Suspected Malignant Hyperthermia Reactions in New Zealand

2002 ◽  
Vol 30 (4) ◽  
pp. 453-461 ◽  
Author(s):  
A. N. Pollock ◽  
E. E. Langton ◽  
K. Couchman ◽  
K. M. Stowell ◽  
M. Waddington
Keyword(s):  
New Zealand ◽  
Malignant Hyperthermia ◽  
Dna Analysis ◽  
Anaesthetic Agent ◽  
Clinical Signs ◽  
Malignant Hyperthermia Susceptibility ◽  
In Vitro Contracture Test ◽  
Grading Scale ◽  
Clinical Grading

Early clinical signs, triggering agents, time to onset of reaction, mortality and methods of treatment were identified in 123 suspected malignant hyperthermia reactions. In vitro contracture test results were compared with clinical signs and the Malignant Hyperthermia Clinical Grading Scale. Increased end-tidal carbon dioxide is the earliest sign when not preceded by masseter spasm. Earlier diagnosis reduces the incidence of rigidity and severe metabolic acidosis. The combination of suxamethonium and a potent volatile anaesthetic agent triggers an earlier reaction compared with a volatile agent alone. There has been zero mortality since 1981, essentially due to a combination of advanced monitoring capability, increased anaesthetist awareness of malignant hyperthermia, and dantrolene availability. DNA analysis has identified nine New Zealand families with ryanodine receptor gene mutations. A positive DNA test indicates malignant hyperthermia susceptibility with “causative” mutations but discordance requires that negative DNA tests are confirmed with in vitro contracture test. This test also demonstrated the shortcomings of the Malignant Hyperthermia Clinical Grading Scale.

scholarly journals Administration of Anaesthetic Triggering Agents to Patients Tested Malignant Hyperthermia Normal and Their Relatives in New Zealand: An Update

2017 ◽  
Vol 45 (5) ◽  
pp. 611-618 ◽  
Author(s):  
D. Frei ◽  
K. M. Stowell ◽  
E. E. Langton ◽  
L. McRedmond ◽  
N. A. Pollock ◽  
...  
Keyword(s):  
New Zealand ◽  
Malignant Hyperthermia ◽  
Dna Analysis ◽  
Quadriceps Muscle ◽  
Period Analysis ◽  
Negative Results ◽  
Wide Range ◽  
Grading Scale ◽  
Result Analysis

Testing for malignant hyperthermia in New Zealand involves two tests—in vitro contracture testing of excised lateral quadriceps muscle and DNA analysis. In vitro contracture testing is regarded as the gold standard in malignant hyperthermia diagnosis but several publications have questioned the reliability of a normal result. Analysis of 479 anaesthetic records in 280 patients or their descendants throughout New Zealand who had tested negative for malignant hyperthermia, demonstrated there was no evidence of malignant hyperthermia episodes in this group who had been administered anaesthetic triggering agents. A wide range of anaesthetics were used over the study period. Analysis of each anaesthetic record was undertaken using the malignant hyperthermia grading scale which determines the likelihood that an anaesthetic event represents a malignant hyperthermia episode. Confirmation of the negative results was further supported by normal DNA analysis of patients in 48% of anaesthetics. There are advantages to using inhalational agents in certain situations and although demonstrating a zero risk of a malignant hyperthermia episode is not statistically possible, evidence in this large series suggests that the risk of an episode in these patients is extremely low and may be negligible. We suggest that anaesthetic triggering agents can be used safely in patients with normal in vitro contracture tests, and in their descendants.

scholarly journals Masseter muscle rigidity and the role of DNA analysis to confirm malignant hyperthermia susceptibility

2019 ◽  
Vol 47 (1) ◽  
pp. 60-68 ◽  
Author(s):  
Kate Hudig ◽  
Neil Pollock ◽  
Terasa Bulger ◽  
Roslyn G Machon ◽  
Andrew Woodhead ◽  
...  
Keyword(s):  
Creatine Kinase ◽  
Malignant Hyperthermia ◽  
Masseter Muscle ◽  
Dna Analysis ◽  
Malignant Hyperthermia Susceptibility ◽  
Muscle Rigidity ◽  
Autosomal Dominant Disorder ◽  
In Vitro Contracture Test ◽  
Normal Individuals

