BACKGROUND: Delays in treating anaesthesia-induced malignant hyperthermia increase risks of complications and death. NPJ5008 is a novel formulation of the indicated treatment, dantrolene sodium, developed to shorten preparation and administration times compared with the reference formulation Dantrium®. The two formulations have been compared preclinically.
OBJECTIVE: Assess bioequivalence of overall dantrolene (free acid) exposure of NPJ5008 versus Dantrium® and ascertain similarities in their pharmacokinetics and safety/tolerability profiles. Evaluate preparation/administration time savings for the new formulation.
METHODS: Part 1 of this open-label trial in humans was a 1 : 1 randomised crossover study; part 2 was a single-arm study. Trial pharmacy data and laboratory simulations assessed preparation/administration step timings.
METHODS: Single clinical centre in the UK, April to July 2021.
METHODS: Twenty-one healthy male and female individuals.
METHODS: Part 1: single intravenous 60 mg dose of NPJ5008 or Dantrium®, sequentially. Part 2: single intravenous 120 mg dose of NPJ5008. Simulation: five vials per formulation using paediatric and adult cannulas.
METHODS: Overall drug exposure to last measurable concentration (AUC 0 to last ) and extrapolated to infinity (AUC 0 to ∞ ) were primary endpoints. Other pharmacokinetic, clinical and muscle-function parameters, and adverse events, were monitored.
RESULTS: Adjusted geometric mean ratios of NPJ5008 versus Dantrium® were 90.24 and 90.44% for AUC 0 to last and AUC 0 to ∞ , respectively, with the 90% confidence intervals (CI) within the 80 to 125% acceptance interval, establishing bioequivalence. No new safety issues emerged: any adverse events were of a similar magnitude across treatments and related to pharmacological properties of dantrolene. Pharmacy and simulation data revealed that every step in preparation and administration was 26 to 69% faster for NPJ5008 than Dantrium®.
CONCLUSIONS: NPJ5008 showed comparable pharmacokinetic and safety profiles to Dantrium®, while reducing dantrolene dose preparation/administration times, potentially reducing patient complications/healthcare resourcing in malignant hyperthermia.
BACKGROUND: EudraCT Number: 2020-005719-35, MHRA approval.

Malignant hyperthermia (MH) is a rare anesthetic emergency with a high mortality rate in China. We developed a WeChat applet-based National Remote Emergency System for Malignant Hyperthermia (MH-NRES) to provide a real-time emergency system to help Chinese anesthesiologists deal with MH crises. However, it is imperative that close attention should be paid to the usability of the applet.
The objectives of this study were to (1) evaluate the usability of the applet-based MH-NRES for anesthesiologists; and (2) to test the validity and reliability of a modified mHealth app usability questionnaire.
A modified User Version of the Mobile Application Rating Scale (uMARS) was designed. Together with System Usability Scale (SUS) and Post-Study System Usability Questionnaire (PSSUQ), another two well-validated questionnaires, uMARS were then used to evaluate the usability of MH-NRES. The Cronbach alpha of the total score and the subscales of uMARS was calculated to evaluate the internal consistency. The correlation coefficients among three questionnaires were calculated.
In this study, 118 anesthesiologists provided responses to the questionnaire. The overall mean uMARS score was 4.43 ± 0.61, which ranged from 3 to 5. The mean PSSUQ score were in good to excellent range with mean of 6.02 ± 0.97, which ranged from 3.19 to 7. The overall SUS score was 76.0 ± 17.6, which ranged from 45 to 100. The total uMARS score had excellent internal consistency (Cronbach alpha = 0.984). uMARS and its subscales were strongly correlated with PSSUQ (coefficient 0.758-0.819, P < 0.001) and SUS (coefficient 0.535-0.561, P < 0.001), respectively.
Data obtained from the usability evaluation questionnaires in this study indicated a high quality of the MH-NRES on the ease of use, satisfaction and perceived usefulness, which suggest this system might be a useful tool for anesthesiologists\' education and management of MH crises. Future feedback from high-fidelity simulation and clinical scenarios are need for further usability evaluation of this system.

