Pain Most common reason people seek health care Tissue damage activates free nerve endings (pain...
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Transcript of Pain Most common reason people seek health care Tissue damage activates free nerve endings (pain...
PainPain
Most common Most common reason people seek reason people seek health carehealth care
Tissue damage Tissue damage activates free activates free nerve endings nerve endings (pain receptors)(pain receptors)
Generally indicates Generally indicates tissue damage tissue damage
PainPain
Defined as Defined as whatever the whatever the patient says it ispatient says it is
It exists whenever It exists whenever he or she says it he or she says it doesdoes
Gate TheoryGate TheoryPg 122 Fig 9-1Pg 122 Fig 9-1
Injury results in release (from the tissues) Injury results in release (from the tissues) of of Bradykinin Bradykinin HistamineHistamine ProstoglandinsProstoglandins
Action potential along nerve fiberAction potential along nerve fiber Activates pain receptorActivates pain receptor Enter the spinal cord via the dorsal hornEnter the spinal cord via the dorsal horn If impulses can be stopped here…pain stopsIf impulses can be stopped here…pain stops
Gate TheoryGate Theory
Brain can evaluate, identify and Brain can evaluate, identify and localize painlocalize pain
BradykininBradykinin
Strongest pain producing substancesStrongest pain producing substances May be involved in acute painMay be involved in acute pain Prostglandins increase sensitivity to Prostglandins increase sensitivity to
painpain Chemical mediators activate and Chemical mediators activate and
sensitize pain receptors or stimulate sensitize pain receptors or stimulate the release of pain producing the release of pain producing substancessubstances
Endogenous AnalgesiaEndogenous Analgesia
Activated by nerve Activated by nerve signals or by signals or by morphine-like morphine-like substances substances entering the brainentering the brain
Opiate receptorsOpiate receptors Endogenous Endogenous
peptidespeptides
Pain TreatmentPain Treatment Often UNDER treatedOften UNDER treated Cancer pain Cancer pain
management in management in particularparticular Not aimed at Not aimed at
prevention of addictionprevention of addiction Patient comfortPatient comfort
Tolerance may occur Tolerance may occur Pg 123 (do not confuse Pg 123 (do not confuse
with addiction)with addiction)
Opiod AnalgesicsOpiod Analgesics
Moderate to Moderate to severe painsevere pain
Reduction of pain Reduction of pain sensationsensation
SedationSedation Decreases Decreases
emotional upsetemotional upset Most are schedule Most are schedule
IIII
Opioid AnalgesicsOpioid Analgesics
Oral, IM, SQ, & IVOral, IM, SQ, & IV PO requires high doses PO requires high doses Prevent or relieve acute or chronic Prevent or relieve acute or chronic
pain pain Bind to opioid receptors in the brain Bind to opioid receptors in the brain
and spinal cord and activate the and spinal cord and activate the endogenous systemendogenous system
Agonist-binds to a receptor site and Agonist-binds to a receptor site and causes a responsecauses a response
Partial agonist-binds to a receptor Partial agonist-binds to a receptor and causes only limited actionsand causes only limited actions
Antagonist-bind to a receptor and Antagonist-bind to a receptor and produce no responseproduce no response
AgonistsAgonistsPrototype: Morphine Prototype: Morphine
SulfateSulfate Morphine and morphine like drugsMorphine and morphine like drugs Activity at Mu, Kappa, & ??? Delta Activity at Mu, Kappa, & ??? Delta
receptorsreceptors Severe & Chronic PainSevere & Chronic Pain IV, IM, SQ, Suppository, Epidural,&, POIV, IM, SQ, Suppository, Epidural,&, PO Impaired kidney function may cause Impaired kidney function may cause
prolonged drug action and accumulationprolonged drug action and accumulation Nonceiling drugNonceiling drug
Prototype:Prototype:CodeineCodeine
PO onset 15-30 PO onset 15-30 minutes duration 4-6 minutes duration 4-6 hourshours
Naturally occurring Naturally occurring opium alkaloidopium alkaloid
ANTI-TUSSIVEANTI-TUSSIVE AnalgesicAnalgesic Milder adverse Milder adverse
effects than effects than morphinemorphine
May be combined May be combined with Acetaminophenwith Acetaminophen
ContraindicationsContraindications
Respiratory Respiratory depressiondepression
Chronic lung Chronic lung diseasedisease
Liver or kidney Liver or kidney diseasedisease
Prostatic Prostatic hypertrophyhypertrophy
Increased ICPIncreased ICP
Agonist/AntagonistAgonist/AntagonistPrototype: Nalbuphine Prototype: Nalbuphine
(Nubain)(Nubain) Agonist activity at some sites and Agonist activity at some sites and
antagonist at othersantagonist at others Low abuse potentialLow abuse potential Potent analgesicsPotent analgesics May produce withdrawal symptoms May produce withdrawal symptoms
in those with opiate dependencein those with opiate dependence SyntheticSynthetic
Opioid AntagonistOpioid AntagonistPrototype: Naloxone Prototype: Naloxone
(Narcan)(Narcan) Reverse or block Reverse or block
