Anesthesia-induced rhabdomyolysis in a patient with Duchenne's muscular dystrophy

Association of a novel dystrophin (DMD) genetic nonsense variant in a cat with X-linked muscular dystrophy with a mild clinical course

X-linked muscular dystrophy in cats (FXMD) is an uncommon disease, with few reports describing its pathogenic genetic variants. A 9-year-old castrated male domestic shorthair cat was presented with persistent muscle swelling and breathing difficulty from 3 years of age. Serum activity of alanine aminotransferase, aspartate transaminase, and creatine kinase were abnormally high. Physical and neurological examinations showed muscle swelling in the neck and proximal limb, slow gait, and occasional breathing difficulties. Electromyography showed pseudomyotonic discharges and complex repetitive discharges with a "dive-bomber" sound. Histopathology revealed muscle necrosis and regeneration. Whole-genome sequencing identified a novel and unique hemizygous nonsense genetic variant, c.8333G > A in dystrophin (DMD), potentially causing a premature termination codon (p.Trp2778Ter). Based on a combination of clinical and histological findings and the presence of the DMD nonsense genetic variant, this case was considered FXMD, which showed mild clinical signs and long-term survival, even though immunohistochemical characterization was lacking.

[Anesthesia for patients suffering from neuromuscular diseases]

Neuromuscular diseases (NMD) are a heterogeneous group of motor unit disorders. Common to all is the main clinical symptom of muscle weakness. Depending on entity and phenotype, a broad range of disorders of neuronal, junctional or myocytic structures occurs. In addition to a weakness of the skeletal musculature, NMD can also affect throat musculature, respiratory and heart muscles. The possible consequences are immobility, deformities, tendency to aspiration as well as respiratory and cardiac insufficiency. In the context of surgery and anesthesia, complications that can result from the underlying disease and its interaction with anesthesia must be anticipated and averted. This article describes along the treatment pathway how preoperative evaluation, choice of the anesthetic procedure and postoperative care can be effectively and safely tailored to the needs of patients with NMD. Concise and practical recommendations for carrying out anesthesia for the most important NMDs are presented as well as relevant external sources of practice recommendations.

Laparoscopic gynecological surgery in an adult woman with Becker muscular dystrophy performed with sevoflurane with cisatracurium anesthesia: A case report

RATIONALE

Becker muscular dystrophy (BMD) and Duchenne muscular dystrophy (DMD) are progressive neuromuscular disorders caused by mutations in the dystrophin gene. The management of anesthesia in patients with BMD is complicated because they are highly sensitive to the conventional anesthetics such as volatile anesthetics and muscle relaxants. It is reported that anesthesia in patients with DMD is associated with several complications. However, a few case reports have been published on adult patients with BMD undergoing surgery with general anesthesia. Reports indicate that children with BMD may experience some serious complications with flurane-inhaled anesthesia. However, no study has yet shown that the use of flurane-induced anesthesia in adults with DMD carries high risks.

PATIENT CONCERNS

We describe a 56-year-old woman with BMD who was scheduled for laparoscopic hysterectomy and bilateral adnexectomy under general anesthesia due to a mass in the uterus. The patient was diagnosed with BMD 20 years back and reported that during this period, she was able to walk slowly with help during her daily life. Additionally, she also had a history of hypertension since 4 years and type 2 diabetes mellitus since 2 years.

DIAGNOSIS

The patient was postmenopausal and presented with abnormal uterine bleeding and elevated CA125. Abdominal ultrasonography revealed diffuse enlargement of the uterus and hypoechoic internal echoes. These findings were suggestive of diffuse adenomyosis with multiple uterine leiomyomas, which would have adverse effects later in her life. Therefore, the patient required surgery to address the symptoms and further confirm the diagnosis. The final diagnosis was confirmed by histopathological analysis.

INTERVENTIONS

The patient was scheduled for laparoscopic hysterectomy and bilateral adnexectomy. Anesthesia was induced and maintained by a combination of intravenous and inhalation anesthetic agents, particularly cisatracurium besilate and inhaled. sevoflurane.

OUTCOMES

The duration of anesthesia and postoperative period were uneventful. At the end of the operation, the patient had normal vital signs and was fully conscious. The patient was followed up for 8 months and no complications were noted during this period.

