IV (Intravenous) Sedation
When a drug, usually of the anti-anxiety variety, is administered into the blood system during dental treatment, this is referred to as Intravenous Conscious Sedation (aka "IV sedation"). Conscious sedation is sometimes (incorrectly) referred to as "twilight sleep" or "sleep dentistry". These terms are more descriptive of deep sedation. Deep sedation isn't commonly used, and is more closely related to general anaesthesia (even though sedation occurs on a continuum). This page answers the most common questions regarding conscious IV sedation.
What does it feel like? Will I be asleep?
A lot of dental offices use terms such as "sleep dentistry" or "twilight sleep" when talking about IV sedation. This is confusing, because it suggests that IV sedation involves being put to sleep. In reality, you remain conscious during IV sedation. You will also be able to understand and respond to requests from your dentist.
However, you may not remember much about what went on because of two factors: firstly, in most people, IV sedation induces a state of deep relaxation and a feeling of not being bothered by what's going on. Secondly, the drugs used for IV sedation can produce either partial or full memory loss (amnesia) for the period of time when the drug first kicks in until it wears off. As a result, time will appear to pass very quickly and you will not recall much, or perhaps even nothing at all, of what happened. So it may, indeed, appear as if you were "asleep" during the procedure.
Is it still necessary to be numbed with local anaesthetic? Will my dentist numb my gums before or after I'm sedated?
The drugs which are usually used for IV sedation are not painkillers (although some pain-killing drugs are occasionally added, see below for a more detailed discussion), but anti-anxiety drugs. While they relax you and make you forget what happens, you will still need to be numbed.
If you have a fear of injections, you will not be numbed until the IV sedation has fully kicked in. If you have a phobia of needles, you will very probably be relaxed enough not to care by this stage. Your dentist will then wait until the local anaesthetic has taken effect (i. e. until you're numb) before starting on any procedure.
How is IV sedation administered?
"Intravenous" means that the drug is put into a vein. An extremely thin needle is put into a vein close to the surface of the skin in either the arm or the back of your hand. This needle is wrapped up with a soft plastic tube. The needle makes the entry into the vein, then is slid out leaving the soft plastic tube in place. The drugs are put in through that tube (which is correctly referred to as an "indwelling catheter", but more commonly known by the tradename of Venflon). The tube stays in place throughout the procedure.
Throughout the procedure, your pulse and oxygen levels are measured using a "pulse oximeter". This gadget clips onto a finger or an earlobe and measures pulse and oxygen saturation. It gives a useful early warning sign if you're getting dangerously low on oxygen, although if your dentist and the nurses are paying attention they should see it before the machine does =). The warning signs are unresponsiveness and slow breathing. Blood pressure before and after the procedure should be checked with a blood pressure measuring machine (a tongue-twister called "sphygmomanometer", which for obvious reasons is referred to as "sphyg").
Is it safe?
IV sedation is EXTREMELY safe when carried out under the supervision of a specially-trained dentist. Purely statistically speaking, it's even safer than local anaesthetic on its own!
What are the advantages of IV sedation?
- IV sedation tends to be the method of choice if you don't want to be aware of the procedure - you "don't want to know". The alternative in the US is oral sedation using Halcion, but oral sedation is not as reliably effective as IV sedation.
- The onset of action is very rapid, and drug dosage and level of sedation can be tailored to meet the individual's needs. This is a huge advantage compared to oral sedation, where the effects can be very unreliable. IV sedation, on the other hand, is both highly effective and higly reliable.
- The maximum level of sedation which can be reached with IV is deeper than with oral or inhalation sedation.
- Benzos produce amnesia for the procedure.
- The gag reflex is hugely diminished - people receiving IV sedation rarely experience difficulty with gagging. However, if minimizing a severe gag reflex is the main objective, inhalation sedation is usually tried first. Only if that fails to diminish the gag reflex should IV sedation be used for this purpose.
- Can be ideal for those with a phobia of dental injections.
- Unlike General Anaesthesia or Deep Sedation, conscious IV sedation doesn't really introduce any compromises per se in terms of carrying out the actual procedures, because people are conscious and they can cooperate with instructions, and there is no airway tube involved.