TheSuperNO2VA™foramorbidlyobesepatientwithOSAforcolonoscopy:Acasereport.
MarcoGidaro,CRNA
EinsteinMedicalCenter,Philadelphia,PA
Introduction
Theprevalenceofmorbidobesityandobstructivesleepapneahasbeenontheriseforthelast
15-20years.Alongsidethesetrends,weappreciateasimultaneousincreaseintheuseof
monitoredanesthesiacareanddeepsedationanesthesia.Hypoxemiaduringsedationremains
oneofthemostcommonanddifficulttotreatadverseevents,occurringin5-42%ofall
patients.1-6Thesefiguresareexacerbatedbymorbidobesityandobstructivesleepapnea,
secondarytoincreasedriskofupperairwayobstructionandhypoventilation,poorFRC,and
increasedoxygenconsumption.1,5Maintainingupperairwaypatency,deliveringhigh
concentrationsofinspiredoxygen,andprovidingpositiveairwaypressuresupportcontinuesto
bethegoalinairwaymanagementofthesepatients.TheSuperNO2VA™isasealednasal
anesthesiamaskdesignedtodelivertitratablepositivepressurewhileconnectedtostandard
anesthesiaequipment.Bymaintainingairwaypatencyandallowingforventilatorysupport
duringdeepsedation,thisdevicemaybeausefulairwayadjunctforairwaymanagementof
obesepatientspresentingwithOSAinordertominimizehypoxemia.
CaseReport
A56-year-oldmalewithHTN,DM,morbidobesityandOSAonhomeCPAPwasscheduledfora
colonoscopytoevaluateforpolyps.Theanesthesiateamoptedfordeepsedationviapropofol
infusiontitratedtoeffectwithairwaypatencymaintainedwiththeapplicationofthe
SuperNO2VA™mask.TheSuperNO2VA™andstandardASAmonitorswereappliedpriorto
sedationandthepatientwaspositionedintheleftlateralposition.Themaskwasconnectedto
anexternalMaplesoncircuitwithasemi-closedpressurereliefvalveandpressurizedwith10
L/minofoxygen.Followinglossofconsciousness,thepatienttoleratedrectalintubationwith
thecolonoscope.TheSuperNO2VA™remainedpressurizedandthepatientfreefrom
obstructionordesaturation.SpO2was100%,whileadequateventilationwasconfirmedvia
capnographyandcontinuousexpansionandcollapseoftheMapleson'sreservoirbag.
After40minutes,thepatientexperiencedaprecipitousandcompleteupperairwayobstruction
withlossofend-tidalCO2andnoappreciableevidenceofventilationintheMaplesoncircuit.
SpO2droppedfrom100%to86%within20seconds.Theoxygentankhadbeendepleted
resultinginalossofoxygenflowandpositivepressuretotheSuperNO2VA™mask.The
Maplesoncircuitwasimmediatelyconnectedtothewalloxygensourceat10L/min,followedby
pressurizationoftheSuperNO2VA™maskandimmediateresolutionoftheupperairway
PR0006A
obstruction.Ventilationwasreestablishedandconfirmedviacapnographyandthepatient's
SpO2returnedto100%.Therewerenootherincidencesofobstructionordesaturationforthe
remainderoftheprocedure.
Discussion
Thissinglecasemaysuggesttheutilityofpressurizednasalmaskventilationwiththe
SuperNO2VA™onamorbidlyobesepatientwithOSAundergoingadeepsedationanesthetic.
Withtheuseofstandardequipmentforsedation,suchasnasalcannulaornon-rebreather
mask,itmayhavebeenchallengingtomaintainairwaypatency.Potentialuseofan
oropharyngealairwaywithanon-rebreathermaskmayhavemitigatedobstructionbutwould
nothaveaddressedatelectasisorhypoventilation.TheSuperNO2VA™wassimpletoemploy
anddidnotrequirecapitalequipment.Assuch,itmaypresentalow-costoptionforairway
managementinhigh-riskpatientsandwarrantsprospective,wellcontrolledresearchtofully
elucidateitsclinicalutility.
References
1. TurkishJournalofGastroenterology2002;13(4):203-8
2. AnnalsofEmergencyMedicine2008;52(1):1-8
3. ClinicalGastroenterologyandHepatology2010;8:137-42
4. AnnalsofEmergencyMedicine2010;55(3):258-64
5. GastrointestinalEndoscopy2011;74(6):1238-47
6. Endoscopy2014;46(3):236-44
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