anaesthesia for medical students-review questions
Post on 23-Sep-2014
237 Views
Preview:
TRANSCRIPT
1
AnaesthesiaforMedicalStudents‐ReviewQuestionsChapter3:Preoperativeassessment**Problemidentification
• Cardiovascular:ischemicheartdisease→riskformyocardialischaemia/infarctioninperiopperiod
o Hxforstabilityofangina,exercisetoleranceo Considerationofvalvularheartdisease,arrhythmias,hypertension
• Respirology:cigarette,(stopfor8weeks,butstoppingfor24hstillimpartsbenefits)o COPD→↑riskrespcomplications;asthma→bronchospasm;ensurenoacute
URTIo ExercisecapacitybyHx;restrictivelungdz,alteredcontrolofbreathing
• Neuromuscular:intracraniallesion→seeksignsof↑edICP(nausea,vomiting,confusion,papilledema)
o Pituitarylesions,TIAs/CVAs;SCI→riskofcomplicationsoffailureandothershit;lowermotorneuronlesions→documentnervedeficitsbeforeusingregionalanaesthesia
• Endocrine:DM,thyroid,phaeochromocytoma,adrenalsuppression,• GI‐Hepatic:hepaticdz,GERD• Renal:disordersoffluid/electrolytebalance,renalfailure• Haematologic:anemias,coagulopathies• Elderly:coexistingdiseaseanddiminishedorganfunction/organreserve• Meds/allergies:needlist!Generallyptscantakeondayofsurgery
o Exceptions;ASA,NSAIDs,insulin,oralhypoglycemics,antidepressants,MAOi• Previousanaesthetics:responsetoprevious;FamHxofmalignanthyperthermiaand
plasmacholinesterasedeficiency• Surgeryproblems:pt’sgeneralmedicalconditionandanticipatedintraoperative
problems• PhysEx:focusonairwayeval,CV,resp,othersystemswithsymptomsofdzfromHx
o General:physicalandmentalstatuso Upperairway:teeth,opening(2fingers),thyromentaldistance(3fingers),
TMJ(1finger)/c‐spinemobility(rememberthe3‐2‐1rule)o Lowerairway:resprate,thoraciccage,auscultation,peripheralsigns
(clubbing,cyanosis)o CV:rate,rhythm,pressure,apicalimpulse,JVP,peripheraledema,S1/2,
murmurs/S3/S4 Assessanatomyforarterialline/centralvenous/intravenousaccess
• Laboratorytesting:o Onlyifindicatedo CBCwheresignifbloodlossanticipated,suspectedhaemdisorder,recent
chemoo Lytesifptonantihypertensivemedications,ordiuretics,chemo,
renal/adrenal/thyroiddisorders
2
o ECGforpts>50orHxofcardiacdz,HTN,periphvascdz,DM,renal/thyroid/metabolicdz
o X‐rayfordebilitatingCOPD,asthma,ΔinrespSxinpast6moso Urinalysisforptsw/DM,renaldz,recenturinarytractinfection
1) DefinetheASAphysicalstatusclassification.
I‐HealthyptII‐Mildsystemicdz;nofNallimitationIII‐Severesystemicdz;definitefNallimitationIV‐Severesystemicdz;aconstantthreattolifeV‐Moribundpt;notexpectedtosurvivew/orw/outanoperationfor24hours
2) Howlongshouldelectivesurgerybepostponedfollowingamyocardialinfarction?Whatisthebasisofthisrecommendation?
‐6months,accordingtobothGoldman’sCardiacRiskIndex,andDetsky’sMultifactorialIndex,andthreeothercardiacstudies**Planningtheanaesthetic(5questionstoaskaboutptcondition)1.Isthept’sconditionoptimal?2.Arethereanyprobswhichrequireconsultationorspecialtests?3.Isthereanalternativeprocedurewhichmaybemoreappropriate?4.Whataretheplansforpost‐opmanagementofthept?5.Whatpremedicationifanyisappropriate?
3) Whatinformationshouldbeobtainedintheanaesthetichistory?‐HPI,Meds,Allergies,PMH/SurgHx,pastanaestheticHx,FamHxofanaestheticprobs,functionalinquiry,focusingoncardiorespsystems,NPOstatus,specificquestionsaboutidentifiedproblemlist
4) Whatcommonanaesthetictechniquescanbeusedtoprovideanaesthesiaforlowerabdominalsurgery?(e.g.inguinalherniarepair)
‐general,spinal(avoidintubation→sympatheticstim[↑HR/BP],airwayreflexes[bronchospasm])
5) A)Whatanaestheticrisksmightbeassociatedinapatientwhosmokesregularly?B)Whatinformationobtainedfromhistory,physical,orlaboratoryexaminationmightbeusefulinassessingthisrisk?C)Aretheremeansofdecreasingtherisksofperioperativecomplicationsrelatedtosmoking?
A)airwaysecretions,asthma,COPD,infectionsB)smoker’scough,wheeze,medicationsforbreathing,limitstophysicalactivity/exercisetolerance,chronicinfections,asthma,COPD,CXR,PFTC)“optmizept”Chapter4:Premedication
1) Whyarepatientspremedicatedpriortosurgery?‐pt‐relatedreasons:sedation,amnesia,analgesia,antisialogogueeffect,↓gastricacidity/volume,facilitateanaesthesiainduction
3
‐procedure‐relatedreasons:Abxprophylaxis,gastricprophylaxis,corticosteroidcoverage,avoidreflexes(vagal),anticholinergic‐coexistingdiseases:continuept’sownmeds,optimizept’sstatuspriortoprocedure(e.g.bronchodilators,nitroglycerine,β‐blockers,Abx)
2) Whatarethegeneralcontraindicationstotheuseofbenzodiazepineoropioidpremedications?(p.30generalcontraindicationstouseofpremedication)
‐allergyorhypersensitivitytodrug;upperairwaycompromise/respfailure;hemodynamicinstability/shock;decreasedlevelofconsciousnessor↑ICP;severeliver,renal,thyroiddz;obstetricalpts;elderlyordebilitatedptsChapter6:Intubationandanatomyoftheairway
1) Whatisthe“1‐2‐3”test?Usedtoassessseveralfactorsthatmayaffectdecisionsconcerningpt’sairwaymgmt.1)IDanyrestrictedmobilityoftheTMJ‐openmouthwideaspossibleandnotemobilityatmandibularcondyle/TMjoint→spacecreatedb/ttragusofearandmandibularcondyleis~1fingerbreadthinwidth2)Mouthopening:atleast2fingers;noteloose/capped/missingteeth,bridges;withtonguemaximallyprotruded,shouldvisualizepharyngealarches,uvula,softpalate,hardpalate,tonsillarbeds,posteriorpharyngealwall3)Thyromentaldistance‐thyroidnotchtomentum;≥3cmpreferable
2) WhatdoesaclassIhypopharyngealviewmean?WhatstructuresarevisualizedinaclassIhypopharyngealview?
