Excess comorbidities associated with malignant hyperthermia diagnosis in pediatric hospital discharge records

Epidemiological and clinical features of malignant hyperthermia: A scoping review

Malignant hyperthermia (MH) is a potentially fatal inherited pharmacogenetic disorder related to pathogenic variants in the RYR1, CACNA1S, or STAC3 genes. Early recognition of the occurrence of MH and prompt medical treatment are indispensable to ensure a positive outcome. The purpose of this study was to provide valuable information for the early identification of MH by summarizing epidemiological and clinical features of MH. This scoping review followed the methodological framework recommended by Arksey and O'Malley. PubMed, Embase, and Web of science databases were searched for studies that evaluated the epidemical and clinical characteristics of MH. A total of 37 studies were included in this review, of which 26 were related to epidemiology and 24 were associated with clinical characteristics. The morbidity of MH varied from 0.18 per 100 000 to 3.9 per 100 000. The mortality was within the range of 0%-18.2%. Identified risk factors included sex, age, disorders associated with MH, and others. The most frequent initial clinical signs included hyperthermia, sinus tachycardia, and hypercarbia. The occurrence of certain signs, such as hypercapnia, delayed first temperature measurement, and peak temperature were associated with poor outcomes. The epidemiological and clinical features of MH varied considerably and some risk factors and typical clinical signs were identified. The main limitation of this review is that the treatment and management strategies were not assessed sufficiently due to limited information.

Cost-benefit relationship of keeping dantrolene stocks from the point of view of healthcare institutions

Introduction: Malignant hyperthermia (MH) is an acute syndrome triggered by certain anesthetic medications. Dantrolene is the only specific treatment for MH crises. Without treatment, lethality may be as high as 80%. In Colombia, it is not mandatory to keep dantrolene supplies in stock. Objective: To establish the cost-benefit ratio, from the perspective of healthcare institutions, of keeping dantrolene supplies in stock in the operating theater. Methods: Using a decision tree, a Monte Carlo simulation was run with 10,000 scenarios to determine the median annual cost of keeping full or partial stocks (36 or 12 vials x 20 mg, respectively) of dantrolene. For the option of not keeping supplies in stock, the cost threshold was calculated where the expected value of both alternatives of the decision tree is equalized. Indifference curves were constructed for complete and partial supplies. Results: The median annual cost was estimated at 6.6 million Colombian pesos (COP) for full dantrolene supplies, and at COP 2.2 million for partial supplies. The median economic consequence threshold for 1 death due to the unavailability of dantrolene was estimated at COP 18.5 million for full supplies, and at COP 57.0 million for partial supplies. Conclusion: If, as a result of the unavailability of dantrolene, the economic consequences of a death due to MH exceed the threshold of COP 57.0 or COP 18.5 million, the purchase of full or partial stocks, respectively, is justified.

Prevalence of malignant hyperthermia diagnosis in obstetric patients in the United States, 2003 to 2014

Background

The cost-benefit of stocking dantrolene in maternity units for treating malignant hyperthermia (MH) has been recently questioned because of the low incidence of MH crisis in the general population and the low utilization of general anesthesia in obstetrics. However, no study has examined the prevalence of MH susceptibility in obstetrics. This study aimed to assess the prevalence of MH diagnosis and associated factors in obstetric patients.

Methods

Data for this study came from the National Inpatient Sample from 2003 to 2014, a 20% nationally representative sample of discharge records from community hospitals. A diagnosis of MH due to anesthesia was identified using the International Classification of Diseases, Ninth Revision, Clinical Modification code 995.86. MH prevalence was estimated according to the delivery mode and patient and hospital characteristics.

Results

During the 12-year study period, 47,178,322 delivery-related discharges [including 15,175,127 (32.2%) cesarean deliveries] were identified. Of them, 215 recorded a diagnosis of MH, yielding a prevalence of 0.46 per 100,000 [95% confidence interval (CI), 0.40 to 0.52]. The prevalence of MH diagnosis in cesarean deliveries was 0.81 per 100,000 (95% CI, 0.67 to 0.97), compared with 0.29 per 100,000 (95% CI, 0.23 to 0.35) in vaginal deliveries (P <  0.001). Multivariable logistic regression revealed that cesarean delivery was associated with a significantly increased risk of MH diagnosis [adjusted rate ratio (aOR) 2.88; 95% CI, 2.19 to 3.80]. Prevalence of MH diagnosis was lower in Hispanics than in non-Hispanic whites (aOR 0.47; 95% CI, 0.29 to 0.76) and higher in the South than in the Northeast census regions (aOR 2.44; 95% CI, 1.50 to 3.96).

