Analgesia Options GL

7/28/2019 Analgesia Options GL

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Defini=ionIASP

• “Unpleasantsensoryandemo=onal

experienceassociatedwithactualorpoten=al

=ssuedamageordescribedintermsofsuch

damage”

• Acutepain:Painofshortandlimiteddura=on.





Today

1. Analgesiaoutsidethe

recoveryroomismostoNenleNtothesurgeon

2. Analgesiaishopelesslyinadequate

Gallup1995

Bostrom1997

Won1999



Barrierstoeffec=veanalgesia

1. Patient/family fears of addiction2. The “Good Patients Don’t Complain” syndrome

3. Physician/Nursing fears of addiction

4. Concern for side-effects

5. Delays inherent in PRN dosing

6. Dosage ranges default to minimum (e.g. 4-6mg 2-4hrly)7. Lack of knowledge regarding alternatives

8. Concern regarding legal/regulatory issues9. Low priority given to pain concerns

10. Analgesia can be labour intensive

11. PAIN IS INVISIBLE







PAIN

Anxiety

Demoralized

patient

Sleeplessness↑ Regional

blood flows

↑ Sympathetic

activity

Pulmonary

compromise

Hypoxia

AtelectasisInfection

Hypercarbia

↑ O2 consumption

Tachycardia

Myocardialischaemia





Painmodula=on

• 1.Decreaseexita=on(Opioids,achannelblockers,Ketamine)

• 2.Increaseinhibi=on(Alphaagonism,GABA

agonists)



Op=malacutepainmangement

Mul=factorial• Pa=entco-morbidity

• Magnitudeofinjury

• Previousopioiduse• Mentalcapacity

• Ethniccustoms…

• Bestachievedbyacombina=onofagentsortechniques





Extentofinjury

• Determinetheneedforanalgesia

– Minor

– Moderate

– Major



SYSTEMICAALGESIA



Opiates

• Mostcommonlyused

– Oral – IM

• 75%ofhospitalizedpa=entsremaininpainon

IMregimenCohen1989

• Typicalside-effects



Opiates



Opiates



Opiates



Opiatereceptor(κ)



PharmacodynamicsofOpioids

• Cardiovascular• Endocrineeffects• Respiratoryeffects



PharmacodynamicsofOpioids

• on-therapeu=ceffects• PostOpera=veauseaandVomi=ng

• Seda=on• Itching• Ileus• Urinaryreten=on• SphyncterofOddi



Dosagerecommenda=onsfor

Tradi=onalOpioidAnalgesics

Recommended Starting dose

(Weight >50kg)


(Weight <50kg)

Oral Parenteral Oral Parenteral

Morphine 30mg 4 hourly 10mg 4 hourly0.3mg/kg

4hourly

0.1mg/kg 4

hourly

Codeiene 60mg 4 hourly30mg 2 hourly

(SC IM)

1 mg/kg 4

hourly

Not

recommended

Meperidine 100mg 4 hourly0.75mg/kg 2-4

hourly



Dosagerecommenda=onsfor

Tradi=onalOpioidAnalgesics


(Weight >50kg)


(Weight <50kg)

Oral Parenteral Oral Parenteral

Methadone 20mg 6 hourly 10mg 6 hourly0.2mg/kg 6-8

hourly

0.1mg/kg 6-8

hourly

Oxycodone 10mg 4 hourly Not available0.2mg/kg 4

hourlyNot available



Par=alAgonists-Antagonists

• Pentazosine• Butorphanol• albuphine

• Buprenorphine



Tramadol



EpiduralandIntrathecalopioids

• Three types of receptor

• Location in the spinal cord:

– Pre-synaptic Aδ +C fibres

– Post synaptic

– On WDR neurons

– Enhancing descending

inhibitory pathways





EpiduralandIntrathecalopioids



__ Morphine

--- Alfentanil

… Fentanil

-.- Sufentanil



onSteroidalAn=-

inflammatoryagents





ARACHIDONIC ACID

Prostacyclins

Endoperoxidases

Thromboxane Prostaglandins

Cyclo-oxygenase



Selec=veCOX2inhibi=on

• Twoisoforms

• COX1(Cons=tu=ve):• Gastricmucosa

• Renalvascularbed• ThromboxaneA2inplatelets

• COXII(Inducable):• Inducedundercondi=onsofinflamma=on



Immer et al 2003

U r e a



Adverseeffects

• Gastrointes=nal• Renal• Hemostasis

• Respiratory





Salicylates

• Aspirin• Hydrolysedtosalicylicacid• Halflife2-3h• Dosedependantduetorate-limi=nghepa=c

conjuga=on

• Highincidenceofside-effects• Contra-indicatedinchildren(ReyeSyndrome)