‐adequateexposureoftheglottisduringdirectlaryngoscopyshouldbeeasilyachieved‐canseetongue,hard/softplate,uvula,pharyngealarches,tonsilarbeds,posteriorpharyngealwall
3) WhatstructuresarevisualizedinagradeIIIlaryngealview?‐Onlyepiglottisandaportionofthearytenoids;possiblyahintofthespacebetweenthevocalcords**Trachealintubation
I. PositioningofpatientII. Openingpatient’smouthIII. PerforminglaryngoscopyIV. InsertionoftheETTthroughthevocalcordsandremovingthelaryngoscopeV. Confirmationofcorrectplacement,andsecuringtheETT
4) Whatistheoptimalpositionoftheheadandneckforintubationusingdirect
laryngoscopy?‐headandneckpositionedusingcombinationofbothcervicalflexionandatlanto‐occipitalextension(the“sniffingposition”).Enablesalignmentofaxesofmouth/pharynx/larynx→permitsdirectvisualizationoflarynxduringlaryngoscopy
5) Howistrachealintubationconfirmed?
4
‐Immediateabsoluteproof→observingETTpassingthroughvocalcords;observingCO2returningwitheachrespiration;visualizingtracheallumenthroughETTusingafibreopticscope‐Indirectconfirmation→listeningoverepigastriumforabsenceofbreathsoundswithventilation,observingchesttorise/fallw/+pressureventilation,listeningtoapexofeachlungfieldforbreathsoundswithventilation**IFINDOUBT,TAKEITOUTIfunsureoftubeplacement,removeitandresumemaskventilationw/100%O2,stabilizeptandcallforhelp,ratherthanriskhypoxicinjuryandgastricaspiration.**IFINDOUBT,LEAVEITINwhenconsideringextubationafterptwasintubatedforatime,andthereareconcernsaboutsafeextubation,itissafertodelayextubation,continuetosupportventilation,ensuringhemodynamicstability,analgesia,andoxygenation,thanprematurelyextubatingpt.
6) Name4simplemanoeuvresthatcanbeusedtoovercomeanupperairwayobstruction.
‐clearingtheairwayofanyforeignmaterial‐usingachinliftmanoeuvre‐usingajawthrustmanoeuvre‐insertinganoraland/ornasalairway‐positioningtheptontheirsideinthesemi‐pronerecoverypositionChapter7:Intubationdecisions
1) Whatlaboratorycriteriashouldyouusetoassesstheobjectiveneedforintubationandventilation?
• Oxygenationo PaO2<70mmHgwithFiO2=70%o A‐aDO2gradient>350mmHg(normalis≤15mmHg,andincreasesupto37
withincreasingage;PAO2=(Patm–PH2O)xFiO2–PaCO2/0.8• Ventilation
o RR>35/mininadults(muscleswillfatigue)o PaCO2>60innormaladultso PaCO2>45instatusasthmaticus(andrising,despitemaximummedical
mgmt)o RespiratoryacidosiswithpH<7.20inCOPDpts
• Mechanicso VC<15mL/kg(normalvitalcapacity=70mL/kgorapprox.5L;aVCof
15ml/kgisneededtocougheffectivelyandclearsecretionso NIF>‐25cmH2O(normalnegativeinspiratoryforceis~‐80to‐100cmH2O)
2) Whataresomeimportanthistoricalandclinicalfactorsthatsuggesttheneedtointubateandventilateapatient?
5
• Realorimpendingairwayobstruction(epiglottitis,thermalburns,mediastinaltumours…)
• Protectionofairway(↓LOC,drugoverdoseetc.)• Trachealbronchialtoilet‐ptswhoareunabletocleartheirsecretions,theETT
providesdirectaccessforsuctioningsecretions(e.g.,COPDw/pneumonia)• Positivepressureventilation‐duringgeneralanaesthesia;otherindicationsforETT
underGAinclude:longprocedure,difficultmaskventilation,operativesitenearpt’sairway,thoraciccavityopened,musclerelaxantsreq’d,andifptindifficultpositiontomaintainmaskanaesthesia
• Clinicalsignsofrespiratoryfailureandfatigue(diaphoresis,tachypnea,tachycardia,accessorymuscleuse,pulsusparadoxus,cyanosis…)
• Shocknotimmediatelyreversedwithmedicaltreatment(i.e.notrespondingtomedicalmgmtinfirst35‐45minutes)
Chapter8:Laryngealmaskairway
1) WhatisthedifferencebetweenaLMAandanendotrachealtube?‐LMA:wideborePVCtubingwithdistalinflatablenon‐latexlaryngealcuff;insertedw/ospecialequipment,inbackofpt’spharynxw/softlaryngealcuffrestingabovevocalcordsatjNoflarynxandesophagus‐ETT:genreq’slaryngoscopeforinsertionintotrachea;passesthroughvocalcordsw/tippositionedinmid‐trachea
2) Whywouldalaryngealmaskairwaybeusedratherthananendotrachealtube?‐pt’swhohavenoID’driskfactorsforaspirationandwhodonotreqintubationandcontrolledventilation‐makebedifficulttoobtainadequatesealw/facemaskinptsw/noteethorfullbeard,soLMAgoodforthosepts‐alsoLMAiseasytoinsert,canbepositionedw/minimalanaestheticdrugs(doesn’treqmusclerelaxants),doesn’tcauseasmuchtraumaandpositioningcomplicationsasETT,doesn’tcauseforeignbodyintracheareflexorlaryngospasm(whenremoved)Chapter9:Rapidsequenceinduction
1) WhatisthepurposeofaRSI?‐usedwhenaptreqGAwhohasbeenID’dashavingriskfactorsforgastricaspiration:↓LOC,trauma,mealw/in6hours,sphincterincompetencesuspected(GERD,hiatushernia,NGtube),↑edabdominalpressure(pregnancy,obesity,bowelobstruction,acuteabdomen)
2) DescribethesequenceofmanoeuvresusedinaRSI.1.SetupIVaccess,cardiacmonitor,oximetry,andpossiblycapnography.2.Planprocedureincorporatingassessmentofphysiologicstatusandairwaydifficulty.3.Prepareequipment,suction,andpotentialrescuedevices.4.Preoxygenate/denitrogenate:ptbreathes100%O2for3‐5minutesorfor4vitalcapacitybreathspriortoinductionofanaesthesia(doNOTbagventilate)5.Considerpretreatmentagentsbasedonunderlyingconditions.*(e.g.Lidocaine,fentanyl,atropine)
6
6.Inducewithpotentsedativeagent.7.Giveneuromuscularblockingagentimmediatelyafterinduction.(=fast‐actingmusclerelaxant,e.g.SCh)8.Bag‐maskventilateONLYifhypoxic,considercricoidpressure.(Sellick’smanoeuvre:pressureoncricoidcartilagetocompressesophaguseagainstC6)9.Intubatetracheaaftermusclerelaxationhasbeenachieved.(45‐60saftermusclerelaxantgiven).MustusecuffedETTtopreventaspirationofgastriccontents10.Confirmplacementandsecuretube.11.Providepostintubationsedationandpostintubationmanagement.(ventilatewhenETTinplaceandcuffinflated)
3) Whatisthepurposeofpre‐oxygenation?‐Getridofnitrogenandfloodalveoliw/oxygen,tobuymoretimebeforeaptdesats<90%,ifyoucandoyourshitright;e.g.takes2minutesforahealthypttodesatnormally,buttakes6minutesifyoupreoxygenatefirst
4) Whichpatientsshouldberegardedasbeingatriskofpulmonaryaspirationofgastriccontents?