LESSONS

The combination of sevoflurane and cisatracurium besilate is a safe and effective method for the anesthetic management of adult patients with BMD scheduled for laparoscopic gynecological surgery. On the other hand, it is important to be aware of even rare complications of procedures, so that necessary precautions can be undertaken. Further investigations are necessary to determine the safe dosage of volatile anesthetics specifically for this clinical scenario so that anesthesiologists can use this combination method more accurately and precisely.

Anesthesia-induced rhabdomyolysis or malignant hyperthermia: is defining the crisis important?

Anesthesia-induced rhabdomyolysis and malignant hyperthermia occur in response to the same agents and present with similar clinical features. Distinguishing between these diagnoses can be challenging in a clinical crisis yet making the distinction is critical as prompt appropriate management may be life-saving, whereas delayed recognition and/or inappropriate management will almost certainly result in death. This focused review examines the differences between these conditions and focuses on the emergency management of anesthesia-induced rhabdomyolysis.

Anesthetic management of 877 pediatric patients undergoing muscle biopsy for neuromuscular disorders: a 20-year review

BACKGROUND

The objectives are to review the anesthetic management and anesthetic-related adverse events in patients undergoing muscle biopsy for a broad spectrum of neuromuscular disorders (NMD).

AIM

The study aims to assess the hypothesis that perceived awareness of potential anesthesia-induced hyperkalemia and MH in patients with NMD reduces the frequency of such events.

METHODS

A 20-year retrospective review of 877 consecutive patients undergoing muscle biopsy to establish diagnoses of NMD has been performed. Patients were categorized prebiopsy into six groups: M (myopathy and muscular dystrophy), MM (mitochondrial or metabolic myopathy), N (neurodegenerative, peripheral neuropathy or spinal muscular atrophy disorder), D (dermatomyositis), C (cardiomyopathy), or S (seizure disorder). Data were collected for demographics, anesthetic management, pre- and postoperative anesthesia-induced muscle injury, postbiopsy histopathologic diagnosis, and concordance comparisons between pre- and postbiopsy diagnoses.

RESULTS

There were 513 males (58.5%) and 364 females (41.5%) (1.4:1) with 137 individuals (15.6%) operated on under 1 year of age and two-thirds by 6 years of age. NMD diagnosis was reached in 409 (46.6%) while 468 (53.4%) had no specific pathology. No patients exhibited signs of anesthesia-induced muscle injury (malignant hyperthermia, rhabdomyolysis, cardiac arrest, or postoperative deterioration of weakness). MM was the largest group pre biopsy (367, 41.8%). Anesthetic agents were: nitrous oxide in 657 (74.9%); volatile agents in 139 (15.8%); intravenous agents in 836 (95.3%) (primarily propofol, midazolam, and fentanyl); nondepolarizing muscle relaxants in 404 (46.1%); and regional anesthesia in 112 (12.8%) [most commonly spinal anesthesia in 80 (71.4%)]. Comparing preoperative diagnostic category with postoperative diagnosis, there was a concordance of 78% (319/409) between the two for cases with a definitive diagnosis and 89.7% (787/877) for all cases.

CONCLUSIONS

In this retrospective study, no patient exhibited signs or symptoms of hyperkalemia or MH probably because the incidence is very low and becomes even less likely due to the selection of the various anesthetic agents and strategies administered.

