Central Anticholinergic Syndrome: A Case Report

[Central anticholinergic, neuroleptic malignant and serotonin syndromes]

Impaired consciousness is a frequent phenomenon after general anesthesia. In addition to the classical causes (e.g., overhang of sedatives), an impairment of consciousness can also be an adverse side effect of drugs. Many drugs used in anesthesia can trigger these symptoms. Alkaloids, such as atropine can trigger a central anticholinergic syndrome, opioids can promote the occurrence of serotonin syndrome and the administration of a neuroleptic can lead to neuroleptic malignant syndrome. These three syndromes are difficult to diagnose due to the individually very heterogeneous symptoms. Mutual symptoms, such as impaired consciousness, tachycardia, hypertension and fever further complicate the differentiation between the syndromes; however, more individual symptoms, such as sweating, muscle tension or bowl sounds can be helpful in distinguishing these syndromes. The time from the trigger event can also help to differentiate the syndromes. The central anticholinergic syndrome is the fastest to appear, usually taking just a few of hours from trigger to clinical signs, serotonin syndrome takes several hours up to 1 day to show and neuroleptic malignant syndrome usually takes days. The clinical symptoms can range from mild to life-threatening. Generally, mild cases are treated with discontinuation of the trigger and extended observation. More severe cases can require specific antidotes. The specific treatment recommended for central anticholinergic syndrome is physostigmine with an initial dose of 2 mg (0.04 mg/kg body weight, BW) administered over 5 min. For serotonin syndrome an initial dose of 12 mg cyproheptadine followed by 2 mg every 2 h is recommended (maximum 32 mg/day or 0.5 mg/kgBW day-1) but this medication is only available in Germany as an oral formulation. For neuroleptic malignant syndrome 25-120 mg dantrolene (1-2.5 mg/kgBW maximum 10 mg/kgBW day-1) is the recommended treatment.

[Central anticholinergic, neuroleptic malignant and serotonin syndromes : Important differential diagnoses in postoperative impairment of consciousness]

Impaired consciousness is a frequent phenomenon after general anesthesia. In addition to the classical causes (e.g., overhang of sedatives), an impairment of consciousness can also be an adverse side effect of drugs. Many drugs used in anesthesia can trigger these symptoms. Alkaloids, such as atropine can trigger a central anticholinergic syndrome, opioids can promote the occurrence of serotonin syndrome and the administration of a neuroleptic can lead to neuroleptic malignant syndrome. These three syndromes are difficult to diagnose due to the individually very heterogeneous symptoms. Mutual symptoms, such as impaired consciousness, tachycardia, hypertension and fever further complicate the differentiation between the syndromes; however, more individual symptoms, such as sweating, muscle tension or bowl sounds can be helpful in distinguishing these syndromes. The time from the trigger event can also help to differentiate the syndromes. The central anticholinergic syndrome is the fastest to appear, usually taking just a few of hours from trigger to clinical signs, serotonin syndrome takes several hours up to 1 day to show and neuroleptic malignant syndrome usually takes days. The clinical symptoms can range from mild to life-threatening. Generally, mild cases are treated with discontinuation of the trigger and extended observation. More severe cases can require specific antidotes. The specific treatment recommended for central anticholinergic syndrome is physostigmine with an initial dose of 2 mg (0.04 mg/kg body weight, BW) administered over 5 min. For serotonin syndrome an initial dose of 12 mg cyproheptadine followed by 2 mg every 2 h is recommended (maximum 32 mg/day or 0.5 mg/kgBW day^-1) but this medication is only available in Germany as an oral formulation. For neuroleptic malignant syndrome 25-120 mg dantrolene (1-2.5 mg/kgBW maximum 10 mg/kgBW day^-1) is the recommended treatment.

Malignant syndromes: current advances

Introduction: Many drugs are known to induce malignant syndromes. The most common malignant syndromes are induced by the use of antipsychotics and anesthetics and the withdrawal of anti-Parkinson drugs. As the clinical manifestations of antipsychotic malignant syndrome, Parkinson's disease hyperpyrexia syndrome and anesthetic-induced malignant syndrome are very similar, they are easily confused in the clinic.Areas covered: We reviewed articles published between 1960 and April 2021 describing malignant syndromes. This paper provides a detailed literature review of malignant syndromes and important guidance for the diagnosis and treatment of malignant syndromes to clinicians.Expert opinion: Although malignant syndromes are rare conditions with a low incidence, these conditions usually progress rapidly and can endanger patients' lives, meriting attention from clinicians. The typical clinical manifestations of malignant syndromes are hyperpyrexia, muscular rigidity, an altered mental status and increased levels of creatine kinase; however, the pathophysiology, treatment and prognosis of different malignant syndromes are quite different. Prompt diagnosis and treatment may significantly improve the prognosis of patients with malignant syndromes.

Scopolamine Toxicity in an Elderly Patient

We present a case of a 66-year-old female who was to undergo a scheduled operation and placed on our institution’s ERAS (Enhanced Recovery After Surgery) protocol. The intraoperative course was unremarkable. The patient developed delayed emergence in the Post-Anesthesia Care Unit. On physical exam, the patient was noted to have a transdermal scopolamine patch adjacent to an area of skin breakdown. She also displayed signs of central anti-cholinergic toxicity including mydriasis and tachycardia. Following removal of the scopolamine patch and administration of physostigmine, her mental status returned to baseline. This interesting case highlights the importance of considering patient specific factors such as age when implementing ERAS protocols perioperatively. It also demonstrates the risks associated with scopolamine and the importance of risk/benefit analysis prior to administration.

