ANESTHESIA FOR PATIENT WITH NEUROMUSCULAR DISEASE

1. ANESTHESIA FOR PATIENT WITH NEUROMUSCULAR DISEASE

2. MYASTHENIA GRAVIS –개요 • Weakness and easy fatigability of skeletal muscle • Ocular or nonocular muscle weakness 에 따라 분류 • 30대 여자, 60-70 대 남자에게서 호발 • Autoimmune destruction or inactivation of postsynaptic Ach receptor • Ab against the nicotinic Ach receptor : 80-90 % of generalized MG • MG 환자의 10-15% 는 Thymoma, 65% 는 thymic hyperplasia • Clinical manifestation • Ocular involvement : ptosis, diplopia • Bulbar involvement : dysarthria, swallowing difficulty, pulmonary aspiration • Severe disease 의 경우, proximal muscle weakness, 및 respiratory muscle weakness 동반 • Muscle strength : 휴식 시 호전, 운동시 악화 • Infection, stress, surgery, pregnancy 등이 악화 요인

3. MYASTHENIA GRAVIS –치료 • Anticholinesterase drug • Muscle weakness treatment 의 가장 많이 쓰이는 약물 • Pyridostigmine : 2-4 시간 효과 ( P.O) • 과량 투여 시 cholinergic crisis 유발  weakness 증가 및 excessive muscarinic effect • Edrophonium test : 10 mg iv 후 관찰  cholinergic or myasthenic crisis • Moderate to severe disease 시에는 anticholinesterase 외에 도 immunomodulating therapy • Plasmapheresis : dysphagia, respiratory failure, 수술 전 정상 muscle strength 회복이 필요한 경우

4. MYASTHENIA GRAVIS – Anesthetic Consideration • Best possible medical control prior to operation • Respiratory and oropharyngeal weakness  iv IG, plasmapheresis • Anticholinesterase, immunomodulating drug, steroids • Preoperative evaluation • Respiratory muscle, bulbar involvement  aspiration • H2 blocker, metoclopramide premedication • Respiratory depressant 에 대해 매우 sensitive • BDZ, opioids premedication  stop • NMBA 를 제외한 일반적인 마취약제는 모두 사용 가능 • Barbiturate,propofol 의 moderate dose  호흡억제 가능 • Propofol may be preferable • Volatile agent-based anesthetic  generally most satisfactory

5. MYASTHENIA GRAVIS – Anesthetic Consideration • Succinylcholine 에 대한 반응은 unpredictable • Nondepolarizing NMBAs  매우 sensitive • 만약 NMBA 가 필요한 경우, short-acting nondepolarizing agent 를 소량 사용 • NMBA 를 사용시, nerve stimulator 을 이용, close monitoring • Extubation 시, ventilatory function 을 주의 깊게 evaluation • Postoperative respiratory failure • 6년 이상, 동반된 pulmonary disease, peak inspiratory pr <-25 cm H2O,vital capacity < 4ml/kg, PSTG dose >750 mg/ day • 가임기 여성의 MG • Increased weakness  last trimester of preg, early postpartum period • MG 산모에게서 태어난 영아의 경우, 1-3 개월간 MG 증상 지속

6. LAMBERT-EATON MYASTHENIC SYNDROME • Proximal muscle weakness 를 특징적으로 가지는 paraneoplastic syndrome • Lower extremity  upper limb, bulbar, respiratory muscle • Sx : dry mouth, male impotence, other autonomic dysfunction • Small cell carcinoma of lung  가장 많은 원발 종양 • 기타 neoplasm of unknown origin, autoimmune disorder • MG 와 다르게, muscle weakness 는 repeated effort 에 의해 호전되며, Anticholinesterase drug 에 의한 반응이 less dramatic • Treatment • DAP (Guanidine hydrochloride and 3,4-diaminopytidine)  Ach 분비를 촉진하여 높은 효과를 보임 limited by hepatoxicity • Immunosuppression, plasmapheresis

7. MUSCULAR DYSTROPHIES-Preoperative considerations • Heterogeneous group of hereditary disorders • Muscle fiber necrosis and regeneration • Progressive weakness and degeneration of muscle