Conclusion

The prevalence of MH-susceptibility is about 1 in 125,000 in cesarean deliveries, similar to the prevalence reported in non-obstetrical surgery inpatients. The findings of this study suggest that stocking dantrolene in maternity units is justified.

Succinylcholine Use and Dantrolene Availability for Malignant Hyperthermia Treatment: Database Analyses and Systematic Review

BACKGROUND

Although dantrolene effectively treats malignant hyperthermia (MH), discrepant recommendations exist concerning dantrolene availability. Whereas Malignant Hyperthermia Association of the United States guidelines state dantrolene must be available within 10 min of the decision to treat MH wherever volatile anesthetics or succinylcholine are administered, a Society for Ambulatory Anesthesia protocol permits Class B ambulatory facilities to stock succinylcholine for airway rescue without dantrolene. The authors investigated (1) succinylcholine use rates, including for airway rescue, in anesthetizing/sedating locations; (2) whether succinylcholine without volatile anesthetics triggers MH warranting dantrolene; and (3) the relationship between dantrolene administration and MH morbidity/mortality.

METHODS

The authors performed focused analyses of the Multicenter Perioperative Outcomes Group (2005 through 2016), North American MH Registry (2013 through 2016), and Anesthesia Closed Claims Project (1970 through 2014) databases, as well as a systematic literature review (1987 through 2017). The authors used difficult mask ventilation (grades III and IV) as a surrogate for airway rescue. MH experts judged dantrolene treatment. For MH morbidity/mortality analyses, the authors included U.S. and Canadian cases that were fulminant or scored 20 or higher on the clinical grading scale and in which volatile anesthetics or succinylcholine were given.

RESULTS

Among 6,368,356 queried outcomes cases, 246,904 (3.9%) received succinylcholine without volatile agents. Succinylcholine was used in 46% (n = 710) of grade IV mask ventilation cases (median dose, 100 mg, 1.2 mg/kg). Succinylcholine without volatile anesthetics triggered 24 MH cases, 13 requiring dantrolene. Among 310 anesthetic-triggered MH cases, morbidity was 20 to 37%. Treatment delay increased complications every 10 min, reaching 100% with a 50-min delay. Overall mortality was 1 to 10%; 15 U.S. patients died, including 4 after anesthetics in freestanding facilities.

CONCLUSIONS

Providers use succinylcholine commonly, including during difficult mask ventilation. Succinylcholine administered without volatile anesthetics may trigger MH events requiring dantrolene. Delayed dantrolene treatment increases the likelihood of MH complications. The data reported herein support stocking dantrolene wherever succinylcholine or volatile anesthetics may be used.

Prevalence of malignant hyperthermia diagnosis in hospital discharge records in California, Florida, New York, and Wisconsin

STUDY OBJECTIVE

Malignant hyperthermia (MH) is a rare yet potentially fatal pharmacogenetic disorder triggered by exposure to inhalational anesthetics and the depolarizing neuromuscular blocking agent succinylcholine. Epidemiologic data on the geographic variation in MH prevalence is scant. The objective of this study is to examine the prevalence of recorded MH diagnosis in patients discharged from hospitals in four states in the United States.

DESIGN

Observational study.

SETTING

Healthcare Cost and Utilization Project (HCUP) State Inpatient Database (SID) for California (2011), Florida (2011), New York (2012) and Wisconsin (2012).

PATIENTS

A total of 164 hospital discharges that had a recorded diagnosis of MH using the International Classification of Disease, 9th Revision, Clinical Modification code 995.86.

METHODS

MH prevalence was assessed by patient demographic and clinical characteristics.

MAIN RESULTS

The prevalence of MH per 100,000 hospital discharges ranged from 1.23 (95% Confidence Interval [CI], 0.80-1.66) in New York to 1.91 (95% CI, 1.48-2.34) in California, and the prevalence of MH per 100,000 surgical discharges ranged from 1.47 (95% CI, 0.93-2.02) in New York to 2.86 (95% CI, 2.00-3.71) in Florida. The prevalence of MH in male patients was more than twice the prevalence in female patients. Of the 164 patients with MH diagnosis, 11% were dead on discharge.

