Effect of different modes of NIV in neuromuscular disease

Background: Noninvasiveventilation(NIV)isusedinpatientswithchronicneu- romusculardisorders,butwhichmodeofventilationisassociatedwithanoptimal patient-ventilatorinteractionispoorlyknown Objectives: WecompareddifferentmodesofNIVi.e.pressuresupportwithvol- ume guarantee(PSV-VG),pressuresupport(PSV)andassistedpressuresupport (APCV)inneuromuscularpatientsonnocturnalpolygraphicvariables,including patient-ventilatorsynchrony,andondiurnalbloodgases. Methods: Twentyeightpatientswithneuromusculardiseasewereincluded.The threeventilatorymodeswereappliedinthreeconsecutivenights.Duringeachnight a cardio-respiratorypolygraphicmonitoringwasperformed.Thenextmornings arterialbloodgasesweremeasured.Analysiswasextendedtorecurrenceofmajor patternsofasynchrony Results: No significantdifferencesinnocturnalanddiurnalbloodgaseswere found.Prolongedinsufflationwasthemost frequentasynchronyandwasstrictly correlatedwiththemagnitudeofleaksineachmodalityofNIV(PSV-VGr=0.53 p=0.005,PSVr=0.67p=0.0004,PSVplusPEEPr=0.61p=0.001,APCVr=0.62 p=0.0001,APCVplusPEEPr=0.55p=0.003).Thenumberofprolongedin- spirationswasstatisticallyhigherinPSVmodethaninAPCVmode(p=0.028). Ineffectiveefforts(IE)werefoundmainlyinthePSV-VTGmodeandwere correlatedwithdurationofleaks(r=-0.49,p=0.027)andBMI(r=-0.39,p=0.03 Conclusion: Differentmodesofventilationmaybeassociatedwithadifferentin- cidenceofpatient-ventilatorasynchronies,althoughsignificantdifferencesintheir effectsondiurnalornocturnalrespiratoryfunctionmaynotbeacutelydetected