‐↓LOC(drugoverdose,anaesthesia,headinjury,CNSpathology,traumaorshock)‐impairedairwayreflexes(prolongedtrachealintubation,localanaesthetictoairway,myopathies,CVA,↓LOC‐abnormalanatomy(Zenker’sdiverticulum,esophagealstricture)‐↓GEcompetence(NGtube,elderly,pregnant,hiatushernia,obesity,curare)‐↑intragastricpressure(preggo,obese,bowelobstruction,largeabdotumours,ascites)‐delayedgastricemptying(narcotics,anticholinergics,fear,pain,labour,trauma,preggo,renalfailure,diabetes)
5) Whatmeasurescanbetakentodecreasetheriskofaspiration?‐preopfasting,H2antagonists/antacids(↓acidity),metoclopramide(↓motility),antiemetics,regional/localanaesthesiaratherthanGA,NGtubetoemptystomach,cricoidpressureoninductionofGA,extubationawakeonsideChapter10:monitoringinanaesthesia
1) Whatinformationdoestheanaesthetistusetoassessdepthofanaesthesia?‐GA→lackofresponsetoverbalcommands,lossofblinkreflex(ifinadequate→facialgrimacingtopainfulstimulus,ormovementofarmorleg)‐w/fullparalysisw/musclerelaxants→inadequateanaesthesiashownbyHTN,tachycardia,tearingorsweating‐excessiveanaestheticdepth→cardiacdepression(bradycardia,hypotension),orifexcessivemusclerelaxant→hypoventilationandhypercapnia,hypoxemia
2) Whatinformationcanbeobtainedbymonitoringthecapnograph?‐CapnometryisthemeasurementoftheCO2concentrationduringinspirationandexpiration‐capnogramisthecontinuousdisplayofthe[CO2]waveformsampledfromthept’sairwayduringventilation
• Confirmationoftrachealintubation• Recognitionofaninadvertentesophagealintubation
7
• Recogofaninadvertentextubationordisconnection• AssessmentoftheadequacyofventilationandanindirectestimateofPaCO2• Aidsthediagnosisofapulmonaryembolism(airorclot)• Aidstherecogofapartialairwayobstruction(e.g.kinkedETT)• Indirectmeasurementofairwayreactivity(e.g.bronchospasm)• Assessmentoftheeffectofcardiopulmonaryresuscitationefforts3) WhatrelationshipdoestheETCO2valuehavetothePaCO2?• DuringGA,thePaCO2toETCO2gradientistypicallyabout5mmHg(PaCO25mmHg
higher);increasesordecreasesinETCO2valuesmaybetheresultofeitherincreasedCO2productionordecreasedCO2elimination
WhatconditionsmightresultinanETCO2measurementof20mmHgw/aPaCO2measurementof40mmHg?(Seerightcolumn)
↑edETCO2 ↓edETCO2ChangesinCO2production
HyperthermiaSepsis,thyroidstorm
MalignanthyperthermiaMuscularactivity
HypothermiaHypometabolism
ChangesinCO2elimination
HypoventilationRebreathing
HyperventilationHypoperfusionEmbolism
Chapter11:intravenousanaestheticagents
1) Whydoptsawakenfromasleepdoseofthiopentalwithin5to10minutesofitsadministrationwhentheeliminationhalf‐lifeisoftheorderof5‐12hours?
‐b/cthethiopentalhasmovedawayfromthebrainandisenteringthemoreslowlyperfusedorgans,its‘redistribution’fromthebraintoothertissues/organs
2) Whywouldonechoosepropofoloverthiopentalasanintravenousinductionagent?‐ifptallergictothiopental,hasstatusasthmaticusorporphyria,liverdz,myxedema
3) Whenwouldonechooseketamineovereitherthiopentalorpropofolastheintravenousinductiondrug?
‐ketaminepreserveslaryngealandpharyngealairwayreflexes‐producesbothcentralsympatheticstimulationanddirectnegativeionotropiceffectontheheart→↑HR,BP,SVR,pulmartpressure,coronarybloodflow,myocardialoxygenuptake‐∴goodforanaestheticinductioninthesevereasthmaticptortheptwithcardiovascularcollapserequiringemergencysurgery
4) Whataretheconcentrationsandinductiondosesofthiopentalandpropofol?• Thiopental
o Concentration:2.5%(25mg/mL)o Inductiondose:3‐5mg/kg
• Propofolo Concentration:1%(10mg/mL)
8
o Inductiondose:2.5‐3.0mg/kgforhealthy,unpremedicatedpt Whenpremedicationgiven,reduceto2.5‐2.0mg/kg Elderly→≤1mg/kg
Chapter12:Musclerelaxants
1) Whatisthedifferencebetweenadepolarizingandnon‐depolarizingmusclerelaxant?Giveexamplesofeach.
