What is conscious sedation?
Sedatives and pain relievers as well as local anesthetic are used to induce conscious sedation.
Conscious sedation, medically known as procedural sedation and/or moderate sedation, is a procedure to relieve anxiety and depress the level of consciousness in patients, before minor procedures. Conscious sedation is usually performed by physicians in their office, with the administration of sedatives and pain relievers (analgesic).
The doctor uses low doses of rapid- and short-acting anesthetic agents to achieve minimal or moderate sedation.
Procedural sedation makes it easier for patients to tolerate unpleasant procedures, while being partially conscious and able to breathe on their own. The patients are usually able to respond to verbal commands and physical stimulation.
What drugs are used for conscious sedation?
Many of the conscious sedation drugs are common for children and adults, though dosages may vary. Sedation is usually administered intravenously for adults, but for children it be administered using one of the following methods:
- Oral
- Intranasal
- Intramuscular
- Intravenous
- Rectal
The drugs that are commonly used for procedural sedation and analgesia include the following:
Midazolam
Midazolam is a benzodiazepine class of drug that is used for both adults and children.
Advantages of midazolam include:
- Rapid sedation
- Minimal sedation
- Complete amnesia of the procedure
- Anticonvulsant properties
- Very little pain on injection
Risks include:
- Lack of analgesic effects
- Possible hypotension and respiratory depression
Fentanyl
Fentanyl is an opiate used for both adults and children.
Advantages of fentanyl include:
- Rapid and short-acting sedation
- Analgesia and increase in pain threshold
- Minimal cardiovascular depression
- Suppresses cough reflex
Risks include:
- Chest wall rigidity
- Respiratory depression or apnea (cessation of breathing)
- Hypotension (rare)
- Uneasiness (dysphoria)
- Nausea and vomiting
- EEG changes
Ketamine
Ketamine is a dissociative anesthetic used for both children and adults.
Advantages of ketamine include:
- Rapid onset and very short duration of effects
- Consistent state of sedation
- Lack of respiratory depression
- Lack of effects on laryngeal and pharyngeal reflexes
Risks include:
- Patients may not be able to speak or respond purposefully
- Delirium and hallucinations in patients older than 15
- Excessive bronchial secretions and salivation (needs pretreatment with a medication known as glycopyrrolate)
- Hypertension and increased heart rate (tachycardia)
- Increased intracranial pressure
Propofol (Diprivan)
Propofol is a hypnotic sedative agent used in both adults and children. Often an anesthesiologist is required to administer propofol and monitor its use because of the deep sedation it can induce.
Advantages of propofol include:
- Rapid onset of deep sedation and ultra-short duration of effects, useful for initiating sedation
- Anticonvulsant properties
Risks include:
- Burning, stinging and pain with injection
- Lack of analgesic properties
- Respiratory depression and apnea
- Cardiovascular depression and hypotension
Etomidate (Amidate)
Etomidate is a hypnotic sedative agent useful in adults with hypotension and trauma.
Advantages include:
- Rapid onset and ultra-short duration of effects
- Lack of histamine release and allergic reactions
- Minimal cardiovascular and respiratory effects
Risks include:
- Pain with injection
- Lack of analgesic effects
- Brief suppression of the adrenal gland
- Nausea and vomiting
- Involuntary muscle jerk (myoclonus)
- Lower seizure threshold
- Brief decrease in intracranial pressure
Dexmedetomidine (Precedex)
Dexmedetomidine is a hypnotic sedative that produces light sedation effects, used in children and adults.
Advantages include:
- Rapid onset and ultra-short duration of effects
- Lack of respiratory depression
- Light sedation allows patient response to verbal and physical stimulation
Risks include:
- Minimal analgesic effects
- Hypotension
- Slow heart rate (bradycardia)
Methohexital
Methohexital is a barbiturate used in pediatric patients.
Advantages include:
- Rapid onset and ultra-short duration of effects
Risks include:
- Lower seizure threshold
- Paradoxical excitation (opposite-to-intended effects)
- Respiratory depression
- Nitrous oxide
- Nitrous oxide has been used for sedation and analgesia for years in children and adults. It is most commonly used for pediatric dentistry.
Advantages include:
- Short duration of effects and quick recovery
- Minimal sedation
- Less respiratory and cardiovascular risk compared to other anesthetics
Risks include:
- Nausea and vomiting
- Weak anesthetic effects and not suitable for painful procedures
Chloral hydrate
Earlier used in pediatric patients but no longer recommended.
What reversal agents bring people out of conscious sedation?
Reversal agents are used to reverse the effects of the anesthetic drugs after completion of the procedure. The two reversal agents available are:
Naloxone
Naloxone reverses the effects of opioid anesthetic agents.
Risks include:
- Rebound sedation
- Withdrawal symptoms in patients with chronic opioid use
Flumazenil
Flumazenil reverses the effects of benzodiazepines.
Risks include
- Rebound sedation
- Withdrawal symptoms in patients with chronic benzodiazepine use
- Precipitation of seizures that do not respond to benzodiazepines