Analgesic and anaesthetic

[bluefin]

Anesthetic is a drug that causes temporary loss of bodily sensations

Analgesic is a medicine used to relieve pain

[african_anesthetist]

to complete a genral anaesthesia you need to accomplish the triat of:
1. Anesthesia (Amnesia, unconsiousness) which is (according to D. Chung & A. Lam)
the "reversable state of loss of sensation and/or consiousness)".
2. Analgesia (pain relieve): The reduction of pain in both consious and unconsious states.
3. Muscle relaxation: Paralysis of muscle activity during opration.

each have specific drugs and combos according to surgery and pt. state of illness...etc.
I hope that was usefull.

[Dr-Robien]

lol. I did my work experience in Anaesthetics- and wondered exactly the same! I think that african_anaesthetist summed it up very well from how I remember the Consultant Anaesthetist explained it to me.

[andy2]

AA is almost correct:
The triad of anaesthesia is
1) 'anaesthesia' or 'hypnosis' - rendering the patient unaware and amnesic
2) 'analgesia' - pain relief
3) 'relaxation' -the muscles are relaxed. This does not necesscarily mean paralyzed - although for most major body cavity surgery (abdominal, thoracic, cranial) it does. However for many operations relaxation can be achieved with adequet amounts of anaesthesia and analgesia, and for these operations patients can breath for themselves rather than having to be ventilated manually.

[african_anesthetist]

touche andy2

[curlysin]

induction agents induce anaesthesia and are also used for maintenance of anaesthesia although at much lower doses, it induces a state of deep anaesthesia which is why the patient often stops breathing at that point , this is normal in skilled hands.

oh and btw most muscle relaxants are not curare derivatives - nasty drug - the BP drops like a stone and quite a few ppl get reactions to it

Muscle relaxants are'nt really the drugs that cause the CV instability, this is caused by the induction agent usually Propofol and the opioid used along side usually Fentenyl. Then when you add the volatile agent into the mix say Sevo this causes even further CV instability!! Add on the fact that the patient maybe already fluid depleted - and have multiple other medical conditions! You can see why this could be a receipe for disaster and why it should only be used in the hands of a skilled practitioner!!


Anaesthesia can be defined as a lack of response and recall to noxious stimuli. It includes the triad of paralysis, unconsciousness and analgesia.

The patient stops breathing due to the effects of the anaesthetic agents on the respiratory centre .Opioid drugs, such as morphine or fentanyl, depress the respiratory centre's response to hypercarbia. These effects can be reversed by naloxone. Volatile anaesthetic agents depress the respiratory centre in a similar fashion, although ether has less effect on respiration than the other agents. Volatile agents also alter the pattern of blood flow in the lungs, resulting in increased ventilation/perfusion mismatch and decreasing the efficiency of oxygenation. Nitrous oxide has only minor effects on respiration.

The depressant effects of opioids and volatile agents are additive and close monitoring of respiration is necessary when they are combined.

[Clarkey]

Please have a look at the date of posts before replying if you are expecting a reply, some of these posts are 4 years old!

[andy2]

I think that reply neatly illustrates why chiropractors are treated with suspicion by most doctors - come on man, if you are going to try and give an answer at least make a stab at getting it right (for a clue you could just read the posts above) rather than just burble some semi-correct garbage.

[gasdoc]

Anesthetics induce unconsciousness (deep deep sleep), and cuts down all sensations. Patients become unaware of there surroundings. They can't hear , see, feel touch, pressure etc. Hot and cold sensations are gone and to some extent feeling of pain is also not there. General anesthetics also block many protective reflexes of the body and cardiorespiratory system is compromised. So in anesthesia patient is in much deeper state then simple sleep, and there is a threat to his life unless some anaesthesiologist quickly take over the reins and provides ventilatory and cardiac support.

But anesthetics do not block the pain pathway completely and to similar extent. Some group of drugs known as 'local anesthetics' are better in blocking pain sensations then 'general anesthetic' group of drugs.
So Analgesics like narcotics, NSAIDS etc. are required to fulfill that deficiency .

Muscle relaxants are used to relax muscles. They do nothing except relaxation. They do not relieve pain, nor induce any unconciousness.

Giving Anaesthesia is a combination of all the three, so that goals are met, patient is able to tolerate the cutting and sewing of surgery and is able to come out alive from the operation theatre.