Central anticholinergic syndrome vs. idiosyncratic reaction triggered by a small IV dose of atropine

A 58-year-old male was scheduled to undergo radical gastrectomy for cancer under general anesthesia. The patient developed agitation and irregular breathing after receiving a single dose of atropine (0.5 mg) to treat bradycardia immediately prior to induction of anesthesia. Within 5 min after the atropine injection, the patient became unresponsive with facial flushing and diaphoresis. When a drop in oxygen saturation was observed, a laryngeal mask airway was inserted after administering a small bolus dose of propofol (80 mg) and the patient was ventilated with 100% oxygen. Physostigmine was not administered because of the relatively low dose of atropine and the fact that his symptoms were not totally consistent with central anticholinergic syndrome (CAS). The differential diagnosis at the time also included an acute cardiovascular event and an idiosyncratic reaction to atropine. The patient fully recovered within 80 min from this highly unusual reaction to a single 0.5 mg IV dose of atropine.

Effects of acetylcholinesterase inhibition on quality of recovery from isoflurane-induced anesthesia in horses

OBJECTIVE

To compare effects of 2 acetylcholinesterase inhibitors on recovery quality of horses anesthetized with isoflurane.

ANIMALS

6 horses in phase 1, 7 horses in phase 2A, and 14 horses in phase 2B.

PROCEDURES

The study comprised 3 phases (2 randomized, blinded crossover phases in horses undergoing orthopedic procedures and 1 prospective dose-determining phase). In phase 1, horses were anesthetized with isoflurane and received neostigmine or saline (0.9% NaCl) solution prior to anesthetic recovery. Phase 2A was a physostigmine dose-determining phase. In phase 2B, horses were anesthetized with isoflurane and received neostigmine or physostigmine prior to recovery. Objective recovery events were recorded and subjective visual analogue scale scores of recovery quality were assigned from video recordings.

RESULTS

Recovery measures in phase 1 were not different between horses receiving neostigmine or saline solution. In phase 2A, 0.04 mg of physostigmine/kg was the highest cumulative dose that did not cause clinically relevant adverse behavioral or gastrointestinal effects. Horses receiving physostigmine had higher mean ± SD visual analogue scale recovery scores (70.8 ± 13.3 mm) than did horses receiving neostigmine (62.4 ± 12.8 mm) in phase 2B, with fewer attempts until sternal and standing recovery. Incidence of colic behavior did not differ among groups.

CONCLUSIONS AND CLINICAL RELEVANCE

Inhibition with physostigmine improved anesthetic recovery quality in horses anesthetized with isoflurane, compared with recovery quality for horses receiving neostigmine. Inhibition of central muscarinic receptors by inhalation anesthetics may underlie emergence delirium in horses recovering from anesthesia.

An interesting case of serotonin syndrome precipitated by escitalopram

Serotonin syndrome is a known entity, which occurs with multiple drugs acting on serotonergic receptors. A 73-year-old lady presented with a history of agitation, altered sensorium, and autonomic hyperactivity after starting escitalopram on therapeutic dosage for her depressive syndrome who was on selegiline for her parkinsonism. This syndrome with therapeutic dose escitalopram warrants the careful and judicious use of the drug especially with other serotonergic drugs, so that this serious medical complication can be avoided.

Comparison of the efficacy and impact on cognition of glycopyrrolate and biperiden for clozapine-induced sialorrhea in schizophrenic patients: a randomized, double-blind, crossover study

BACKGROUND

Clozapine-induced sialorrhea (CIS) is a subjective distressing adverse effect and occurs in 31%-57% of schizophrenic patients receiving clozapine therapy. Current pharmacotherapy on CIS has focused on anticholinergic agents, even though they may impair cognitive function. Previous case reports have suggested the benefit of glycopyrrolate or biperiden in treating this condition, but no randomized controlled trial has provided evidence. The objective of our study was to evaluate the efficacy and impact on cognition of glycopyrrolate and biperiden treatments for schizophrenic patients suffering from CIS.

METHODS

Patients who satisfied the inclusion criteria entered a 12-week, randomized, double-blind, crossover, fixed-dose trial. The study consisted of two 4-week crossover phases, which were separated by a 4-week washout period. Sialorrhea and global cognitive function were assessed by using a Drooling Rating Scale (DRS) and the Mini Mental State Examination (MMSE), respectively.

RESULTS

Throughout the study, patients treated with glycopyrrolate or biperiden had significantly reduced DRS scores. Moreover, the DRS scores were significantly lower with glycopyrrolate treatment than with biperiden. In other respects, there were no significant differences in MMSE scores in patients treated with glycopyrrolate. However, we found a significant reduction in MMSE scores in patients treated with biperiden.

CONCLUSION

We provide evidence, for the first time, of the efficacy of glycopyrrolate and biperiden in the treatment of CIS. Furthermore, glycopyrrolate displays less impact on cognitive function. Consequently, glycopyrrolate can become a valid option for treating CIS. Observations from our study serve as a springboard for additional large-scale prospective trials.

Postoperative delirium in the elderly: diagnosis and management

Delirium is a common but often undiagnosed complication in the elderly following a major operation. Recognizing the presentation of delirium and the criteria to establish the diagnosis of delirium will improve a clinician’s ability to detect this complication. Treating delirium with environmental, supportive, and pharmacologic interventions reduces the incidence and side effects of postoperative delirium. The purpose of this review is to describe the diagnosis and treatment of postoperative delirium.