暂无摘要。

Malignant hyperthermia (MH) is a life-threatening syndrome caused by sudden, uncontrolled skeletal muscle hypermetabolism in response to inhalation anesthetics and depolarizing relaxants. The estimated incidence of MH is between 1:10,000 and 1:250,000 anesthetic procedures. In Poland, due to lack of reporting, the incidence of MH is unknown. Dantrolene is imported as a life-saving drug (target import) and temporally authorized for sale. The aim of the study was to evaluate the prevalence of malignant hyperthermia in Poland and to assess the accessibility to dantrolene in Poland. A questionnaire was conducted among the chiefs of anesthesia and intensive care units in Poland. During the years 2014 to 2019, 10 episodes of MH have been reported in 238 surveyed polish anesthesia departments. The estimated prevalence is 1:350,000. Eight patients survived the MH crisis. Dantrolene is stocked in 48 (20%) anesthesiology departments. Among the surveyed hospitals, only in 38 (16%) it is possible to administer dantrolene within 5 minutes of suspecting a MH reaction. Less than half units (44%) have an algorithm for the management of MH episode in the operating theaters. The results of the study revealed, that the prevalence of MH in Poland is lower than the prevalence reported in other countries. Access to dantrolene in Poland is limited.

UNASSIGNED: Malignant hyperthermia (MH) is a rare but fatal pharmacogenetic disorder, triggered by inhalational anesthetics or succinylcholine. Since the first nonprofit academic organization China Malignant Hyperthermia Emergency Assistance WeChat-based Group (CMHEA Group) was established in 2015, they have actively participated in the diagnosis and treatment of MH patients. Based on the CMHEA Group, the aim of the study was to retrospectively analyze the characteristics of suspected MH in China from 2015 to 2020.
UNASSIGNED: We conducted a retrospective analysis of the suspected MH patients from 2015 to 2020, for analyzing the current clinical diagnosis, treatment and prognosis of MH in China.
UNASSIGNED: A total of 58 suspected MH cases occurred from 2015 to 2020, of these, 36 cases were collected with detailed data. The MH clinical grading score of 36 patients ranged from 33 to 73, with a median of 55. Abnormal hyperthermia and hypercarbia were the most common early signs of MH. Four patients were confirmed carrying six different potential MH-causative mutations. Of the total 58 cases, 14 patients (24.1%) received dantrolene and the whole mortality rate was 53.4%. Compared to the patients not receiving dantrolene treatment, the survival rate of patients receiving dantrolene treatment was significantly higher than that of patients not receiving dantrolene (78.6% vs 36.4%, p = 0.007).
UNASSIGNED: The current main diagnostic methods of suspected MH in China are still clinical diagnosis. Hence, it is critical to keep dantrolene for immediate accessibility with the introduction of domestic dantrolene to China. The WeChat group model has played an important but limited role in quick diagnosis and treatment of MH.

Patients susceptible to malignant hyperthermia (MH) may experience disabling manifestations of an unspecified myopathy outside the context of anesthesia, including myalgia, fatigue, or episodic rhabdomyolysis. Clinical observations suggest that oral dantrolene may relief myopathic symptoms in MH-susceptible (MHS) patients. However, high-dose oral dantrolene has been associated with severe hepatotoxicity.
In a retrospective database review (1994-2018), we investigated a cohort of patients who were diagnosed as MHS by a positive caffeine-halothane contracture test (CHCT), had myopathic manifestations, and received oral dantrolene. Our aim was to investigate the occurrence of serious adverse effects and the adherence to oral dantrolene therapy. We also explored factors associated with self-reported clinical improvement, considering as nonresponders patients with intolerable adverse effects or who reported no improvement 8 weeks after starting treatment.
Among 476 MHS patients with positive CHCT, 193 had muscle symptoms, 164 started oral dantrolene, 27 refused treatment, and 2 were excluded due to abnormal liver function before starting therapy. There were no serious adverse effects reported. Forty-six of 164 patients (28%; 95% confidence interval [CI], 22%-35%) experienced mild to moderate adverse effects. Twenty-two patients (22/164, 13%; 95% CI, 9%-19%) discontinued treatment, among which 16 due to adverse effects and 6 due to lack of improvement. One hundred forty-two patients (87%; 95% CI, 80%-90%) adhered to therapy and reported improvement of myalgia (n = 78), fatigue (n = 32), or rhabdomyolysis/hiperCKemia (n = 32). The proportion of responders was larger among patients with MH history than among those referred due to a clinical myopathy with nonpertinent anesthetic history (97% vs 79%, respectively; 95% CI of the difference, 8.5-28; P < .001). Patients with a sarcoplasmic reticulum Ca2+ release channel ryanodine receptor gene ( RYR1 ) variant had higher odds of responding to dantrolene treatment (OR, 6.4; 95% CI, 1.3-30.9; P = .013). Dantrolene median dose was 50 (25-400) and 200 (25-400) mg·day -1 in responders and nonresponders, respectively.
We found that oral dantrolene produced no serious adverse effects within the reported dose range, and was well tolerated by most MH-susceptible patients presenting myopathic symptoms. Our study provides dosing and adverse effect data as a basis for further randomized controlled clinical trials to determine the efficacy of oral dantrolene for symptomatic relief in MHS-related myopathies.

BACKGROUND: Patients with neuromuscular disorders are at increased risk of suffering perioperative complications. Current knowledge concerning this topic is based on small retrospective studies and expert opinion. Therefore, an individualized multidisciplinary approach to perioperative anaesthesia planning is invaluable to anticipate difficulties and to optimize outcomes.
OBJECTIVE: To evaluate current practice regarding preoperative counselling and perioperative care of neuromuscular patients, with the aim to facilitate standardization and improvement of perioperative care for neuromuscular patients.
METHODS: A questionnaire-based cross-sectional, observational study was conducted between July, 1st 2020 and December, 31st, 2020 in Dutch anaesthesia, neurology and clinical genetics departments. Main outcome measures were 1.) frequency of consultation requests for neuromuscular patients prior to surgery, 2.) current practice, educational activities and departmental approach to this topic and 3.) preoperative counselling of neuromuscular patients.
RESULTS: A total of 83 departments participated. Consultations for a neuromuscular patient scheduled for anaesthesia were requested from anaesthesia and neurology department only infrequently. Local guidelines concerning perioperative care of neuromuscular patients were available in 36.4% of the participating departments. Quality of specific training for residents and staff anaesthetists/neurologists covering perioperative care of neuromuscular patients was rated as \'very good\' or \'good\' by 42.9% . Neuromuscular patients scheduled for surgery were \'always\' or \'often\' discussed in multidisciplinary meetings involving anaesthesiologists and neurologists in 20.8% of the participating departments.
CONCLUSIONS: Perioperative care for neuromuscular patients in the Netherlands is highly variable and might benefit from guidelines, education of health care professionals and multidisciplinary meetings between anaesthesiologists and neurologists on a regular basis.

Introduction A simple indicator of muscle damage is creatine kinase (CK). Although CK elevation is informative for malignant hyperthermia, no study has examined the relationship between the anesthetically awake state and CK in children. We aimed to prospectively examine the relationship between the awakening state and CK on the day after surgery in children who have undergone anesthesia with volatile inhalation anesthetics. Methods The study included 119 patients aged 0-15 years and scheduled to undergo general anesthesia for cleft lip and palate-related surgery. Emergence agitation (EA) was assessed after completion of general anesthesia using the five-point EA scale, and patients were divided into the following five groups according to the EA score: EA1, EA2, EA3, EA4, and EA5. The primary outcome was ΔCK (comparison of CK values one week prior to surgery to CK values on the day after surgery) in each EA group. The secondary outcome was ΔCK when the EA score was divided into the following two groups: EA ≤2 (EA score of 1 or 2) and EA ≥3 (EA score of 3, 4, or 5). Results The median ΔCK values in the EA1 to EA5 groups were 3 (quartile -19~9), 5 (-32~88), 99.5 (-18~190.5), 121 (29~219.5), and 144 (41~340.5), respectively, indicating a statistically significant difference overall. Statistically significant differences were also observed between the EA1 and EA4 groups and between the EA2 and EA4 groups. The median ΔCK values in the EA ≤2 and EA ≥3 groups were 3 (quartile -27~85) and 108 (23.5~206.7), respectively, indicating a statistically significant difference. Conclusion The results of this study revealed that a higher EA score at the time of anesthesia awakening is associated with a larger ΔCK, indicating that a high CK level on the day after surgery is highly related to the state of the patient upon awakening.