Sulforaphane alleviates muscular dystrophy in mdx mice by activation of Nrf2

Sulforaphane (SFN), one of the most important isothiocyanates in the human diet, is known to have chemo-preventive and antioxidant activities in different tissues via activation of nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated induction of antioxidant/phase II enzymes, such as heme oxygenase-1 and NAD(P)H quinone oxidoreductase 1. However, its effects on muscular dystrophy remain unknown. This work was undertaken to evaluate the effects of SFN on Duchenne muscular dystrophy. Four-week-old mdx mice were treated with SFN by gavage (2 mg·kg body wt(-1)·day(-1) for 8 wk), and our results demonstrated that SFN treatment increased the expression and activity of muscle phase II enzymes NAD(P)H quinone oxidoreductase 1 and heme oxygenase-1 with a Nrf2-dependent manner. SFN significantly increased skeletal muscle mass, muscle force (∼30%), running distance (∼20%), and GSH-to-GSSG ratio (∼3.2-fold) of mdx mice and decreased the activities of plasma creatine phosphokinase (∼45%) and lactate dehydrogenase (∼40%), gastrocnemius hypertrophy (∼25%), myocardial hypertrophy (∼20%), and malondialdehyde levels (∼60%). Furthermore, SFN treatment also reduced the central nucleation (∼40%), fiber size variability, and inflammation and improved the sarcolemmal integrity of mdx mice. Collectively, these results show that SFN can improve muscle function and pathology and protect dystrophic muscle from oxidative damage in mdx mice associated with Nrf2 signaling pathway, which indicate Nrf2 may have clinical implications for the treatment of patients with muscular dystrophy.

Anesthesia and Duchenne or Becker muscular dystrophy: review of 117 anesthetic exposures

BACKGROUND

Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are associated with life-threatening perioperative complications, including rhabdomyolysis, hyperkalemia, and hyperthermia. Current recommendations contraindicate use of succinylcholine and volatile anesthetics; however, the latter recommendation remains controversial.

OBJECTIVE

To review the perioperative outcomes of patients with DMD and BMD.

METHODS

We reviewed records of patients with DMD or BMD who underwent anesthetic management at our institution from January 1990 through December 2011.

RESULTS

We identified 47 patients (DMD, 37; BMD, 10) who underwent 117 anesthetic exposures (DMD, 101; BMD, 16). Volatile anesthetic agents were used 66 times (DMD, 59; BMD, 7). One patient with undiagnosed BMD received succinylcholine and developed acute rhabdomyolysis and hyperkalemic cardiac arrest. All other major complications were attributed to the procedure (i.e., large bleeding), to preexisting comorbidities (i.e., respiratory failure, cardiac disease), or to both.

CONCLUSIONS

Use of succinylcholine in children with dystrophinopathy is contraindicated. These patients have significant comorbidities and are frequently undergoing extensive operations; complications related to these factors can develop, as evidenced by our series. These complications may occur with use of volatile and nonvolatile anesthetics. However, because most of our patients were older than 8 years at the time of surgery, our observation cannot be generalized to younger dystrophin-deficient children.

[Malignant hyperthermia-like reactions in Duchenne or Becker muscular dystrophy: review and hypothesis]

Adverse reactions to genral anesthesia, which partly resembled malignant hyperthermia (MH), were more frequent in muscular dystrophy than in controls. In the present study, 35 cases so far reported in Duchenne or Becker muscular dystrophy (DMD or BMD) were analyzed and their pathogenesis was discussed. Cardiac involvements were sole manifestations in 7 cases. In other 28 cases, the acute rhabdomyolysis was the most prevailing manifestation. About 60% of myolysis cases were associated with muscle contracture (rigidity) or other hypermetabolic signs such as hypercapnia, hyperthermia and metabolic acidosis. Cases with BMD were more hyperthermic than with DMD. These results suggest Ca ion-induced hypermetabolic reactions are also present in dystrophinopathy, which have been assumed as core syndromes of the classical (gene-defined) MH. However, question whether the abnormal Ca ion is from the extracellular or intracellular stores is still unclear. Circumstancial evidences suggest that the Ca-induced Ca release (CICR) mechanism might also be involved. Endogenous redox modulators such as nitric oxide or reactive oxygen species in the dystrophic muscle might contribute to the perturbed Ca ion homeostasis.

Duchenne muscular dystrophy: an old anesthesia problem revisited

Patients with Duchenne and Becker muscular dystrophy suffer from a progressive deterioration in muscle secondary to a defect in the dystrophin gene. As such, they are susceptible to perioperative respiratory, cardiac and other complications, such as rhabdomyolysis. Inhalational anesthetic agents have been implicated as a cause of acute rhabdomyolysis that can resemble malignant hyperthermia (MH). This article reviews perioperative 'MH-like' reactions reported in muscular dystrophy patients and groups them into three categories according to clinical presentation. The etiology and underlying pathophysiological process responsible for these reactions is discussed and recommendations are proposed for the safe anesthetic management of these patients.

