1、Department of Critical CareCui WeiContentsRespiratory FailureShockRespiratory FailureGeneral PrinciplesHypercapnic respiratory failure may produce a respiratory acidosis(pH 7.35).Hypoxic respiratory failure can result in hypoxemia(arterial oxygen tension PaO2 60 mm Hg or arterial oxygen saturation S
2、aO2 90%).The acute respiratory distress syndrome(ARDS)is a form of hypoxic respiratory failure caused by acute lung injury.The common end result is disruption of the alveolar capillary membrane,leading to increased vascular permeability and accumulation of inflammatory cells and protein-rich edema f
3、luid within the alveolar space.The American-European Consensus Conference has defined ARDS as follows:(a)acute bilateral pulmonary infiltrates,(b)ratio of PaO2 to inspired oxygen concentration(FIO2)90%,PaO260mmHgMinute Volume of VentilationDetermined by Vt and fIn COPD patients,the goal of PaCO2 is
4、the baseline level,not the normal levelVentilator ManagementPEEP:Positive End-Expiratory PressureIncrease the risk of barotrauma and cardiovascular compromiseInitial:3-5cmH2OIncerments:3-5cmH2OHigh level:20-25cmH2OGoal 1:PaO255-60mmHgGoal 2:FiO260%Goal 3:Avoid CV compromiseVentilator ManagementInspi
5、ratory Flow40-80L/min for adult ptsTrigger Sensitivity-2-5cmH2O or 3-5L/minFlow-byIn flow-triggered systemDecrease pts work of breathingProblems and ComplicationsWorsening respiratory distressNOTE alarm,Vt,airway pressureDisconnected ventilator circuitVentilate manually Suction if manual ventilation
6、 is difficultCheck vital sign and rapid physical examinationVentilator is never used again unless making sure its working properlyProblems and ComplicationsHigh PIPPneumothorax,hemothorax,or hydropneumothoraxAirway occlusionBronchospasmIncreased accumulation of condensate in the ventilator circuit t
7、ubingMain-stem intubationWorsening pulmonary edemaDevelopment of gas trapping with auto-PEEPProblems and ComplicationsLoss of VtLeakage:circuit,tube or patientAsynchronous BreathingUnmet respiratory demandsInappropriate setting of ventilationPatients condition worseningHypotensionDue to positive ins
8、piratory pressureIncrease preloadAdministration of dobutamineProblems and ComplicationsAuto-PEEPGas trapped of pts due to airway diseases or inadequate expiratory timeAdjust ventilation parameter,increase PEEPBarotrauma or VolutraumaAssociated with high PIP,PEEP,or Pplatsubcutaneous emphysema,pneumo
9、peritoneum,pneumomediastinum,pneumopericardium,air embolism,and pneumothorax Maybe life-threateningReduce inspiratory pressureProblems and ComplicationsPositive fluid balanceCardiac arrhythmiasAspirationVentilator-Associated Pneumonia(VAP)Upper gastrointestinal hemorrhageAcid-base complicationsOxyge
10、n toxicityWeaning from Mechanical VentilationGradual withdrawal of mechanical ventilatory support,depending on the condition of the patient and on the status of the cardiovascular and respiratory systems MethodsSIMVT-tubePSVProtocol-guided weaning is safe and successfulExtubationShould be performed
11、early in the dayPatient educated about the necessity of extubation,the need of cough,and the possibility of reintubationExtubated after the cuff is deflated completelyEncourage the patient for cough and deep breathing,and vital sign should be moniteredExtubation should not be reattempted for 24 to 7
12、2 hours after reintubationSHOCKGeneral PrinciplesOxygen DeliveryBlood FlowTissue HypoxiaOrgan MalfuctionCellular MetabolismOliguriaUnconsciousPulseGeneral PrinciplesClassificationHemodynamicHemodynamicBleedingMass fluid lossMyocarditisAMICardiomyo-pathyPericardial TamponadePulmonary EmbolismSepticAl
13、lergicNeurogenicHemodynamic patternsType of ShockCISVRPVRSvO2RAPRVPPAPPAOPCardiogenicNHypovolemicNDistributiveN-NN-N-N-N-N-Obstructive-NN-N-Cardiogenic ShockMostly followed by acute myocardial infarction(AMI)due to pump failureBP60mmHgCO18mmHgSVRHypoperfusionCardiogenic ShockCertain ConcernPaO260mmH
14、gHct30%Non-invasive or invasive ventilation Necessary fluid managementPharmacological treatmentInotropes and vasopressorsVasodilators not used in severe hypotensive pts.DOPAMINE used as the first-line drug(BP60mmHg)An PAC maybe help for inotropes and fluid infusionCardiogenic ShockMechanically Circu
15、latory Assist DevicesIn pts.not respond to medical therapyIABP is controlled electronically for synchronizing with the pts ECGDefinitive treatment must be considered including non-invasive or invasive proceduresSeptic ShockSeptic ShockSIRSSEPSISSEVERE SEPSISSEPTIC SHOCKResuscitative PrinciplesFluid
16、ResuscitationInitial IV fluid challenge The amount of fluid based on clinical parameters Arterial BP,Urine Output,Cardiac filling pressure,COCrystalloid fluid solutions prefer to colloid fluidHematocrits of 20%to 25%for the young,and 30%for the olderResuscitative PrinciplesVesopressors and inotropes
17、Dopamine 10mcg/kg/minincrease BPDobutamineEpinephrineNorepinephrineVasopressinMilrinoneHemodynamic MonitoringPulmonary artery catheterizationPulmonary Artery CatheterizationIndicationAllows to measure intravascualr and intracardiac pressure(CVP,RAP,PAP,PAWP),CO,PvO2Differentiate cardiogenic or nonca
18、rdiogenic pulmonary edemaIdentify the etiology of shockEvaluate acute renal failure or unexplained acidosisEvaluate cardiac disordersMonitor high-risk surgical patients in the perioperative settingPulmonary Artery CatheterizationMethodInterpretation of Hemodynamic ParametersPAOP used as the left ven
19、tricular filling(preload)and the propensity of pulmonary edemaOptimize cardiac functionOptimize preloadInotropes or vasodilators followedFluid bolus and followed by repeated measurements of PAOP,CI,SV,HR,etc.PAOP 5mmHg as cutoff for additional fluid bolus Interpretation of Hemodynamic ParametersReduce unnecessary lung waterDifferentiating hydrostatic from nonhydrostatic pulmonary edemaAdequacy of organ perfusionNoninvasive hemodynamic monitoringEsophageal Doppler Aortic blood flow velocity CO,SV,SVR can be calculatedCorrelate well with thermodilution values
