icu病人困难脱机原因与处理对策13.ppt

ICU病人困难脱机的原因及处理对策撤机撤机(weaning)是一个缓慢、逐渐地降低呼吸支持的过程,20%-30%的患者出现撤机困难,有的患者甚至出现严重的呼吸机依赖,总的来说用来撤机的时间约占整个机械通气时间的40%,而在某些特殊的疾病状态下(如COPD)撤机时间可占总通气时间的60%左右。撤机快速撤机:几个小时内成功撤机缓慢撤机:需要几天、几周的撤机技术COPD,高龄或虚弱,ARDS困难撤机:呼吸机依赖或脑损伤或神经肌肉病变困难撤机标准(WeaningFailureCriteria)MAPchange>20mmHgPulseratechang>20bpmPaCO2increae>10-20mmHgPaCO2decreae>10-20mmHgorSpO2<90%despiteincreasingFiO2to45%PH<>30-40bpm困难撤机的表现呼衰的病理生理学困难脱机的常见原因FAILURETOWEANOFFVENTILATOR:CAUSES-1Respiratory: -Usewiderboreartificialairway– ETtube/tracheostomy -Treatbronchospasmadequately -pliancebyremovingexcessfluid (“wetlungs”)byusingdiureticsifvolumeoverloaded/ congestivecardiacfailureisthecause. -Cardiovascular: leftventriculardysfunction -pulmonaryoedema(backwardfailure) -inabilityofthecardiovascularsystemto providetheincreaseindeliveryofoxygen neededbytherespiratorymusclesduringweaning (forwardfailure) Appropriatetherapy(diuretics/vasodilators/inotropes) essfulweaningfrom mechanicalventilatorysupport. Haemoglobinmustalsobeoptimized >8g% >10g%withmyocardialischemia/cerebralischemiaFAILURETOWEANOFFVENTILATOR:CAUSES-2Neurological: -brainstemdysfunctionduetotrauma,hypoxiaor infection,criticalillnesspolyneuropathy -anophosphorus insecticidesFluidBalance: Positivecumulativefluidbalanceisassociatedwith failuretoweanandanegativefluidbalancewas : anysepsisand/orrespiratoryinfectionshouldhave resolvedFAILURETOWEANOFFVENTILATOR:CAUSES-3Drugs -stopsedativesanddrugslikelytoimpair neuromuscularfunction. -giveantidotes(flumazenil,nalorphine,neostigmine) asindicatedElectrolytes-maintainnormalserumpotassiumand phosphorousAlkalosis -respiratory–don’tchasethePaCO2 -metabolic–reducebaseexcess(?acetazolamide)PaO2Endocrine-hypothyroidism