Myoglobinuria

Myoglobinuria refers to an abnormal pathologic state in which an excessive amount of myoglobin is found in the urine, imparting a cola-like hue, usually in association with myonecrosis and a clinical picture of weakness, myalgias, and edema. Myoglobinuria is produced by multiple causes: any condition that accelerates the use or interferes with the availability of oxygen or energy substrates to muscle cells can result in myoglobinuria, as can events that produce direct muscle injury, either mechanical or chemical. Acute renal failure is the most serious complication, which can be prevented by prompt, aggressive treatment. In patients surviving acute attacks, recovery of muscle and renal function is usually complete.

Succinylcholine: adverse effects and alternatives in emergency medicine

Succinylcholine has long been the favored neuromuscular blocking agent for emergent airway management because of its rapid onset, dependable effect, and short duration. However, it has a plethora of undesirable side effects, ranging from the inconsequential to the catastrophic. When patients requiring tracheal intubation present with potential contraindications to succinylcholine use, the emergency physician will need to substitute a rapid-onset nondepolarizing neuromuscular blocking agent, such as rocuronium or mivacurium. An understanding of the pharmacology of these agents is essential.

Lumbar muscle rhabdomyolysis after abdominal aortic surgery

Lumbar muscle rhabdomyolysis has been very rarely reported after surgery. The aim of this study was to determine its incidence and main characteristics in a large population undergoing abdominal aortic surgery. Over a 21-mo period, 224 consecutive patients, 209 male and 15 female, mean age 65 +/- 10 yr, underwent abdominal aortic surgery (aortic aneurysm in 142 patients and occlusive aortic degenerative disease in 82 patients). Surgical incision was a midline incision with exaggerated hyperlordosis in 173 patients and a flank incision with a retroperitoneal approach in 51 patients. Postoperative rhabdomyolysis was diagnosed in 20 patients. In these patients, 9 (4%) experienced severe low back pain, and lumbar muscle rhabdomyolysis was confirmed by tomodensitometry (n = 6) or muscle biopsy (n = 3). The remaining 11 patients had lower limb muscle rhabdomyolysis. Rhabdomyolysis occurred after surgery of longer duration, which involved more frequent visceral artery reimplantation, with longer duration of aortic clamping and greater intraoperative bleeding. Lumbar rhabdomyolysis occurred in younger patients who were more frequently obese. On first postoperative day, the mean creatine kinase (CK) value was greater in lumbar rhabdomyolysis than in lower limb rhabdomyolysis (17,082 +/- 15,003 vs 3,313 +/- 3,120 IU/L, P < 0.05). Acute renal failure and postoperative death did not occur in patients with lumbar muscle rhabdomyolysis. Lumbar rhabdomyolysis was not a rare event after abdominal aortic surgery (4%). This syndrome was characterized by postoperative low back pain of unusual severity, which required analgesic therapy, and induced a very high increase in CK with typical findings at tomodensitometry or muscle biopsy but was not associated with postoperative renal failure.

Rhabdomyolysis and anesthesia: a report of two cases and review of the literature

Rhabdomyolysis occurred in two apparently healthy boys aged 9.5 and 5.5 years after general anesthesia with suxamethonium. Mild hyperkalemia and renal failure were observed in the first patient, who was subsequently diagnosed with Becker dystrophy. In the second patient, the clinical presentation was not classic for malignant hyperthermia and a muscle biopsy failed to disclose any pathological finding. A review of the literature revealed 66 pediatric cases (56 boys and 10 girls) of anesthesia-associated rhabdomyolysis. Forty-nine (74%) cases were caused by an underlying, mostly unrecognized congenital muscle disease, and 14 (21%) cases were caused by malignant hyperthermia susceptibility. Hyperkalemia (23 patients), cardiac arrhythmias (38 patients), renal failure (4 patients), and death (11 patients) were the most serious complications of anesthesia-associated rhabdomyolysis. The neuromuscular blocking agent suxamethonium had been used in at least 43 of the patients reported in the literature.

