Diazepam or midazolam for external DC cardioversion (The DORM Study)

Sedation in cardiac arrhythmias management

INTRODUCTION

Procedural sedation is of paramount importance for a plethora of electrophysiological procedures. From electrical cardioversion to electrophysiology studies, device implantations, and catheter ablations, intraprocedural sedation and anesthesia have a pivotal role in allowing procedural success while ensuring patient safety and avoiding discomfort. Areas covered: The present review will discuss the current state-of-the-art in sedation and anesthesia during electrical cardioversion, cardiac implantable electronic device implantation, catheter ablation and electrophysiology studies. Specific information will be provided for each procedure in order to reach the core of this important clinical issue, and specific protocols will be compared. The main pro-arrhythmic and anti-arrhythmic effects of the most commonly used sedatives will also be discussed. Expert commentary: According to much recent evidence, the cardiologist can be the only person responsible for sedation administration in many settings, highlighting few safety issues associated with the absence of a dedicated anesthesiologist thus a concomitant reduction in costs. However, many concerns have been raised in allowing non-anesthesiologists to manage sedatives, as adverse events, while rare, could have catastrophic consequences. The present paper will highlight when a cardiologist-directed sedation is considered safe, how it should be performed, and the pros and cons related to this strategy.

The use of conscious sedation in elective external direct current cardioversion: a single centre experience

External direct current (DC) cardioversion is a commonly used method of terminating atrial arrhythmias. The chance of procedural success is inversely related to the duration of the arrhythmia. In many hospitals, the procedure is carried out under general anaesthesia, necessitating the presence of anaesthetic as well as medical staff. Frequently, it may be difficult to coordinate the availability of the two teams, causing delays to each patient, waste of staff time, an inefficient service and increased costs. The primary aim of the study was to determine the safety and tolerability of conscious sedation using intravenous midazolam in elective external DC cardioversion of patients with atrial flutter or atrial fibrillation attending University Hospital Limerick, Ireland.

Patients who were electively admitted for DC cardioversion for atrial fibrillation or atrial flutter were recruited. A pre-defined sedation protocol using intravenous midazolam was used. The midazolam was given by the cardiology registrar without the presence of an anaesthetist. DC cardioversion was then performed according to the hospital protocol. Any complications arising during the procedure were noted. Prior to discharge, patients were given a questionnaire to determine their awareness of the procedure and if they would have the procedure done again in the future if needed.

A total of 100 patients were recruited. The median number of shocks was one (highest number of shocks being four). The median dose of midazolam was 7.5 mg, with the highest dose being 20 mg. All of patients surveyed were not aware of the shock that was administered to them. All of the patients surveyed were happy with the service and would be happy to return for a repeat cardioversion in the future if required.

The use of conscious sedation for DC cardioversion of patients with atrial fibrillation / atrial flutter was found to be safe and tolerable.

Anaesthetic and sedative agents used for electrical cardioversion

BACKGROUND

Electrical cardioversion is an effective procedure for restoring normal sinus rhythm in the hearts of patients with irregular heart rhythms. It is important that the patient is not fully conscious during the procedure, as it can be painful and distressing. The drug used to make patients unaware of the procedure should rapidly achieve the desired level of sedation, should wear off quickly and should not cause cardiovascular or respiratory side effects.

OBJECTIVES

We aimed to compare the safety, effectiveness and adverse events associated with various anaesthetic or sedative agents used in direct current cardioversion for cardiac arrhythmia in both elective and emergency settings.We sought answers to the following specific questions.• Which drugs deliver the best outcomes for patients undergoing electrical cardioversion?• Does using a particular agent confer advantages or disadvantages?• Is additional analgesic necessary to prevent pain?

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) on 27 March 2014. Our search terms were relevant to the review question and were not limited by outcomes. We also carried out searches of clinical trials registers and forward and backward citation tracking.