Malignant hyperthermia (MH) is an uncommon, autosomal dominant disorder of skeletal muscle, triggered by inhalational anaesthetics or depolarizing muscle relaxants. Masseter muscle rigidity (MMR) can be regarded as potentially a preceding sign for an MH reaction. Susceptibility to MH can be determined by the in vitro contracture test (IVCT) or DNA analysis where a familial variant is known. Our aims were to review patients with MMR, where IVCT and DNA analysis had been undertaken, to determine if DNA analysis could be used as an initial screening tool for MH susceptibility, and, by reviewing standard monitored variables (SMVs), to determine if any clinical characteristics could be used to differentiate between MMR patients who are MH susceptible (MHS) and those who are not. Patients with MMR were identified from the Palmerston North Hospital MH Reactions Database. IVCT and DNA analysis results were documented. DNA testing was performed retrospectively in the majority of patients as many patients had presented before DNA analysis was available. Forty-one patients were analysed. Fourteen were DNA positive/IVCT positive and six DNA positive only (48% in total), seven were IVCT positive/DNA negative and 14 were IVCT normal. Increased creatine kinase (>18,000 units/L) was consistent with MH susceptibility. Severity of MMR was not linked to MH susceptibility. This study confirmed that DNA analysis can be used as a first-line test for MH susceptibility in patients presenting with MMR (consistent with European MH Group recommendations). Creatine kinase was the only SMV that was significantly different between MHS and MH normal individuals.

A Clinical Grading Scale to Predict Malignant Hyperthermia Susceptibility

1994 ◽  
Vol 80 (4) ◽  
pp. 771-779 ◽  
Author(s):  
Marilyn Green Larach ◽  
A Russell Localio ◽  
Gregory C. Allen ◽  
Michael A. Denborough ◽  
F Richard Ellis ◽  
...  
Keyword(s):  
Malignant Hyperthermia ◽  
Malignant Hyperthermia Susceptibility ◽  
Grading Scale ◽  
Clinical Grading

scholarly journals Muscle Biopsy and In Vitro  Contracture Test in Subjects with Idiopathic HyperCKemia

2008 ◽  
Vol 109 (4) ◽  
pp. 625-628 ◽  
Author(s):  
Alessandro Malandrini ◽  
Alfredo Orrico ◽  
Carmen Gaudiano ◽  
Simona Gambelli ◽  
Lucia Galli ◽  
...  
Keyword(s):  
Malignant Hyperthermia ◽  
Muscle Biopsy ◽  
Malignant Hyperthermia Susceptibility ◽  
Manual Muscle Testing ◽  
In Vitro Contracture Test ◽  
Muscle Testing ◽  
Malignant Hyperthermia Susceptible ◽  
Fiber Size ◽  
Precise Diagnosis

Background Persistent high creatine kinase (CK) levels may reflect underlying subclinical myopathies. In most cases, pathogenesis is unknown and clinical management is unclear. Though clinically asymptomatic, these subjects are potentially susceptible to malignant hyperthermia. Methods The authors analyzed 37 subjects with persistent elevation of CK without significant weakness or other neurologic symptoms. Neurologic examination was performed according to manual muscle testing. Muscle biopsy and the in vitro contracture test were performed in all subjects. Results Twenty-three subjects (51.1%) were completely asymptomatic. The others had minor symptoms such as occasional cramps (11 subjects, 24.4%), fatigue (5 subjects, 11.1%), a combination of cramps and fatigue (5 subjects, 11.1%), and muscle pain (1 case, 2.2%). Muscle biopsy enabled precise diagnosis in 3 cases and was normal in 3 cases. The more frequent changes were variation in fiber size (31.1%), a combination of nuclear internalization and variation in fiber size (26.6%), nuclear internalization (6.6%), minor mitochondrial changes (4.4%), and neurogenic atrophy (4.4%). Immunocytochemical analysis was normal in all patients. In vitro contracture testing detected one malignant hyperthermia-susceptible and one malignant hyperthermia-equivocal subject. Conclusions The evidence of malignant hyperthermia susceptibility by in vitro contracture test seems to be relatively infrequent among subjects with idiopathic hyperCKemia, but the incidence of true malignant hyperthermia in idiopathic hyperCKemia is unknown. Muscle biopsy should be considered a useful, though not very sensitive, diagnostic tool in idiopathic hyperCKemia, because it enables potentially treatable disorders, such as inflammatory myopathies, to be discovered. No uniform morphologic finding typical of idiopathic hyperCKemia or malignant hyperthermia susceptibility was identified by muscle biopsy.

