preoperative medications goals of pre-op medication
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Preoperative MedicationsPreoperative Medications
Goals of Pre-op MedicationGoals of Pre-op Medication Optimize physical conditionOptimize physical condition Relief of anxietyRelief of anxiety Relief of painRelief of pain AmnesiaAmnesia Facilitate induction Facilitate induction
Goals (con’t)Goals (con’t) Facilitate smooth operative Facilitate smooth operative
coursecourse Facilitate smooth wake-upFacilitate smooth wake-up Antiemetic effectAntiemetic effect Prophylaxis against aspirationProphylaxis against aspiration
Psychological PreparationPsychological Preparation Pre-op visit lays the foundationPre-op visit lays the foundation– Trust and confidence are Trust and confidence are
essentialessential– Be efficient, informative and Be efficient, informative and
reassuringreassuring– More effective than sedativesMore effective than sedatives
Psychological Prep (con’t)Psychological Prep (con’t) All patients have some anxietyAll patients have some anxiety– May be outwardly calm, inwardly May be outwardly calm, inwardly
terrified terrified Patients on sedatives have Patients on sedatives have
more anxietymore anxiety
Preoperative MedicationPreoperative Medication
Should be individualized Should be individualized
Give for specific indicationsGive for specific indications
Monitoring should be Monitoring should be
appropriateappropriate
Contraindications to SedationContraindications to Sedation
Poor physiologic reservePoor physiologic reserve
Extremes of ageExtremes of age
Head injuryHead injury
HypovolemiaHypovolemia
Routes of AdministrationRoutes of Administration Oral (60-90 minutes)Oral (60-90 minutes) Intramuscular (30-60 minutes)Intramuscular (30-60 minutes) IntravenousIntravenous RectalRectal NasalNasal DermalDermal
Specific Drugs and DosagesSpecific Drugs and Dosages
Know drugs in each classKnow drugs in each class
Know characteristics of classKnow characteristics of class
BenzodiazepinesBenzodiazepines AnxiolysisAnxiolysis AmnesiaAmnesia SedationSedation Anti-convulsantAnti-convulsant All effects are dose-dependentAll effects are dose-dependent
BenzodiazepinesBenzodiazepines Minimal respiratory depressionMinimal respiratory depression Minimal cardiovascular Minimal cardiovascular
depressiondepression Work well with opioidsWork well with opioids Few side effectsFew side effects
CNS ActionCNS Action SedationSedation
– Enhancement of GABAEnhancement of GABA AnxiolyticAnxiolytic
– Glycine mediated inhibition of brain Glycine mediated inhibition of brain stemstem
AmnesiaAmnesia– Unknown mechanismUnknown mechanism
Specific BenzodiazepinesSpecific Benzodiazepines Diazepam (standard)Diazepam (standard)– Pain on injectionPain on injection– Active metabolitesActive metabolites– Good anticonvulsantGood anticonvulsant– Used as P.O.. pre-opUsed as P.O.. pre-op
Specific Benzodiazepines (con’t)Specific Benzodiazepines (con’t)
LorazepamLorazepam
– Slow onset, long durationSlow onset, long duration
– ProfoundProfound amnesia amnesia
– Not good for outpatientsNot good for outpatients
Specific Benzodiazepines (con’t)Specific Benzodiazepines (con’t)
MidazolamMidazolam– No irritation or phlebitisNo irritation or phlebitis– 2-3x potent as diazepam2-3x potent as diazepam– Rapid onset, rapid metabolismRapid onset, rapid metabolism– Excellent short-term amnesiaExcellent short-term amnesia– Given IV prior to surgeryGiven IV prior to surgery– Given P.O.. to childrenGiven P.O.. to children