‐NON‐depolarizingneuromuscularblockingagents• CompetewithAChforthecholinergicnicotinicreceptor• As[]ofmusclerelaxant↑attheNMJ,theintensityofmuscleparalysis↑• Anticholinesteraseagents(neostigmine,edrophonium)inhibitthebreakdownof
ACh→↑ACh[]attheNMJ→competitivelyreversetheeffectsofanon‐depolarizingneuromuscularblockade
‐Depolarizingneuromuscularblockingagents• Succinylcholine(SCh)ismostfrequentlymusedmusclerelaxantusedbynon‐
anaesthetists,andistheonlydrugofthisclassthatisclinicallyused• Depolarizingmusclerelaxantsbindanddepolarizetheend‐platecholinergic
receptors• Theinitialdepolarizationcanbeobservedasirregular,generalizedfasciculations
occurringintheskeletalmuscles2) WhataretheabsolutecontraindicationstotheuseofSCh?• Inabilitytomaintainanairway• Lackofresuscitativeequipment• Knownhypersensitivityorallergy• Positivehistoryofmalignanthyperthermia• Myotonia(M.Congenita,M.Dystrophyica…)• PtsID’dasbeingatriskofahyperkalemicresponsetoSCh3) Whichpt’saresusceptibletohyperkalemiafollowingSCh?• CholinergicreceptorslocatedonskeletalmusclemembranesoutsideofNMJcanbe
dramaticallyincreasedinnumberovera24hrperiodwhenevernerveimpulseactivitytothemuscleisinterrupted
• Ptswhohavesustained3rd‐degreeburnsortraumaticparalysis,neuromusculardiseaseslikemusculardystrophy,severeintra‐abdominalinfections,severeclosedheadinjury,UMNlesions,ptsinrenalfailure
• GivingSCh→abnormallyhighfluxofK(dueto↑edreceptors)→acuteriseinpotassiumtolevelsashighas13meq/L→suddencardiacarrest
4) WhatistheconcentrationatwhichSChissupplied?Whatisthedoseforintubation?‐Formulatedat20mg/mL‐Intubationdose:(withcurarepretreatment)1.5‐2mg/kgIV→NOTE:Initialdoseofsuccinylcholinemustbeincreasedwhennondepolarizingagentpretreatmentusedbecauseoftheantagonismbetweensuccinylcholineandnondepolarizingneuromuscular‐blockingagents. ‐withoutcurarepretreatment→1.1.5mg/kgIV
5) Whichdrugscanbeusedtoantagonizeaneuromuscularblock?
9
• Musclerelaxationproducedbynon‐depolarizingneuromuscularagentsmaybereversedbyanticholinesteraseagentslikeedrophonium,neostigmine
o PreventbreakdownofAChinNMJ→competeswithdrugtoallowreceptortobecomeresponsivetoreleaseofAChfromnerves
o The↑ed[]sofAChalsostimulatethemuscariniccholinergicreceptors,resultinginbradycardia,salivation,andincreasedbowelperistalsis
o Anti‐cholinergicagentssuchasatropineandglycopyrrolateareadministeredpriortoreversal,toblocktheseunwantedmuscariniceffects
Chapter13:Inhalationalanaestheticagents
1) WhatisMAC?‐SimilartoED50,theminimumalveolarconcentrationisthealveolarconcentrationinoxygenatoneatmospherethatwillprevent50%ofthesubjectsfrommakingapurposefulmovementinresponsetoapainfulstimulussuchasasurgicalincision‐itisnecessarytoestablishananaestheticdepthequivalentto1.2to1.3oftheMACvaluetopreventmovementin95%ofpts
2) Whatistherelationshipbetweentheanaestheticconcentrationthatissetontheanaestheticvaporizerandtheanaestheticconcentrationinthept’sbrain?
‐theanaesthetictensioncascadeovertime‐thedelivered[]tendstobe>inspired>alveolar>brain‐increasingeitherthefreshgasflowrateoranaestheticconcentrationwillresultinafasterdeliveryoftheinhaledanaestheticagenttothebrain(duetoafasterriseinthealveolarconcentration)‐amountofalveolarventilation(VA=respratextidalvolume)‐intermsofalveoli→braintime,thiswillbefasterwith: ‐rateofbloodflowtobrain ‐solubilityoftheinhalationalagentinthebrain ‐differenceinthearterialandvenous[]softheinhalationalagent
3) Whatisdiffusionhypoxia?‐mayresultatendofanaesthetic‐asnitrousoxideisdiscontinued,thebodystoresofitarereleasedandfloodthealveoli,dilutingtheO2presentinthealveoli‐whenonlyroomairisadministeredattheendoftheanaesthetic,thedilutionofO2maybesufficienttocreateahypoxicmixture,andresultinhypoxemia‐othercausesofhypoxemiaincludeanaestheticagents,neuromuscularblockade,painwithsplintedrespirations‐∴administer100%O2attheendofananaesthetictoavoidthis
4) WhataretheMACvaluesofisoflurane,enfluraneandhalothaneinoxygen?Isoflurane:1.16%Enflurane:1.68%Halothane:0.75%Desflurane:6%Sevoflurane:2%
10
Chapter14:Narcoticagonistsandantagonists
1) Whatundesirableeffectsdoopioidshave?‐maycausedysphoricrxnswhenadministeredtoptswhoarenotexperiencingpain‐nausea,emesis‐respdepression(↓rate,minuteventilation;↑tidalvolume)→slow,deepbreatihing‐vasodilation→↓BP/SVR,bradycardia‐slowGImotility→constipation/postopileus;↑biliarytracttone→pptbiliarycolic;↑urinarybladdersphinctertone→postopurinaryretention‐anaphylaxis,bronchospasm,chestwallrigidity,pruritis
2) Nameanopioidantagonist.Whatdoseofthisdrugwouldbeappropriatetoreverseopioidinducedrespiratorydepression?What,ifany,areanypotentialproblemsofgivingtoomuchofthisantagonist?