Malignant hyperthermia in a patient with Becker muscular dystrophy: dystrophin analysis and caffeine contracture study

We present a 17-year-old boy with Becker muscular dystrophy (BMD) who developed hyperthermia and heart failure after general anesthesia. He presented clinical features of malignant hyperthermia (MH), and had masseter spasm and elevated body temperature (38.7 degrees C) with very high serum CK activity (107,000 IUl-1). Dystrophin tests confirmed a clinical diagnosis of BMD in the patient, i.e. faint and patchy immunostaining pattern of skeletal muscle, truncated dystrophin protein and a deletion of exons 3 and 4 of the dystrophin gene. To inquire into the mechanism of MH associated in the patient, we tested caffeine contracture reaction by the skinned fiber method. We found an increased sensitivity to caffeine only in type 1 muscle fibers. The rate of Ca(2+)-induced Ca2+ release (CICR) was normal, suggesting that the mechanism of "MH" observed in our patient with BMD is not the same as that of classical MH. A possible mechanism might be related to derangements of the sarcoplasmic reticulum membrane in BMD, which sensitize the membrane to caffeine or other agents.

Succinylcholine-induced cardiac arrest in children with undiagnosed myopathy

Two paediatric cases are reported in which unexpected, life-threatening arrhythmias occurred. Routine induction of general anaesthesia with thiopentone, 5 mg.kg-1, in one and with halothane in the other, and succinylcholine 1.25-1.5 mg.kg-1 i.v. was followed by the development of wide complex tachyarrhythmia with hypotension in the first case and asystole in the second case despite pre-treatment with atropine in both cases. The first patient was resuscitated with tracheal intubation, 100% oxygen, manual ventilation and intravenous lidocaine and bicarbonate. The second patient required intubation, manual ventilation, 12 min of CPR and i.v. calcium, epinephrine and bicarbonate, as well as DC counter shock. Neither patient received dantrolene. Early recovery in both patients was uneventful with no neurological sequelae. Subsequent investigations revealed the presence of a dystrophin-deficient muscular dystrophy, Duchenne muscular dystrophy and Becker muscular dystrophy respectively, previously unsuspected, in both patients. The aetiology of the observed arrhythmias was presumably hyperkalaemia, secondary to succinylcholine-induced rhabdomyolysis. It is suggested that when faced with sudden, life-threatening arrhythmias following succinylcholine at induction of anaesthesia for paediatric patients, clinicians should include occult myopathy in the differential diagnosis, and thus consider the aggressive management of hyperkalaemia in addition to basic resuscitative efforts.

Malignant Hyperthermia

Malignant hyperthermia (MH) is a rare, genetically inherited hypermetabolic syndrome that remains dormant until triggered by exposure to certain conditions (emotional and physical stresses) or pharmacological agents (anesthetic gases and succinylcholine) in susceptible individuals. It is believed that MH is caused by a derangement in the control of intracellular calcium ions, which results in a hypermetabolic state from sustained muscle contractures. Without supportive measures and immediate treatment with the antidote, dantrolene, the mortality rate from MH can be as high as 70%. A complete personal and family medical history before surgery can show important clues that might alter the anesthetic regimen preoperatively and postoperatively (eg, the use of nontriggering agents) in MH-susceptible patients. Anesthesia personnel need to recognize the early signs of a MH crisis (eg, tachycardia, muscle stiffness, hypercapnia, and tachypnea), then monitor for other signs (eg, arrhythmias, blood pressure changes, fever, metabolic and respiratory acidosis, and mottling cyanosis), and initiate prompt treatment. Because immediate recognition and treatment of this potentially fatal hyperpyrexic episode increase a patient's chance of survival, other health care personnel (eg, nurses, pharmacists) play key roles in the emergency treatment of a MH crisis. A suspected episode of MH should be followed up with contracture testing to determine MH susceptibility (MHS). Reports of MH should be reported to the North American MH Registry.

[Rhabdomyolysis after ORL surgery in prolonged lateral position]

Two cases are reported of upper limb rhabdomyolysis occurring after prolonged ENT cancer surgery, the patient being part of the time in the right lateral position, with the left forearm outstretched. Surgery consisted of a vertical hemilaryngectomy with immediate parascapular free graft reconstruction in a 48-year-old man (10 h of surgery, with 6 h in a lateral position) and the surgical removal of a neoplasm involving the mouth floor and larynx in a 62-year-old man including parascapsular free graft reconstruction (10 h of surgery, with 7 h in a lateral position). In the early postoperative period, the patients complained of severe pain in the left forearm. There was a tense painful swelling of the forearm, combined with an increase in creatinine kinase plasma concentration, and myoglobinaemia. The mechanism involved was most likely a compression of the forearm muscles, together with prolonged surgery and the patient position. The part played by the state of the patients is discussed. Diagnosis must be made as soon as possible, as the only efficient treatment consists of an early fasciotomy together with the administration of alkali to avoid renal failure.

