Effects of amiodarone and thoracic epidural analgesia on atrial fibrillation after coronary artery bypass grafting

Navigating the Incidence of Postoperative Arrhythmia and Hospitalization Length: The Role of Amiodarone and Other Antiarrhythmics in Prophylaxis

Antiarrhythmic drugs play a pivotal role in managing and preventing arrhythmias. Amiodarone, classified as a class III antiarrhythmic, has been used prophylactically to effectively prevent atrial fibrillation postoperatively in cardiac surgeries. However, there is a lack of consensus on the use of amiodarone and other antiarrhythmic drugs as prophylaxis to reduce the occurrence of all types of postoperative arrhythmias in cardiac and non-cardiac surgeries. A comprehensive PubMed query yielded 614 relevant papers, of which 52 clinical trials were analyzed. The data collection included the class of antiarrhythmics, timing or method of drug administration, surgery type, type of arrhythmia and its incidence, and hospitalization length. Statistical analyses focused on prophylactic antiarrhythmics and their respective reductions in postoperative arrhythmias and hospitalization length. Prophylactic amiodarone alone compared to placebo demonstrated a significant reduction in postoperative arrhythmia incidence in cardiac and non-cardiac surgeries (24.01%, p<0.0001), and it was the only treatment group to significantly reduce hospitalization length versus placebo (p = 0.0441). Prophylactic use of class 4 antiarrhythmics versus placebo also demonstrated a significant reduction in postoperative arrhythmia incidence (28.01%, p<0.0001), and while there was no significant statistical reduction compared to amiodarone (4%, p=0.9941), a lack of abundant data provides a case for further research on the prophylactic use of class 4 antiarrhythmics for this indication. Amiodarone prophylaxis remains a prime cornerstone of therapy in reducing postoperative arrhythmia incidence and hospitalization length. Emerging data suggests a need for a broader exploration of alternative antiarrhythmic agents and combination therapies, particularly class 4 antiarrhythmics, in both cardiac and non-cardiac surgeries. This meta-analysis depicts the effectiveness of amiodarone, among other antiarrhythmics, in postoperative arrhythmia incidence and hospitalization length reduction in cardiac and non-cardiac surgeries.

Thoracic Epidural Anesthesia in Cardiac Surgery: A Systematic Review, Meta-Analysis, and Trial Sequential Analysis of Randomized Controlled Trials

BACKGROUND

Research on fast-track recovery protocols postulates that thoracic epidural anesthesia (TEA) in cardiac surgery contributes to improved postoperative outcomes. However, concerns about TEA's safety hinder its widespread usage. We conducted a systematic review and meta-analysis to assess the benefits and risks of TEA in cardiac surgery.

METHODS

We searched 4 databases for randomized controlled trials (RCTs) assessing the use of TEA against only general anesthesia (GA) in adults undergoing cardiac surgery, up till June 4, 2022. We conducted random-effects meta-analyses, evaluated risk of bias using the Cochrane Risk-of-Bias 2 tool, and rated certainty of evidence via the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach. Primary outcomes were intensive care unit (ICU), hospital length of stay, extubation time (ET), and mortality. Other outcomes included postoperative complications. Trial sequential analysis (TSA) was conducted on all outcomes to elicit statistical and clinical benefit.

RESULTS

Our meta-analysis included 51 RCTs (2112 TEA patients and 2220 GA patients). TEA significantly reduced ICU length of stay (-6.9 hours; 95% confidence interval [CI], -12.5 to -1.2; P = .018), hospital length of stay (-0.8 days; 95% CI, -1.1 to -0.4; P < .0001), and ET (-2.9 hours; 95% CI, -3.7 to -2.0; P < .0001). However, we found no significant change in mortality. TSA found that the cumulative Z-curve passed the TSA-adjusted boundary for ICU length of stay, hospital length of stay, and ET, suggesting a clinical benefit. TEA also significantly reduced pain scores, pooled pulmonary complications, transfusion requirements, delirium, and arrhythmia, without additional complications such as epidural hematomas, of which the risk was estimated to be <0.14%.

CONCLUSIONS

TEA reduces ICU and hospital length of stay, and postoperative complications in patients undergoing cardiac surgery with minimal reported complications such as epidural hematomas. These findings favor the use of TEA in cardiac surgery and warrant consideration for use in cardiac surgeries worldwide.

Comparison of regional anesthetic techniques for postoperative analgesia after adult cardiac surgery: bayesian network meta-analysis

Background

Patients usually suffer acute pain after cardiac surgery. Numerous regional anesthetic techniques have been used for those patients under general anesthesia. The most effective regional anesthetic technique was still unclear.