8. DUCHENNE’S MUSCULAR DYSTROPHY • Most common & most severe form of muscular dystrophy • Other major variants : Becker’s myotonic facioscapulohumeral & limb girdle dystrophy • X-linked recessive disorder  affect males almost • 3-5 세에 대부분 발병 • Symmetric proximal muscle weakness, gait disturbance • Pseudohypertrophy  fatty infiltration of muscle • Kyphoscoliosis  12세 경애 대부분 보행 불가 • glucocorticoid 병의 진행을 2-3년 정도 늦춤, • Intellectual impairment, but not progress • Plasma creatin kinase  정상보다 10-100 배 증가, plasma myoglobin 증가 • Dx : Bx 로 확진, southern blot analysis of abnormal dystrophin gene

9. DUCHENNE’S MUSCULAR DYSTROPHY (continued) • Degeneration of the respiratory muscles • interferes with an effective coughing mechanism, retention of secretion  frequent pulmonary infections • Restrictive ventilatory defect , pulmonary HTN • Degeneration of cardiac muscle  10% 환자가 dilated or hypertrophic cardiomyopathy • ECG  P-R prolongation, QRS, ST segment abnormality, prominent R wave • Death is usually due to • Recurrent pulmonary infections, respiratory failure, cardiac failure

10. BECKER’S MUSCULAR DYSTROPHY • X-linked recessive muscular dystrophy • Dystrophin gene 의 deletion or point mutation • 임상증상이 Duchenne’s muscular dystrophy 와 유사 • Present later in life (adolescence), more slowly progression • MR 은 rare

11. MYOTONIC DYSTROPHY • Myotonia : electrical or percussive stimuli 에 반응하여 muscle 이 contraction 후 느리게 relaxation 하는 것 • M/C cause of myotonia, multisystemic disorder • Autosomal dominant, 1:8000 • 20-30 대에 주로 발병 • Clinical manifestation • Myotonia  muscle weakness, atrophy • Affect cranial muscles : orbicularis oris, oculi, masseter, SCM 등 • Plasma CK level  normal or slightly increase • Multiple organ system involve, presenile pattern • Premature frontal baldness, sleep apnea, endocrine dysfunction • Respiratory involvement  decreased vital capacity, cor pulmonale • Alveolar hypoventilation  pulmonary or central nervous system

12. MYOTONIC DYSTROPHY (continued) • G-I hypomotility  leading to pulmonary aspiration • Uterine atony  prolonged labor and retained placenta • Cardiac manifestation  다른 clinical Sx 전에 생길 수도 있음 • Atrial arrhythmia, heart block, depression of ventricular function • Stiffness : ease with continued activity, cold temperature 는 악화 시킴 • Treatment • Phenytoin, quinine sulfate, procainamide

13. FACIOSCAPULOHUMERAL DYSTROPHY • AD trait • 남.녀 모두 에게 발생하나, 여자에게 발생시 더 asymptomatic • 20-30 대에 facial and shoulder girdle 에서 잘 발생  lower extremity 는 rare • Respiratory function 은 spared • CK level  Normal or slight increase • Cardiac involvement  rare

14. LIMB-GIRDLE DYSTROPHY • Several variants of neuromuscular disease • Childhood autosomal recessive muscular dystrophy (SCARMD) • Autosomal recessive muscular dystrophy • Etc. (Erb’s and Leyden-Mobius) • 대부분 소아 – 20-30 대에 발병 • Shoulder, hip girdle or 양쪽 모두 다에 weakness • Progression  very slow • CK level  증가 • Cardiac involvement • Duchenne’s 와 유사 하게 종종 arrhythmia 및 CHF 발생 • Hypoventilation, recurrent respiratory infection

15. ANESTHETIC CONSIDERATION- Musculodystrophy (1) • Duchenne’s and Becker’s Musculodystrophies • Muscle weakness, cardiac and pulmonary manifestation 을 고려 • Malignant hyperthermia • Premedication : opioids, sedatives  avoid, • Intraoperative positioning, difficult intubation • Succinylcholine  avoided • non-depolarizing NMBA’s  normal or very sensitive reaction • Volatile anesthetics  marked respiratory & circulatory depression • Regional & local anesthetics may be preferable • Post op Cx : respiratory complication

