Brief Answer:
insomnia not an indication

Detailed Answer:
Thank you for asking
Before explaining the difference between twilight sleep and induced coma , let me explain insomnia is not the indication for induced coma.

Twilight sleep is A term applied to the combination of analgesia (pain relief) and amnesia (loss of memory) produced by a mixture of morphine and scopolamine ("scope") given by a hypodermic injection (an injection under the skin).

A barbiturate-induced coma, or XXXXXXX coma, is a temporary coma (a deep state of unconsciousness) brought on by a controlled dose of a barbiturate drug, usually pentobarbital or thiopental. Barbiturate comas are used to protect the brain during major neurosurgery, and as a last line of treatment in certain cases of status epilepticus that have not responded to other treatments.

Barbiturates reduce the metabolic rate of brain tissue, as well as the cerebral blood flow. With these reductions, the blood vessels in the brain narrow, decreasing the amount of space occupied by the brain, and hence the intracranial pressure. The hope is that, with the swelling relieved, the pressure decreases and some or all brain damage may be averted. Several studies have supported this theory by showing reduced mortality when treating refractory intracranial hypertension with a barbiturate coma.

Controversy exists, however, over the benefits of using barbiturates to control intracranial hypertension. Some studies have shown that barbiturate-induced coma can reduce intracranial hypertension but does not necessarily prevent brain damage. Furthermore, the reduction in intracranial hypertension may not be sustained. Some randomized trials have failed to demonstrate any survival or morbidity benefit of induced coma in diverse conditions such as neurosurgical operations, head trauma, intracranial aneurysm rupture, intracranial hemorrhage, ischemic stroke, and status epilepticus. If the patient survives, cognitive impairment may also follow recovery from the coma.

About 55% of the glucose and oxygen utilisation by the brain is meant for its electrical activity and the rest for all other activities such as metabolism.[citation needed] This is recognized by a device such as an electroencephalogram (EEG), which measures electrical activity in the brain. When barbiturates are given to brain injured patients for induced coma, they act by reducing the electrical activity of the brain, which in theory reduces the metabolic and oxygen demand.[citation needed] Once there is improvement in the patient's general condition, the barbiturates are withdrawn gradually and the patient regains consciousness.

Induced coma was used in the treatment of symptomatic rabies through the XXXXXXX protocol

Nut shell, Induced coma is not even an indication for insomnia irrespective of the etiology.

Following general principles help the sleep trouble reduce
Develop regular sleep habits; this means keeping a regular sleep and wake time, sleeping as much as needed to feel refreshed the following day, but not spending more time in bed than needed
Avoid staying in bed in the morning to catch up on sleep
Avoid daytime naps; if a nap is necessary, keep it short (less than 1 hour) and avoid napping after 3 pm
Keep a regular daytime schedule; regular times for meals, medications, chores, and other activities helps keep the inner body clock running smoothly
Do not read, write, eat, watch TV, talk on the phone, or play cards in bed
Avoid caffeine after lunch; avoid alcohol within 6 hours of bedtime; avoid nicotine before bedtime
Do not go to bed hungry, but do not eat a big meal near bedtime either
Avoid sleeping pills, particularly over-the-counter remedies
Slow down and unwind before bed (beginning at least 30 minutes before bedtime (a light snack may be helpful); create a bedtime ritual such as getting ready for bed, wearing night clothes, listening to relaxing music, or reading a magazine, newspaper, or book
Avoid watching TV in the bedroom or sleeping on the sofa and then going to bed later in the night
Avoid stimulating activities prior to bedtime (eg, vigorous exercise, discussing or reviewing finances, or discussing stressful issues with a spouse or partner or ruminating about them with oneself)
Keep the bedroom dark, quiet, and at a comfortable temperature
Exercise daily; this is best performed in the late afternoon or early evening (but not later than 6-7 pm)
Do not force yourself to sleep; if you are unable to fall asleep within 15-30 minutes, get up and do something relaxing until sleepy (eg, read a book in a dimly lit room, watch a non-stimulating TV program); avoid watching the clock or worrying about the perceived consequences of not getting enough sleep
Cognitive behavioural therapies help the issue too.it includes
Sleep hygiene education
Cognitive therapy
Relaxation therapy
Stimulus-control therapy
Sleep-restriction therapy
Try Acupressure too, it works like charm on insomnia issues.
Avoid caffeinated beverages in the late afternoon or evening, since the stimulant activity of adenosine antagonism can promote hyperarousal
Avoid alcohol in the evening, since this can worsen sleep-disordered breathing leading to frequent arousals; furthermore, while alcohol promotes sleep early in the night, it leads to more sleep disruption later in the evening
Avoid large meals near bedtime, particularly with gastroesophageal reflux disease or delayed gastric emptying.
Exercise in the late afternoon or early evening (at least 6 hours before bedtime) can promote sleep. However, vigorous physical activity in the late evening (< 6 hours before bedtime) can worsen insomnia.

I hope it helps. Seek a sleep disorder specialist and let them take care of the patient.

Take good care of yourself and dont forget to close the discussion please.

May the odds be ever in your favour.
Regards
Khan

---