Serotonin syndrome after therapeutic hypothermia for cardiac arrest: a case series

Dexmedetomidine in the treatment of toxicologic conditions: a systematic review and review of the toxicology investigators consortium database

INTRODUCTION

Dexmedetomidine is an alpha-2 adrenoceptor agonist which is widely used for sedation. Dexmedetomidine does not suppress the respiratory drive and produces a state of cooperative sedation; it may be associated with beneficial outcomes in the general critical care population. The role of dexmedetomidine in the treatment of toxicologic conditions (excluding alcohol withdrawal) is unclear.

OBJECTIVES

To critically assess and summarize the literature regarding the use of dexmedetomidine in toxicologic conditions other than alcohol withdrawal.

METHODS

We performed a systematic review of the medical literature to identify all existing evidence regarding the use of dexmedetomidine for toxicologic conditions. We excluded reviews and commentary, studies reporting exclusively on alcohol withdrawal, and studies reporting the use of dexmedetomidine to treat iatrogenic sedative withdrawal in the intensive care unit. We also performed a review of the Toxicology Investigators Consortium (ToxIC) database for patients treated with dexmedetomidine.

RESULTS

We identified 98 studies meeting inclusion criteria; 87 of these were case reports or case series, representing 99 unique cases. Eleven articles with other designs were identified, which included 138 patients treated with dexmedetomidine for toxicologic conditions. Ninety-three cases from the ToxIC registry met inclusion criteria. Common indications for dexmedetomidine included stimulant intoxication, sedative withdrawal, serotonin syndrome, antimuscarinic toxidrome, opioid withdrawal, and cannabinoid intoxication. Dexmedetomidine was usually administered by continuous infusion; bolus administration was reported in a minority of cases. Adverse effects were uncommon. The quality of evidence was generally low, given the preponderance of case reports, the rate of missing or poorly reported data, and the near-universal co-administration of other sedatives.

TREATMENT OF STIMULANT POISONING

Fifty-nine patients with stimulant poisoning were treated with dexmedetomidine. There was reasonably good evidence that dexmedetomidine was helpful in the treatment of stimulant poisoning.

TREATMENT OF SEDATIVE WITHDRAWAL

Twenty-two patients with sedative withdrawal were treated with dexmedetomidine. Several case reports of very high-quality suggested efficacy of dexmedetomidine for this indication, particularly for baclofen withdrawal.

TREATMENT OF SEROTONIN SYNDROME

Twenty-six patients with serotonin syndrome were treated with dexmedetomidine. This evidence was of lower quality due to missing clinical details, potential overdiagnosis of serotonin syndrome, and near-universal concomitant treatment with other sedatives.

TREATMENT OF ANTIMUSCARINIC POISONING

Forty-two patients with antimuscarinic poisoning were treated with dexmedetomidine. This evidence was of low quality and was limited by infrequent use of the preferred antidote, physostigmine.

TREATMENT OF OPIOID WITHDRAWAL

Forty-four patients with opioid withdrawal were treated with dexmedetomidine. This evidence was of low quality due to missing clinical details and near-universal concomitant treatment with other agents. The one high-quality trial reported the use of dexmedetomidine in ultra-rapid opioid detoxification, which is not indicated in modern practice.

TREATMENT OF CANNABINOID INTOXICATION

Five patients with cannabinoid intoxication were treated with dexmedetomidine. No definite conclusion can be drawn from the limited available evidence.

DISCUSSION

It is important to distinguish between the use of dexmedetomidine as a general sedative, which is likely to increase as the overall utilization of dexmedetomidine in critical care settings increases, and the use of dexmedetomidine as a specific pharmacologic treatment for a toxicologic condition. Well-established pharmacologic data from animal and human studies suggest dexmedetomidine counteracts stimulant-induced norepinephrine release. The mechanism by which dexmedetomidine treats sedative withdrawal is unclear. Some animal data show that dexmedetomidine may indirectly suppress serotonin release, which may suggest a role for dexmedetomidine in this condition.