16. ANESTHETIC CONSIDERATION- Musculodystrophy (2) • Myotonic dystrophy • High risk for perioperative respiratory & cardiac Cx • 마취 전 환자의 Hx 에 대해 주의 깊게 evaluation • Opioids, sedatives, inhalation & iv anesthetics 에 대한 반응이 매우 민감한 경우도 있음  sudden & prolonged apnea 유발 • Premedication  가능한 한 시행하지 않음 • Succinylcholine  avoided • Myotonic contraction  respiratory, chest wall, laryngeal muscle • Physostigmine, neostigmine 등은 myotonia 를 aggravation • Nondepolarizing NMBAs : response 는 normal, but not prevent or relieve myotonic contraction • Post-operative shivering  volatile agent 에 의해 발생 하며, 낮은 체온과 함께 muscle contraction 을 유발함 (Tx : meperidine)

17. ANESTHETIC CONSIDERATION- Musculodystrophy (3) • Myotonic dystrophy (continued) • Induction agent : thiopental, inhalation agent, propofol • Short acting NMBA’s • Reverse with anticholinesterase  avoided • Maintenance : Nitrous oxide, inhalation anesthetics • Postoperative complication • Pulmonary complication (main) • Prolonged hypoventilation, atelectasis, pneumonia • Pulmonary hygiene with physical therapy, incentive spirometry, postoperative monitoring • Aspiration prophylaxis : upper abd. surgery, severe prox. weakness • Malignant hyperthermia : suggested, but not firmly established

18. MYOTONIAS (1) • Myotonia congenita • Early in life with generalized myotonia • Skeletal muscle fiver surface membrane 에 존재하는 chloride channel gene 의 defect • AD (Thomsen’s), AR (Becker’s) • Confined to skeletal muscle, no or minimal progression • Antimyotonic therapy : Phenytoin, mexiletine, quinine sulfate, procainamide • 그 외, tocainide, dantrolene, prednisone, acetazolamide, taurine • No cardiac involvement, normal life span (myotonia congenita)

19. MYOTONIAS (2) • Paramyotonia congenita • Very rare autosomal dominant disorder, sodium channel gene defect • Transient stiffness , cold exposure 후 weakness, serum potassium level 증가 • Treatment : tocainide, mexiletine

20. MYOTONIAS –anesthetic consideration • Abnormal response to succinylcholine • Intraoperative myotonic contraction • Need to avoid hypothermia • NMBAs  generalized muscle spasm • Trisimus, difficult intubation and ventilation • In vitro, malignant hyperthermia 와 연관 없음

21. PERIODIC PARALYSIS • Sudden attacks of transient muscle weakness or paralysis • Sx 은 대개 childhood 에 시작, attack 은 대개 몇 시간 동안만 지속되며 respiratory muscle 은 sparing • Partial depolarization of the resting potential  loss of muscle fiber  weakness • Primary genetic channelopathy, secondary acquired forms • Genetic, inherited types : dominantly inherited mutation, voltage-gated sodium, calcium, potassium ion channel • Dominant inherited disorder • Defect in voltage-gated, calcium channel  attack 시 low potassium • Sodium channel  periodic paralysis, weakness 발생시, high potassium level • Direct & indirect stimulation 에 대해 inexcitable muscle membrane • Sporadic episode of weakness, attack 사이에는 potassium level 이 normal • Hypothermia 에 의해 증상이 악화  1시간 이내 ~ 2 days

22. PERIODIC PARALYSIS – Anesthetic Consideration • Preventing attack 이 가장 중요 • Careful ECG monitoring • Frequent intraoperative measurement of plasma potassium • Glucose containing fluid  hypokalemia 시는 avoid • NMBA’s  response 가 unpredictable, increased sensitivity in hypokalemia type • Succinylcholine  hyperkalemic type 에 금기 • Shivering & cold  trigger attack, 중심 체온 유지가 중요