Turn Up the Heat: A Case Report of Malignant Hyperthermia During Ambulatory Surgery.

Malignant hyperthermia is a rare complication of general anesthesia involving the uncontrolled release of calcium when exposed to triggers such as depolarizing muscle relaxants or volatile anesthetics. It presents as a hypercatabolic skeletal muscle syndrome that results in tachycardia, hyperthermia, hypercapnia, muscle rigidity, acidosis, rhabdomyolysis, and hyperkalemia. This report presents the case of a 67-year-old female without a personal or family history of complications with anesthesia who experienced malignant hyperthermia during an elective hysterectomy. The patient was given multiple doses of dantrolene, with the ultimate resolution of her symptoms several days after surgery. She was discharged one week after surgery.

Caution for psychiatrists: malignant hyperthermia risks with the anesthetic agent succinylcholine (Suxamethonium) during electroconvulsive therapy.

BACKGROUND: Malignant hyperthermia is a potentially lethal condition triggered by specific anesthetic drugs, especially a depolarizing muscle relaxant of succinylcholine (Suxamethonium). Despite the frequent use of succinylcholine with electroconvulsive therapy (ECT), there has been no reported case of potentially lethal malignant hyperthermia following ECT. In addition, the time interval between the administration of succinylcholine and the onset of malignant hyperthermia has not been outlined in the context of ECT. CASE PRESENTATION: We present the case of a 79-year-old woman suffering from severe depression, who experienced severe malignant hyperthermia due to succinylcholine administration during an ECT session. She presented with a high fever of 40.2 °C, tachycardia of 140/min, hypertension with a blood pressure exceeding 200 mmHg, significant muscle rigidity, and impaired consciousness. These symptoms emerged two hours after ECT, which occurred in a psychiatric ward rather than an operating room, and reached their peak in less than 24 h. She was given 60 mg of dantrolene, which quickly reduced the muscular rigidity. Subsequently, she received two additional doses of 20 mg and 60 mg of dantrolene, which brought her fever down to 36.2 °C and completely eased her muscle rigidity within two days after ECT. CONCLUSIONS: This is the first reported case of potentially lethal malignant hyperthermia after ECT. In addition, it highlights the delayed onset of malignant hyperthermia following an ECT procedure, emphasizing the necessity for psychiatrists to recognize its onset even after the treatment. In the light of potentially lethal consequences of malignant hyperthermia, it is critically important for psychiatrists to closely monitor both intraoperative and postoperative patient's vital signs and characteristic physical presentations, promptly identify any symptomatic emergence, and treat it immediately with dantrolene.

Dexmedetomidine for reducing succinylcholine-induced myalgia in patients undergoing electroconvulsive therapy: A randomised controlled trial.

Background and Aim: Electroconvulsive therapy (ECT) is an effective intervention for psychiatric patients. Succinylcholine is considered the drug of choice for muscle relaxation for ECT. Significant adverse effects of succinylcholine include fasciculation and myalgia. Dexmedetomidine is a highly selective α-2 adrenergic agonist. This study aims to determine the efficacy of a low dose of dexmedetomidine in reducing succinylcholine-induced myalgia in patients receiving ECT. Methods: This randomised controlled trial was conducted on 100 patients, aged 18-65 years, undergoing ECT, who were randomly allocated into two groups with an allocation ratio of 1:1. Group D received intravenous (IV) dexmedetomidine 0.25 µg/kg, and Group C received IV normal saline (0.9%). Patients' self-reported myalgia scores were measured after 60 min of the procedure. Fasciculations were noted after IV succinylcholine administration. Heart rate (HR) and mean blood pressure (MBP) were measured at baseline, after infusion (5 min) and after ECT (0, 2.5, 5, 10, 15, 30 min). Continuous data were analysed using a Student's t-test for two-group comparisons, a mixed model analysis of variance for group comparisons and various time point analyses. Categorical data were analysed using the Chi-square/Fisher's exact test. Results: There were no differences between the groups regarding demographics. Myalgia and fasciculations were less in Group D than in Group C (P < 0.001). MBP and HR changes were comparable (P > 0.05). Conclusion: A low dose of dexmedetomidine (0.25 µg/kg) effectively reduces myalgia and fasciculations due to succinylcholine in patients undergoing electroconvulsive therapy.

The key role of muscle spindles in the pathogenesis of myofascial trigger points according to ramp-and-hold stretch and drug intervention in a rat model.

This study investigated whether abnormal peak inversion spontaneous potentials (PISPs) recorded at resting myofascial trigger points (MTrPs) stem from the discharge of muscle spindles. Forty-eight male Sprague-Dawley rats were randomly divided into six groups. Five groups underwent MTrP modeling intervention, whereas one group did not receive intervention and was duly designated as the blank control. After model construction, five rat models were randomly subjected to ramp-and-hold stretch tests, succinylcholine injection, eperisone hydrochloride injection, saline injection, and blank drug intervention. By contrast, the rats in the blank control group were subjected to ramp-and-hold stretch tests as a control. Frequencies and amplitudes of PISPs were recorded pre- and post-interventions and compared with those of the blank group. Stretch tests showed that the depolarization time and amplitude of PISPs ranged from 0.4 ms to 0.9 ms and from 80 uV to 140 µV, respectively. However, no PISPs were observed in the control rats. The frequency of PISPs in the ramp and hold phases and the first second after the hold phase was higher than that before stretching (p < 0.01). Succinylcholine and eperisone exerted excitatory and inhibitory effects on PISPs, respectively. In the group injected with 0.9% saline, no considerable differences of the PISPs were observed during the entire observation period. In conclusion, PISPs recorded at resting MTrPs are closely related to muscle spindles. The formation of MTrPs may be an important factor that regulate dysfunctional muscle spindles.

Airway management of postburn neck contracture in pediatric patient - A challenge for anesthesiologist!

Pediatric difficult airway management is more challenging for an anesthesiologist due to anatomical and physiological differences as compared to adults. Moreover, the familiarity with the use of difficult airway equipment in adults does not equate to proficiency for the same in children. So, here we are presenting the management of a unique case of a difficult airway due to postburn neck contracture in a 4-year-old child, which was managed successfully with the help of a video laryngoscope after the failure attempt with a flexible fiberoptic bronchoscope.

Pregabalina preoperatoria previene las fasciculaciones y mialgias inducidas por succinilcolina: metaanálisis de ensayos aleatorizados / Preoperative pregabalin prevents succinylcholine-induced fasciculations and myalgias: A meta-analysis of randomized trials

La succinilcolina es el bloqueador neuromuscular de referencia para la inducción de secuencia rápida. Sin embargo, su uso se asocia a fasciculaciones y mialgias. Se realizó una revisión sistemática y un metaanálisis. Se incluyeron ensayos clínicos controlados aleatorizados comparando gabapentinoides frente a placebo, para la prevención de fasciculaciones y mialgias inducidas por succinilcolina. Se incluyeron seis estudios clínicos aleatorizados. El número total de pacientes fue de 481, de los cuales 241 se incluyeron en el grupo de intervención y 240 en el grupo de placebo. Los gabapentinoides redujeron la incidencia de mialgia inducida por succinilcolina (RR=0,69; IC95%: 0,56-0,84; p<0,001), que siguió siendo estadísticamente significativa para pregabalina (RR=0,71; IC95%: 0,54-0,93; p=0,013) y gabapentina (RR=0,61; IC95%: 0,45-0,82; p=0,001) por separado. No hubo diferencia entre los grupos en cuanto a fasciculaciones (RR=0,92; IC95%: 0,82-1,03; p=0,148). El uso preoperatorio de gabapentinoides se asocia a una menor incidencia de mialgias inducidas por succinilcolina dentro de las primeras 24horas posteriores al procedimiento. (AU)

Succinylcholine is the gold standard neuromuscular blocker for rapid sequence induction, however, its use is associated with fasciculations and myalgias. A systematic review and meta-analysis including randomized controlled clinical trials was performed comparing gabapentinoids versus placebo for the prevention of fasciculations and succinylcholine-induced myalgias. Six randomized clinical studies were included. The total number of patients was 481, of which 241 were in the intervention group and 240 in the placebo group. Gabapentinoids reduced the incidence of succinylcholine-induced myalgia (RR=.69; 95%CI: .56-.84; P<.001), which remained statistically significant for pregabalin (RR=.71; 95%CI: .54-.93; P=.013) and gabapentin (RR=.61; 95%CI: .45-.82; P=.001) separately. There was no difference between the groups in fasciculations (RR=.92; 95%CI: .82-1.03; P=.148). Preoperative use of gabapentinoids is associated with lower incidence of succinylcholine-induced myalgias within the first 24hours after the procedure. (AU)

Quantitative Neuromuscular Monitoring Permits Early Diagnosis of Abnormal Butyrylcholinestrase: Two Case Studies Demonstrating Prevention of Awareness from Premature Awakening.

Administration of succinylcholine to patients with a variant in the butyrylcholinesterase (BChE) gene increases the risk of anesthesia emergence prior to recovery from neuromuscular blockade (NMB). Application of quantitative neuromuscular monitoring (NMM) can identify residual NMB. We present two patients with abnormal BChE gene variants. In the first case, quantitative monitoring was applied too late to prevent awareness, but allowed diagnosis and prevented admission to the intensive care unit. In the second case, monitoring was applied prior to NMB, which enabled early diagnosis and prevented premature awakening from anesthesia. These cases illustrate the importance of quantitative NMM, even in short cases and with short-acting depolarizing agents such as succinylcholine. The clinical implications of this report include a more consistent use of NMM to identify and manage patients with undiagnosed abnormal BChE and to prevent premature anesthesia emergence.

Laryngospasm Treated With Intramuscular Rocuronium in a Pediatric Patient Without Intravenous Access: A Case Report.

We present a case in which intramuscular rocuronium was used successfully to treat laryngospasm in a pediatric patient. An 11-month-old infant weighing 9.7 kg was scheduled for an elective laparoscopic inguinal hernia repair surgery. Anesthesia was induced with oxygen, nitrous oxide, and sevoflurane. After loss of consciousness, mask ventilation became impossible, and laryngospasm was suspected. Intravenous access was attempted without success; as there was no immediate access to succinylcholine, rocuronium 10 mg (1.0 mg/kg) was injected intramuscularly into the vastus lateralis muscle. We were able to mask-ventilate the patient within one minute of intramuscular rocuronium, followed by successful endotracheal intubation with a video laryngoscope. The duration of hypoxia (saturation of peripheral oxygen (SpO2) < 90%) was approximately two minutes, and the patient's lowest oxygen saturation during induction was 76%. At the end of the surgery, the patient was uneventfully extubated. We conclude that intramuscular rocuronium may provide an alternative treatment for laryngospasm in pediatric patients with no intravenous access and no availability of succinylcholine.

A Randomized Double-Blind Comparative Study of the Intubating Conditions and Hemodynamic Effects of Rocuronium and Succinylcholine in Pediatric Patients.

BACKGROUND: The incidence of unanticipated difficult airways is higher in pediatric age groups than in adults due to the different airway anatomy, difficulty in airway examination, and congenital malformations. Rocuronium bromide has a comparable onset time to succinylcholine at its proportionate dose. Hence, we compared rocuronium bromide with succinylcholine to assess intubating conditions and their side effects, if any. METHOD: A total of 200 pediatric patients of American Society of Anesthesiologists (ASA) grades I and II between one and 14 years of age of either sex posted for elective surgery were included in the study. After randomization, group R (n = 100) received 1.2 mg/kg rocuronium, and group S (n = 100) received 2 mg/kg succinylcholine intravenously. After confirming the mask ventilation, the study drugs were administered, and intubating conditions were assessed as excellent, good, poor, or impossible. Hemodynamic changes post-intubation were recorded as our secondary outcome. RESULT: Intubating conditions were excellent( 65%), good( 25%) and fair (10%) in patients of group R, while results in group S were excellent( 60%), good( 20%), fair (15%), and poor (5%) (p = 0.010). The heart rate was significantly increased post-intubation in group S, while there was no significant increase in systolic or diastolic blood pressure in either group. CONCLUSION: At a dose of 1.2 mg/kg body weight, rocuronium was a better alternative to succinylcholine for providing rapid intubating conditions and stable hemodynamics without associated adverse effects.

Preoperative pregabalin prevents succinylcholine-induced fasciculation and myalgia: A meta-analysis of randomized trials.

Succinylcholine is the gold standard neuromuscular blocker for rapid sequence induction; however, its use is associated with fasciculation and myalgia. We performed a systematic review and meta-analysis of randomized controlled clinical trials comparing gabapentinoids versus placebo for the prevention of fasciculations and succinylcholine-induced myalgias. Six randomized clinical studies were included with a total of 481 patients - 241 in the intervention group and 240 in the placebo group. Gabapentinoids reduced the incidence of succinylcholine-induced myalgia (RR = 0.69, 95% CI 0.56-0.84, P < .001), which remained statistically significant for pregabalin (RR = 0.71, 95% CI 0.54-0.93, P = .013) and gabapentin (RR = 0.61, 95% CI 0.45-0.82, P = .001) separately. There was no difference in fasciculations between the groups (RR = 0.92, 95% CI 0.82-1.03, P = .148). Preoperative use of gabapentinoids is associated with lower incidence of succinylcholine-induced myalgias within the first 24 h of surgery.

The Effects of Prophylactic Intravenous Lignocaine vs Vecuronium on Succinylcholine-Induced Fasciculation and Postoperative Myalgia in Patients Undergoing Elective Surgery at Debre Markos Comprehensive Specialized Hospital, Ethiopia, 2022: Prospective Cohort Study.

Background: The incidence and severity of succinylcholine-induced fasciculation and postoperative myalgia have been shown to decrease when vecuronium bromide or preservative-free 2% plain lignocaine hydrochloride is administered before induction. The aim of this study is to examine the effectiveness of defasciculation dosages of vecuronium bromide and 2% preservative-free plain lignocaine hydrochloride in decreasing succinylcholine-induced fasciculation and postoperative myalgia in patients undergoing elective surgery. Methods: A total of 110 participants were included in a prospective observational cohort study that was located in an institution. Patients were randomly assigned to (Group L) and (Group V) based on the prophylactic measures they received from the responsible anesthetist utilizing preservative-free 2% plain lignocaine and defasciculation dose of vecuronium bromide, respectively. We recorded, socio-demographic variables, fasciculation, postoperative myalgia, total number of analgesics administered following surgery in 48hrs, and kind of procedure. The descriptive data were compiled using descriptive statistics. Categorical and continuous data were evaluated, respectively, using chi-square statistics and the independent sample t-test. To compare the prevalence of fasciculation and myalgia across the various groups, the Fischer exact test was performed. A 0.05 p-value was deemed statistically significant. Results: This study found that the incidence of fasciculation in the groups receiving the defasciculation doses of vecuronium bromide and preservative-free 2% plain lignocaine hydrochloride was 14.6% and 20% (p-value 0.007), respectively. The rate of mild-to-moderate postoperative myalgia in the vecuronium bromide group was 23.7%, 30.9%, and 16.4% in the first, 24th, and 48th hours, respectively (p-value 0.001), as opposed to 0%, 37.3%, and 9.1%, respectively (p-value 0.008) in the group receiving preservative-free 2% plain lignocaine hydrochloride. Conclusion: Pretreatment with 2% plain lignocaine that is preservative-free is more efficient than vecuronium bromide at reducing the frequency and intensity of postoperative succinylcholine-induced myalgia, whereas defasciculation dose of vecuronium was more effective prevention of succinylcholine-induced fasciculation.

The effect of shoulder muscle succinylcholine injection on the foreleg raising power: Sion's local paralysis.

Objective: We examined the change in foreleg raising power after Sion's local paralysis (SLP) with succinylcholine in the shoulder muscle. Methods: A randomized, double blind, placebo-controlled, porcine study was designed and performed at a research institution. Ten male Korean native pigs were randomized into an intervention group (n = 5) and a control group (n = 5). The injection points were in the middle of the left trapezius muscle and the middle of the left deltoid muscle. The control group received 2 ml normal saline (NS), 1 ml injected in each point. The intervention group received 0.4 mg/kg succinylcholine diluted to 2 ml in NS, and 1 ml was injected in each point. To represent the foreleg raising power, the height of the left forelegs from baseline (experiment table) was measured. We measured the foreleg height and oxygen saturation at -4, -2, 0, +2, +4, +6, +8, +10, +20, +30, and +60 min. Results: After SLP, foreleg height immediately declined in the intervention group. It recovered slightly for a few minutes and declined from 4 to 8 min. In the control group, foreleg height was relatively similar throughout the study period. A repeated-measure analysis of variance revealed a significant group × time interaction (F10,80 = 2.37, P = 0.017), a significant main effect for group (F1,8 = 6.25, P = 0.037), and a significant main effect for time (F10,80 = 4.41, P < 0.001). Post hoc analysis demonstrated that the intervention group showed significantly less foreleg raising power than the control group at 0, 4, 6, 8, 20, and 30 min (P < 0.05). Conclusions: Compared with the control group, the foreleg raising power in the intervention group immediately decreased significantly and persisted for a period after SLP, without hypoxia, in a pig model.

Hipertermia maligna / Malignant hyperthermia

Resumen: La hipertermia maligna es un raro desorden farmacogenético potencialmente mortal, que se presenta como una respuesta hipermetabólica a los anestésicos volátiles y relajantes musculares despolarizantes en individuos susceptibles. Esta susceptibilidad se asocia a mutaciones en tres genes: RYR1, CACNA1S y STAC3. Puede manifestarse con síntomas leves o como una crisis fulminante, con rabdomiólisis severa, fibrilación ventricular e insuficiencia renal y circulatoria aguda, por lo tanto, el pronóstico depende de qué tan pronto se sospeche del diagnóstico y qué tan rápido se inicie el tratamiento. El diagnóstico definitivo se basa en una prueba de sensibilidad en biopsia muscular fresca y en pruebas genéticas. La mejor manera de prevenir un evento es la detección precoz de los pacientes susceptibles así como contar con el equipo para responder ante una crisis en cada centro donde se administren anestésicos volátiles y la capacitación del personal. Esta revisión sintetiza los conceptos actuales clínicos y biomédicos para detección, prevención, diagnóstico y manejo de la hipertermia maligna.

Abstract: Malignant hyperthermia is a rare, life-threatening pharmacogenetic disorder which presents as a hypermetabolic response to volatile anesthetics and depolarizing muscle relaxants in susceptible individuals. This susceptibility is associated with mutations in three genes: RYR1, CACNA1S and STAC3. Can manifest with mild symptoms or as a fulminant crisis, with severe rhabdomyolysis, ventricular fibrillation and acute renal and circulatory failure, therefore the prognosis depends on how soon the diagnosis is suspected and how fast treatment is started. The definitive diagnosis is based on a fresh muscle biopsy sensitivity test and genetic testing. The best way to prevent an event is the early detection of susceptible, as well as have equipment to respond to a crisis in each center where volatile anesthetics are administered and the training of staff. This review synthesizes current clinical and biomedical concepts for detection, prevention, diagnosis and management of malignant hyperthermia.

Does the Use of Rocuronium-Sugammadex Instead of Succinylcholine in Electroconvulsive Therapy Affect Seizure Duration?

OBJECTIVE: We compared retrospectively the seizure variables of electroconvulsive therapy (ECT) patients after administration of rocuronium-sugammadex or succinylcholine as a muscle relaxant with propofol anesthesia. METHODS: The sample comprised 134 ECT patients. The mean age was 33.6±10.48 years. Anesthesia induction was provided with propofol one mg kg-intravenously (IV) followed by succinylcholine 0.5 mg kg-1 IV (n=68) (Group S) or rocuronium 0.3 mg kg-1 IV (n=66) (Group R). For patients who were given rocuronium, reversal of the residual neuromuscular block was accomplished with sugammadex (1.5 mg kg-1 IV). First session seizure variables were compared between the two groups. We also presented the clinical outcome with Clinical Global Impression-Improvement (CGI-I) and overall adverse effects. RESULTS: EEG seizure durations in Group R (55.09±36.11 s) and Group S (47.00±26.33 s) were comparable and were not significantly different (p=0.432). The clinical efficacy of ECT measured by CGI-I in both groups was comparable (p=0.075). There were no major complications or death during or after ECT. CONCLUSION: The results of this study show that the use of rocuronium-sugammadex as a neuromuscular blocker instead of succinylcholine during ECT with propofol anesthesia produces similar results in terms of seizure variables and clinical outcomes.

Trismus during tracheal extubation as a complication of general anaesthesia - A case report.

Tracheal extubation is a risky phase of anaesthesia. Most complications that occur when an endotracheal tube is removed are of minor nature, but those that require critical action can end in serious complications or even death. Patient - A 55-year-old woman was admitted for elective transabdominal hysterectomy and adnexal procedures. Anaesthesia - Standard monitoring. For induction, we used fentanyl, propofol, and rocuronium. The maintenance phase of anaesthesia was without complications. After extubation, the patient presented with severe trismus and mask ventilation was unsuccessful (cannot ventilate) - It was not until 200 mg of succinylcholine was administered that the masseter muscle spasm subsided. Extubation is a process that must always be planned. A routine approach and lack of a contingency plan is responsible for a number of complications related to the period of patient awakening and associated with the removal of the endotracheal tube. Trismus, in response to extubation, is a phenomenon not described in the literature in non-high risk patients.

Malignant Hyperthermia in PICU-From Diagnosis to Treatment in the Light of Up-to-Date Knowledge.

Malignant Hyperthermia (MH) is a rare, hereditary, life-threatening disease triggered by volatile anesthetics and succinylcholine. Rarely, MH can occur after non-pharmacological triggers too. MH was detected more often in children and young adults, which makes this topic very important for every pediatric specialist, both anesthesiologists and intensivists. MH crisis is a life-threatening severe hypermetabolic whole-body reaction. Triggers of MH are used in pediatric intensive care unit (PICU) as well, volatile anesthetics in difficult sedation, status asthmaticus or epilepticus, and succinylcholine still sometimes in airway management. Recrudescence or delayed onset of MH crisis hours after anesthesia was previously described. MH can also be a cause of rhabdomyolysis and hyperpyrexia in the PICU. In addition, patients with neuromuscular diseases are often admitted to PICU and they might be at risk for MH. The most typical symptoms of MH are hypercapnia, tachycardia, hyperthermia, and muscle rigidity. Thinking of the MH as the possible cause of deterioration of a patient's clinical condition is the key to early diagnosis and treatment. The sooner the correct treatment is commenced, the better patient´s outcome. This narrative review article aims to summarize current knowledge and guidelines about recognition, treatment, and further management of MH in PICU.

Postoperative weakness and anesthetic-associated rhabdomyolysis in a pediatric patient: a case report and review of the literature.

BACKGROUND: Anesthesia-associated rhabdomyolysis is a rare complication of surgery that causes postoperative myalgia, weakness, and potential renal failure if not managed promptly. Predisposing conditions that may lead to this complication include muscular dystrophies and myopathies. CASE PRESENTATION: This rare case describes a pediatric non-Indigenous Australian patient developing this complication, with no known predisposing risk factors, and no clear etiology. A 9-year-old child with a background of asthma underwent an elective removal of keloid scar on her chest wall. The procedure was brief and uncomplicated, with an uneventful induction of anesthesia. During the emergence period, she developed acutely raised airway pressures with bronchospasm and laryngospasm requiring the use of salbutamol and suxamethonium with good effect. In the initial postoperative period, the patient complained of generalized myalgia and muscle weakness and was unable to mobilize independently. There was transient recovery to normal function; however, a recurrence of symptoms the following day with associated myalgias warranted admission to hospital. She was found to have rhabdomyolysis that was managed conservatively with a full recovery of several weeks. She was thoroughly investigated for any underlying cause, including genetic testing for malignant hyperthermia susceptibility (she had a variant of unknown significance but was negative for the known genetic abnormalities that cause malignant hyperthermia). CONCLUSION: This case report demonstrates the importance of considering anesthesia-associated rhabdomyolysis as a differential for acute postoperative weakness, and outlines an investigative approach. To the best of our knowledge, it is the first case described in the pediatric literature to report biphasic progression of symptoms.

Intravenous dantrolene in hypermetabolic syndromes: a survey of the U.S. Veterans Health Administration database.

BACKGROUND: Intravenous dantrolene is often prescribed for hypermetabolic syndromes other than the approved indication of malignant hyperthermia (MH). To clarify the extent of and indications for dantrolene use in conditions other than MH, we sought to document current practices in the frequency, diagnoses, clinical characteristics and outcomes associated with dantrolene treatment in critical care settings. METHODS: Inpatients receiving intravenous dantrolene from October 1, 2004 to September 30, 2014 were identified retrospectively in the U.S. Veterans Health Administration national database. Extracted data included; diagnoses of hypermetabolic syndromes; triggering drugs; dantrolene dosages; demographics; vital signs; laboratory values; in-hospital mortality; complications; and lengths of stay. Frequency and mortality of patients who did not receive dantrolene were obtained in selected diagnoses for exploratory comparisons. RESULTS: Dantrolene was administered to 304 inpatients. The most frequent diagnoses associated with dantrolene treatment were neuroleptic malignant syndrome (NMS; N = 108, 35.53%) and sepsis (N = 47, 15.46%), with MH accounting for only 13 (4.28%) cases. Over half the patients had psychiatric comorbidities and received psychotropic drugs before dantrolene treatment. Common clinical findings in patients receiving dantrolene included elevated temperature (mean ± SD; 38.7 ± 1.3 °C), pulse (116.33 ± 22.80/bpm), respirations (27.75 ± 9.58/min), creatine kinase levels (2,859.37 ± 6,646.88 IU/L) and low pO2 (74.93 ± 40.16 mmHg). Respiratory, renal or cardiac failure were common complications. Mortality rates in-hospital were 24.01% overall, 7.69% in MH, 20.37% in NMS and 42.55% in sepsis, compared with mortality rates in larger and possibly less severe groups of unmatched patients with MH (5.26%), NMS (6.66%), or sepsis (41.91%) who did not receive dantrolene. CONCLUSIONS: In over 95% of cases, dantrolene administration was associated with diagnoses other than MH in critically-ill patients with hypermetabolic symptoms and medical and psychiatric comorbidities. Exploratory survey data suggested that the efficacy and safety of dantrolene in preventing mortality in hypermetabolic syndromes other than MH remain uncertain. However, randomized and controlled studies using standardized criteria between groups matched for severity are essential to guide practice in using dantrolene.

Effects of Short-Acting Opioids on Intraocular Pressure during General Anesthesia: Systematic Review and Network Meta-Analysis.

Intraocular pressure (IOP) is crucial to the well-being of eyes. During anesthesia, the administration of succinylcholine and endotracheal intubation are associated with an increase in IOP, which may be attenuated by short-acting opioids. However, the drug of choice among the commonly used short-acting opioids is unclear. This study aimed to evaluate the effects of fentanyl, sufentanil, alfentanil, and remifentanil on IOP measured after the administration of succinylcholine and after endotracheal intubation in patients undergoing general anesthesia. Five databases were searched. Randomized controlled trials (RCTs) that compared short-acting opioids and reported at least one of the clinical outcomes of interest were included. Nine RCTs with 357 patients were included. Remifentanil (1 µg kg-1) more effectively alleviated the increase in IOP than the placebo after the administration of succinylcholine [mean difference (MD) of IOP, -3.64; confidence interval (CI), -5.47 to -1.81 and after endotracheal intubation (MD, -9.71; CI, -11.91 to -7.51). Remifentanil (1 µg kg-1) ranked the best in terms of both attenuating the increase in IOP after the administration of succinylcholine [surface under the cumulative ranking curve (SUCRA), 0.91; normalized entropy (NE), 0.47; and after endotracheal intubation (SUCRA, 0.89; NE, 0.54) among all of the treatments. Remifentanil (1 µg kg-1) should be considered the drug of choice in the circumstances where increased IOP is a great concern.