Analgesia vs. Anesthesia BY ARNESHIA MCCONNELL

Analgesia: Word BreakdownPrefix “an-” means without

Suffix “-algesia” means pain, sensitivity

ANALGESIA: LACK OF SENSATIONSA deadening or absence of the sense of pain

without the loss of consciousness.

AnalgesicsAn analgesic (also known as a

painkiller) is any member of the group of drugs used to relieve pain.

The main pharmacological action of analgesics is on the cerebrum and medulla of the central nervous system.

Classes of AnalgesicsParacetamol and NSAIDs

The exact mechanism of action of paracetamol/acetaminophen is uncertain, but it appears to be acting centrally (in the brain rather than in nerve endings).

Aspirin and the other non-steroidal anti-inflammatory drugs (NSAIDs) inhibit cyclooxygenases, leading to a decrease in prostaglandin production.

This reduces pain and also inflammation (in contrast to paracetamol and the opioids).

Classes of Analgesics (cont’d)COX-2 inhibitors

These drugs have been derived from NSAIDs.Opiates and morphinomimetics

Morphine, the archetypal opioid, and various other substances (e.g. codeine, oxycodone, hydrocodone, dihydromorphine, pethidine) all exert a similar influence on the cerebral opioid receptor system.

FlupirtineFlupirtine is a centrally acting K+ channel opener

with weak NMDA antagonist properties. It is used in Europe for moderate to strong pain and

migraine and its muscle relaxant properties.

Specific FormsCombinations

Found in paracetamol and codeine preparations found in many non-prescription pain relievers.

Found in vasoconstrictor drugs such as pseudoephedrine for sinus-related preparations, or with antihistamine drugs for allergy sufferers.

Topical or SystemicTopical analgesia is generally recommended to

avoid systemic side-effects.Painful joints, for example, may be treated with

an ibuprofen- or diclofenac-containing gel

Specific Forms (continued)Psychotropic Agents

Tetrahydrocannabinol (THC) and some other cannabinoids, either from the Cannabis sativa plant or synthetic, have analgesic properties, although the use of cannabis derivatives is currently illegal in many countries.

A recent study finds that inhaled cannabis is effective in alleviating neuropathy and pain resulting from e.g. spinal injury and multiple sclerosis.

Specific Forms (continued)Atypical and/or adjuvent analgestics

Orphenadrine, cyclobenzaprine, scopolamine, atropine, gabapentin, first-generation antidepressants and other drugs possessing anticholinergic and/or antispasmodic properties are used in many cases along with analgesics to potentiate centrally acting analgesics such as opioids when used against pain especially of neuropathic origin and to modulate the effects of many other types of analgesics by action in the parasympathetic nervous system

The use of adjuvant analgesics is an important and growing part of the pain-control field and new discoveries are made practically every year.

Many of these drugs combat the side effects of opioid analgesics.

Patient Controlled Analgesia (PCA)Patient Controlled Analgesia (PCA) is a method

of pain control that gives the patient the power to control their pain.Pain medication is administered through a

computerized pump.The pump contains a syringe of pain medication

as prescribed by a doctor that is connected directly to a patient’s intravenous (IV) line. The pump is set to deliver a small, constant flow of

pain medication. Additional doses can be self-administered as needed by

the patient pressing a button.

PCA PUMP

Safety of PCA PumpsPCA pumps have built in safety

features.

The total amount of analgesic (pain reliever) that a patient can self-administer is within a safe limit.

Because of these features, there is no worry of overdose.

Who uses PCA?Patients recovering from surgery most often are equipped with PCA pumps.

Patients coping with other kinds of pain can also use the PCA pump.

Advantages of PCAThe physician determines the dosage based

on the patient’s weight to prevent overdose.Narcotic addiction can be avoided because

the drug is taken on a short-term controlled basis.

Pain relief is available around the clock.The PCA unit is programmed to control the

dosage; the unit “locks out” if the dosing frequency is exceeded.

Most adults and children can use PCA

Disadvantages of PCAThe button on the PCA pump can be

accidentally pressed, delivering an unneeded dose of medication.

If the PCA pump isn’t programmed properly, results include an under-dose or overdose in medicine.

AnesthesiaPrefix “an-” means without.

Suffix “-esthesia” means feeling, sensation.

Anesthesia means without feeling or sensation.Local or general insensibility to pain with or

without the loss of consciousness, induced by an anesthetic (drug that produces anesthesia).

Types of AnesthesiaThere are four main types:

Local – numbs one small area of the body. You stay alert and awake

Conscious or IV sedation - uses a mild sedative to relax you and pain medicine to relieve pain. You stay awake but may not remember the procedure afterwards.

Regional anesthesia- blocks pain in an area of the body, such an arm or leg. Epidural anesthesia, which is sometimes used during childbirth, is a type of regional anesthesia.

General anesthesia- affects your whole body. You go to sleep and feel nothing. You have no memory of the procedure afterwards.

Features of AnesthesiaThere are four features of anesthesia:

The lack of motor response to instructions

suppression of autonomic and skeletal responses to intraoperative stimuli such as incisions

absence of retrospective awareness of pain

postoperative amnesia for surgical events such as conversations among the medical team

How Does Anesthesia Work?It is currently unknown how anesthesia

works, but there a number of plausible hypotheses.The most common accepted theory is that that

general anesthetics operate directly on the central nervous system to temporarily inhibit synaptic transmission (the chemical means by which neural impulses are transmitted between adjacent neurons).

This results in a general loss of consciousness that affects sensory awareness in all modalities and at all body loci.

Major Differences Between Analgesia and AnesthesiaAnalgesia is lack of pain, anesthesia refers to

lack of sensationAnesthesia is usually accompanied by

analgesiaPatients are fully aware and awake while

using analgesia; with anesthesia, patient can be either unconscious and asleep or awake and fully comprehensible.

Analgesia is patient controlled, anesthesia is controlled by a person specializing in administration of anesthesia.

SOURCESwww.elmhurst.edu/~chm/vchembook/674nar

cotic.htmlHttp://en.wikipedia.org/wiki/Analgesichttp://www.webmd.com/pain-management/gui

de/pcahttp://www.answers.com/topic/anesthesiahttp://www.nlm.nih.gov/medlineplus/anesthes

ia.htmlhttp://www.institute-shot.com/anesthesia_and

_surgery.htm