Methods

Five databases were searched, including PubMed, MEDLINE, Embase, ClinicalTrials.gov, and Cochrane Library. The efficiency outcomes were pain scores, cumulative morphine consumption, and the need for rescue analgesia in this Bayesian analysis. Postoperative nausea, vomiting and pruritus were safety outcomes. Functional outcomes included the time to tracheal extubation, ICU stay, hospital stay, and mortality.

Results

This meta-analysis included 65 randomized controlled trials involving 5,013 patients. Eight regional anesthetic techniques were involved, including thoracic epidural analgesia (TEA), erector spinae plane block, and transversus thoracic muscle plane block. Compared to controls (who have not received regional anesthetic techniques), TEA reduced the pain scores at 6, 12, 24 and 48 h both at rest and cough, decreased the rate of need for rescue analgesia (OR = 0.10, 95% CI: 0.016-0.55), shortened the time to tracheal extubation (MD = -181.55, 95% CI: -243.05 to -121.33) and the duration of hospital stay (MD = -0.73, 95% CI: -1.22 to -0.24). Erector spinae plane block reduced the pain score 6 h at rest and the risk of pruritus, shortened the duration of ICU stay compared to controls. Transversus thoracic muscle plane block reduced the pain scores 6 and 12 h at rest compared to controls. The cumulative morphine consumption of each technique was similar at 24, 48 h. Other outcomes were also similar among these regional anesthetic techniques.

Conclusions

TEA seems the most effective regional postoperative anesthesia for patients after cardiac surgery by reducing the pain scores and decreasing the rate of need for rescue analgesia.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, ID: CRD42021276645.

Epidural analgesia for adults undergoing cardiac surgery with or without cardiopulmonary bypass

BACKGROUND

General anaesthesia combined with epidural analgesia may have a beneficial effect on clinical outcomes. However, use of epidural analgesia for cardiac surgery is controversial due to a theoretical increased risk of epidural haematoma associated with systemic heparinization. This review was published in 2013, and it was updated in 2019.

OBJECTIVES

To determine the impact of perioperative epidural analgesia in adults undergoing cardiac surgery, with or without cardiopulmonary bypass, on perioperative mortality and cardiac, pulmonary, or neurological morbidity.

SEARCH METHODS

We searched CENTRAL, MEDLINE, and Embase in November 2018, and two trial registers up to February 2019, together with references and relevant conference abstracts.

SELECTION CRITERIA

We included all randomized controlled trials (RCTs) including adults undergoing any type of cardiac surgery under general anaesthesia and comparing epidural analgesia versus another modality of postoperative pain treatment. The primary outcome was mortality.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as expected by Cochrane.

MAIN RESULTS

We included 69 trials with 4860 participants: 2404 given epidural analgesia and 2456 receiving comparators (systemic analgesia, peripheral nerve block, intrapleural analgesia, or wound infiltration). The mean (or median) age of participants varied between 43.5 years and 74.6 years. Surgeries performed were coronary artery bypass grafting or valvular procedures and surgeries for congenital heart disease. We judged that no trials were at low risk of bias for all domains, and that all trials were at unclear/high risk of bias for blinding of participants and personnel taking care of study participants.Epidural analgesia versus systemic analgesiaTrials show there may be no difference in mortality at 0 to 30 days (risk difference (RD) 0.00, 95% confidence interval (CI) -0.01 to 0.01; 38 trials with 3418 participants; low-quality evidence), and there may be a reduction in myocardial infarction at 0 to 30 days (RD -0.01, 95% CI -0.02 to 0.00; 26 trials with 2713 participants; low-quality evidence). Epidural analgesia may reduce the risk of 0 to 30 days respiratory depression (RD -0.03, 95% CI -0.05 to -0.01; 21 trials with 1736 participants; low-quality evidence). There is probably little or no difference in risk of pneumonia at 0 to 30 days (RD -0.03, 95% CI -0.07 to 0.01; 10 trials with 1107 participants; moderate-quality evidence), and epidural analgesia probably reduces the risk of atrial fibrillation or atrial flutter at 0 to 2 weeks (RD -0.06, 95% CI -0.10 to -0.01; 18 trials with 2431 participants; moderate-quality evidence). There may be no difference in cerebrovascular accidents at 0 to 30 days (RD -0.00, 95% CI -0.01 to 0.01; 18 trials with 2232 participants; very low-quality evidence), and none of the included trials reported any epidural haematoma events at 0 to 30 days (53 trials with 3982 participants; low-quality evidence). Epidural analgesia probably reduces the duration of tracheal intubation by the equivalent of 2.4 hours (standardized mean difference (SMD) -0.78, 95% CI -1.01 to -0.55; 40 trials with 3353 participants; moderate-quality evidence). Epidural analgesia reduces pain at rest and on movement up to 72 hours after surgery. At six to eight hours, researchers noted a reduction in pain, equivalent to a reduction of 1 point on a 0 to 10 pain scale (SMD -1.35, 95% CI -1.98 to -0.72; 10 trials with 502 participants; moderate-quality evidence). Epidural analgesia may increase risk of hypotension (RD 0.21, 95% CI 0.09 to 0.33; 17 trials with 870 participants; low-quality evidence) but may make little or no difference in the need for infusion of inotropics or vasopressors (RD 0.00, 95% CI -0.06 to 0.07; 23 trials with 1821 participants; low-quality evidence).Epidural analgesia versus other comparatorsFewer studies compared epidural analgesia versus peripheral nerve blocks (four studies), intrapleural analgesia (one study), and wound infiltration (one study). Investigators provided no data for pulmonary complications, atrial fibrillation or flutter, or for any of the comparisons. When reported, other outcomes for these comparisons (mortality, myocardial infarction, neurological complications, duration of tracheal intubation, pain, and haemodynamic support) were uncertain due to the small numbers of trials and participants.

