Conscious Sedation is a technique in which the use of a drug or drugs produces a state of depression of the central nervous system enabling treatment to be carried out, but during which verbal contact with the patient is maintained throughout the period of sedation (UK Department of Health 2003). In other words it is a type of sedation in which the sedated individual can respond to verbal directions, but he or she feels little to no pain, and has an altered level of consciousness.

The drugs and techniques used to provide conscious sedation for dental treatment should carry a margin of safety wide enough to render loss of consciousness unlikely. The level of sedation must be such that the patient remains conscious, retains protective airway reflexes, and is able to respond to verbal commands (UK Department of Health 2003).

The effective management of pain and anxiety is of paramount importance for patients requiring minor surgical procedures and dental care, and Conscious Sedation is a fundamental component of this. Competently provided Conscious Sedation is safe, valuable and effective.

It is absolutely essential that a wide margin of safety is maintained between Conscious Sedation and the unconscious state of general anaesthesia where verbal communication with the patient and protective reflexes are lost. It is important that there is a clear understanding by the patient (or where appropriate the parent or carer), the sedationist and all the team that Conscious Sedation must under no circumstances be interpreted as light general anaesthesia.

Like any form of anesthesia and sedation, there are some risks to conscious sedation, but it is significantly less dangerous than general anesthesia.

MIDAZOLAM: Midazolam is a short acting benzodiazepine with a short half life. It has potent anxiolytic, amnestic, hypnotic, anticonvulsant, skeletal muscle relaxant, and sedative properties. It can be administered by several different routes and is often given in combination with other sedative agents. Midazolam is the primary choice for conscious sedation because of relief of anxiety, and it typically causes patients to have no or minimal recollection of the medical procedure which thus reduces likelihood of any unpleasant memories of the procedure. It is of particular value for short procedures and can have good effect without causing excessive sedation. Midazolam is ineffective for pain and has no analgesic effect during conscious sedation, so it is sometimes used in conjunction with an opioid such as fentanyl. In general, midazolam has a fast-acting, short-lived sedative effect when given intravenously, achieving sedation within one to five minutes and peaking within 30 minutes. The effects of midazolam typically last one hour but may persist for six hours (including the amnestic effect). It can cause marked respiratory depression so this must be monitored closely during administration, and it can be associated with profound sedation when high doses are given intravenously or when used with certain other drugs. Administration should always be titrated to effect.
PROPOFOL: Propofol is a short acting hypnotic agent that can be given in low doses to achieve
short acting and controlled sedation. Propofol is not considered an analgesic, so opioids such as fentanyl may be combined with propofol to alleviate pain. Propofol is administered intravenously. Propofol is the most widely used anaesthetic agent in children and adults. Very effective sedative when used in sub-anaesthetic doses. Has a rapid recovery and less hangover effects than other anaesthetic agents. Causes more marked bradycardia as well as decrease in blood pressure than other commonly used sedative agents. Prolonged infusion > 60 minutes contraindicated in children under 17 years. May cause local pain when injected, and rarely may be associated with convulsions,anaphylaxis, and delayed recovery. Administration should always be titrated to effect.
KETAMINE: Ketamine is an N-methyl d-aspartate (NMDA) receptor antagonist which causes a trance-like sedation with few appreciable effects on the respiratory and cardiovascular systems. Its analgesic effect is a major advantage. Administered intravenously it can be titrated. A single intramuscular dose is predictable and effective whenever venous access is impractical. Ketamine has good analgesic and sedation properties at sub anaesthetic doses. Used particularly for paediatric sedation, particularly when repeated administration is required. Causes less hypotension than propofol when used, but recovery slower. Higher incidence of transient hallucinations or nightmares, but these can be reduced by concomitant use of benzodiazepines such as diazepam or midazolam. Administration should always be titrated to effect.
FENTANYL: Opioid drugs can be used as sedatives for painful procedures however it is important to separate the use of opioids used as sedation from when they are used specifically for analgesia alone. Intravenous morphine and fentanyl are commonly used opioids whose sedative action can be improved by the addition of another sedative such as midazolam. Fentanyl is an opioid narcotic analgesic (pain reliever) that is 50 to 100 times more potent than morphine. Given intravenously, the onset of action of fentanyl is almost immediate, it acts within minutes, and peak analgesia occurs within 10 to 15 minutes. A single dose of fentanyl given intravenously can produce good analgesia for only 20 to 45 minutes for most patients because the drug's distribution shifts from the brain (central nervous system) to peripheral tissues. The key to correct dosage is titration, or giving the medication in small amounts until the desired patient response is achieved. Alfentanil and remifentanil are opioid alternatives to fentanyl, with very similar effects. Administration should always be titrated to effect.
NITROUS OXIDE GAS: Nitrous oxide gas, delivered with oxygen, like Ketamine also acts as an NMDA receptor antagonist. It has a rapid anxiolytic/sedative/analgesic effect and is delivered by
inhalation. Doses may be titrated to achieve target effect.
CHLORAL HYDRATE: Chloral hydrate was the first synthetic drug employed for its sedative-hypnotic
effect. Unlike opioids, it produces sedation without significant adverse effects on cardiovascular or respiratory function at therapeutic doses. In children it is orally administered for painless imaging.
SEVOFLURANE: Sevoflurane is a fluorinated isopropyl ether which has a rapid induction and quick
elimination effect. It is delivered by inhalation and may be titrated for sedative effect.
TRICLOFOS: Triclofos is a sedative-hypnotic drug, similar to chloral hydrate but with less gastric irritation. It is orally administered for painless imaging.
LOCAL ANAESTHESIA: The use of local anaesthesia such as lignocaine to provide analgesia is crucial to the success of any sedation for painful procedures.