CONCLUSIONS

There is a small and generally low-quality body of evidence which suggests that dexmedetomidine may be helpful in the treatment of certain toxicologic conditions, particularly stimulant intoxication and sedative withdrawal. Further high-quality research is needed to clarify the role of dexmedetomidine in patients with toxicologic conditions.

Management of severe arterial hypertension associated with serotonin syndrome: a case report analysis based on systematic review techniques

Serotonin syndrome is thought to arise from serotonin excess. In many cases, symptoms are mild and self-limiting. But serotonin syndrome can become life threatening, when neuromuscular hyperexcitability spins out of control. Uncontainable neuromuscular hyperexcitability may lead to cardiovascular complications, linked to extreme changes in blood pressure. Currently, there is little guidance on how to control blood pressure in hyperserotonergic states. We report a case with treatment-resistant arterial hypertension, followed by a clinical review (using systematic review principles and techniques) of the available evidence from case reports published between 2004 and 2016 to identify measures to control arterial hypertension associated with serotonin syndrome. We conclude that classic antihypertensives may not be effective for the treatment of severe hypertension associated with serotonin syndrome. Benzodiazepines may lower blood pressure. Patients with severe hypertension not responding to benzodiazepines may benefit from cyproheptadine, propofol or both. In severe cases, higher cyproheptadine doses than currently recommended may be necessary.

Serotonin syndrome: a spectrum of toxicity

Serotonin syndrome (serotonin toxicity or serotonin toxidrome) is a potentially serious and theoretically predictable reaction that appears to be rarely diagnosed in practice in the UK. Some symptoms of serotonin syndrome overlap with features of other presentations in psychiatry and thus may be misattributed to mental illness (‘diagnostic overshadowing’). Further, there may be diagnostic dilemmas in patients on combinations of drugs, those receiving drugs with previously unknown serotonergic properties or where there are drug interactions. Prescriber vigilance and holistic review of the patient, including the pharmacotherapy, may be helpful in avoiding progression of serotonin syndrome to more serious outcomes.

Post-ischemic Myoclonic Status Following Cardiac Arrest in Young Drug Users

BACKGROUND

Myoclonic status may be observed following cardiac arrest and has previously been identified as a poor prognostic indicator in regard to return of neurologic function. We describe a unique situation in post-cardiac arrest patients with myoclonic status and hypothesize possible predictors of a good neurologic outcome.

METHODS

Case series.

RESULTS

We illustrate two cases of cardiac arrest due to a respiratory cause in young patients with evidence of illicit drug use at the time of hospital admission that suffered post-ischemic myoclonic status. These patients subsequently recovered with good neurologic outcomes.

CONCLUSIONS

On rare occasions, myoclonic status does not imply a poor functional outcome following cardiac arrest. Other clinical and demographic characteristics including young age, presence of illicit substances, and primary respiratory causes of arrest may contribute to a severe clinical presentation, with a subsequent good neurologic outcome in a small subset of patients.

Rhabdomyolysis Secondary to Therapeutic Hypothermia After Cardiopulmonary Resuscitation: A Rare Complication

Patient maintenance after successful cardiopulmonary resuscitation starts with decreasing the neurological damage despite serious difficulties such as hypoxic ischemic infarcts and reperfusion infarcts. Therapeutic hypothermia is the most rejoicing method in use to prevent neurological damage. Here, we discuss about a 35-year-old woman resuscitated for 20 minutes in hospital who was followed because of postpartum cardiomyopathy. Sudden onset of ventricular fibrillation subsequent to ventricular tachycardia was the underlying cause of cardiac arrest. To prevent neurological damage, therapeutic hypothermia was used, and she was cooled for 24 hours. After therapeutic hypothermia, her Glasgow coma score was 15, fortunately no sequela appeared. Although we were successful to prevent neurological damage, rhabdomyolysis arose secondary to therapeutic hypothermia. As a result, the intubation process was prolonged, and acute tubular necrosis due to myoglobinuria was occurred. Despite all complications patient faced, she was discharged on her 31th day; without sequela and with no need for hemodialysis; under medical therapy.