Anesthesia-induced rhabdomyolysis in infants with unsuspected Duchenne dystrophy

Anesthesia-induced rhabdomyolysis in infancy may represent an unsuspected Duchenne dystrophy. In order to establish the diagnosis of this genetic disease more definitively, a dystrophin test is a requisite following the conventional creatine kinase test and light and electron microscopies of the muscle biopsy.

Spinal fusion in Duchenne muscular dystrophy: a multidisciplinary approach

We studied 27 Duchenne muscular dystrophy patients having spinal fusion for scoliosis. One patient died intraoperatively of cardiac arrest; all others have done well with no instances of malignant hyperthermia, postoperative ventilatory system dependence, pneumothorax, persisting infection, neurologic damage, nonunion, or pain. The anesthetic management included primarily intravenous general anesthetics with minimal myocardial depressant effects, avoiding succinylcholine and inhalation agents. Preoperative cardiac studies aided anesthetic management intra-operatively. There was an almost universal sinus tachycardia. Holter monitoring defined 4 of 16 with ventricular premature beats, 4 of 16 with atrial premature beats, and no ventricular tachycardia or atrial flutter or fibrillation. Echocardiogram demonstrated mitral prolapse in 2 of 22, frequent abnormal systolic performance with abnormal shortening fraction less than 28% in 7 of 16, and reduced rate-corrected velocity of fiber shortening in 9 of 15. Afterload was elevated in 7 of 15. The mean forced vital capacity (FVC) preoperatively was 45.3 +/- 15.9% with continuing diminution to 28.7 +/- 14.9% at 3.3 +/- 2.2 years after surgery. The main benefit of surgical stabilization is the relative ease and comfort of wheelchair seating compared with those nonoperated patients who develop progressive deformity. We have not seen lasting improvement or stabilization in FVC following surgery as decreasing function is related primarily to muscle weakness.

Malignant hyperthermia and neuromuscular disease

Malignant hyperthermia (MH) is a rare clinical syndrome characterized by hypermetabolism and triggered by specific anesthetic agents. The mechanism of this abnormal reaction is due to uncontrolled calcium flux in the skeletal muscles resulting in a variable clinical syndrome of muscle rigidity, respiratory and metabolic acidosis, and elevation of temperature. The specific genetic defect underlying this condition has not been identified in humans, though in susceptible swine a mutation of the gene for the ryanodine receptor, a large protein which comprises the calcium channel in the sarcoplasmic reticulum, has been identified recently. Inheritance in humans appears to be autosomal dominant with variable penetrance. Patients with MH rarely have physical or laboratory signs of muscle disease. However, scattered case reports and investigations of individuals with known myopathies and other muscle related problems, such as acute rhabdomyolysis or idiopathic persistently elevated creatine kinase, suggest a possible association of MH with a variety of neuromuscular diseases and stress syndromes. This association is very strong in the case of central core disease (CCD) where it is supported by clinical and laboratory evidence, including the proximity of the CCD gene to the ryanodine receptor gene on chromosome 19. A variety of other diseases have been implicated and can be classified as possibly associated (King-Denborough syndrome, Duchenne muscular dystrophy) or unlikely to be associated (myotonia congenita, sudden infant death syndrome, limb girdle dystrophy, neuroleptic malignant syndrome, etc.).(ABSTRACT TRUNCATED AT 250 WORDS)

Absence of malignant hyperthermia contractures in Becker-Duchenne dystrophy at age 2

Two 2-year-old males underwent muscle biopsy that established the histopathologic diagnosis of Becker dystrophy in one, and Duchenne dystrophy in the other. Concomitant contracture testing with caffeine or halothane was normal for malignant hyperthermia (MH). The results suggest that acute hypermetabolism or acute rhabdomyolysis during anesthesia, in patients with these disorders, is related to the X-linked myopathy and its associated muscle deterioration, rather than to the autosomal dominant MH.

