What is conscious sedation (Intravenous)?
Intravenous Conscious Sedation (aka “IV sedation”) is when medication, usually of the anti-anxiety variety, are administered into the blood system during dental or other surgical treatment.
What does it feel like? Will I be asleep?
In reality, you remain conscious during conscious sedation. You will also be able to understand and respond to requests from your dentist. However, you may not remember much (or anything at all) about what went on because of two things:
1. Conscious sedation induces a state of deep relaxation and a feeling of not being bothered by what’s going on.
2. The medication used for conscious sedation produce either partial or full memory loss (amnesia) for the period of time when the medication first kicks in until it wears off. As a result, time will ap-pear to pass very quickly and you will not recall much of what happened. Many people remember nothing at all. So it may, indeed, appear as if you were “asleep” during the procedure.
What do patients say?
“Sedation makes you feel as if you don’t care about anything.”
“I felt as if I were lying on the beach in the sun.”
“I would not hesitate to use it again if I needed to. I really don’t remember too much, just bits and pieces of conversations.”
Is it still necessary to be numbed with local anaesthetic? Will my dentist numb my gums before or after I’m sedated?
The medications which are usually used for conscious sedation are not painkillers (although some pain-killing medications are occasionally added, see below for more info), but anti-anxiety medica-tion. 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 conscious sedation has fully kicked in. If you have a phobia of needles, you will be relaxed enough not to care by this stage. Dr van Heerden will then wait until the local anaesthetic has taken effect (i.e. until you’re numb) before starting on any procedure.
“But how does the dentist know whether I’m numb?”
You will be awake enough to tell Dr van Heerden if you are not numb.
How is conscious sedation given?
“Intravenous” means that the medication is put into a vein. An extremely thin needle is inserted 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. It makes the entry into the vein, then is slid out leaving the soft plastic tube in place. The medications 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.
Your pulse, ECG, blood pressure and oxygen levels are measured throughout the procedure. A “pulse oximeter” clips onto a finger and measures pulse and oxygen saturation. It gives a useful early warning sign if you’re getting too low on oxygen.
But I’m terrified of all needles, not just dental injections!
You can get Ametop or EMLA numbing cream to make the site where the needle goes profoundly numb.
What medications are used? Are there different types of conscious sedation? Good question. The most commonly used medication for conscious sedation are benzodiazepines. These are anti-anxiety sedative medication.
1. Anti-anxiety sedatives (benzodiazepines): Midazolam and Diazepam
The medication most used in conscious sedation is a short acting benzodiazepine, or “benzo” for short. This is an anti-anxiety sedative. IV administered benzos have 3 main effects: they reduce anxiety/relax you, they make you sleepy, and they produce partial or total amnesia (i.e. make you forget what happened during some or, less frequently, all of the procedure). Total amnesia is more common with midazolam compared to diazepam.
By far the most commonly used benzodiazepine for conscious sedation is Midazolam.
Midazolam is the first choice because of its relatively short duration of action (meaning that it’ll be out of your system faster).
The Venflon is left in place during the procedure so that the sedation can either be topped up or so that the reversal agent for benzos (Flumazenil) can be put in in the unlikely event of an emergency.
Opioids (strong pain-killers) can be used as an add-on to avoid the pain of dental injections and for more painful major dental surgery. Alfentanyl, or Rapifen, lasts for 10 minutes and is used when the dentist injects local. Tramadol, which is acts for four to six hours, is used for post-operative pain relief in major surgical procedures.
Propofol is run as an infusion with benzodiazepines. The advantage of this is a very rapid recovery time, less than 5 minutes. The medication must be continuously administered, so the medication is pumped in using an electric infusion pump, the dose rate is set by the anaesthetist.
This is added to the propofol infusion to increase analgesia and also to allow more dissociation without causing too deep a level of sedation.
Why so many different medications?
Sedation works best with small doses of several medications. At higher doses, side effects are more likely to be encountered, and by using several medications, all at lower doses, these side effects can be avoided.
Is it safe? Are there any contraindications?
Conscious sedation is extremely safe when carried out under the supervision of a specially-trained sedationist/anaesthetist. Purely statistically speaking, it’s even safer than local anaesthetic on its own!
However, contraindications include:
• known allergy to any of the medication
• alcohol intoxication or other substance abuse
• CNS depression, and
• some instances of glaucoma.
Cautions (relative contraindications) include psychosis, impaired lung or kidney or liver function, advanced age, and sleep apnea. Many people who have sleep apnea haven’t been officially diag-nosed – if you are overweight and you snore, do mention this.
Heart disease is generally not a contraindication.
If you have been taking benzodiazepines for many years, your tolerance may be very high – so let your dentist know that you’ve been taking them!
What are the main advantages of conscious sedation?
- The onset of action is very rapid, and medication 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. Conscious sedation, on the other hand, is both highly effective and highly reliable.
- The maximum level of sedation which can be reached with IV is deeper than with oral or inhalation sedation.
- Benzodiazepines produce amnesia for the procedure.
- The gag reflex is hugely diminished – people receiving conscious sedation rarely experience difficulties with gagging.
- Unlike General Anaesthesia or Deep Sedation, conscious 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.
- Sedated patients are more relaxed and less stressed. This leads to less hypertension and slower heart rates. In people with heart disease, or other medical problems, this can make the procedure safer.
- You will be closely monitored by a doctor trained in the management of emergencies, rather than just being with the dentist alone.
Are there any disadvantages?
- It is possible to experience complications at the site where the needle entered, for example hematoma (a bruise).
- Recovery from IV administered medication is not complete at the end of dental treatment. You need to be escorted by a responsible adult.
- Cost is another disadvantage – conscious sedation is more expensive than other sedation options.
Can I take valium tablets or other benzodiazepines beforehand?
Discuss all medication with your sedationist/ anaesthetist first. This will also apply to your other regular medication. The anaesthetist will attempt to call you before the procedure and will have seen a copy of your medical records. Please make sure you tell the dentist if there have been any changes to your health or medications.
What about eating and drinking before sedation?
No food or non-clear liquids for six hours before the procedure. Clear liquids like water, black tea or clear apple juice may be taken up to two hours before the procedure.
After conscious sedation:
1. Have your escort take you home and rest for the remainder of the day.
2. Have an adult stay with you until you’re fully alert.
3. Don’t perform any strenuous or hazardous activities and don’t drive a motor vehicle for the rest of the day.
4. Don’t eat a heavy meal immediately. If you’re hungry, eat something light, e.g. liquids and toast.
5. If you experience nausea, lie down for a while or drink a glass of coke.
6. Don’t drink alcohol or take medications for the rest of the day unless you’ve contacted your dentist first.
7. Take medications as directed by your dentist.
8. If you have any unusual problems, call your dentist.
For any queries regarding conscious sedation or to book a specialist consultation, please contact the surgery.