SELECTION CRITERIA

We considered all randomized controlled trials and quasi-randomized and cluster-randomized studies with adult participants undergoing electrical cardioversion procedures in the elective or emergency setting.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data, consulting with a third review author for disagreements. We used standard Cochrane methodological procedures, including assessment of risk of bias for all studies.

MAIN RESULTS

We included 23 studies with 1250 participants that compared one drug with one or more other drugs. Of these comparisons, 19 studies compared propofol with another drug. Seven of these compared propofol with etomidate (four of which combined the drugs with remifentanil or fentanyl), five midazolam, six thiopentone and two sevoflurane. Three studies compared etomidate with thiopentone, and three etomidate with midazolam. Two studies compared thiopentone with midazolam, one thiopentone with diazepam and one midazolam with diazepam. Drug doses and the time over which the drugs were given varied between studies. Although all studies were described as randomized, limited information was provided about the methods used for selection and group allocation. A high level of performance bias was observed across studies, as study authors had not attempted to blind the anaesthetist to group allocation. Similarly, study authors had rarely provided sufficient information on whether outcome assessors had been blinded.Included studies presented outcome data for hypotension, apnoea, participant recall, success of cardioversion, minor adverse events of nausea and vomiting, pain at injection site and myoclonus, additional analgesia and participant satisfaction. We did not pool the data from different studies in view of the multiple drug comparisons, differences in definitions and reporting of outcomes, variability of endpoints and high or unclear risk of bias across studies.

AUTHORS' CONCLUSIONS

Few studies reported statistically significant results for our relevant outcomes, and most study authors concluded that both, or all, agents compared in individual studies were adequate for cardioversion procedures. It is our opinion that at present, there is no evidence to suggest that current anaesthetic practice for cardioversion should change.

Diazepam or midazolam for orotracheal intubation in the ICU?

OBJECTIVE

to compare clinical and cost effectiveness of midazolam and diazepam for urgent intubation.

METHODS

patients admitted to the Central ICU of the Santa Casa Hospital Complex in Porto Alegre, over the age of 18 years, undergoing urgent intubation during 6 months were eligible. Patients were randomized in a single-blinded manner to either intravenous diazepam or midazolam. Diazepam was given as a 5 mg intravenous bolus followed by aliquots of 5 mg each minute. Midazolam was given as an intravenous bolus of 5 mg with further aliquots of 2.5 mg each minute. Ramsay sedation scale 5-6 was considered adequate sedation. We recorded time and required doses to reach adequate sedation and duration of sedation.

RESULTS

thirty four patients were randomized, but one patient in the diazepam group was excluded because data were lost. Both groups were similar in terms of illness severity and demographics. Time for adequate sedation was shorter (132 ± 87 sec vs. 224 ± 117 sec, p = 0.016) but duration of sedation was similar (86 ± 67 min vs. 88 ± 50 min, p = 0.936) for diazepam in comparison to midazolam. Total drug dose to reach adequate sedation after either drugs was similar (10.0 [10.0-12.5] mg vs. 15.0 [10.0-17.5] mg, p = 0.248). Arterial pressure and sedation intensity reduced similarly overtime with both drugs. Cost of sedation was lower for diazepam than for midazolam (1.4[1.4-1.8] vs. 13.9[9.4-16.2] reais, p <0.001).

CONCLUSIONS

intubation using intravenous diazepam and midazolam is effective and well tolerated. Sedation with diazepam is associated to a quicker sedation time and to lower costs.

Sedation for electrophysiological procedures

Administration of intravenous sedation (IVS) has become an integral component of procedural cardiac electrophysiology. IVS is employed in diagnostic and ablation procedures for transcutaneous treatment of cardiac arrhythmias, electrical cardioversion of arrhythmias, and the insertion of implantable electronic devices including pacemakers, defibrillators, and loop recorders. Sedation is frequently performed by nursing staff under the supervision of the proceduralist and in the absence of specialist anesthesiologists. The sedation requirements vary depending on the nature of the procedure. A wide range of sedation techniques have been reported with sedation from the near fully conscious to levels approaching that of general anesthesia. This review examines the methods employed and outcomes associated with reported sedation techniques. There is a large experience with the combination of benzodiazepines and narcotics. These drugs have a broad therapeutic range and the advantage of readily available reversal agents. More recently, the use of propofol without serious adverse events has been reported. The results provide a guide regarding the expected outcomes of these approaches. The complication rate and need for emergency assistance is low in reported series where sedation is administered by nonspecialist anesthesiology staff.