Detection of Proton Release from Cultured Human Myotubes to Identify Malignant Hyperthermia Susceptibility

2002 ◽  
Vol 97 (5) ◽  
pp. 1059-1066 ◽  
Author(s):  
Werner Klingler ◽  
Christoph Baur ◽  
Michael Georgieff ◽  
Frank Lehmann-Horn ◽  
Werner Melzer
Keyword(s):  
Skeletal Muscle ◽  
Malignant Hyperthermia ◽  
Metabolic Activation ◽  
Malignant Hyperthermia Susceptibility ◽  
Proton Release ◽  
Release Channel ◽  
Proton Secretion ◽  
In Vitro Contracture Test ◽  
Human Myotubes

Background Malignant hyperthermia (MH) is a pharmacogenetic disorder of skeletal muscle. During general anesthesia, a life-threatening hypermetabolic state may occur resulting from increased release of Ca2+ from the sarcoplasmic reticulum in skeletal muscle. Diagnosis of MH susceptibility requires surgical muscle biopsies to measure force in response to chemical stimulation (in vitro contracture test, IVCT). Here, the authors investigated an alternative way of discriminating MH-susceptible (MHS) from normal (MHN) subjects by using cultured human myotubes and measuring proton release as an indicator of cellular metabolism. Methods Myotubes were stimulated with the Ca2+ release channel agonist 4-chloro-m-cresol (4-CmC), leading to metabolic activation and proton secretion. The rate of extracellular acidification was recorded with a silicon sensor chip. Results A stepwise increase in 4-CmC concentration led to a phasic-tonic increase in the acidification rate. The response, measured at different concentrations of 4-CmC, was considerably larger in cultures from MHS compared with MHN subjects and correlated well with the force response in the IVCT. Conclusions The enhanced metabolism of cultured skeletal myotubes, likely originating from an increased myoplasmic Ca2+ concentration, can be monitored by studying the proton secretion rate. Because the method seems to be able to distinguish normal from pathologic phenotypes, it is a promising technique for possible future use in less invasive MH testing.

scholarly journals Evidence of Malignant Hyperthermia in Patients Administered Triggering Agents before Malignant Hyperthermia Susceptibility Identified: Missed Opportunities Prior to Diagnosis

2017 ◽  
Vol 45 (6) ◽  
pp. 707-713 ◽  
Author(s):  
T. Y. Chan ◽  
T. F. Bulger ◽  
K. M. Stowell ◽  
R. L. Gillies ◽  
E. E. Langton ◽  
...  
Keyword(s):  
Malignant Hyperthermia ◽  
Dna Analysis ◽  
High Index ◽  
Malignant Hyperthermia Susceptibility ◽  
Causative Mutation ◽  
Muscle Rigidity ◽  
High Association ◽  
Early Presentation ◽  
High Index Of Suspicion

Malignant hyperthermia (MH) is a hypermetabolic disorder of skeletal muscle triggered almost exclusively by potent inhalational agents and suxamethonium. Signs of an MH reaction are non-specific and may be confused with the presentation of other problems such as sepsis and overheating of a patient. A high index of suspicion is needed to be aware of an early presentation of MH. Nine patients are presented who showed abnormal signs with an earlier anaesthetic where the possible diagnosis of an MH reaction was missed. These patients either presented later with an MH reaction, confirmed by DNA analysis and in some cases in vitro contracture testing, or were diagnosed by the identification of a causative mutation confirming MH susceptibility. The MH clinical grading scale is helpful in determining the likelihood that clinical indicators indicate a possible MH reaction. Masseter muscle rigidity is a known sign of MH, confirmed in this report by positive in vitro contracture testing and DNA analysis. Several uncommon muscle disorders have a high association with MH, and postoperative myalgia unrelated to suxamethonium can be a sign which is associated with MH. These reports emphasise the importance of a thorough family history (as the MH status was known by the family in four patients), a high index of suspicion for MH, and documentation of the possibility of MH susceptibility in the anaesthesia record.

A997 PREDICTION OF MALIGNANT HYPERTHERMIA SUSCEPTIBILITY WITH THE CLINICAL GRADING SCALE

1997 ◽  
Vol 87 (Supplement) ◽  
pp. 997A ◽  
Author(s):  
V. von Richthofen ◽  
F. Wappler ◽  
J. Scholz ◽  
M. Fiege ◽  
A. Kochling
Keyword(s):  
Malignant Hyperthermia ◽  
Malignant Hyperthermia Susceptibility ◽  
Grading Scale ◽  
Clinical Grading
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