QUIZ17thJune2020(answersbelow)

1. Whatarethesignsoflocalanaesthetictoxicity?

2. Whatisthemanagementoflocalanaesthetictoxicity?

3. Howdoyouusetheslitlamptolookforcellsintheanteriorchamber?

4. Whereontheslitlampisthecobaltbluefilterforthefluorosceinexam?

5. DescribeandinterpretthefollowingECG.

QUIZanswers17thJune2020

1. Whatarethesignsoflocalanaesthetictoxicity?

Earliestsymptomsareneurologicalandincludetinnitus,dizziness,anxiety,confusionandperioralnumbness.More severe signs are seizures, coma, bradycardia, hypotension, and arrhythmiasincludingVFandasystoleandrespiratorydepression

2. Whatisthemanagementoflocalanaesthetictoxicity?

Earlyrecognitionofsymptomsandprompttreatmentisimportant.Thedevelopmentof even mild symptoms during or shortly after local anaesthetic administrationmandatescardiovascularmonitoringinresuscitationarea.

Toxicity is theresultofsodiumchannelblockade,somanagement isverysimilartoothersodiumchannelblockingagents,liketricyclicantidepressants.Specificinterventionsinclude:

BicarbonateforCVStoxicityEarlyintubationtopreventacidosisminimisesriskofcardiacarrestSeizuresaretreatedwithbenzodiazepinesLipidemulsioninsevereCVStoxicityorrefractorycardiacarrest

ThethresholdforadministeringintralipidiscontroversialIntralipid20%500mLbottlesarekeptintheEDdrugcupboard

Give100mLstatandthenrunremaining400mLover20minutes

3. Howdoyouusetheslitlamptolookforcellsintheanteriorchamber?

Shorten the slit light beamandwiden it slightly. Angle the beam so that the lightpathhitsthecorneaononesideofwhereyouseethepupil,andhitstheirisontheotherside,inorderthattheanteriorchamberisseenagainsttheblackbackgroundofthepupil.Focusonthecornea,andthenlengthenthefocustotheiris.Slowlyshortenthefocustothecorneaonceagain,sothatthefocuspointrunsthroughtheanteriorchamber,potentiallyfocusingoncellsintheaqueoushumor.Cellscanbeseenasmovingwhitedots.Thecellsmaymoveupwardsatthebackoftheanteriorchamberanddownwardinthefront,duetotheconvectioncurrentsetupbytheincreasedwarmthatthebackoftheeye.

Flareisthesmokyorcloudyappearanceofthebeamoflightintheanteriorchamber.Thisisduetoincreasedprotein,alsocausedbyinflammation.

4. Whereontheslitlampisthecobaltbluefilterforthefluoresceinexam?

5. DescribeandinterpretthefollowingECG.Rate Bradycardic25/min Exceptbeats#4and#6whichoccurearlyat55/minPwave IcanonlyseeonePwavebetween#5and#6PRinterval IfthatPwaveisconductedto#6,thePRintervalisprolonged0.28secQRS Narrow Normalaxis QwavesV1-2Twaves PeakedV3-6 TWIinaVLQTc Notprolonged

è Junctionalbradycardia PossibleconductedPwavebutwith1stdegreeHB PeakedTwaves

è ThispatienthadK+6.8mmol/L