analgesia, analgesia, respiratory respiratory depressiondepression
Onset within Onset within minutes and last 1-2 minutes and last 1-2 hourshours
Shorter duration Shorter duration than opioidsthan opioids
May give repeated May give repeated injectionsinjections
WithdrawalWithdrawalPg 125Pg 125
Anxiety, aggressiveness, Anxiety, aggressiveness, restlessness, lacrimation, rhinorhea, restlessness, lacrimation, rhinorhea, perspiration, pupil dilation, perspiration, pupil dilation, piloerection, elevated body temp, piloerection, elevated body temp, diarrhea, BPdiarrhea, BP
Begin within few hours of last doseBegin within few hours of last dose Early recognition and treatment keyEarly recognition and treatment key
Side Effects & Side Effects & AssessmentsAssessments
Respiratory Respiratory depressiondepression
HypotensionHypotension N & VN & V ConstipationConstipation
Monitor Monitor respirationsrespirations
Orthostatic Orthostatic pressurespressures
BPBP Bowel regimenBowel regimen
TeachingTeaching
No EtohNo Etoh Do not increase Do not increase
dose (unless Rx’d)dose (unless Rx’d) Stay in bed 30-60 Stay in bed 30-60
minutes after minutes after receivingreceiving
No heavy No heavy machinerymachinery
High fiber foods & High fiber foods & increase fluidsincrease fluids
Non Opioid AnalgesicsNon Opioid Analgesics
Analgesic, Antipyretic, & Analgesic, Antipyretic, &
Anti-inflammatory DrugsAnti-inflammatory Drugs
Acetylsalic Acid (Aspirin)Acetylsalic Acid (Aspirin) Acetominophen (Tylenol)Acetominophen (Tylenol) Ibuprofen (Motrin)Ibuprofen (Motrin)
PrototypePrototypeAcetominophenAcetominophen
Does not cause N & V or GI bleedingDoes not cause N & V or GI bleeding Does not interfere with clottingDoes not interfere with clotting Lacks anti-inflammatory activityLacks anti-inflammatory activity Metabolized in liverMetabolized in liver Alters pain perceptionAlters pain perception
Side EffectsSide Effects
Hepatic necrosis (Acute overdose)Hepatic necrosis (Acute overdose) Nephropathy (Chronic overuse)Nephropathy (Chronic overuse) Liver toxicity increase with alcohol Liver toxicity increase with alcohol
ingestion!ingestion!
Mucolytic Mucolytic Prototype: Acetylcysteine Prototype: Acetylcysteine
(Mucomyst)(Mucomyst) Antidote to Antidote to
Acetaminophen Acetaminophen overdoseoverdose
Give POGive PO Must be given Must be given
within 24 hourswithin 24 hours Bad smellBad smell 17 doses17 doses Pg 132Pg 132
Activated Charcoal Activated Charcoal
May be given for an overdose of May be given for an overdose of AcetaminophenAcetaminophen
Other NSAIDSOther NSAIDS
Arachidonic Acid Arachidonic Acid PathwayPathway
Released after injuryReleased after injury MetabolizedMetabolized Both paths result in inflammation Both paths result in inflammation
and painand pain
GI DistressGI Distress
Prostaglandins maintain the Prostaglandins maintain the integrity of stomachintegrity of stomach
Inhibition sets upInhibition sets up UlcerationUlceration GI bleedsGI bleeds
MisoprostolMisoprostol
PrototypePrototypeASA (Aspirin)ASA (Aspirin)
Inhibits the Inhibits the synthesis of synthesis of prostaglandinsprostaglandins
Non selective COX Non selective COX inhibitorinhibitor
Antiplatelet and Antiplatelet and AntipyreticAntipyretic
Prevent sensitization Prevent sensitization of pain receptors to of pain receptors to various chemical various chemical substancessubstances
ContraindicationsContraindications
PUDPUD GI or other bleeding disordersGI or other bleeding disorders HypersensitivityHypersensitivity Impaired renal functionImpaired renal function Children with viral infections (pg Children with viral infections (pg
671)671) Intoxication (table 42-2)Intoxication (table 42-2)
PrototypePrototypeIbuprofen (Motrin)Ibuprofen (Motrin)
Anti-inflammatory agentAnti-inflammatory agent OTCOTC May be better tolerated than aspirin May be better tolerated than aspirin
but work in a similar fashionbut work in a similar fashion Hypersensitivity may occur in people Hypersensitivity may occur in people
with allergy to aspirinwith allergy to aspirin Contraindications similar to ASA Contraindications similar to ASA
(except Reye’s)(except Reye’s)
Selective COX-2 InhibitorSelective COX-2 InhibitorPrototype: Celecoxib Prototype: Celecoxib
(Celebrex)(Celebrex) Designed to relieve Designed to relieve
pain, fever, and pain, fever, and inflammationinflammation
Fewer side effects Fewer side effects than older NSAIDSthan older NSAIDS
Contraindicated with Contraindicated with ulcers, GI bleeds, ulcers, GI bleeds, asthma, severe renal asthma, severe renal impairment, & impairment, & allergy to other allergy to other NSAIDSNSAIDS
FeverfewFeverfew
Relieves HA, fever, and menstrual Relieves HA, fever, and menstrual irregularitiesirregularities
Can increase bleeding with aspirin, Can increase bleeding with aspirin, dipyridamole, warfarindipyridamole, warfarin
Contraindicated in pregnant patients, Contraindicated in pregnant patients, breastfeeding, and children < 2 y/obreastfeeding, and children < 2 y/o
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