CONCLUSIONS

There exists a modest variation in the prevalence of recorded MH diagnosis in hospital discharges in California, Florida, New York and Wisconsin. Epidemiologic patterns of MH diagnosis in hospital discharges appear to be similar across the four states. Further research is needed to better understand the geographic variation and contributing factors of MH in different populations.

Neuromuscular conditions associated with malignant hyperthermia in paediatric patients: A 25-year retrospective study

Malignant Hyperthermia (MH) is a rare pharmacogenetic syndrome that can be fatal and the risk of MH in non RYR1-related disorders is unknown. We conducted a retrospective study to determine the prevalence of neuromuscular disorders among patients with MH at our centre. Patients who were admitted to the Hospital for Sick Children during the study period of January 1, 1990 to April 1, 2015 with a CK level > 8000 IU/L, or who received dantrolene, or who had a clinical diagnosis of MH were included. Medical records of 166 patients who met the inclusion criteria were reviewed and 13 patients were identified with MH-like reactions. Nine patients were classified as having true MH after review of the anaesthesia record and genetic testing results were available for 7 patients, 5 of whom had mutations in RYR1. Of the four patients who had severe reactions to anaesthesia but did not meet the criteria for true MH, two had Duchenne muscular dystrophy (DMD). In this retrospective study over 25 years, RYR1 mutations were the most common cause of MH in our cohort, and of these, one third had an underlying neuromuscular diagnosis. Genetic testing of RYR1 is indicated for all patients with MH, and anaesthetic precautions should be considered for any child with symptoms of neuromuscular disease.

Anaesthesia Management and Use of Sugammadex in a Patient with Ullrich's Disease

Here, we report anaesthesia management and the successful use of total intravenous anaesthesia and sugammadex in a patient with Ullrich's disease. Propofol and remifentanyl infusion was used for anaesthesia. After the end of the surgery, when the train-of-four value was 0%, 4 mg kg(-1) sugammadex was administered, and the patient was successfully extubated after 36 s. No adverse effects or safety concerns were observed. In conclusion, we suggest that the use of propofol infusion to avoid the use of inhalation anaesthetics and the use of sugammadex for the reversal of the effects of rocuronium is safe in patients with Ullrich's disease.

Accuracy of Malignant Hyperthermia Diagnoses in Hospital Discharge Records

Background:

In 1997, the International Classification of Diseases (ICD), 9th Revision Clinical Modification (ICD-9) coding system introduced the code for malignant hyperthermia (MH) (995.86). The aim of this study was to estimate the accuracy of coding for MH in hospital discharge records.

Methods:

An expert panel of anesthesiologists reviewed medical records for patients with a discharge diagnosis of MH based on ICD-9 or ICD-10 codes from January 1, 2006 to December 31, 2008 at six tertiary care medical centers in North America. All cases were categorized as possible, probable, or fulminant MH, history of MH (family or personal) or other.

Results:

A total of 47 medical records with MH diagnoses were reviewed; 68.1% had a documented surgical procedure and general anesthesia, and 23.4% (95% CI, 12.3–38.0%) had a possible, probable, or fulminant MH event. Dantrolene was given in 81% of the MH events. All patients judged to have an incident MH event survived to discharge. Family and personal history of MH accounted for 46.8% of cases. High fever without evidence of MH during admission accounted for 23.4%, and the reason for MH coding was unclear in 6.4% of cases.

Conclusions:

Approximately one quarter of ICD-9 or ICD-10 coded MH diagnoses in hospital discharge records refer to incident MH episodes and an additional 47% to MH susceptibility (including personal history or family history). Information such as surgical procedure, anesthesia billing data, and dantrolene administration may aid in identifying incident MH cases among those with an ICD-9 or ICD-10 coded MH diagnosis in their hospital discharge records.

Pediatric malignant hyperthermia: risk factors, morbidity, and mortality identified from the Nationwide Inpatient Sample and Kids' Inpatient Database

BACKGROUND

Malignant Hyperthermia (MH) is a potentially fatal metabolic disorder. Due to its rarity, limited evidence exists about risk factors, morbidity, and mortality especially in children.