Cardiac arrest after isoflurane anaesthesia in a patient with Duchenne's muscular dystrophy

An 8-year-old boy known to have Duchenne's muscular dystrophy suffered a cardiac arrest 10 minutes after he regained consciousness after isoflurane anaesthesia for an orchidopexy procedure. Resuscitation was successful 2 hours after the start of external cardiac compression and after correction of hyperkalaemia and the administration of dantrolene. He later developed myoglobinuria elevated creatine kinase and a metabolic and respiratory acidosis. He demonstrated a delayed increase in rectal temperature.

Serum creatine kinase levels after succinylcholine in children with "muscle, eye and brain disease"

Four boys belonging to a group of children affected by a rare form of muscular dystrophy with eye and brain involvement, termed the "muscle, eye and brain disease" (MEB), were anaesthetized for various eye examinations and surgery. On some occasions succinylcholine was used during anaesthesia and the initially elevated serum creatine kinase (CK) values increased from a range of 122 to 1200 units.L-1 to a range of 4350 to 9690 units.L-1 22 hours after anaesthesia. CK values after anaesthesia without succinylcholine remained at the initially elevated levels. Rectal temperatures of the children were normal. These findings suggest that succinylcholine should be avoided in patients with MEB disease.

Duchenne muscular dystrophy and malignant hyperthermia--two case reports

The case histories are presented including the anaesthetic and postoperative management, of two children, a two-year-old with undiagnosed Duchenne muscular dystrophy (DMD) and a three-year-old with known DMD. The child with undiagnosed DMD had no symptoms of DMD and had received halothane twice before, without succinylcholine, with no apparent difficulty. Following an uneventful induction of anaesthesia with halothane, nitrous oxide and O2, succinylcholine resulted in bilateral masseter muscle spasm and then, in rapid sequence, ventricular tachycardia and cardiac arrest. Resuscitation was difficult, prolonged and associated with hyperkalaemia (K+ = 12.57 mEq X L-1), severe metabolic and respiratory acidosis, high peripheral venous pressure and massive hepatosplenomegaly, but not hyperthermia. The patient was finally resuscitated but died two days later. Skeletal muscle biopsy results were consistent with malignant hyperthermia. The second patient was known to have DMD but did not receive prophylactic or intraoperative dantrolene nor have his anaesthetic machine flushed with oxygen for an extended period prior to induction of anaesthesia. This child was anaesthetized with fentanyl and N2O and, with the exception of a high intraoperative heart rate (155-160 beats X min-1), had an uncomplicated anaesthetic and operation (intraoperative axillary temperatures ranged between 36.8-37.9 degrees C). Postoperatively his temperature rapidly increased to 38.8 degrees C and then 40.3 degrees C and he became metabolically acidotic. Intravenous administration of dantrolene for 48 hours reduced the temperature and allowed normal recovery and discharge. A postoperative muscle biopsy was consistent with DMD.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia for pediatric neurological and neuromuscular diseases

Children with neurological and neuromuscular diseases often present anesthetic problems in the perioperative period. The anesthetic technique can play a significant role in altering the state of the brain during neurosurgical procedures through effects on the cerebral circulation and metabolism. Pre-existing neuromuscular disease may also have specific anesthetic implications such as cardiorespiratory involvement (eg, myotonia dystrophica), the potential for drug interactions (eg, myasthenia gravis) or abnormal responses to commonly used drugs (eg, malignant hyperthermia). In this review, the perioperative anesthetic considerations in a number of common neurological and neuromuscular conditions in the pediatric patient are discussed.

Succinylcholine-induced cardiac arrest in unsuspected Duchenne muscular dystrophy

A case history is presented of a three-year-old boy with unsuspected Duchenne muscular dystrophy, who suffered a cardiac arrest following the administration of a single dose of succinylcholine during a halothane anaesthetic. The arrest was associated with lack of fasciculations, muscle rigidity, hyperkalemia, myoglobinuria, and massive elevation of serum creatine phosphokinase. Asystole was prolonged and refractory to treatment, although cardiac activity was eventually restored. The possible cause of the circulatory collapse is discussed and reports of similar cases reviewed. Neither succinylcholine nor halothane should be employed in cases with known or suspected Duchenne muscular dystrophy.