Conscious sedation is safe, and can be used for most patients. However, it is important to ensure that patients are medically fit. A full medical history is required for all patients. This must be recorded and retained with the patient's records. When sedation is to be considered, special note should be made of the following conditions:
• Cardiovascular disease
• Respiratory disease
• Liver or kidney disease
• Pregnancy
• Psychiatric conditions

Care must be taken in the choice of technique and where it is to be provided, depending on the patient's medical status. The American Society of Anaesthesiology Classification of Physical Status (ASA) classification helps when making this decision.
I - Normal, healthy patient
II - A patient with mild systemic disease
eg: well controlled diabetes, epilepsy, mild asthma, controlled hypertension
III - A patient with severe systemic disease limiting activity but not incapacitating
eg: uncontrolled hypertension, recent myocardial infarct, uncontrolled epilepsy,
IV - A patient with incapacitating disease that is a constant threat to life
V - Moribund patient not expected to live more than 24 hours with/without treatment

Only patients who fall into the ASA categories I and II are suitable for treatment in the general practice or peripheral community situation. ASA III patients are best treated in an environment where more experienced support is available. This should be in a hospital based clinic or a sedation clinic where medical support is available. ASA IV and V are normally hospitalized or bed-ridden and are generally only seeking emergency medical or dental treatment.

AGE: Care must be taken in using intravenous sedation for older patients. Age is not a contraindication however as long as the patient is physically fit. Intravenous sedation with benzodiazepines is not predictable for children and early teenagers. Inhalation sedation can be used for children of any age. Currently there is limited information and data on the use of intravenous sedation for children, although it is widely practiced.

MEDICATION: All drugs that are currently being taken should be recorded. This includes prescribed medication, alternative remedies and recreational drugs. Special note should be made of central nervous system depressants. There are no absolute contraindications for sedation, apart from allergy to the sedative agent, but relative contraindications may arise from the medical history.


PREASSESSMENT: Following booking, patients must be assessed either on the day of surgery or prior to surgery.  If the patient is to undergo a minor surgical procedure, screening and assessment of medical conditions that may interfere with conscious sedation must be explored. These potential risk factors include advanced age, history of adverse reactions to the proposed medications and a past medical history of severe cardiopulmonary (heart/lung) or other systemic diseases.  Vital signs should be recorded including blood pressure, and pulse.

SEDATION: Just prior to the surgery or procedure, the patient receives the sedating drug intravenously.  Dosing of medications that produce conscious sedation is individualized, and the medication is administered and titrated slowly to gauge a patient's response to the sedative effect. The two most common medications used to sedate patients for medical procedures are midazolam and fentanyl (see SEDATION DRUGS).  The incidence of oversedation, decreased respiration, or cardiovascular compromise is low using sedation medications if the medication is carefully titrated.

MONITORING: Patient monitoring during conscious sedation is performed by a trained and licensed health care professional. This practitioner should not be involved in the procedure, but should have primary responsibility of monitoring and attending to the patient. Equipment must be in place and organized for monitoring the patient's blood pressure, pulse, respiratory rate, level of consciousness, and, most important, the oxygen saturation (the measure of oxygen perfusion inside the body) with a pulse oximeter.  A pulse oximeter clip placed on the patient's finger provides a continuous real time oxygenation recording during the sedation.   The oxygen saturation is the most sensitive parameter affected during increased levels of conscious sedation. Vital signs and other pertinent recordings must be monitored before the start of the administration of medications, and then at regular intervals thereafter until the procedure is completed. After the procedure has been completed, monitoring continues while the patient recovers.

DISCHARGE: Sedation requires that patients leave the surgery in the company of a responsible adult escort. If the patient is unable to comply with this instruction, sedation cannot be considered. Exceptions may be made occasionally in the case of inhalation sedation with nitrous oxide and oxygen when, at the discretion of the sedationist, the patient may leave unaccompanied if the patient is medically fit and responsible.  Sedation patients should be very carefully warned about the risk of driving afterwards. For intravenous benzodiazepines the risk extends to at least 24 hours after administration. Responsible persons must be available to take patients home.  The dangers of taking alcohol should also be emphasized.  Full post operative instructions will be given to the patient escort including.