• Naloxone(Narcan)• Givesmallincrementaldosesof40mcg• Suddenreversaloftheanalgesiceffectsofopioidsmayresultifhighdosesof
naloxonearegiven→abruptreturnofpaincanresultinHTN,tachycardia,pulmedema,ventriculardysrhythmiasandcardiacarrest
• Continuousinfusionsof3‐10mcg/kg/hrcanbeusedifsedationorrespdepressionrecur
Chapter15:Localandregionalanaesthesia
1) Name2classesoflocalanaestheticagents,angiveexamplesofeachAmides:lidocaine(maxdose4mg/kg,7withepi),bupivicane(2.5mg/kg,3withepi)Esters:chlorprocaine(11mg/kg,14withepi)
2) WhatisPABA,andwhatroledoesithaveinlocalanaesthesia?• Para‐aminobenzoicacid,usedasapreservativeinlocalanaestheticsolutions,and
mayincreaseaLA’spotentialneuro‐andmyo‐toxicities3) Name4techniquesofadministeringalocalanaestheticdrug.• Topical,infiltrative,intravenousregional,peripheralneuralblockade,centralneural
blockade4) Whyisavasoconstrictoroftenusedwithalocalanaesthetic?Giveanexampleofa
LAvasoconstrictoranditsconcentration.Whenwouldtheuseofavasoconstrictorbecontraindicated?
• Vasoconstrictor(e.g.epinephrine,phenylephrine)usedtoretardvascularabsorptiontoreducesystemicsideeffectsofLA
• Epinephrine[]stypically1:100000to1:200000o 1:200000has5mcg/mLofepinephrine
• Vasoconstrictorscontraindicatedinfingers,toesandpenis5) Whichregionalblockresultsinthehighest[]oflocalanaestheticintheblood?
‐intercostalnerveblocksresultinthehighestpeaklocalanaestheticbloodconcentrations6) Whatisthemaxrecommendeddoesofplainlidocaine,andoflidocainewitha
vasoconstrictor?‐4mg/kg;withepi→7mg/kg
11
7) Whymightaregionalanaestheticbegivenaswellasageneralanaesthetic?‐forpost‐oppainmgmt
8) Describesomeofthesignsandsymptomsoflocalanaesthetictoxicity.‐neurotoxicity→immediateandseverepain→pathologicdamagetonerve‐myotoxicity→histologicalchangesinthetissues,buttransientandreversible
9) Describethestepsintreatinganacutelocalanaesthetictoxicity.‐ensureclearairway(suction,chinlift/jawthrust,airways,positioninginlatdecub)‐ensureadequateventilation(bag/mask,avoidhypoventilation→↑LAuptake,considerintubation)‐providesupplementalO2(8‐10L/minforambubagoxflow)‐AssesstheHRandrhythm,applymonitors(treatbradyw/atropine;useepiforprofoundCVcollapse;considerearlyelectricalcardioversionforarrhythmias)‐AssesstheBPandperfusion‐determineresponsiveness(ifpthypotensive→Trendelenburgposition;administerbolusofringer’slactate;supportBPw/ephedrineorphenylephrine)‐stopseizures(protectptfrominjuryduringseizure;considerdiazepamorsodiumthiopentaltostopseizure)
10) Whatisthedifferenceb/taspinalandanepiduralanaesthetic?‐botharecentralneuralblockade‐epiduralanaesthesiaisinjectingdrugsintotheepiduralspace(b/tligamentumflavumandduramater,exteriortospinalfluid);drugmustpassthroughmyelinsheathscoveringthenerveroots ‐duraactsasbarriertoepiduralLAmovingintotheCSFspace ‐sloweronsetb/cnervesareinsulated;produceslessintenseblock ‐req5‐10timestheamountofLAthatwouldbeusedforspinalanaesthesia‐spinalanaesthesiainvolvespassinganeedlethroughepiduralspace,throughduraandintotheCSFspace‐thesubarachnoidspace,directlyincontactwiththebarenerveroots ‐drugsproduceaveryrapidandintensenerveblock
11) Howmanymilligramsoflidocainearein20mLofa2%solution?400mgChapter16:Acutepainmanagement
1) Listthephysiologicaleffectsofacutepain.• E.g.chest/abdoincisionw/outpainmgmt→musclesplinting,Ø
coughing→atelectasisandpneumonia• Barrageofnociceptivestimuli→↑sympathetictone→HTN,tachycardia,
↑contractility/worko Ifinsettingof↓O2supply→myocardialischemia,CHF,MI
• ↑symptonealso→↑intestinalsecretions,slowsgutmotility,↑smoothmuscletone→gastricstasisw/nausea,emesis,ileus,urinaryretention
• pain→stressresponse→hypercoagulablestate→PE,MIo also→↓immunocompetence,hypermetabolism,mobilizationofenergy
stores→hyperglycemia,largenetproteinlosses→delayedwoundhealing
12
2) ContrastintramuscularandPCAopioidadministration• IntermittentIMadministration→widefluctuationsinserumopioidconcentrations
→periodsofover‐sedationalternatingwithperiodsofpoorpaincontrol• IVPCAopioidadministration→rapidlyadjustedbypt→analgesic[]sofopioidsin
serummaintainedforlongperiodsoftime3) Whataretheadverseeffectsresultingfromtheadministrationofexcessiveopioid
analgesics?• Sedation,respiratorydepression,pruritis,↑edincidenceofnausea/vomiting4) Whatnon‐opioidanalgesicagentsareavailableforthecontrolofacutepain?• Aspirin,ibuprofen,indomethacin,naproxen,ketorolac(toradol),[gabapentin,
acetaminophen)5) Whatarethecontraindicationstoadministeringanon‐steroidalanti‐inflammatory
drug?• AllergytoASAorotherNSAID;relativecontraindicationwhenthereisahxof
asthma,nasalpolypsorangioedema• Renalinsufficiency,CHF,pepticulcerdz,activeIBD,pregnancy/lactation,bleeding
disorders6) ListanappropriatedoseandschedulefortwocommonNSAIDsusedtocontrol
acutepain.• Ibuprofen400‐800mgPOq6‐8h• Ketorolac10mgPOq4‐6h,maxpo40mg/day
o 10‐30mgIMq4‐6h,maxIM120mg/dayChapter17:Chronicpain
1) Whatisthedifferenceb/tacuteandchronicpain?• Acutepainisthenociceptionduetotissueinjuryandreleaseofnociceptiveagents• Chronicpainisan“unpleasantsensoryandemotionalexperienceassociatedwith
