重症疾病性神经肌肉病(英文)CIP critical illness polyneuropathyCIM critical illness myopathyCMAP compound muscl action potentialsSNAP sensory nerve action potentialEMG electromyogramSIRS systematic inflammatory response syndrome重症疾病性神经肌肉病(英文)In 1955 observed a polyneuropathy after shock or cardiac arrestIn 1961 described “coma-polyneuropathies” In 1971 described a polyneuropathy in patients with burnsin 1977 severe polyneuropathy about septic patients重症疾病性神经肌肉病(英文)By 1983 the term “critical illness polyneuropathy”（CIP） was appliedRecently the termed “critical illness myopathy ”（CIM） was applied重症疾病性神经肌肉病(英文)The various factors associated with the SIRS CIP and CIM (Fig. 1) A simplified depiction of theoretical mechanisms of dysfunction in CIP and CIM.(Fig. 2 )Disorder of microcirculation（Fig. 3)重症疾病性神经肌肉病(英文) Adapted with permission from Bolton.Figure. 1重症疾病性神经肌肉病(英文)Adapted with permission fromBolton25.Figure. 2重症疾病性神经肌肉病(英文) Figure.3 Schematic, theoretical presentation of disturbances in the microcirculation to various organs, including brain, peripheral nerve, and muscle, in SIRS.重症疾病性神经肌肉病(英文)重症疾病性神经肌肉病(英文)Incidence 50%70% SIRS 20%50% ICU重症疾病性神经肌肉病(英文) Weakness of limb and respiratory muscle Tendon reflexes absent or decrease Distal loss to pain, temperature, and vibrationClinical Features重症疾病性神经肌肉病(英文)The diagnostic criteria for CIP are shown in following TableDiagnosis重症疾病性神经肌肉病(英文)Diagnostic criteria for CIPThe patient is critically ill (sepsis and multiple organ failure,SIRS)Difficulty weaning patient from ventilator afternonneuromuscular causes such as heart and lung diseasehave been excludedPossible limb weaknessElectrophysiologic evidence of axonal motor and sensory polyneuropathy重症疾病性神经肌肉病(英文)Decline in the CMAP amplitude firstly (Fig. 4)Dcline in the SNAP amplitudeMotor unit potentials may be reduced in numberSingle-fiber EMG indicate dysfunction of terminal motor axonsElectrophysiologic Features重症疾病性神经肌肉病(英文)FIG.4重症疾病性神经肌肉病(英文)Peripheral axonal degeneration.Moderate loss of dorsal root ganglion cellsCentral chromatolysis of anterior horn cellsNo inflammation in the peripheral nervous systemMorphologic Features重症疾病性神经肌肉病(英文)Muscle biopsy Acute and chronic denervation Occasional myopathic changes重症疾病性神经肌肉病(英文) Pathology of critical illness polyneuropathy. There is chromatolysis of anterior horn cells (A); severe axonal degeneration in this cross-section of superficial peripheral nerve (B) and longitudinal section of deep peroneal nerve (C); and acute and chronic denervation of intercostal muscle (D)重症疾病性神经肌肉病(英文)Axonal variants of GuillainBarre syndromeDevelop earlierOften associated with CJ infectionAbnormal cerebral spinal fluidDifferential Diagnosis重症疾病性神经肌肉病(英文)Transient neuromuscular blockadeRepetitive nerve stimulationMeasurement of anti-MuSK (muscle specific receptor tyrosine kinase) antibodies重症疾病性神经肌肉病(英文)Treatment of sepsis and multiple organ dysfunction syndrome Management of difficulty in weaning from the ventilator Attempts at direct treatment of CIP (still unproven) Physiotherapy and rehabilitationTreatment重症疾病性神经肌肉病(英文) Two newer research approaches are being exploredIntensive insulin therapyThe administration of recombinant human activated protein C 重症疾病性神经肌肉病(英文)Recovery depends on the distanceRecovery for weeks in mild cases and months in severe casesSlowing of nerve conduction may have a poor prognosisPrognosis重症疾病性神经肌肉病(英文)重症疾病性神经肌肉病(英文)IncidenceAt least one-third of ICU patients（ treated for status asthmaticus）In 7% of patients after transplantation重症疾病性神经肌肉病(英文)Clinical FeaturesMajor feature is flaccid weaknessTendon reflexes depressedOphthalmoplegia may be presentMyalgias are uncommon重症疾病性神经肌肉病(英文) Diagnostic criteria of CIM SNAP amplitudes 80% of the lower limit of normal Needle EMG with short-duration, low-amplitude MUPs with early or normal full recruitment, with or without fibrillation potentials Absence of a decremental response on repetitive nerve stimulationDiagnosis重症疾病性神经肌肉病(英文) Muscle histopathologic findings of myopathy with myosin loss CMAP amplitudes 80% of the lower limit of normal in two or more nerves without conduction block Elevated serum creatine kinase (CK） Demonstration of muscle inexcitability*For a definite diagnosis of critical illness myopathy, patients should have all of the first five features.重症疾病性神经肌肉病(英文)Nerve conduction studiesLow-amplitude CMAPs Long duration CMAPsNormal SNAPsPhrenic nerve conduction normal latencies diaphragm CMAP amplitudes reduceElectrophysiologic Features重症疾病性神经肌肉病(英文)EMGFibrillation potentials and positive sharpMotor unit potentials low amplitude and short durationElectrical inexcitability by direct needle stimulation重症疾病性神经肌肉病(英文)Features of the histopathology in thick filament myosin loss (Fig. 5)Electron microscopy reveals selective loss of thick (myosin) filaments (Fig. 6)Inflammatory changes are conspicuously absent Morphologic Features重症疾病性神经肌肉病(英文) Figure. 5 Muscle histopathology in a critically ill patient with thick filament myosin loss. (original magnification, 100) (courtesy of Dr. Andrew Engel).重症疾病性神经肌肉病(英文) Figure. 6 Electron microscopy of muscle in CIM. (original magnification, 44,000) (courtesy of Dr. Andrew Engel).重症疾病性神经肌肉病(英文)CIPDirect needle stimulation of the muscle Electrical inexcitability in CIMThere is a response in CIP (Fig. 7)Serum CKMuscle biopsy重症疾病性神经肌肉病(英文)FIGURE. 7 Results of direct and indirect muscle stimulation. CMAPs from the anterior tibial muscles of a patient with critical illness polyneuropathy (left) and critical illness myopathy (right).重症疾病性神经肌肉病(英文)Subtypes of CIMMuscle morphologicDifferentiating feature of neuromuscular disorders in critical illness Table 1.重症疾病性神经肌肉病(英文)重症疾病性神经肌肉病(英文)No specific therapy available as to nowPositioning to avoid additional nerve damage by pressureAvoid administering muscle relaxants and corticosteroidsTreatment重症疾病性神经肌肉病(英文)重症疾病性神经肌肉病(英文)