360 likes | 618 Views
Muscle Biopsies and Anaesthesia. BCH Data 2005-2008. So what is the problem?. Links between muscular disorders and anaesthetics MH risk and volatiles 25% linkage to CCD Weak linkage to minicore disease Propofol and mitochondria?
E N D
Muscle Biopsies and Anaesthesia BCH Data 2005-2008
So what is the problem? • Links between muscular disorders and anaesthetics • MH risk and volatiles • 25% linkage to CCD • Weak linkage to minicore disease • Propofol and mitochondria? • How can we decide what anaesthetic to give in the absence of a confirmed diagnosis?
Anaesthetic Database and ICE lab results • Anaesthetic given and histological diagnosis • Searched anaesthetic database for all procedures including muscle biopsy where full data is available (2005 >) • Pre op conditions • Anaesthetic details • Searched ICE for muscle biopsy histology
Results 1 • 35 cases identified • Histology available in 32 • Median age 2 (IQR 0.5-8) • 33 anaesthetised by Consultant • 2 anaesthetised by SpR
Induction Sevoflurane 17 Propofol 16 Ketamine 1 Spinal 1 Maintenance Volatile 30 Isoflurane 18 Sevoflurane 12 Propofol 2 Propofol / ketamine 1 Ketamine 1 Spinal 1 Results 3: Anaesthetics
Results 4: local blocks • Infiltration 25 • Regional 6 • Caudal 4 • Epidural 1 (other surgery also) • Spinal 1 • None stated 2
Did the Pre-op diagnosis match the histology? • Yes 10 • No 12 • Unstated 11 • No report 3 • For 2 CCD: • no diagnosis recorded • For 3 MCD: • 1 minicore, 1 cong. myopathy, 1 none recorded
Search of all cases on database where there is risk of MH • Central core disease 6 • 25% linkage • Induction: 2 propofol 4 sevo • Maintenance: 1 propofol 5 volatile • Minicore disease 8 • Weak linkage • Induction: 7 propofol 1 sevo • Maintenance: 4 propofol 4 volatile
Duchenne Muscular Dystrophy • Risk of rhabdomyolysis with volatiles? • 17 cases recorded (9 spine surgery) • Induction: 14 propofol 3 sevo • Maintenance: 8 propofol 9 volatile (2 both)
Conclusions and Questions • ? Recording of pre existing conditions • Pre op diagnosis wrong >50% of time • CCD or MCD and potential MH • 5/35 of muscle biopsies had this diagnosis • 9/14 CCD or MCD patients received volatiles • 9/17 DMD patients received volatiles • What should we do for muscle biopsies where diagnosis is unknown? • What should we do for CCD, MCD and DMD where diagnosis is known?
Anaesthesia for Muscle Biopsies Rob Alcock RJAH Orthopaedic and General Hospital NHS Trust
Anaesthesia for Muscle Biopsies • What Should We Do for Muscle Biopsies Where Diagnosis is Unknown? • What Should We Do for CCD, MCD and DMD Where Diagnosis is Known? • What Neuromuscular Diseases are Out There? What are their Frequencies? • What Problems Might We Encounter? • What are the Risks?