Remifentanil-midazolam sedation provides hemodynamic stability and comfort during epicardial ablation of ventricular tachycardia

Epicardial ablation of ventricular tachycardia (VT) presents multiple challenges for anesthetic management. General anesthesia lowers blood pressure, may interfere with arrhythmia mapping, and use of muscle relaxants precludes identification of the phrenic nerve. We describe a case in which remifentanil with minimal doses of midazolam was employed in a series of epicardial VT ablations and noninvasive programmed stimulations (NIPS), including 5 external cardioversions and discuss the advantages of this approach.

First time and repeat cardioversion of atrial tachyarrhythmias - a comparison of outcomes

INTRODUCTION

Repeat cardioversion may be necessary in over 50% of patients with persistent atrial fibrillation (AF), but identifying responders remains challenging. This study evaluates the long-term success of direct current cardioversion (DCCV) and the clinical and echocardiographical parameters that influence them, in over 1000 sedation-cardioversion procedures undertaken at Eastbourne General Hospital between 1996 and 2006.

METHODS

A total of 770 patients of mean age (SD) 70.1(10.1) underwent 1013 DCCVs (first n = 665, repeat n = 348) for atrial tachyarrhythmias from 1996 to 2006. Time to persistent arrhythmia recurrence was compared between first and multiple DCCV, and the effect of age, gender, presence of heart disease, left atrial size, fractional shortening, arrhythmia duration, anti-arrhythmic drug therapy (AAD) and other concomitant cardiac medication was evaluated using the Kaplan-Meier method and Cox's Proportional-hazards model.

RESULTS

In all, 33% of first and 29% of repeat DCCVs were in sinus rhythm (SR) at 12 months (m). There was no difference in median time to arrhythmia recurrence (SE) between first and multiple procedures: 1.5 +/- 0.1 m (1.3-1.7) and 1.5 +/- 0.0 m (1.4-1.6) respectively, p = 0.45. AAD use was significantly higher, arrhythmia duration shorter and more diabetic patients underwent repeat procedures. Amiodarone, OR 0.56, p = 0.04, sotalol, OR 0.61, p = 0.02 and arrhythmia duration, < 6 m, OR 0.72, p = 0.03 were independent predictors of improved outcome in first procedures only. In patients undergoing first procedures on amiodarone or sotalol, median time to arrhythmia recurrence was longer and 12 m SR rates higher, 6.0 +/- 2.4 m (42%) than those who had a repeat procedure on the same medication, 1.5 +/- 0.1 m (33%), p = 0.06.

CONCLUSIONS

The efficacy of first and subsequent DCCV procedures is similar, achieving a similar proportion of SR maintenance at 1 year. However, the benefits of AAD therapy are the greatest following first time procedures. Concomitant AAD therapy should be considered for all first time procedures for persistent AF.

[Implantation of cardioverter-defibrillators. How much anesthesia is necessary?]

Updated cardiologic guidelines constitute the background for an extended spectrum of indications for the implantation of automatic implantable cardioverter defibrillators (AICDs) and lead to an increasing number of operative implantations of AICDs. Moreover, during implantation of devices for cardiac resynchronization therapy the anesthesiologist is responsible for the most critically ill patients with the longest duration of surgery. As a result anesthesiologists face an increasing number of critically ill patients, whose management contributes to perioperative outcome. Automatic implantable cardioverter defibrillators can be implanted either during general anesthesia, local anesthesia or during a combination of local anesthesia combined with deep conscious sedation accomplished by an anesthesiologist. Besides economic aspects there is an increasing demand for anesthesia with the least cardiovascular side effects and rapid recovery in the often seriously ill patient with preexisting limitations of cardiac and pulmonary functions. Accordingly procedure and anesthesia-associated risks are reviewed and an algorithm for anesthesia management is suggested.