BarbituratesBarbiturates SedativeSedative Dose dependent respiratory Dose dependent respiratory
depressiondepression Less safe than benzodiazepinesLess safe than benzodiazepines Do notDo not give to patients with give to patients with
porphyriaporphyria
Butyrophenones (Droperidol)Butyrophenones (Droperidol) Dopamine antagonistDopamine antagonist Appear calm and tranquilAppear calm and tranquil
– Inner terror is reportedInner terror is reported– High rate for refusing surgeryHigh rate for refusing surgery
Alpha blockadeAlpha blockade Excellent anti-emeticExcellent anti-emetic
Other SedativesOther Sedatives HydroxyzineHydroxyzine– Used to augment opioidsUsed to augment opioids
DiphenhydramineDiphenhydramine– Histamine blockerHistamine blocker– Sedative and anticholiergicSedative and anticholiergic
Other Sedatives (con’t)Other Sedatives (con’t)
PhenothiazinesPhenothiazines
– Used to augment opioidsUsed to augment opioids
Chloral hydrateChloral hydrate
– P.O.. pre-op for elderly patientsP.O.. pre-op for elderly patients
OpioidsOpioids Produce analgesiaProduce analgesia Useful prior to painful procedureUseful prior to painful procedure Establish baseline analgesiaEstablish baseline analgesia Reduce anesthetic requirementsReduce anesthetic requirements Comfort upon awakeningComfort upon awakening Work well with sedativesWork well with sedatives
Problems with OpioidsProblems with Opioids
Respiratory depressionRespiratory depression
Orthostatic hypertensionOrthostatic hypertension
Histamine release (morphine)Histamine release (morphine)
Shift in COShift in CO2 2 response curve response curve
Problems with Opioids (con’t)Problems with Opioids (con’t)
Occasional dysphoriaOccasional dysphoria
Nausea and vomitingNausea and vomiting
PruritusPruritus
Sphincter of Oddi spasmSphincter of Oddi spasm
Opioid PremedicationOpioid Premedication Usually given IV in holding Usually given IV in holding
areaarea– Monitor pulse oximetryMonitor pulse oximetry
Fentanyl lollipopFentanyl lollipop Nasal sufentanilNasal sufentanil Oral codeineOral codeine
Prophylaxis for AspirationProphylaxis for Aspiration
Who is at risk?Who is at risk? Full stomach (all emergencies)Full stomach (all emergencies) PregnancyPregnancy ObesityObesity DiabetesDiabetes Hiatal hernia / refluxHiatal hernia / reflux
Prophylaxis / Aspiration (con’t)Prophylaxis / Aspiration (con’t)
Critical valuesCritical values
– Volume > 25 ml.Volume > 25 ml.
– pH < 2.5pH < 2.5
Prophylaxis / Aspiration (con’t)Prophylaxis / Aspiration (con’t) NPO GuidelinesNPO Guidelines– NPO after midnightNPO after midnight» Tradition of strict enforcementTradition of strict enforcement»Now being challengedNow being challenged»Clear liquids may be o.k.Clear liquids may be o.k.»Dehydration and hypoglycemiaDehydration and hypoglycemia
Pharmacologic PreparationPharmacologic Preparation
Reduce gastric volumeReduce gastric volume
Increase gastric pHIncrease gastric pH
Increase gastric motilityIncrease gastric motility
AnticholinergicsAnticholinergics
Atropine / RobinulAtropine / Robinul
Probably not effectiveProbably not effective
Relax lower esophageal toneRelax lower esophageal tone
Have CV side effectsHave CV side effects
Histamine-Receptor AntagonistsHistamine-Receptor Antagonists Cimetidine / RanitidineCimetidine / Ranitidine Reduce gastric acid secretionReduce gastric acid secretion– Increase gastric pHIncrease gastric pH
Few side effectsFew side effects Give H.S. and A.M..Give H.S. and A.M..