actualorpotentialtissuedamage,ordescribedintermsofsuchdamage”o So,doesn’tactuallyrequirepresenceoftissuedmg,andtendstolastwell
beyondthehealingperiodoftissueinjury2) WhatisRSD?WhatconditionsmayleadtothedevelopmentofRSD?• ReflexSympatheticDystrophy
o Varietyofconditionsincludingminorcausalgia,posttraumaticpainsyndrome,Sudeck’satrophy,shoulderhandsyndrome
• Pptfactorsincludeaccidental/surgicaltrauma,diseasestates• Characterizedbypain,vasomotorchanges,autonomicdisturbances,delayed
recoveryoffN,trophicchanges• Commonoutcomeoforthopaedicinjuriesandindustrialaccidents(butno
correlationb/tseverityofinjuryanddevelopmentofRSD;mustbepromptlyrecog’dandtreated
3) WhatmodalitiesarecommonlyusedtotreatRSD?• Earlytxwithsympatheticinterruptionresultsinpainreliefandreversesthe
pathophysiologicalabnormalities
13
o Treatoriginalinjuriesproperlyandrapidly(removeforeignbodies,immobilize,repairshit,relievepain)
o Txmodalitiesincludeearlyuseofsympatheticblocks,physio,psychotherapy,medicaltherapyandifthesefail,surgicalsympathectomy
4) HowisadxofRSDmade?• Criteriaare
o Hxofrecentorremoteaccidentaloriatrogenictraumaordzo Ptcomplainsofpersistentpainthatisburning,achingorthrobbingo Oneormoreof:
Vasomotor/sudomotorchanges Trophicchanges,edema,hypersensitivitytocold Muscleweaknessoratrophy
o ReliefofSxobtainedafterregionalsympatheticblockade5) Whataretriggerpoints?• Inmyofascialpainsyndrome,triggerpointsarehypersensitivepointsproducing
pain,musclespasm,tenderness,stiffness,andweakness• Inaffectedareas,tautmusclebandsmaybepalpable,arecalledTPs
o Painfromtheseisdescribedassteady,deepandaching,andmaybeexacerbatedbystretch,cold,stress,fatigue,viralillnessesordirectpressure
6) Name2surgicalconditionsthatmaypresentw/backpainandrequireemergencysurgicalintervention.
• CaudaEquinaSyndromeo Discherniation,tumourmass,abscesso Signs:neurodeficitinlowerextremities(paralysis,lossofsensation),lossof
bowelorbladdercontinence,weakness,depressedreflexes,saddleanaesthesia
• Aorticaneurysmo Leaking,dissecting,ruptured
Chapter18:Obstetricalanaesthesia
1) Whatissupinehypotensivesyndrome?Howcanitbeprevented?• WhenthegraviduteruscompressestheIVCand/oraortawhentheparturientliesin
thesupineposition(about15%ofptsasearlyas20tweek,↑freqin3rdtrimester)• IVCcompressioncauses↓venousreturntoheart→signsofshock:hypotension,
pallor,sweating,nausea/vomiting,Δsinmentationo ↑venouspressureinlowerextremitiesanduterus∴↓uterinebloodflow
• aortacompression→arterialhypotensioninuterus→↓uterinebloodflow→fetaldistress/asphyxia
• Prevention:avoidsupineposition;liesonside;judicioususeoflumbarregionalanaesthetics,whichcanexaggeratehypotensiveeffects
2) Whatfactorsmayinfluenceapt’sexperienceofpainduringlabouranddelivery?
14
• Psychologicalstate,mentalpreparation,familysupport,medicalsupport,culturalbackground,primivsmultipara,sizeandpresentationoffetus,sizeandanatomyofpelvis,useofmedicationstoaugmentlabour(e.g.oxytocin),durationoflabour
3) Whatoptionsareavailablefordealingwiththepainoflabouranddelivery?• Nothing,psychologicalsupport(coaches,partner,familymembers),behavioural
modification(psychoprophylaxis‐Lamaze),hypnotherapy,education(expectations,classes),massage,walking,sedatives,opioidanalgesics(+/‐antiemetics),epiduralanalgesia,spinalanaesthesia,generalanaesthesia
4) Whatarethemajorrisksofgeneralanaesthesiaintheparturientundergoingacaesareansection?
• AllparturientsconsideredtohavefullstomachandgastricprecautionsincludingRSIareindicatedwithGA
• Upperairwayedemaoccursinpregnancy;allparturientsconsideredtohavepotentiallydifficultairwaytointubate
• GAintroducesrisksoffailedintubation,andriskofhypoxemiaand/orpulmonaryaspirationofgastricacid
• GAcreatespotentialofhavingmaternaldrugstransferredtoneonate→neonataldepressionandneedforresuscitation
Chapter19:Basicneonatalresuscitation
1) WhatistheApgarscoreofababythatislimp,blue,hasnoresponsetooropharyngealsuctioning,aheartrateof60bpm,andirregulargaspingrespiratoryefforts?
• APGAR:Appearance(colour),Pulse(HR),Grimace(reflexirritability),Activity(Muscletone),Respiration
• Muscletone‐0,Colour‐0,Reflexirritability‐0,HR<100‐1,Respiration‐1=22) Describethebasicstepsinneonatalresuscitation.• Opentheairway
o Positioning,suctionmouththennose,monitorheartrateforbradycardia,considerspecialendotrachealsuctioningindepressedinfant.
• Keeptheinfantwarmanddryo Overheadradiantheater,drytheinfant;thegentlestimulationwillalsohelp
initiateandmaintainbreathing• Physicalstimulation
o Ifdrying/suctioningdonotinduceeffectivebreathing→gentleslapping/flickingofsolesoffeet,orrubbinginfant’sbackmaybeuseful
o Donotwastetimecontinuingtactilestimifnoresponseafter10‐15s• Evaluatetheinfant
o Respirations:apneicorgaspinginfants(despitebriefstim)shouldreceivepositivepressureventilation(PPV)
o Heartrate:monitorbyauscultationorpalpation;if<100bpm,beginPPV,evenifinfantmakingsomerespiratoryefforts
o Colour:presenceofcentralcyanosismeansinfantnotwelloxygenated;providefacemaskw/O2at5L/minuntilinfantbecomespink
15
3) Whenispositivepressureventilation(PPV)indicatedinthenewborninfant?DescribethetechniqueofPPV.