Sedation with midazolam for electrical cardioversion

BACKGROUND

Electrical cardioversion (ECV) usually requires the assistance of the anesthesiology team. To avoid this dependence, previous studies have considered the use of sedation with benzodiazepines administered by cardiologists. We describe our experience with intravenous Midazolam during cardioversion.

METHODS

We performed 280 ECV in 202 patients sedated with intravenous Midazolam, without anesthesiology supervision. In scheduled cardioversions, we tested two protocols of Midazolam administration: a bolus of 3 mg, followed by 2 mg each minute until necessary, and a loading dose of 0.09-0.1 mg/kg. In cardioversions performed during electrophysiology studies or defibrillator implant, Midazolam was administered by small repeated doses during the entire procedure.

RESULTS

Midazolam was effective to obtain adequate sedation in 99% of cases. All patients had amnesia with regards of the cardioversion. A loading dose of Midazolam allowed a shortening of the procedural time without serious adverse events. Intubation or the assistance of an anesthetist was never necessary.

CONCLUSION

Sedation with Midazolam for ECV is effective and well tolerated, with some cautions discussed. A loading dose of Midazolam is well tolerated and further reduces the procedural time.

Fast cardiologist-administered midazolam for electrical cardioversion of atrial fibrillation

AIM

To evaluate the safety and the feasibility of sedation administered by cardiologists with rapid intravenous bolus of midazolam followed by flumazenil infusion during transthoracic biphasic electrical cardioversion (TEC) for atrial fibrillation (AF).

METHODS

Two hundred and sixty-five consecutive patients (119 females, mean age 67.4 +/- 8.5 years) with either acute (24 patients) or persistent AF (mean arrhythmia duration 3.7 +/- 3.0 months) underwent TEC. Midazolam (0.05 mg/kg) was administered as rapid intravenous bolus by the cardiologist, whereas the anaesthesiologist was simply alerted. At the end of the procedure, intravenous flumazenil 0.25 mg was given, followed by 0.25 mg over 1 h. Patients received continuous electrocardiographic and pulse-oxymetric monitoring.

RESULTS

Adequate sedation was obtained in 262 patients (98.9%), with a mean midazolam dose of 4.4 +/- 0.9 mg. After drug administration, the mean time to patient's sedation and reawakening were 3.1 +/- 1.9 and 6.1 +/- 2.7 min, respectively. The mean reduction in oxygen saturation was 5.4 +/- 3.7%. Sinus rhythm was restored in 254 patients (95.8%). All but 41 patients (15.5%) were completely amnesic. None reported pain. No adverse events were registered. No urgent call for the anaesthesiologist was made.

CONCLUSIONS

Conscious sedation with fast-administered midazolam followed by flumazenil for cardioversion of atrial fibrillation is safe, effective and well tolerated, easing the procedure and shortening its duration.

DC cardioversion of persistent atrial fibrillation: A comparison of two protocols

BACKGROUND

Current guidelines for transthoracic direct-current cardioversion (DCCV) of atrial fibrillation (AF) recommend a step-up energy protocol. The aim of this study was to compare such a protocol with a protocol involving a high initial energy shock, anteroposterior paddle position and reversal of shock polarity, on cardioversion efficacy, total energy delivery, use of sedation and patient tolerability.

METHODS

261 patients (mean age 71+/-10 years, 62% male) referred for elective DCCV of persistent AF were enrolled. Patients were randomised to either protocol A: (1) 200 J anteroapical, (2) 360 J anteroapical, (3) 360 J anteroposterior; or protocol B: (1) 360 J anteroapical, (2) 360 J anteroposterior, and (3) 360 J posteroanterior. All procedures were performed under sedation with intravenous diazepam.

