Twilight anesthesia is a type of anaesthesia where a lower dose of medication normally used in general anaesthesia is applied .

Twilight anesthesia is commonly known as I.V. or , simply twilight.

Close monitoring by theanaesthesiologist is mandatory, to help keep the patient comfortable during the surgical procedure, along with checking the oxygen saturation in the blood, the ECG and the blood pressure.

There are different levels of anaesthesia which include the following:

Minimal sedation (anxiolysis) – a drug induced state in which the patient responds normally to verbal commands. Although the cognition and coordination of the patient are impaired, cardiovascular and ventilatory functions remain unaffected.

Moderate sedation/analgesia (“conscious sedation”) – a drug induced depression of consciousness during which the patient responds purposefully to verbal commands. Breathing tubes are not required for this type. This is Twilight Anesthesia.

Deep sedation/analgesia – a drug-induced depression of consciousness during which the patient cannot be easily aroused, but respond purposefully following repeated or painful stimulation. Breathing functions may be impaired, breathing tubes are requiredCardiovascular (heart) functions are normal.

General Anesthesia –Ventilatory (lung) function is impaired and cardiovascular functions may be impaired. Therefore , breathing tubes (like a laryngeal mask or a tracheal tube) is mandatory, plus ECG, blood pressure, CO2 monitoring etc…

Drugs used

The same drugs used in general anaesthesia also used for twilight anesthesia, except in smaller doses and in a bolus interval (A concentrated mass of a substance administered intravenously for diagnostic or therapeutic purposes).

Usually :

Midazolam, propofol, sufentanyl, ketamine.

Sometimes : nitrous oxide as well

It’s important to remember that twilight anesthesia alone is not used to provide relief from surgical pain, therefore, it is always given in conjunction with a local or regional anesthetic. Additionally, IV sedation is frequently administered as a cocktail of several agents including those previously mentioned for induction and maintenance of anesthesia, as well as a

Recovery

Twilight anesthesia offers a limited recovery period after procedures, and is usually associated with less nausea and vomiting than general anaesthesia which makes it a popular choice among doctors who are performing procedures such as minor plastic surgeries. 

Also, there is a lower risk for DVT or deep venous thrombosis.