Histamine Receptor Antagonists (con’t)Histamine Receptor Antagonists (con’t)
CimetidineCimetidine– Slows metabolism of other drugsSlows metabolism of other drugs
RanitidineRanitidine– More effectiveMore effective– Does not alter hepatic functionDoes not alter hepatic function
AntacidsAntacids Neutralize stomach acidsNeutralize stomach acids Onset is rapidOnset is rapid Increase gastric volumeIncrease gastric volume
– Antacid can be aspiratedAntacid can be aspirated
Use Use onlyonly non-particulate non-particulate antacidsantacids
MetoclopramideMetoclopramide
Gastrokinetic agentGastrokinetic agent
– Increases upper GI motilityIncreases upper GI motility
– Increases G.E. sphincter toneIncreases G.E. sphincter tone
– Relaxes pyloris and duodenumRelaxes pyloris and duodenum
Metoclopramide (con’t)Metoclopramide (con’t) Has antiemetic propertiesHas antiemetic properties May be offset by atropine or May be offset by atropine or
opioidsopioids Combine with HCombine with H22 antagonist antagonist Do notDo not use on bowel cases use on bowel cases
AntiemeticsAntiemetics Emesis is cause for admissionEmesis is cause for admission– Treatment is cost effectiveTreatment is cost effective
Treat high risk patientsTreat high risk patients– History of N and VHistory of N and V– Ophthalmologic surgeryOphthalmologic surgery– Gyn proceduresGyn procedures– ObesityObesity
Antiemetics (con’t)Antiemetics (con’t)
DroperidolDroperidol
– Effective in low doseEffective in low dose
MetoclopramideMetoclopramide
– Antiemetic effect in addition to Antiemetic effect in addition to
reduction in gastric volumereduction in gastric volume
Antiemetics (con’t)Antiemetics (con’t)
OndansetronOndansetron
– Highly effective new drugHighly effective new drug
– Very expensiveVery expensive
– Good rescue drugGood rescue drug
AnticholinergicsAnticholinergics AntisialagogueAntisialagogue– GlycopyrrolateGlycopyrrolate– Ophthalmic proceduresOphthalmic procedures– ENT proceduresENT procedures
Vagolytic effectVagolytic effect– AtropineAtropine
Anticholinergics (con’t)Anticholinergics (con’t)
Sedation and amnesiaSedation and amnesia
– ScopolamineScopolamine
See Barash for side effectsSee Barash for side effects
ClonidineClonidine
AntihypertensiveAntihypertensive
– Alpha-2 blockerAlpha-2 blocker
Produces sedationProduces sedation
Reduces anesthetic requirementsReduces anesthetic requirements
Acute withdrawal causes reboundAcute withdrawal causes rebound
Other Pre-op MedicationsOther Pre-op Medications
AntibioticsAntibiotics
– Ordered by surgeonOrdered by surgeon
– Protocol for valvular heart Protocol for valvular heart
diseasedisease
– Give slowlyGive slowly
Other Preop Medications (con’t)Other Preop Medications (con’t)
SteroidsSteroids
– Adrenals may be suppressed up Adrenals may be suppressed up
to one year after taking steroidsto one year after taking steroids
– Hydrocortisone 100 mg IVHydrocortisone 100 mg IV
Other Preop Medications (con’t)Other Preop Medications (con’t)
InsulinInsulin
– Agree on plan prior to surgeryAgree on plan prior to surgery
– AlwaysAlways start IV with dextrose start IV with dextrose
prior to giving insulinprior to giving insulin
Other Preop Medications (con’t)Other Preop Medications (con’t) Insulin (con’t)Insulin (con’t)– Treatment plansTreatment plans»No insulinNo insulin»1/2 dose of insulin1/2 dose of insulin» Insulin infusionInsulin infusion
Pediatric ConsiderationsPediatric Considerations Always approach a child as if Always approach a child as if
you will have to do him/her you will have to do him/her againagain
Use oral medication where Use oral medication where possiblepossible
Consider needs of the parentConsider needs of the parent
Small InfantsSmall Infants
Separation not a problemSeparation not a problem
High vagal toneHigh vagal tone
– Consider anticholinergicConsider anticholinergic
Preschool ChildrenPreschool Children Separation extremely traumaticSeparation extremely traumatic Use oral premedicationUse oral premedication– VersedVersed– FentanylFentanyl
Anticholinergic after asleepAnticholinergic after asleep Avoid cyclobrutaneAvoid cyclobrutane
Older ChildrenOlder Children Assess level of anxietyAssess level of anxiety Include in decision makingInclude in decision making Premedicate as appropriatePremedicate as appropriate Pre-op visit extremely Pre-op visit extremely
importantimportant