METHODS

Using the Nationwide Inpatient Sample and the Kid's Inpatient Database (KID), admissions with the ICD-9 code for MH (995.86) were extracted for patients 0-17 years of age. Demographic characteristics were analyzed. Logistic regression was performed to identify patient and hospital characteristics associated with mortality. A subset of patients with a surgical ICD-9 code in the KID was studied to calculate the prevalence of MH in the dataset.

RESULTS

A total of 310 pediatric admissions were seen in 13 nonoverlapping years of data. Patients had a mortality of 2.9%. Male sex was predominant (64.8%), and 40.5% of the admissions were treated at centers not identified as children's hospitals. The most common associated diagnosis was rhabdomyolysis, which was present in 26 cases. Regression with the outcome of mortality did not yield significant differences between demographic factors, age, sex race, or hospital type, pediatric vs nonpediatric. Within a surgical subset of 530,449 admissions, MH was coded in 55, giving a rate of 1.04 cases per 10,000 cases.

CONCLUSIONS

This study is the first to combine two large databases to study MH in the pediatric population. The analysis provides an insight into the risk factors, comorbidities, mortality, and prevalence of MH in the United States population. Until more methodologically rigorous, large-scale studies are done, the use of databases will continue to be the optimal method to study rare diseases.

Cost-effectiveness analysis of stocking dantrolene in ambulatory surgery centers for the treatment of malignant hyperthermia

BACKGROUND

Malignant hyperthermia (MH) is a rare hypermetabolic syndrome of the skeletal muscle and a potentially fatal complication of general anesthesia. Dantrolene is currently the only specific treatment for MH. The Malignant Hyperthermia Association of the United States has issued guidelines recommending that 36 vials (20 mg per vial) of dantrolene remain in stock at every surgery center. However, the cost of stocking dantrolene in ambulatory surgery centers has been a concern. The purpose of this analysis is to assess the cost-effectiveness of stocking dantrolene in ambulatory surgery centers as recommended by the Malignant Hyperthermia Association of the United States.

METHODS

A decision tree model was used to compare treatment with dantrolene to a supportive care-only strategy. Model assumptions include the incidence of MH, MH case fatality with dantrolene treatment and with supportive care-only. Sensitivity analyses were performed to assess the robustness of the estimated cost-effectiveness.

RESULTS

The estimated annual number of MH events in ambulatory surgery centers in the United States was 47. The incremental effectiveness of dantrolene compared with supportive care was 33 more lives saved per year. The incremental cost-effectiveness ratio was $196,320 (in 2010 dollars) per life saved compared with a supportive care strategy. Sensitivity analysis showed that the results were robust for the plausible range of all variables and assumptions tested.

CONCLUSION

The results of this analysis suggest that stocking dantrolene for the treatment of MH in ambulatory surgery centers as recommended by the Malignant Hyperthermia Association of the United States is cost-effective when compared with the estimated values of statistical life used by U.S. regulatory agencies.

[Anesthetic malignant hyperthermia: what's new in 2012?]

Malignant hyperthermia (MH) is a pharmacogenetic disorder of anesthesia. Recent advances dealing with epidemiology of MH and the safe anesthetic course of MH susceptible patients are shortly presented here with a special insight into the preparation of modern anesthesia workstations, which they will share in operating room.

Neuromuscular disease and the pulmonologist

PURPOSE OF REVIEW

The heterogeneous nature of neuromuscular disorders (NMDs) continues to promote slow but steady advances in diagnosis, classification, and treatment. This review focuses on the updates in the general management and treatment of NMDs, with emphasis on key updates in muscular dystrophy, myotonic dystrophy, mitochondrial myopathy, spinal muscular atrophy, and hereditary neuropathies.

RECENT FINDINGS

Current research shows that improvements in morbidity and mortality in various NMDs may be possible. Key components include advances in identification and classification of individual NMDs; attention to anesthetic and surgical risks; aggressive pulmonary care; and implementations of a proactive, multidisciplinary, standard-of-care approach. Innovative molecular and pharmaceutical therapeutic options are being investigated in many of these disorders, but unfortunately no new intervention has borne out.

SUMMARY

Important advances were made in the last year in the field of neuromuscular disease. However, because of their heterogeneous nature and rarity, diagnosis and treatment of these disorders either as a single disorder or as a group continue to be both a clinical and a research challenge. It is of utmost importance that clinicians and researchers be aware of these disorders to aid in identification and treatment.