• Ventilatorysupportrequiredwhenapneaorgaspingrespirationsarepresent,theHRis<100bpm,orcentralcyanosispersistsdespite100%O2
• Mostneonatescanbeadequatelyventilatedw/abag‐masko Theassistedventilatoryrateshouldbeb/t40‐60breathsperminuteo Initiallunginflationpressuresmaybeashighas30‐40cmH2Otoovercome
theelasticforcesofthelungsiftheinfanthasnottakeitsfirstbreatho Subsequentventilationshouldbeachievedwithairwaypressuresof15‐20
cmH2O**Adequateventilationisassessedby:‐Observingchestwallmotionandhearingbreathsoundsbilaterally**WhenshouldIstartchestcompressions?‐whenHRremains<80bpmdespitePPVwith100%O2‐chestcompressionscanbediscontinuedwhentheHRis≥80bpm**Whatisthepropertechniqueforadministeringchestcompressionstoaninfant?
• 2methodso thumbmethod:fingersaroundback,thumbssidebysideoversternum,with
downwarddisplacementofsternumo Twofingerapproach:middleandringfingersofonehandperpendicularto
chestasfingertipsapplypressuretosternum;otherhandsupportsbackbelow
o Pressureenoughtoachieve1.5cmofdisplacemento 120compressionsperminute(2/sec)
**The4commondrugsusedinresuscitationofthedepressedneonate:
1. Oxygen2. Intravenousfluids3. Epinephrine4. Naloxone
4) Assuminganewborninfantweighs3kg,whatisthe[]anddoseofepinephrine,and
howoughtitbeadministered?• Epinephrine[]inneonateresuscitationissuppliedas0.1mg/mLdilution• IVdoseis0.01to0.03mg/kg• Ina3kginfant,0.25mLto0.75mLofepinephrinewouldbeanappropriatestarting
dose• IfIVrouteunavailable,epicanbegiventhroughETT
o Shouldbedilutedw/1‐2mLofsalineo IfinfantdoesnotrespondtoinitialETTdose,increasebyafactorof10(0.1‐
0.2mg/kg)
16
Chapter20:Intravenousfluidandbloodcomponenttherapy
1) Howarethehourlyanddailymaintenancefluidrequirementscalculated?Maintenancewaterrequirements
Perhour Perday1stto10thkg 4ml/kg 100ml/kg11thto20thkg 2ml/kg 50ml/kg21sttonthkg 1ml/kg 20ml/kg
2) Listconditionsthatmaybeassociatedwithasignificantpreoperativefluiddeficit.• Fracturedhip,femur,pelvis;bowelobstruction;preoperativebowelprep;trauma;
protractedvomitinganddiarrhea;burns;sepsis;pancreatitis3) Whatisthedifferenceb/tacrystalloidandacolloid?Giveexamplesofeach.• Crystalloidsolutionsaresaltcontainingsolutionsthataresemipermeabletocellular
membraneso E.g.NS,RL,“2/3,1/3”IVsolutions
• ColloidIVsolutionscontainaggregatesofmoleculesthatresistdiffusionacrosscellularmembranes
o Maybesynthetic,e.g.pentaspan,hetaspan(?sp),dextrano Maybecollectedfromdonorbloodpool,e.g.albumen,plasma,wholeblood
4) Whichptsshouldconsiderautologousblooddonation?Forwhichpatientsisthisnotsuitable?
• Preopcollectionofbloodfromaptwhoisscheduledtohavesurgery,andforwhomoneanticipatestheneedforaperioperativebloodtransfusion
• Notsuitableforptsw/bacterialorviralinfections,ptswithHb<110g/Landptswithunstableanginaorcriticalaorticstenosis
5) Calculatetheacceptableamountofbloodthatcanbelostin70kgmaleifhisinitialhemoglobinis140g/dL,andtheacceptedminimalhemoglobinaftersurgeryis80g/dL.
• ABL=(Hbi‐Hbf)/HbixEBVo =(140‐80)/140x(70ml/kgx70kg=4900ml)=2100mL
6) WhatisthemostcommoncauseofanABOincompatiblebloodtransfusion?‐clericalerrorinpatientandbloodidentification
7) Name3differentbloodcomponentsthatmaybetransfused.• Wholeblood:autologous• Freshfrozenplasma:indicatedtoreplacecertainfactordeficiencies• Platelets:aftermassivetransfusion,associatedwithabnormalbleedingand
dilutionalthrombocytopenia**Potentialcomplicationsofbloodtransfusions
• Air(embolism)• Volume(circulatoryoverload)• Cold(hypothermia)• RBCs(major/minorreactions)• WBCs(febrilereaction)
• Plasma(Allergicrxn,dilutionalcoagulopathy)
• Platelets(dilutionalcoagulopathy)• Biochem.(citratetoxicity,
hyperkalemia,hypoCa)
17
• Microaggreg.(Dyspnea)• Infections(bacterial,viral,
parasitic)
• Immune(immunesuppression)
Chapter21:Commonperioperativeproblems**Severebradycardiamustbeassumedtobesecondarytohypoxemiauntilprovenotherwise
1) Defineshock.Classifythedifferenttypesofshockandgiveexamplesofeach.Shock(Tintinalli’s)Type CommentHypovolemicCausedbyinadequatecirculatingvolumeCardiogenic CausedbyinadequatecardiacpumpfunctionObstructive CausedbyextracardiacobstructiontobloodflowDistributive Metabolicderangementsthatimpaircellularrespirationsuchascyanide
toxicity,sepsis.• Hypovolemicshock‐themostcommontypeofshock,withlowcentralvenous
pressureandlowpulmonarycapillarywedgepressure• Distributiveshockischaracterizedbysystemicvasodilation,relativehypovolemia,
andanincreaseincardiacoutputo Mostcommonformofthistypeissepticshock,whereateriovenousshunting
atthetissuelevelresultsinanaccumulationoflacticacidandtissueanoxia• Cardiogenicshockwhenheartfailstoperformitspumpingfunction,asaresultofa
myocardial,valvularorelectricalproblemo Myocardialinfarctionisthemostcommoncause,wherecharacteristic
findingsincludeanincreaseinCVP,PCWPandSVR• Obstructiveshockoccurswhenthereisanobstructionpreventingcardiacfillingor
emptyingo Twoimmediatelytreatablecausesofitincludeatensionpneumothoraxand
cardiactamponade**Nauseaandvomitingperioperativelymustbeassumedtobesecondarytobradycardiaandhypotensionuntilprovenotherwise
2) Whataresometreatablecausesofanagitatedpostopstate?• Upperairwayobstruction,residualparalysis,hypercarbia,andhypoxemiaareall
potentstimulantswhichcanproduceanagitatedstate• Commoncausesofagitationinelderlyptsarepainandbladderorboweldistension• Excessivesedationcanbetreatedwithreversingagents,dependingonthecause
Chapter22:Managingthecirculation
1) Whatarethebroadgoalsincontrollingthecirculation?• Theprinciplegoalofcirculatorysupportistooptimizetissueperfusionwith
oxygenatedblood
18
o Toachievethis,onemustassessandoptimizethepreload,afterload,heartrate,contractility,oxygentransportandorganperfusion
2) Whatarethedifferencesb/tanalpha‐1andbeta‐1adrenergicagonist?Giveexamplesofeach.
