in which the patient responds normally to verbal commands. Although the cognitionCognition
In science, cognition refers to mental processes. These processes include attention, remembering, producing and understanding language, solving problems, and making decisions. Cognition is studied in various disciplines such as psychology, philosophy, linguistics, and computer science...
and coordination of the patient are impaired, cardiovascular and ventilatory functions remain unaffected.
Level Two
Moderate sedation/analgesia (“conscious sedation”) – a drug induced depressionDepression (physiology)
Depression in physiology and medicine refers to a lowering, in particular a reduction in a particular biological variable or the function of an organ...
of consciousness during which the patient responds purposefully to verbal commands, either alone or accompanied with light physical stimulation. Breathing tubes
Tracheal tube
A tracheal tube is a catheter that is inserted into the trachea in order for the primary purpose of establishing and maintaining a patent airway and to ensure the adequate exchange of oxygen and carbon dioxide. Many different types of tracheal tubes are available, suited for different specific...
are not required for this type of anesthesia
Anesthesia
Anesthesia, or anaesthesia , traditionally meant the condition of having sensation blocked or temporarily taken away...
. This is Twilight Anesthesia.
Level Three
Deep sedation/analgesia – a drug-induced depressionDepression (physiology)
Depression in physiology and medicine refers to a lowering, in particular a reduction in a particular biological variable or the function of an organ...
of consciousness during which the patient cannot be easily aroused, but respond purposefully following repeated or painful stimulation. Ventilatory functions may be impaired, breathing tubes are required. Cardiovascular functions are usually sustained.
Level Four
Anesthesia – consists of a combination of general anesthesia and spinal or major regional anesthesia. It does not include local anesthesiaLocal anesthesia
Local anesthesia is any technique to induce the absence of sensation in part of the body, generally for the aim of inducing local analgesia, that is, local insensitivity to pain, although other local senses may be affected as well. It allows patients to undergo surgical and dental procedures with...
. Ventilatory function is often impaired and cardiovascular functions may be impaired.
Applications
There are several factors which are taken into considerations when determining which level of anesthesiaAnesthesia
Anesthesia, or anaesthesia , traditionally meant the condition of having sensation blocked or temporarily taken away...
is used under which type of medical procedures. Along with the factors determined, there are different types of anesthesia medications used depending on the medical procedure being done. While the patient is under level two (2) of sedation by anesthesia
Anesthesia
Anesthesia, or anaesthesia , traditionally meant the condition of having sensation blocked or temporarily taken away...
, depending on the type and dose administered, they are in a state that is known as a “twilight” state, thus attaining the name "twilight anesthesia."
Drugs and technology used
The same drugs used in general anesthesia are also used for twilight anesthesia, except in smaller doses and in a bolus interval (A concentrated mass of a substance administered intravenously for diagnostic or therapeutic purposes). These drugs can be administered via gases, such as nitrous oxideNitrous oxide
Nitrous oxide, commonly known as laughing gas or sweet air, is a chemical compound with the formula . It is an oxide of nitrogen. At room temperature, it is a colorless non-flammable gas, with a slightly sweet odor and taste. It is used in surgery and dentistry for its anesthetic and analgesic...
(laughing gas), or intravenously, with drugs such as Ketamine
Ketamine
Ketamine is a drug used in human and veterinary medicine. Its hydrochloride salt is sold as Ketanest, Ketaset, and Ketalar. Pharmacologically, ketamine is classified as an NMDA receptor antagonist...
(Pediatrics primarily, and infrequently in adults), propofol
Propofol
Propofol is a short-acting, intravenously administered hypnotic agent. Its uses include the induction and maintenance of general anesthesia, sedation for mechanically ventilated adults, and procedural sedation. Propofol is also commonly used in veterinary medicine...
, and midazolam
Midazolam
Midazolam is a short-acting drug in the benzodiazepine class developed by Hoffmann-La Roche in the 1970s. The drug is used for treatment of acute seizures, moderate to severe insomnia, and for inducing sedation and amnesia before medical procedures. It possesses profoundly potent anxiolytic,...
. They provide a light sleep, anxiety relief, and amnesia (loss of any memories of surgery). It's important to remember that twilight anesthesia alone is not used to provide relief from surgical pain, therefore, it is always given in conjunction with a local or regional anesthetic. Additionally, IV sedation is frequently administered as a cocktail of several agents including those previously mentioned for induction and maintenance of anesthesia, as well as a Benzodiazepine
Benzodiazepine
A benzodiazepine is a psychoactive drug whose core chemical structure is the fusion of a benzene ring and a diazepine ring...
(usually midazolam
Midazolam
Midazolam is a short-acting drug in the benzodiazepine class developed by Hoffmann-La Roche in the 1970s. The drug is used for treatment of acute seizures, moderate to severe insomnia, and for inducing sedation and amnesia before medical procedures. It possesses profoundly potent anxiolytic,...
, but temazepam
Temazepam
Temazepam is an intermediate-acting 3-hydroxy benzodiazepine. It is mostly prescribed for the short-term treatment of sleeplessness in patients who have difficulty maintaining sleep...
or flunitrazepam
Flunitrazepam
Flunitrazepam is marketed as a potent hypnotic, sedative, anticonvulsant, anxiolytic, amnestic, and skeletal muscle relaxant drug most commonly known as Rohypnol...
are also used via the oral route) and a narcotic/systemic analgesic such as demerol or fentanyl. As discussed in the levels of sedation by anesthesia, assistance with breathing tubes (ETT or LMA
Laryngeal mask airway
The laryngeal mask airway is a supraglottic airway device invented by Archie Brain, a British anaesthetist.-Description:Laryngeal masks consist of a tube with an inflatable cuff that is inserted into the pharynx. Laryngeal mask airways come in a variety of sizes ranging from large adult to infant...
) are not generally used for this type of anesthesia.
Effects
There have been a few studies that have been geared towards studying the effects of post operative analgesicAnalgesic
An analgesic is any member of the group of drugs used to relieve pain . The word analgesic derives from Greek an- and algos ....
regimes that measure the quality of recovery period and health-related quality of life. Factors other than degree of analgesia and presence of analgesic agent-related side effects (e.g., fatigue, physical functioning, and mental health) may potentially influence these outcomes. Twilight anesthesia offers a limited recovery period after procedures, and is usually associated with less nausea and vomiting than general anesthesia which makes it a popular choice among doctors who are performing procedures such as minor plastic surgeries.