analgesics and anesthetics

sodium blockade in the CNS neutrons

local anesthetics have either an ester-bond or amide bond

• ester type are procaine/novocain, marcaine, cocaine and are metabolized by plasma enzymes.
• amide type are lidocaine and are metabolized by the liver.

• CNS excitation and seizures
• anaphylaxis
• respiratory depression
• bradycardia
• tachycardia - especially cocaine
• relaxation of the cardiac muscle - cardiac arrest

• injectable solutions - .5%, 1%, 2%, 10%
• lidocaine- topical cream, ointment, patches (lidoderm), jelly, aerosol are available as well as solutions for injections also used as a sodium block.
• cocaine HCl- powder and topical solutions
• tetracaine- topical forms and eyedrops

rapid onset, usually takes 2-3 minutes, short half life

• topically
• infiltration injection of a local site usually with lidocaine & epinephrine - NEVER use on fingers, toes, or nose.

• a tourniquet to prevent rapid circulatory absorption, the lidocaine is injected into distal vein in the area, ex. hand or arm
• epidural injection
• spinal injection

• the most invasive techniques of injection are the highest risk for adverse reactions:
• hypotension due to blockade of the sympathetic nervous system.
• vagal response: causes bradycardia, possible cardiac arrest
• epidurals for birth can cause CNS depression in the newborn.

• check patient allergies, anesthesia reactions prior to procedure and communicate to the physician.
• constantly monitoring vital signs: respiratory rate and effort, blood pressure, heart rate
• have epinephrine conveniently available for anaphylaxis
• monitor injection site for signs of swelling or infection
• check sensorium distal to injection site - ex. wiggle toes

general inhaled anesthetics

minimum alveolar concentration is the minimum concentration of the drug that will produce immobility in 50% of patients exposed to a painful stimulus. The more concentrated the the air the fater the uptake. Which is why gas is given by a mask.

• was first invented in the 1800's. Nurses administered gases doctors did not take over till after WW2.
• nitrous oxide was used by sigmond freud in sniff parties

• benzodiazapines (anti-anxiety sedatives), ex: midazolam, valium, ativan
• muscle relaxants
• opioids - morphine and fentanyl
• anticholinergics - to counteract the parasympathetic reflex, vagal response of the heart = severe bradycardia and hypotension
• using these drugs to induce relaxation helps the anesthetist to use less gas.
• barbituates = thiopental (pentothal) "truth serum"
• propofol (diprivan)- most commonly used
• etomidate (amidate)
• ketamine (ketalar) not used as much cause hallucinations
• neuroleptics- fentanyl mixed with drosperidol, name brand is innovar.

• halothane
• isoflurane
• enflurane
• desflurane
• sevo flurane
• all of these drugs have a risk for malignant hypthermia and in combination with succynocholine is a higher risk

• respiratory depression
• cardiac vagal response and cardiac arrest
• anaphaylaxis
• hepatotoxicity and renal toxicity
• DRT- dead right there
• prolonged sedation
• malignant hypothermia
• decreased bowel motility and constipation
• nausea and vomiting.

• 1. airway
• 2. circulation- continuous monitoring of cardiac status and blood pressure
• 3. temperature- watch out for a high rise as a result of GAS, malignant hypothermia
• 4. pain management
• 5. LOC

• patient teaching- reduce patient anxiety
• allergy history
• communication with healthcare team about previous adverse reactions and anesthesia

• opiods work on the Mu receptors primarily (MOO makes you happy) and some Kappa receptors = sedation and less pain.
• These receptors block the pain receptors so the patient does not "feel pain". Th problem with these receptors is the patient may become dependent and go through some withdrawal symptoms.

morphine

• alfentanil
• fentanyl IV
• hydromorphone
• levorphanol
• morphine
• heroin
• oxymorphone
• meperidine
• sulfentanil
• methadone

• itching
• pupil constriction
• hypotension - morphine is a vasodilator
• constipation and urinary retention
• nausea and vomiting
• euphoria (MU)
• involuntary orgasm in some patients

• anaphylaxis
• respiratory failure: the client respirations are 12/minute or less
• neurotoxicity
• hepatotoxicity
• oversedation
• drug tolerance- builds up to a larger dose required to kill pain
• physical dependence

• naloxone (narcan) used to reverse overdose or respiratory suppresion , blocks the MU and Kappa receptors.
• problem: if your patient has any kind of pain they will feel it immediatly x 10

• codeine
• oxycodone
• hydrocodone
• prophoxyphene

• orally or IV, used to control mild to moderate pain
• problem: number one abused drug class in the USA

morphine

• analgesia
• sedation
• euphoria
• cough suppression- used in cough syrups
• miosis- pinpoint pupils

nausea/vomiting, respiratory depression, constipation, urinary retention.

Non Steroidal Anti Inflammatory Drugs

OTC

mild to moderate pain levels and inflamed disease processes.

blocking arachnadonic acid cycle ehich produces prostaglandins. As a result can trigger asthma in asthmatics.

absorbed 90% by the GI tract, metabolized by the liver. Some are cleared by the kidneys so doses need to be adjusted for people with renal disease or just avoid them

• motrin, advil, midol, and 2-4 hours
• NSAIDS

• Aleve, 10-20 hours
• NSAIDS

• Indocin 2.6 - 11 h
• NSAIDS

• Mobic, 20 h
• NSAIDS

• specifically used for gout, 30 hours
• NSAIDS

• toradol, 4.5 hours
• NSAIDS

GI bleeds from chronic use, asthma attack, increased BUN, creatinine

take only with food, not to be taken with aspirin or other anticoagulants, avoid alcohol with use. Since T1/2 lives vary, the client may prefer longer acting NSAIDS.

mostly oral, some can be given IV or IM (colchicine and toradol

moderate and inflammatory pain. Also used as a blocker for familial polyptosis (colon polyps) which has an 80% genetic link.

inhibits the enzyme cox 2 which creates prostaglandins metabolized by the liver.

NSAIDS

GI complications

• Celecoxib (Celebrex) 100mg-200mg
• T1/2 is 12 hours