_EMERGENCIES神经肌肉紧急情况（PPT55）课件.pptVIP

Investigations Repetitive motor nerve stimulation Stimulate motor nerve at 2-3 Hz and measure CMAP of stimulated muscle Positive if er 10% decrement in amplitude of CMAP from the 1st to the 5th potential Positive in about 75% of patients with generalized MG, if Proximal clinically involved muscles are tested Muscle is warm More than one muscle is tested Single fibre EMG Tensilon test not recommended in pt suspected of being in crisis False postive, false negative Risk of worsening muscle weakness in pts with anticholinesterase overdose Worsening of bulbar and respiratory symptoms in MuSK-MG Management Monitoring of respiratory status Recognition of impending resp failure Tachypnea, inability to count to 20, saliva pooling, nasal voice, NF weakness, paradoxical breathing Deciding when to intubate (Code status) 20/30/40 rule If in doubt, intubate ?BiPAP Limited experience. May reduce prolonged intubatn and trach Management General Stop any meds that may be contributing Treat any infection Specific PLEX and IVIG comparable efficacy Based on clinical evidence, few RTCs Earlier response seen with PLEX More likely to extubate at 14 days, better 1-month functional outcome (Qureshi, et al. Neurology, 1999). Management PLEX Removal of anti AChR and antiMuSK Abs 1 session/day x 5 No superiority of PLEX qd x 5 vs qod x 5 Rapid onset of action (3-10 days) Need central line with associated complications PTX, hemorrhage, line sepsis Caution in pts with sepsis, hypotension; may lead to increased bleeding and cardiac arrhythmias Management IVIG 0.4gm/kg/day x 5 days Easily administered and widely available Long duration of action May last as long as 30 days Side effects Anaphylaxis in IgA deficiency Renal failure, pulmonary edema Aseptic meningitis Thrombotic complications and stroke MG – Overall Treatment Summary 1. Mild weakness: cholinesterase inhibitors 2. Moderate-marked localized or generalized weakness Cholinesterase inhibitors, and Thymectomy for patients u