RESULTS

Protocol B improved shock success rates (protocol A first shock success rate=42%, protocol B=68%, p<0.001; protocol A second shock success rate=72%, protocol B 86%, p=0.006; protocol A third shock success rate=83%, protocol B=92%, p=0.03) and required fewer shocks to achieve sinus rhythm (1.3+/-0.6) compared with protocol A (1.6+/-0.7, p<0.001). There were no differences in cumulative energy used (protocol A 473+/-286 J, protocol B 436+/-273 J, p=0.24) or sedation requirements (protocol A diazepam 22.1+/-9.0 mg, protocol B 21.7+/-8.9 mg, p=0.75). Both protocols were equally well tolerated by patients.

CONCLUSION

High initial energy increased success rates and decreased the number of shocks but resulted in similar cumulative energy delivery, sedation use and patient tolerability compared with a conventional step-up protocol.

Best evidence topic report. Procedural sedation for cardioversion

A short-cut review was conducted to establish whether any of the available drugs used for procedural sedation in patients with tachydysrhythmias are safer or more effective than the alternatives. In all, 135 papers were found using the reported searches, of which 7 presented the best evidence to answer the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these best papers are tabulated. It is concluded that propofol, methohexital, thiopentone and etomidate all seem to be good choices.

Adverse Events Associated with Sedatives, Analgesics, and Other Drugs That Provide Patient Comfort in the Intensive Care Unit

Since the 2002 publication of multidisciplinary clinical practice guidelines for intensive care unit (ICU) sedation and analgesia, additional information regarding adverse drug events has been reported. Our understanding of the risks associated with these sedative and analgesic agents promises to improve outcomes by helping clinicians identify and respond to therapeutic misadventures sooner. This review focuses on many issues, including the potentially fatal consequences associated with the propofol infusion syndrome, the evolving understanding of propylene glycol intoxication associated with parenteral lorazepam, new data involving high-dose and long-term dexmedetomidine therapy, haloperidol- and methadone-related prolongation of QTc intervals on the electrocardiogram, adverse events associated with atypical antipsychotics, and the potential for nonsteroidal antiinflammatory drugs to interfere with bone healing.

The safety and effectiveness of a nurse led cardioversion service under sedation

OBJECTIVE

To assess the safety and effectiveness of nurse led elective cardioversion of atrial fibrillation under sedation.

DESIGN

Prospective, longitudinal study.

SETTING

Cardiac catheterisation laboratory and recovery area of a district general hospital.

PATIENTS

300 patients referred for elective cardioversion of persistent atrial fibrillation.

INTERVENTIONS

Pre-procedure evaluations (history, physical examination, blood tests), consent, sedation administration, cardioversions, and post-procedure monitoring until discharge by advanced life support certified coronary care unit nurses trained in the techniques. A doctor was immediately available if required but not present.

MAIN OUTCOME MEASURES

Success rates at discharge and at six weeks, energy delivered, number of shocks, dose of sedation, immediate, 24, and 48 hour patient perceptions, complications, waiting times, and cost effectiveness.

RESULTS

Cardioversion success rate was 87% at discharge and 48% at six weeks. Mean (SD) cumulative energy was 497 (282) J and number of shocks 1.6 (0.8). Mean (SD) dose of sedation was 23 (9) mg intravenous diazepam. No patient required reversal of sedation, airway support, or medical intervention. Ninety eight per cent of patients had no pain or recall of the procedure. Four patients who were adequately anticoagulated experienced embolic phenomena. Ninety eight per cent of patients would repeat the procedure if necessary. Without requirement for a physician or anaesthetist, waiting times for elective cardioversion fell from three months to under four weeks. There was a significant reduction in the estimated cost of the procedure from 337 pounds sterling with general anaesthesia to 130 pounds sterling with nurse led sedation and cardioversion (p < 0.001).

CONCLUSION

With appropriate training, a nurse led cardioversion service with sedation is safe, effective, well tolerated, and cost efficient.