What conditions are biopsied? • Muscular Dystrophies • Congenital Myopathies • Mitochondrial Myopathies • Metabolic muscle disease • Myositis and Dermatomyositis • Periodic Paralysis • Myotonias and Myotonic Dystrophy
Muscular Dystrophies • Duchenne Muscular Dystophy (DMD) 1:5,000 • Becker Muscular Dystrophy 1:18,000 • Emery Dreyfuss Dystrophy 1: 100,000 • Fascioscapulohumeral Dystrophy 1:20,000
Congenital Myopathies • Incidence 1:1000 • 6000 in the W Midlands • Main Symptom is Hypotonia • Only 14% of Hypotonic infants
Congenital Myopathies • Nemaline Rod Myopathy 20% • Central Core Myopathy 16% • Centronuclear Myopathy 14% • Minimulticore Myopathy 10% • Disproportionate Fibre Type Myopathy 21% • Rare Forms 19%
What Are We Worrying About? • Malignant Hyperpyrexia • Conditions Associated with Malignant Hyperpyrexia • Muscular Dystrophy • General Considerations
Malignant Hyperpyrexia (MH) • Spectrum of Pharmacogenetic Disorders • Disorder of Calcium Homeostasis • Triggered by Suxamethonium and Volatile Anaesthetics • Frequently associated with Ryanodine Ca Efflux Channel on the Sarcoplasmic Reticulum • Previous Uneventful Exposure to Triggers does not rule out MH • Diagnosed by In vitro Contracture Test
Masseter Spasm • Defined as lasting > 2 mins after Administration of Suxamethonium • 30% may prove to have MH • Wait • Resort to Trigger Free Anaesthesia
Genetics of MH • 19q11.2-13.2 Ryanodine (RyR1):- Release of Ca2+stores from sarcoplasmic reticulum • 17q11.2-q24:- Altered sodium channel functioning • 7q21.1 Dihydropyridine (DHP):- voltage sensor for RyR1 • 1q32 CACNL1A3 gene encoding the alpha 1-subunit of the voltage-gated DHP receptor that interacts with RyR1
Conditions Associated with MH • Central Core Myopathy • Minicore or Multiminicore Myopathy • King Denborough syndrome
Central Core Myopathy • The most common presentation is at birth or in early childhood with weakness and hypotonia, slowly progressive. • Also present in adolescence as slowly progressive limb-girdle syndrome • Skeletal Abnormalities are Common • Asymptomatic individuals may present with CK or MH • 25% of patients are susceptible to MH
Muscular Dystrophy • Malignant Hyperthermia Association of the United States (MHAUS) • 3 Cases Life Threatening Hyperkaemia • Duchenne & Becker • Following Use of Volatile Agents
General Considerations • Avoid Suxamethonium in Children with Neuromuscular Disease • Avoid Hypothermia • Cardiac Problems associated with Dystrophies? • Respiratory muscle weakness
Fulminant MH Abortive MH Overall Incidence Incidence of Different Forms of MH in Relation to Type of Anesthesia • - Total Number of Anesthetics 1:251,063 1:17,435 1:16,303 • - General Anesthesia 1:221,811 1:15,404 1:14,403 • - Anesthesia with Inhalation Agent 1:84,488 1:6,653 1:6,167 • - With Sux 1:61,961 1:4,506 1:4,201 • Without Sux 1:174,597 1:20,541 1:18,379 • Anesthesia with Sux 1:140,006 1:8,819 1:8,297
Anaesthesia for Biopsy? • Randall et al Paediatric Anaesthesia 2007;17:22-27 • 351 Patients with a Variety of NM Disorders • 274 Received Volatile Agents • 3 Received Sux! • No Cases of MH or Rhabdomyolysis • Conclusion: Risk of MH < 1%
Anaesthesia for Biopsy? • Carr et al Can. J Anaes. 1995;42: 281-286 • 2,214 Pts with suspected MH Sensitivity Undergoing Muscle Biopsy • Trigger Free Anaesthesia • 97% GA • 1082 were positive • 5 Patients had MH reactions
Mitocondrial Myopathies • Case Reports of Resp and CV Depression, Lactic Acidosis and Rhabdomyolysis after Prolonged Propofol Anaesthesia • Propofol is Highly Metabolised • Volatiles are Minimally Metabolised • Should Propofol be Avoided?
Conclusion • Patients for Bx Should Ideally be Anaesthetisd in the Absence of Volatiles. • Patients with Known CCD, MCD and DMD Should be Anaesthetised without Volatiles. • Patients with Known Mitochondrial Disease Should be Anaesthetised with Volatiles. • No-one with NMD Should be given Sux!