Concept of the five 'A's for treating emergency arrhythmias

Acute Cardiovascular and Cardiorespiratory Effects of JWH-018 in Awake and Freely Moving Mice: Mechanism of Action and Possible Antidotal Interventions?

JWH-018 is the most known compound among synthetic cannabinoids (SCs) used for their psychoactive effects. SCs-based products are responsible for several intoxications in humans. Cardiac toxicity is among the main side effects observed in emergency departments: SCs intake induces harmful effects such as hypertension, tachycardia, chest pain, arrhythmias, myocardial infarction, breathing impairment, and dyspnea. This study aims to investigate how cardio-respiratory and vascular JWH-018 (6 mg/kg) responses can be modulated by antidotes already in clinical use. The tested antidotes are amiodarone (5 mg/kg), atropine (5 mg/kg), nifedipine (1 mg/kg), and propranolol (2 mg/kg). The detection of heart rate, breath rate, arterial oxygen saturation (SpO2), and pulse distention are provided by a non-invasive apparatus (Mouse Ox Plus) in awake and freely moving CD-1 male mice. Tachyarrhythmia events are also evaluated. Results show that while all tested antidotes reduce tachycardia and tachyarrhythmic events and improve breathing functions, only atropine completely reverts the heart rate and pulse distension. These data may suggest that cardiorespiratory mechanisms of JWH-018-induced tachyarrhythmia involve sympathetic, cholinergic, and ion channel modulation. Current findings also provide valuable impetus to identify potential antidotal intervention to support physicians in the treatment of intoxicated patients in emergency clinical settings.

Efficacy of topical chamomile on the incidence of phlebitis due to an amiodarone infusion in coronary care patients: a double-blind, randomized controlled trial

BACKGROUND

Amiodarone is a useful antiarrhythmic drug. Phlebitis, caused by intravenous amiodarone, is common in patients in coronary care units (CCUs).

OBJECTIVE

The aim of this study was to evaluate the effect of topical chamomile on the incidence of phlebitis due to the administration of an amiodarone infusion into the peripheral vein.

DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS

This was a randomized, double-blind clinical trial, conducted on 40 patients (n = 20 per group) in two groups-an intervention group (chamomile ointment) and a control group (lanoline, as a placebo), hospitalized in the CCUs and undergoing an amiodarone infusion into the peripheral vein over 24 h. Following the cannulation and commencement of the infusion, placebo or chamomile ointment was rubbed in, up to 10 cm superior to the catheter and repeated every eight hours for three days. The cannula site was then assessed based on the phlebitis checklist.

MAIN OUTCOME MEASURES

The incidence and time of occurrence of phlebitis, relative risk, severity of phlebitis were the main outcome measures.

RESULTS

Nineteen patients (19/20) in the control group had phlebitis on the first day of the study and one patient (20/20) on the second day. In the intervention group, phlebitis occurred in 13 cases (13/20) on the first day and another two (2/7) was found on the second day. The incidence of phlebitis was significantly different between two groups (P = 0.023). The cumulative incidence of phlebitis in the intervention group (15/20) is significantly later and lower than that in the control group (20/20) during two days (P = 0.008). Two patients in the intervention group did not develop phlebitis at all during the 3-day study. Also, the relative risk of phlebitis in the two groups was 0.68 (P = 0.008 5). A significant difference was not observed with regard to phlebitis severity in both groups.

CONCLUSION

It seems that phlebitis occurred to a lesser extent and at a later time frame in the intervention group compared to control group. Topical chamomile may be effective in decreasing the incidence of phlebitis due to an amiodarone infusion.

TRIAL REGISTRATION

This protocol was registered in the Iranian Registry of Clinical Trials (IRCT2014042017361N1).

[Incessant or recurrent ventricular tachycardia. Indications for emergency ablation]

Incessant ventricular tachycardia and "electrical storms" are emergencies, requiring urgent action in a close cooperation between critical care physicians and cardiologists. The leading cause of such events is advanced cardiac disease. Besides the patient's history, an ECG and, if applicable, an implantable cardioverter-defibrillator (ICD) interrogation is required for a reliable diagnosis. Further diagnostics include laboratory parameters, an echocardiogram, and possibly a coronary angiography. The medical therapy, consisting of amiodarone and β-blockers, should immediately be initiated after diagnosis. In the case of failed drug therapy, urgent catheter ablation is indicated. This is a complex procedure, in which the clinical tachycardia or the electrical substrate is modified by using an irrigated catheter. The acute success rate of this life-saving procedure is high. However, there might also be complications due to the required extensive procedures.

What an emergency physician needs to know about acute care of cardiac arrhythmias

The treat of cardiac arrhythmias has been studied extensively in the last decades. There has been a major shift in antiarrhythmia treatment from drugs to interventional electrophysiological procedures and implantable devices. Published data indicate that for long-term treatment of arrhythmias, non-pharmacological treatment is more effective than drugs in many patients. Similarly, the overhelming success of radiofrequency catheter ablation of supraventricular tachycardias has almost eliminated the need for chronic drug treatment. Today, catheter ablation plays an increasingly important role in the prevention of atrial fibrillation recurrences. However, in the emergency room or in the intensive care unit, drug treatment remains the gold standard for the treatment of cardiac arrhythmias. Arrhythmias are very common in emergency medicine, occurring in 12% to 20% of all patients in an intensive care unit and there is great need for good diagnostic and therapeutic algorithms to aid the emergency physician dealing with patients suffering from arrhythmias