Increased muscle action potentials by 5 Hz prolonged nerve stimulation in neurological and neuromuscular disorders--clinical usefulness for detecting underlying pathophysiology

The time courses of changes in amplitudes of muscle action potentials (MAPs) obtained from gastrocnemius and soleus muscles by 5 Hz prolonged tibial nerve stimulation were studied. Subjects included muscular dystrophy (MD), spinal muscular atrophy, Issacs syndrome, idiopathic muscle spasms, psychiatric disorders such as autism and schizophrenia, and normal controls. In normal subjects, MAPs obtained at 5 minutes from gastrocnemius muscles was 87-102% of those at initiation of the stimulation. In soleus muscles, MAPs at 5 minutes was 95-105% of those at the beginning. In gastrocnemius muscles, MAPs increased in disorders such as Duchenne MD, Fukuyama type congenital MD, facioscapulohumeral MD, myotonic dystrophy, dermatomyositis, Kugelberg-Welander syndrome, viral myelitis, malignant hyperpyrexia, autism and schizophrenia. In soleus muscles, the increase of MAPs was demonstrated in Duchenne MD, Fukuyama type congenital MD, myotonic dystrophy and autism. MAPs remained within normal range in infants with Werdnig-Hoffman disease, Issacs syndrome and idiopathic muscle spasms. In two cases with Duchenne MD, MAPs obtained from gastrocnemius muscles reduced in amplitudes by the administration of dantrolen sodium. While the pathogenesis of the increased MAPs is not clear, several possible factors are discussed. It is considered that this 5 Hz examination may provide an important information for detecting the effect of dantrolen sodium on Duchenne MD, and it is also suggested that the examination will be a useful test for finding latent malignant hyperpyrexia.

Anaesthesia induced rhabdomyolysis--a case report

Anaesthesia-induced rhabdomyolysis (AIR) is a rare but serious complication of general anaesthesia. We report the occurrence of this event in a previously healthy three-year-old male, with a strongly positive family history of Duchenne muscular dystrophy. Following an uneventful anaesthetic, which included succinylcholine, myoglobinuria developed and led to renal failure which fortunately reversed with conservative treatment. Based on review of reports of similar cases, it is clear that succinylcholine should be avoided in paediatric patients with known myopathy or at high risk for latent myopathy.

Malignant hyperpyrexia and Duchenne muscular dystrophy: A case report

We report a patient with Duchenne muscular dystrophy who developed malignant hyperpyrexia during general anaesthesia. During anaesthesia bradycardia was followed by ventricular fibrillation, on which ventricular flutter supervened and a body temperature rise of 0.6 degrees C for 15 minutes, myoglobinuria and elevation of CPK level were observed. The caffeine sensitivity test of biopsied muscle fibers revealed an increase in sensitivity, although there was no sign of muscle rigidity during or after anaesthesia. Diagnosis of Duchenne muscular dystrophy was first established after the development of malignant hyperpyrexia in the present case as well as in previously reported cases. Determination of serum CPK is very important before general anaesthesia.

Plasma potassium after halothane--suxamethonium induction in children

The changes in plasma potassium following inhalation induction of anaesthesia with halothane followed by suxamethonium were studied in 48 normal children aged 1 to 10 years. Highly significant increases were found in both age groups studied (5 years and under, and 6 to 10 years). The mean percentage increase in plasma potassium and the proportion of children in whom an increase of 0.4 mmol/litre or greater was found, were both greater than in an earlier study on children after thiopentone induction and suxamethonium.

Masseter spasm induced by succinylcholine in children: contracture testing for malignant hyperthermia: report of six cases

We evaluated six boys who had developed isolated masseter muscle spasm following intravenous succinylcholine. All were receiving halothane by inhalation.l In vitro muscle contracture tests utilizing halothane and caffeine were performed. Four of the six boys had contracture response similar to those of malignant hyperthermia susceptible patients. Rigidity following succinylcholine should prompt the clinician to consider malignant hyperthermia but has been associated with other myopathic conditions as discussed.