• Alpha‐1,e.g.phenylephrineo Vasoconstrictionoftheskin,gut,kidney,liverandheart
• Beta‐1,e.g.isoproterenolo Increasedheartrate,myocardialconductionandcontractility
3) Whatarethefactorswhichdeterminecardiacoutput?• CO=HRxSV• Thedeterminantsofcardiacoutputarepreload(theend‐diastolicstretchoftheleft
ventricle),theheartrate,thecontractility(themyocardium’sintrinsicabilitytoperformworkatanygivenlevelofend‐diastolicfibrelength[preload]),andtheafterload(themyocardialwallstressoftheleftventricleduringejection)
Chapter23;Oxygentherapyandhypoxia
1) Listsomedevicesthatarecommonlyusedtodeliveroxygentospontaneouslybreathingpatients.
• Nasalprongs,simplefacemaskoxygen,Venturifacemask,non‐rebreathingfacemaskwithreservoirbag
2) Whenshouldapuritanfacemaskbeused?Whenshouldoneuseamanualresuscitationdevice,suchasanambubagandmaskunit?
• Thepuritanmaskdeliversthehighestlevelofhumidifiedoxygeno Oxygenflowratesof>30L/mincanbeachieved,ensuringaconsistent
inspiredoxygenconcentrationo Shoulduseadoubleflowsetuporanon‐rebreathingfacemaskw/reservoir
bagwhen>50%inspiredO2[]isrequired• Theambubagandmaskunitisusedforprovidingprimaryairwaymgmtinpts
requiringpositivepressureventilationandoxygenationo Canbeusedastheprimarysystemforairwaymgmtintheptrequiring
ventilatorysupport3) Listthefivecategoriesofconditionscausinghypoxemia.
Hypoxemia:lowlevelofO2intheblood• DecreasedFiO2
o ↓edinspiredO2concentrationor↓edbarometricpressure(altitude)• Decreasedalveolarventilation
o Hypoventilation(2°tosedativedrugsorpainiscommon)• Increaseddeadspaceventilation(ventilation‐perfusioninequality)
o RespondstosupplementalO2therapyo CausesincludehypovolemiaandhighairwaypressureswithPPVo Pulmonaryembolism,emphysema,bronchitis
• Increasedshunto Perfusionofalveoliwithoutventilation,e.g.atelectasis,aspiration,CHF,
pneumoniaandendobronchialintubationwithlobarcollapse
19
• Decreaseddiffusiono Highaltitude,anemia,severeexerciseo Pulmonaryfibrosis,emphysema,interstitialpulmonarypathology(e.g.
sarcoidosis)4) Listthefourcategoriesofconditionscausinghypoxia.
Hypoxia:lowlevelofO2intheair,blood,ortissues• Decreasedfunctionalhemoglobin
o Anemia,hemoglobinopathies• DecreasedPaO2
o Hypoxemia• Decreasedtissueperfusion
o Shockstates(hypovolemic,cardiogenic,distributive,obstructive)• Cellularhypoxia
o Histotoxicpoisoning(e.g.cyanide)Chapter24:Unusualanaestheticcomplications
1) WhatisMH?• ArareclinicalsyndromethathasbeenobservedduringGA
o Acutefulminantform,triggeredbycertainanaestheticdrugs→hypermetabolicstateduetoacuteuncontrolledskeletalmusclemetabolism
o RapidincreasesinO2consumption,carbondioxideproductionandheatresultindesaturationorcyanosis,elevatedend‐tidalCO2valuesandrapidincreasesintemperature
2) List2anaestheticagentsthatmaytriggeranMHreaction.• SCh(depolarizingmusclerelaxant)andanyofthevolatileanaestheticagents
(isoflurane,halothane,enflurane,sevoflurane)3) WhichdrugisusedspecificallytotreatanMHreaction?• Dantrolene‐skeletalmusclerelaxant(everyhospitalthatprovidesGAservicesis
req’dtokeepacurrentstock[minimum36vials]ofdantroleneavailableintheirpharmacydepartment)
4) Whatstrategiesareusefulinreducingtheperioperativeriskofpulmonaryaspirationofgastriccontents?
• Avoidimpairingairwayreflexes(chooselocalorregionalanaesthetic)• Reducegastricvolumeandacidity
o Fasting,gastricmotilityagents,H2blockers,antacids(sodiumcitrate),gastricemptyingbyNGtube
• Inptswithanticipateddifficultintubation,topicalizationandlocalanaestheticblocksoftheupperairwayreduceschanceoffailedintubation,difficultmaskventilationandsubsequentgastricaspiration
• Ptsw/ID’driskfactorsforgastricaspirationwhorequireGAmusthaveRSI(seeabove)
5) Describethestepsusedtotreatananaphylacticreaction.• TheABCsforanaphylaxis:
20
o Airway,andadrenalineo Breathing,andBenadrylo Cyrstalloidsandcimetidineo Steroids
• Mgmtofanaphylaxisduringanaesthesiao Stopdrugorallergenadministrationo Provide100%O2o Discontinuesurgeryandanaesthesiaassoonasfeasibleo Giveepi50‐100mcgIVwithhypotension,0.5‐1.0mgIVwithCVcollapseo Epiinfusion0.05‐0.2mcg/kg/mino Crystalloids(NS,RL)IV,mayreq2‐4Lfora70kgadult,i.e.25‐50ml/kgo Diphenhydramine50mgivo Cimetidine300mgIV,orranitidine50mgIVo Hydrocortisone100mgIV,ormethylprednisolone1mg/kgIVq6hx24ho Inhaledsalbutamolforbronchospasmo Avoidbetablockers
top related