Ketorolac

• IVagent(alsoothers,egXefo®)• Soleagentoradjuvant• Decreasedside-effects

• Mayrequiremorepropofol

Bosek et al. J Clin Anes 1992

Souter et al. Anest Analg 1994



Otheranalgesicop=ons

1. Paracetamol

2. Ketamine

3. Mul=modalagents:Tramadol

4. Clonidine



Paracetamol

• Acetaminophen

• Mostcommonanalgesicagent

• Weakan=-inflammatoryeffects(COX

nonselec=ve)

• Analgesic• An=pyre=c



Pharmacokine=cs• Goodoralandrectalabsorb=on• Variablyproteinbound• Inac=vatedintheliver• Conjugatedtoglucoronideorsulphateproduct• Halflife2-4hours• Toxicity: – auseaandvomi=ng

– LiverfailureaNer24-48hours



Paracetamolmetabolism



• Paracetamoldosage:• Rectalloadingrequired40mg/kg

• Oraldosage15mg/kgpo4hourly

• IV(PERFALGA)15MG/KG• Maximum50mg/kgperday



Ketamine



MDAreseptor



MDAreceptor

• Centralinpathogenesisandmaintenanceof

chronicpain.

• Mechanismfortolerancetoopioids–chronic

upregula=onofMDAreceptors

• Ketamineinlowdoseadministeredtopa=ents

withinadequateopioidanalgesiashownto

restoreopioidsensi=vity.



Ketamine

• Resemblephencyclidine

• Racemicmixture

• Blockac=va=onoftheMDAglutamate

receptor

• Dissocia=veanaesthesia• Analgesiaoutlastsanesthesia

• Profoundsoma=candvisceralanalgesiaeven

atsubhypno=cdosages



Ketamine:Clinicalapplica=ons

• Paediatrics• Premedica=on6mg/kgin0.2ml/kgcooldrink

• Soleanaesthe=cagent• Burnsandobstetrics

• Ketamine0.5mg/kgIVor15-30µg/kg/min

• Seda=onandanalgesia• Diasepam0.15mg/kg+Ketamine0.5mg/kg• Midasolamhasnarrowertherapeu=cindex

• Epidural



α2-AGOISTS

• Ac=va=onα2-receptorresltsinhyperpolarisa=on

ofpresynap=cneurons

involvedinpaintransmission

• Reducesympathe=c

oulow

• Seda=ve,anxioly=ceffects• Analgesiceffects• Epiduralclonidineforcancer ain



α2-AGOISTS

• Widevarietyofapplica=ons

• orespiratorydepression• S=llrousable,aen=ve• Specificplaceinthermalinjuries

• Decreasefentanylrequirementby50%

• Aenuatehyperdynamicstate



• Dexmedetomidine(Precedex)

– Moreselec=ve,morepotent

– Specifican=dotea=pamezole

– Postcardiac-surgeryseda=onincombina=onwith

Remifentanyl

– Effec=veadjuvanttoneuraxialanaesthesia

Jaakola wt al. J Clin Anes 1994

Aho et al. Anest Analg 1991



Paediatric pain



Paediatricpain

“EW”ADVACES:• Children,babiesandinfantsdo

experiencepain

• Painhasadverseeffectsevenatbirth

• Primaryaddic=oninchildrenvirtually

unknown

• Childrencandescribepainqualita=vely

• Thesystemthatmediateschildrens’painpercep=onsarecomplex



Paediatricnocicep=on

• Ac=veintegra=vemechanisms,notpassiverelaysystems

àLEARIGmechanism

• Differentpainfromsame=ssuedamage

• PainOTdirectlypropor=onaltothenatureandextentof=ssuedamage

αage

αsex

αDevelopmentlevel

αpriorpain

αpsychologicalfactors

αcontextualfactors







NOXIOUS

STIMULUSPAIN

SENSATION

SITUATIONAL FACTORS

• Expectation

• Control

• Relevance

BEHAVIOURAL FACTORS

• Coping style

• Overt distress

• Parenteral response

EMOTIONAL FACTORS

• Fear

• Anger

• Frustration

Sex

Age

Cognitive level

Previous pain

Family

learning

Culture

C f h i



Commonfactorsthatincrease

children’spainpercep=on

SITUATIONAL FACTORS

Ø Inaccurate information

regarding:

Ø CauseØ Cessation

Ø Treatment efficacy

Ø Little perceived control

Ø Few independent pain-

reducing strategies

Ø Learned pain triggers

BEHAVIOURAL FACTORS

Ø Overt distress behaviours

Ø Inconsistent parental

responsesØ Prolonged physical

distress

Ø Limited physical activity

Ø Limited peer and socialactivities

EMOTIONAL FACTORS

Ø Specific anxiety and

fear about:

Ø Diagnosis,Treatment

Ø Future

implications

Ø General anxiety and

stress

Ø Inability to identify and

express emotions

Ø High expectations for

achievementMcGrath 1993

ASSESS



ASSESS

• Character of pain

• Contributing

situational, emotionaland behavioural

factors

• Contra-indications to

pharmacologicalagents

ASSESS



ASSESS

DEVELOP TREATMENT PLAN

ASSESS



ASSESS


Anesthetics Analgesics

Cognative therapy Physical therapyBehavioural therapy

ASSESS



ASSESS


• Distraction and attention• Choices and control

• Information• Imagery



ASSESS



ASSESS


• Behavioural modification• Exercise

• Relaxation therapy• Biofeedback



ASSESS



ASSESS


• Physiotherapy• Massage

• Thermal stimulation• TENS

• Acupuncture



ASSESS



ASSESS




IMPLEMENT PLAN



• Provide feedback on causes and

contributing factors to CHILD and

PARENTS

• Provide rationale for integratedtreatment

• MEASURE child’s pain regularly

• Evaluate effectiveness

• Revise if necessary

IMPLEMENT PLAN



• Provide children with accurate information

and realistic expectations

• Improve own control by teaching pain-reducing strategies

• Modify any behaviours (child, staff or

parents) that intensify pain

• Reduce emotional distress by reducing the

aversive meaning of the pain

AIM:



Measuringpain

Subjective Biological Behavioural

Mersey 1983

“ Pain is ALWAYS subjective”



Subjec=vemeasurementsofpain

• Selfreports• Directques=oning• McGillPainQues=onnaire(MCQ)

Eland & Anderson 1977

Ross & Ross 1988



Melzack & Torgerson 1971



Melzack & Torgerson 1971




• Selfreports• Directques=oning• Self-ra=ngscales

• Visualanaloguescales• Categoryra=ngscales• umericalra=ngscales

Maunuksela 1987




• Visualanalogscale

NO pain PAIN as badas it can be

Maunuksela 1987

Subjec=ve measurements of pain




inchildren

• Visualanalogscale• Categoryscales

• Descrip=ve

• PokerChipTool• FaceScale

Wilkie 1988Mild Moderate SevereNo pain

Whaley and Wong 1991

Subjec=ve measurements of pain




inchildren

• Visualanalogscale• Categoryscales• umericalscales

– Painthermometer

– Diaries• onverbalra=ngs



OucherScale

Behavioural measurement of



Behaviouralmeasurementof

paediatricpain

• Vocaliza=on,facialexpression,movement

– eonatalFacialAc=onCodingSystem

– InfantPainBehaviourRa=ngScale – TheChildren'sHospitalofEasternOntarioPain

Scale(CHEOPS)

Grunau & Craig 1988

Frank 1987

Beyer 1990

Biological indicators of paediatric



Biologicalindicatorsofpaediatric

pain

ü Heartrateü Transcutaneousoxygentensionü Palmarswea=ng

ü Cor=solû ?Endorphinsû ?respira=onrate

û ?Bloodpressure



Howaccurateis

pain

measurement?



Documents

Analgesia Options GL