Sedation is the reduction of irritability or agitation by administration of sedative drugs, generally to facilitate a medical procedure or diagnostic procedure. Examples of drugs which can be used for sedation include isoflurane, diethyl ether, propofol, etomidate, ketamine, pentobarbital, lorazepam and midazolam.
Sedation is typically used in minor surgical procedures such as endoscopy, vasectomy, or dentistry and for reconstructive surgery, some cosmetic surgeries, removal of wisdom teeth, or for high-anxiety patients. Sedation methods in dentistry include inhalation sedation (using nitrous oxide), 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 so that patients who are being ventilated tolerate having an endotracheal tube in their trachea. Also can be used during a long term brain EEG to help patient relax.
There are studies claiming that sedation accounts for 40 percent to 50 percent procedure-related complications, that is why this process has attracted attention. Airway obstruction, apnea and hypotension are not uncommon during sedation and require the presence of health professionals 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. This process can also reveal if the sedation period needs to be prolonged or additional therapeutic procedures are required.
Sedation scales are used in medical 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:
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.
The most common standard conscious sedation technique for adults is intravenous sedation using Midazolam. This requires a needle to be put into a vein to deliver the medication, this is known as an IV cannula.