Chloroform “knocks you out” for as long as it is applied, this could be for 20 minutes to two hours with a 20–30 minute recovery time; during which there will be intense shivering, severe nausea and more than likely vomiting, then a severe headache lasting hours.
Unless you're asking how long does it take to knock someone out with chloroform.
Firstly the old Hollywood “rag over the mouth” staple is utter nonsense, it takes about 5 minutes to induce anaesthesia with chloroform and that is under conditions with a willing patient (or a patient in restraints), even with a fully soaked rag you're going to have to hold your victim still (implying higher physical strength which begs the question; why not just choke the victim unconscious which takes fifteen seconds maximum, then you can just inject them with 150+ milligrams of ketamine, which would cause unconsciousness in one or two minutes.
Choking someone unconscious isn't difficult at all, you just need to exert pressure on both of their carotid arteries by placing one arm around the neck with your elbow pointing outwards and forwards then use your other arm to squeeze the first arm extremely hard so that your bicep and forearm exert a lot of pressure on the sides of their neck, you go weak in seconds, fall unconscious in about 5–15s then wake up in about 30–40s. I've experienced it myself (a friend and I got bored so we tried it on each-other and both of us collapsed in ten seconds or less with a thirty+ second period of unconsciousness.
If you wanted the (hypothetical) person to stay unconscious for longer, an intramuscular injection of 120+mgs of ketamine would last about thirty minutes and could be “topped up” as necessary.
Intramuscular midazolam would have the same effect, if given in a high enough dose, however ketamine is a better anaesthetic agent.
One thing to remember about chloroform is that it sensitizes the heart to adrenaline and as such, someone who is very anxious of anaesthesia may have a heart attack. Diethyl ether doesn't cause cardiac side effects (although it causes excessive salivation, laringiospasm and other side effects associated with inhalational anaesthetics; which is why an “airway” (a tube) would usually be inserted into the mouth and down into the trachea, or in through the nose and down to the trachea, to keep the airway open. More modern inhalational anaesthetic agents (such as desflurane) have lessened side effects and induce anaesthesia (stage two/three anaesthesia specifically) with a very rapid onset and wear off very rapidly. Inhalational anaesthetics are usually combined (for example desflurane + nitrous oxide (as well as oxygen) to increase efficacy. Or intravenous anaesthetic agents (usually propofol, though occasionally fentanil compounds or barbiturates) are used for anaesthetic induction and then the agent is switched to an inhalational anaesthetic mix, or for short operations, IV anaesthesia is used in its entirety.
Chloroform, ether and ACE mixture (Alcohol, Chloroform, Ether) are all very outdated and are almost never used in first world countries due to the slow onset and therefore slow elimination period (which is a problem in the case of anaesthetic overdose) as well as the serious negative side effects post-anaesthesia.
I hope you're using this for educational purposes only.
Explanation:
