Peri-mortem rigidity in a fatal case of severe salicylate poisoning.

INTRODUCTION: There has been a previous case report of peri-arrest muscle rigidity in the setting of severe salicylate poisoning (serum salicylate concentration 1,500 mg/L), described as paratonia or rapid rigor mortis. We present an image of rapid rigor mortis in another fatal salicylate poisoning. CASE SUMMARY: We report a 42-year-old male with severe salicylate poisoning (peak salicylate concentration 1,600 mg/L). During the peri-arrest period, the patient developed isotonic flexion of the upper and lower extremities, the clinical signs of rapid-occurring rigor mortis. Despite resuscitative efforts, the patient died. IMAGE: Our patient is exhibiting peri-arrest rigidity in the upper extremities. DISCUSSION: Peri-mortem rigidity is due to depletion of adenosine triphosphate. Severe salicylate poisoning causes uncoupling of oxidative phosphorylation which prevents the production of adenosine triphosphate, which is required to release myosin from actin to allow the muscle to relax. A limitation of our report is that we did not definitively exclude other uncouplers of oxidative phosphorylation, such as 2,4-dinitrophenol. However, the history of aspirin ingestion was provided by the patient and corroborated by his mother, and it was confirmed by measurement of his salicylate concentration. CONCLUSION: We hypothesize that in our patient, rapid-occurring rigor mortis likely resulted from depletion of adenosine triphosphate. This occurred as a result of uncoupling of oxidative phosphorylation in the mitochondria from severe salicylate poisoning, as adenosine triphosphate is required for muscle relaxation.

Fentanyl-induced muscle rigidity in a dog during weaning from mechanical ventilation after emergency abdominal surgery: A case report.

A 22.5-kg, 8.4-year-old female mixed breed dog was presented for an emergency ovariohysterectomy for pyometra. No neurological abnormalities were observed on preoperative physical examination. Surgery was completed uneventfully under fentanyl- and sevoflurane-based anaesthesia. Cardiorespiratory indices remained stable under mechanical ventilation throughout the procedure. Approximately 23 min after the discontinuation of fentanyl infusion, the investigator noticed jaw closure and stiffness and thoraco-abdominal muscle rigidity. To rule out fentanyl-induced muscle rigidity, naloxone was administered. Following administration of naloxone, there was a return of spontaneous respiratory effort, indicated by capnogram and visible chest wall excursion. Based on the clinical signs and response to naloxone administration, the dog was diagnosed with suspected fentanyl-induced muscle rigidity. Six minutes after the return of spontaneous respiration, the dog was extubated uneventfully without additional naloxone administration. During 4 days of postoperative hospitalization, no recurrent muscle rigidity was observed, and the patient was discharged safely. The total dose of fentanyl administered was 0.61 mg (27 µg kg-1 ).

Age-Specific Clinical Features of Pediatric Malignant Hyperthermia: A Review of 187 Cases Over 60 Years in Japan.

BACKGROUND: Malignant hyperthermia (MH) is an inherited muscle disorder induced by volatile anesthetics and depolarizing muscle relaxants. While the incidence of MH is high in young, there are few reports on the clinical features of pediatric MH. In this study, we selected pediatric cases from an MH database and analyzed the clinical findings by age group. We hypothesized that there would be age-related differences in the clinical characteristics. METHODS: A retrospective analysis of MH data collected in our database during 1960 to 2020 was performed to identify pediatric subjects (≤18 years) with a Clinical Grading Scale of ≥35, indicating "very likely" or "almost certain" MH. We compared clinical characteristics among the 0 to 24 month, 2 to 12 year, and 13 to 18 year (youngest, middle, and oldest, respectively) age groups. RESULTS: Data were available for 187 patients: 15 in the youngest age group, 123 in the middle-aged group, and 49 in the oldest age group. Of these, 55 patients (29.4%) had undergone muscle biopsy and muscle contracture test. The mortality rates during the study period were 13.3%, 13.8%, 20.4%, and 15.5% in the youngest, middle, and oldest cohorts and overall, respectively. In contrast, the overall mortality rate from 2000 to 2020 was 8.8%. The most frequent initial symptoms of MH were elevated temperature (46.7%) and generalized muscular rigidity (26.7%) in the youngest cohort, masseter spasm (35.0%) and generalized muscular rigidity (19.5%) in the middle cohort, and elevated end-tidal carbon dioxide (26.5%) and tachycardia (22.4%) in the oldest cohort. Physical examination revealed that elevated temperature, sinus tachycardia, and respiratory acidosis occurred frequently in all groups. The middle cohort had high frequencies of masseter spasm (58.4%; P = .02) and dark urine (75.5%; P = .01) compared to those in the oldest groups, and had a higher peak creatine kinase level compared to those in the 3 groups. Skeletal muscle symptoms tended to be more common in patients administered succinylcholine (generalized muscular rigidity, P = .053; masseter spasm, P < .0001; dark urine, P < .0001). In particular, masseter spasm and dark urine were more common in the middle cohort when succinylcholine was administered (masseter spasm: versus youngest cohort, P = .06, versus oldest cohort, P = .027; dark urine: versus youngest cohort, P = .0072, versus oldest cohort, P = .0015). CONCLUSIONS: The clinical characteristics of pediatric patients with MH vary according to age group. The difference in initial symptoms of MH depending on age group is noteworthy information for the early diagnosis of MH.

Atypical Neuroleptic Malignant Syndrome: Case Reports and Diagnostic Challenges.

Neuroleptic malignant syndrome caused by atypical antipsychotic drugs may present in an atypical manner without symptoms such as hyperthermia and/or muscle rigidity. A detailed description of atypical neuroleptic malignant syndrome induced by atypical antipsychotic drugs, practical information to distinguish neuroleptic malignant syndrome from other related conditions, and the diagnostic criteria that may be used to settle the diagnosis of atypical neuroleptic malignant syndrome are highlighted in this paper. This study was conducted searching PubMed and Science Direct, resulting in 525 articles. 26 case reports that met inclusion criteria were identified. Atypical neuroleptic malignant syndrome was found to develop mainly in male patients suffering from schizophrenia (14 cases) and bipolar disorder (2), and was induced by clozapine (6 cases), olanzapine (5 cases), aripiprazole and quetiapine (4 cases). Muscle rigidity did not develop in patients treated with clozapine and quetiapine, whereas a lack of hyperthermia was common with aripiprazole and clozapine treatment. Atypical neuroleptic malignant syndrome is a difficult matter, especially when symptoms of hyperthermia or muscle rigidity is lacking, but using Levenson's or Adityanjee and Aderibigbe's criteria may increase it detectability, can permit earlier intervention and prevent development of life-threatening typical neuroleptic malignant syndrome.

Wooden Chest syndrome: The atypical pharmacology of fentanyl overdose.

WHAT IS KNOWN AND OBJECTIVE: A large percentage of opioid overdose fatalities involve fentanyl or one of its legal or illegal analogs (F/FAs). Is there something about the pharmacology of these drugs that make them unusually dangerous in an overdose? COMMENT: Some of the reasons for the dangers of overdose of F/FAs is their high potency and low cost (that leads to wide distribution). But it is rarely asked if the basic pharmacology of F/FAs differ in some fundamental way from conventional opioids such as morphine and heroin. In addition to centrally mediated respiratory depression via opioid receptors, F/FAs cause rigidity in the key respiratory muscles of the chest, upper airway and diaphragm ("wooden chest syndrome," WCS) by a non-opioid mechanism. WHAT IS NEW AND CONCLUSION: WCS is an atypical pharmacology of F/FAs. Because of its rapid onset and non-opioid mechanism, WCS makes F/FA overdose particularly dangerous.

Wooden Chest Syndrome: A Case Report of Fentanyl-Induced Chest Wall Rigidity.

Wooden chest syndrome (WCS) describes a finding of fentanyl-induced skeletal muscle rigidity causing ventilatory failure. Known primarily to anesthesiology, pulmonary, and critical care fields, WCS is a rare complication that may affect patients of all ages if exposed to intravenous fentanyl, characterized by a patient's inability to properly ventilate. Given the rise of synthetic opioid deaths across the United States in the past decade, an understanding of all of fentanyl's effects on the body is necessary. In this article, we present a case of WCS in a patient with acute respiratory distress syndrome in a 61-year-old female.

Overdoses due to fentanyl and its analogues (F/FAs) push naloxone to the limit.

WHAT IS KNOWN AND OBJECTIVE: Food and Drug Administration (FDA) risk evaluation and mitigation strategies (REMs) encourage emergency responders, paramedics, law enforcement agents, and even laypeople to be trained in the administration of naloxone with the intent of rescuing individuals from a known or suspected opioid overdose. COMMENT: Although naloxone is generally safe and effective at reversing respiratory depression caused by a conventional opioid such as morphine or heroin by competing with the opioid and displacing it from the µ-opioid receptor, questions increasingly are arising as to whether naloxone can adequately reverse opioid overdoses that may involve the potent opioids fentanyl and its analogues (F/FAs). In other words, as more and more opioid overdoses involve F/FAs, can naloxone keep up? WHAT IS NEW AND CONCLUSION: As a competitive antagonist at µ-opioid receptors, naloxone is often a life-saving agent in cases of overdose caused by conventional opioids, but it may not be versatile or powerful enough to combat the rising tide of overdoses due to fentanyl and its illicit analogues, or in cases of overdose involving combinations of opioids and non-opioids.

Suspected Succinylcholine-Induced Masseter Muscle Rigidity During Rapid Sequence Intubation in the Air Medical Setting.

Trismus, or masseter muscle rigidity, is a rare but previously described complication of succinylcholine-induced neuromuscular blockade. We present a case report that details unique aspects of suspected masseter muscle rigidity in the prehospital setting air medical setting after attempted rapid sequence intubation with succinylcholine. We then discuss the need for knowledge base of this life-threatening and rarely described syndrome as well as the importance of working through a differential diagnosis and specific trismus-focused airway algorithm. Trismus, or masseter muscle rigidity (MMR), is a rare but previously described complication of succinylcholine-induced neuromuscular blockade. It has been cited in anesthesia and emergency medicine literature as a potentially life-threatening complication and requires prompt intervention. This case report details a unique case of suspected MMR in the prehospital setting after attempted rapid sequence intubation (RSI) with succinylcholine performed by an experienced aeromedical flight crew.

Wooden chest syndrome: Beware of opioid antagonists, not just agonists.

BACKGROUND: In a constantly increasing world of opioid addiction, naloxone has become a topic of great discussion and use. With seemingly minimal side effects, naloxone has become one of the most wellknown and widely used reversal agents for opioid intoxication. While more common effects of using naloxone include agitation, abdominal cramps, piloerection, diarrhea, nausea, and yawning, lesser known side effects involve muscle spasms, flushing, hyperreflexia in neonates, and seizures. This case study demonstrates a side effect of rigidity secondary to IV naloxone that has not previously been documented. CASE: A 56 year old man was brought in by EMS after being found unresponsive in a car with a bag of drugs beside him. He was given 0.5 mg naloxone IV by EMS and immediately brought to the hospital. On arrival, the pt was noted to have tight rigidity of his upper extremities, with severe flexion. This presentation was not noted before the delivery of naloxone by EMS. CONCLUSIONS: While this case highlights a patient with a rare side effect of naloxone, it reminds physicians that all medications come with a cost. Of course, ABCs remain the highest priority of resuscitation, however when administering a medication to reverse a drug overdose, it is important to keep in mind all possible consequences of said agent. Recognizing that complete muscle rigidity may remain a result of naloxone administration allows physicians to perhaps save patients from further medical workup.

Noradrenergic Mechanisms in Fentanyl-Mediated Rapid Death Explain Failure of Naloxone in the Opioid Crisis.

In December 2018, the Centers for Disease Control declared fentanyl the deadliest drug in America. Opioid overdose is the single greatest cause of death in the United States adult population (ages 18-50), and fentanyl and its analogs [fentanyl/fentanyl analogs (F/FAs)] are currently involved in >50% of these deaths. Anesthesiologists in the United States were introduced to fentanyl in the early 1970s when it revolutionized surgical anesthesia by combining profound analgesia with hemodynamic stability. However, they quickly had to master its unique side effect. F/FAs can produce profound rigidity in the diaphragm, chest wall and upper airway within an extremely narrow dosing range. This clinical effect was called wooden chest syndrome (WCS) by anesthesiologists and is not commonly known outside of anesthesiology or to clinicians or researchers in addiction research/medicine. WCS is almost routinely fatal without expert airway management. This review provides relevant clinical human pharmacology and animal data demonstrating that the significant increase in the number of F/FA-induced deaths may involve α-adrenergic and cholinergic receptor-mediated mechanical failure of the respiratory and cardiovascular systems with rapid development of rigidity and airway closure. Although morphine and its prodrug, heroin, can cause mild rigidity in abdominal muscles at high doses, neither presents with the distinct and rapid respiratory failure seen with F/FA-induced WCS, separating F/FA overdose from the slower onset of respiratory depression caused by morphine-derived alkaloids. This distinction has significant consequences for the design and implementation of new pharmacologic strategies to effectively prevent F/FA-induced death. SIGNIFICANCE STATEMENT: Deaths from fentanyl and F/FAs are increasing in spite of availability and awareness of the opioid reversal drug naloxone. This article reviews literature suggesting that naloxone may be ineffective against centrally mediated noradrenergic and cholinergic effects of F/FAs, which clinically manifest as severe muscle rigidity and airway compromise (e.g., wooden chest syndrome) that is rapid and distinct from respiratory depression seen with morphine-derived alkaloids. A physiologic model is proposed and implications for new drug development and treatment are discussed.

Parkinsonism Relating to Intoxication with Glyphosate.

We herein report the case of a 38-year-old man who developed parkinsonism 4 years after ingesting glyphosate. The patient presented with right-sided bradykinesia and cogwheel rigidity without autonomic symptoms. Magnetic resonance imaging of the brain and [123I]-metaiodobenzylguanidine myocardial scintigraphy were normal. A drastic response to levodopa and the presence of levodopa-induced dyskinesia without strong non-motor symptoms were seen in this patient. We considered that young-onset atypical parkinsonism was associated with a history of sublethal glyphosate ingestion. Epidemiologic investigations have shown that exposure to pesticides is a risk factor for Parkinson's disease (PD). Our findings support the notion that glyphosate exposure might be related to the onset of PD.

Rigidity, dyskinesia and other atypical overdose presentations observed at a supervised injection site, Vancouver, Canada.

OBJECTIVE: In midst of the overdose crisis, the clinical features of opioid overdoses seem to be changing. Understanding of the adverse effects of synthetic opioids such as fentanyl is currently limited to clinical settings. Insite, a supervised injection site in Vancouver, Canada, provides an opportunity to better understand illicit drug overdose presentations. METHODS: A review of clinical records at Insite for October 2016 to April 2017 was undertaken to quantify atypical overdose presentations. Overdose reports were reviewed for the number of atypical opioid overdose presentations, temporal trends over the study period, concurrent symptoms, and interventions employed by staff. RESULTS: Insite staff responded to 1581 overdoses during the study period, including 497 (31.4%) that did not fit a typical presentation for opioid overdoses. Of these, 485 fit into five categories of atypical features: muscle rigidity, dyskinesia, slow or irregular heart rate, confusion, and anisocoria. Muscle rigidity was the most common atypical presentation, observed in 240 (15.2%) of the overdose cases, followed by dyskinesia, observed in 150 (9.2%). Slow or irregular heart rate was observed in 69 (4.4%) cases, confusion in 24 (1.5%), and anisocoria in 2 (0.1%) of overall overdose cases. DISCUSSION: The similarity of atypical overdose cases at Insite with anesthesiology case reports supports the understanding that the illicit drug supply is contaminated by fentanyl and other synthetic opioids. Atypical overdose presentations can affect clinical overdose response. The experience at Insite highlights the potential for supervised consumption sites to be innovative spaces for community learning and knowledge translation.

Contracciones involuntarias, rigidez cervical grave y cervicalgia tras la toma de metronidazol / Involuntary muscle contractions, severe neck stiffness and pain after taking Metronidazole

No disponible