Malignant Hyperthermia (MH) is a pharmacogenetic, hereditary and autosomal dominant syndrome triggered by halogenates/succinylcholine. The In Vitro Contracture Test (IVCT) is the gold standard diagnostic test for MH, and it evaluates abnormal skeletal muscle reactions of susceptible individuals (earlier/greater contracture) when exposed to caffeine/halothane. MH susceptibility episodes and IVCT seem to be related to individual features.
To assess variables that correlate with IVCT in Brazilian patients referred for MH investigation due to a history of personal/family MH.
We examined IVCTs of 80 patients investigated for MH between 2004‒2019. We recorded clinical data (age, sex, presence of muscle weakness or myopathy with muscle biopsy showing cores, genetic evaluation, IVCT result) and IVCT features (initial and final maximum contraction, caffeine/halothane concentration triggering contracture of 0.2g, contracture at caffeine concentration of 2 and 32 mmoL and at 2% halothane, and contraction after 100 Hz stimulation).
Mean age of the sample was 35±13.3 years, and most of the subjects were female (n=43 or 54%) and MH susceptible (60%). Of the 20 subjects undergoing genetic investigation, 65% showed variants in RYR1/CACNA1S genes. We found no difference between the positive and negative IVCT groups regarding age, sex, number of probands, presence of muscle weakness or myopathy with muscle biopsy showing cores. Regression analysis revealed that the best predictors of positive IVCT were male sex (+12%), absence of muscle weakness (+20%), and personal MH background (+17%).
Positive IVCT results have been correlated to male probands, in accordance with early publications. Furthermore, normal muscle strength has been confirmed as a significant predictor of positive IVCT while investigating suspected MH cases.

Malignant Hyperthermia (MH) is a pharmacogenetic disorder triggered by halogenated anesthesia agents/succinylcholine and characterized by hypermetabolism crisis during anesthesia, but also by day-to-day symptoms, such as exercise intolerance, that may alert the health professional.
The study aimed to analyze the incidence of fatigue in MH susceptible patients and the variables that can impact perception of fatigue, such as the level of routine physical activity and depression.
A cross-sectional observational study was carried out with three groups ... 22 patients susceptible to MH (positive in vitro muscle contracture test), 13 non-susceptible to MH (negative in vitro muscle contracture test) and 22 controls (no history of MH). Groups were assessed by a demographic/clinical questionnaire, a fatigue severity scale (intensity, specific situations, psychological consequences, rest/sleep response), and the Beck depression scale. Subgroups were re-assessed with the Baecke habitual physical exercise questionnaire (occupational physical activity, leisure physical exercise, leisure/locomotion physical activity).
There were no significant differences among the three groups regarding fatigue intensity, fatigue related to specific situations, psychological consequences of fatigue, fatigue response to resting/sleeping, depression, number of active/sedentary participants, and the mean time and characteristics of habitual physical activity. Nevertheless, unlike the control sub-group, the physically active MH-susceptible subgroup had a higher fatigue response to resting/sleeping than the sedentary MH susceptible subgroup (respectively, 5.9.ß...ß1.9 vs. 3.9.ß...ß2, t-test unpaired, p.ß<.ß0.05).
We did not detect subjective fatigue in MH susceptible patients, although we reported protracted recovery after physical activity, which may alert us to further investigation requirements.