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IV Sedation

Intravenous sedation is administered into a vein, usually in the back of the hand or the arm. Intravenous sedation is also known as conscious sedation or moderate sedation.

It is an effective form of sedation with a high safety record and success rate. It is used for relieving anxiety and fear for nervous patients during medical and dental procedures. It will  keep you calm, drowsy, at ease with having the treatment and will also, in most cases, make you forget all or almost all of what is going on around you. Due to this degree of amnesia (memory loss), most patients who have had intravenous conscious sedation think that they have been completely unconscious. This is, of course, not true, since general anaesthesia is no longer allowed outside of operating theatres in hospitals.

During sedation, the dentist will be able to communicate with you but you may not remember much or anything at all after the effects of the drugs wear off. Your vital signs like blood pressure, breathing and pulse will be monitored. Your protective reflexes, for example coughing and swallowing should still work efficiently.

Who can benefit from intravenous sedation?

  • Patients with a moderate, high or very high anxiety
  • Patients who undergo difficult procedures
  • Patients who gag easily

Who is not suitable for intravenous dental sedation outside of a hospital setting?

  • Pregnant women
  • Patients with BMI >32
  • Patients with complicated medical histories or patients who are taking certain medications
  • Patients under the influence of alcohol or recreational drugs

Advantages and Disadvantages of intravenous sedation


  • rapid onset
  • good sedative effect
  • good amnesia (useful when you do not want to remember the dental procedure)
  • possibility of increasing the level of sedation in a controlled way
  • possibility of maintaining the level of sedation for longer procedures by administering small amounts of sedative in a controlled way
  • reduced risk of overdose compared to drugs taken orally
  • generally faster and easier recovery compared to general anaesthesia
  • generally fewer and less serious side effects postoperatively compared to general anaesthesia
  • Possibility of reversal in case of emergencies. Reversal of sedation by using a reversal drug can only be done in some instances. Your dentist/sedationist can give you more information.



  • Will need to use a vein to administer the drug. This can sometimes worry severely needle phobic patients even more.

Solution: Severely needle phobic patients can most of the time be treated either by distraction during insertion of the needle, by applying an anaesthetic cream on the injection site or by having gas and air sedation whilst the needle is inserted into the vein.

Important steps to follow if you want to have intravenous sedation

  • Always give us a complete and accurate medical history
  • Please follow fasting requirements on the day of sedation
  • Please arrange for a responsible adult to take you to the surgery and back home (escort) preferably by car. The escort also needs to be able to look after you since you may be a little bit unsteady and forgetful.
  • Please plan your day so as to avoid any activities which can be adversely affected by a decreased level of consciousness (see postoperative advice).


Possible side effects of intravenous sedation

All medicines have effects and side effects. The drugs used for sedation are no exceptions. Fortunately, these side effects are very rare according to existing reports.

In the case of intravenous sedation, the side effects can be linked to the need of administering the sedative drug/drugs into a vein or to the drug itself.

Side effects/complications with venepuncture (putting a needle into a vein) or cannulation (putting a thin, flexible plastic tube (cannula) into a vein)

  • Bruising at the site of injection – This may happen to all of us from time to time. Patients with brittle veins or patients with veins which are difficult to find may suffer this more often. It is not usually painful and may only present with a bruise for a week or two.
  • Inflammation of the vein – The vein can become red, warm, painful and hardened. Most mild cases will resolve by themselves but you should call us and ask for advice if this happens.

Other side effects – Drug related side effects

  • Small risk of not being able to achieve the appropriate level of sedation with Midazolam alone in recommended doses in some patients. (Remember, the majority will respond very well)
  • Hyperactivity, sexual fantasies

The safety record of Midazolam is very good when used intravenously in slowly administered doses in healthy patients or in patients with mild diseases. As with all drugs, there is a risk of side effects. This risk increase in elderly and in patients with more serious conditions, especially if they take other drugs. It is therefore important that all patients present an accurate and complete medical history. All drugs and conditions should be presented, including herbal medicines and recreational drugs.

Very rare side effects are:

  • Unintended loss of consciousness
  • Prolonged drowsiness or dizziness
  • Prolonged loss of memory (Usually this would last for 1-2 hours but in some rare cases it could last longer)
  • Headaches
  • Depressed breathing

What are the steps involved in having intravenous sedation?

  • We need to assess your suitability. You will need to complete a medical questionnaire and a dental anxiety questionnaire.
  • You will need to follow dietary recommendations
  • You will need to arrange for a responsible and healthy adult to take to and from the surgery and look after you on the day of the sedation
  • You will need to plan your day so as not to interfere with the effects of sedation in a negative way ( see information leaflet)
  • During your sedation we will monitor your blood pressure, level of oxygen in your blood, breathing, level of sedation and signs of discomfort.
  • You will be discharged when you are physically fit.

More on the types of sedation available

We offer a range of techniques to support nervous patients. For more information on the types of sedation available please use the links below.