GE CARESCAPE - NMT practicalities; NMT troubleshooting

Neuromusculartransmission
Posttetaniccount(PTC)mode
WhentheresponsetothefourthTOFstimulationpulsedisappearsorthersttwitchis
veryweak,theTOF%isnotavailableandonlythecountscanbeobserved.
Whenthestimulationpulsesnolongergiveanystimulationresponse,thecountalso
disappears.Tomonitortherelaxationlevel,youcanthenstarttetanicstimulationand
estimatetherelaxationlevelfromtheposttetaniccount,PTC.Tetanicstimulation
isacontinuousstimulationofveseconds.Aftertetanicstimulation,singletwitch
stimulationsaregenerated.Thenumberofdetectedresponsesiscountedand
expressedasPTC.Thefewertheresponses,thedeepertherelaxation.
Iftheresponsesdonotfadeaway,amaximumof20responsesarecountedandthe
measurementvalueisreplacedby>20.
Aftertetanicstimulation,NMTmeasurementisstoppedforoneminute.Afterthat,the
monitorautomaticallycontinueswiththepreviouslyselectedcycle.
Singletwitch(ST)mode
Insingletwitchstimulationonepulseisgeneratedanditsresponseismeasured.
NMTpracticalities
●Normally,defasciculatingdosesofnon-depolarizingneuromuscularblocking
agents(precurarisation)donotaffectthesupramaximalcurrentnorthereference
value.
●AveragelifetimeofaMechanoSensoristwoyears,dependingontheuse.The
sensorhasbeenvalidatedtolast700,000twitches.
Inappropriatefunctionofthemeasurementisoftencausedbyincorrectaccessory
connectionormisuseoftheproducts.Therefore,notethefollowing:
●Handlethesensorandcablescarefullytomaximizetheirlifetime.
￭PiezosensorinsidetheMechanoSensorisverysensitivetoshocks.
●AttachtheMechanoSensorcorrectly.
￭ItisrecommendedtosecuretheMechanoSensorwithanarrowtape.Wide
tapemightpreventadequatemovementofthesensorwiththethumbduring
themeasurement.
●Checkthequalityofthestimulationelectrodes.
￭UseGEapprovedNMTelectrodesforstimulation.Theyaretestedwiththe
moduleandprovidelowimpedance,whichiscrucialforaccuratemeasurement.
￭Donotusetheelectrodesaftertheirexpirationdate.
●PerformavisualcheckoftheMechanoSensororElectroSsensorandcable.
￭Regularvisualcheckingofthecableandsensorisrecommended.Ifyouseeany
signsofbrokencablesorjointsoftheMechanoSensor,replacethoseparts.
NMTtroubleshooting
ProblemSolution
NMTreferencesearchandmeasurementfail.●Checktheelectrodequalityandpositioning.
●Replacestimulatingelectrodes.
Measurementisdisturbed.●Checktheblackgroundelectrode.
370CARESCAPEModularMonitors2062971-001