AUTHORS' CONCLUSIONS

Compared with systemic analgesia, epidural analgesia may reduce the risk of myocardial infarction, respiratory depression, and atrial fibrillation/atrial flutter, as well as the duration of tracheal intubation and pain, in adults undergoing cardiac surgery. There may be little or no difference in mortality, pneumonia, and epidural haematoma, and effects on cerebrovascular accident are uncertain. Evidence is insufficient to show the effects of epidural analgesia compared with peripheral nerve blocks, intrapleural analgesia, or wound infiltration.

Thoracic epidural anesthesia improves outcomes in patients undergoing cardiac surgery: meta-analysis of randomized controlled trials

To assess the efficacy of thoracic epidural anesthesia (TEA) with or without general anesthesia (GA) versus GA in patients who underwent cardiac surgery, PubMed, Embase, the Cochrane online database, and Web of Science were searched with the limit of randomized controlled trials (RCTs) relevant to ‘thoracic epidural anesthesia’ and ‘cardiac surgery’. Studies were identified and data were extracted by two reviewers independently. The quality of included studies was also assessed according to the Cochrane handbook. Outcomes of mortality, cardiac and respiratory functions, and treatment-associated complications were pooled and analyzed. The comprehensive search yielded 2,230 citations, and 25 of them enrolling 3,062 participants were included according to the inclusion criteria. Compared with GA alone, patients received TEA and GA showed reduced risks of death, myocardial infarction, and stroke, though there were no significant differences (P > 0.05). With regard to treatment-related complications, the pooled results for respiratory complications (risk ratio (RR), 0.69; 95% CI: 0.51, 0.91, P < 0.05), supraventricular arrhythmias (RR, 0.61; 95% CI: 0.42, 0.87, P < 0.05), and pain (mean difference (MD), −1.27; 95% CI: −2.20, −0.35, P < 0.05) were 0.69, 0.61, and −1.27, respectively. TEA was also associated with significant reduction of stays in intensive care unit (MD, −2.36; 95% CI: −4.20, −0.52, P < 0.05) and hospital (MD, −1.51; 95% CI: −3.03, 0.02, P > 0.05) and time to tracheal extubation (MD, −2.06; 95% CI:−2.68, −1.45, P < 0.05). TEA could reduce the risk of complications such as supraventricular arrhythmias, stays in hospital or intensive care unit, and time to tracheal extubation in patients who experienced cardiac surgery.

Impact of epidural analgesia on mortality and morbidity after surgery: systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

To quantify benefit and harm of epidural analgesia, compared with systemic opioid analgesia, in adults having surgery under general anesthesia.

BACKGROUND

It remains controversial whether adding epidural analgesia to general anesthesia decreases postoperative morbidity and mortality.

METHODS

We searched CENTRAL, EMBASE, PubMed, CINAHL, and BIOSIS till July 2012. We included randomized controlled trials comparing epidural analgesia (with local anesthetics, lasting for ≥ 24 hours postoperatively) with systemic analgesia in adults having surgery under general anesthesia, and reporting on mortality or any morbidity endpoint.

RESULTS

A total of 125 trials (9044 patients, 4525 received epidural analgesia) were eligible. In 10 trials (2201 patients; 87 deaths), reporting on mortality as a primary or secondary endpoint, the risk of death was decreased with epidural analgesia (3.1% vs 4.9%; odds ratio, 0.60; 95% confidence interval, 0.39-0.93). Epidural analgesia significantly decreased the risk of atrial fibrillation, supraventricular tachycardia, deep vein thrombosis, respiratory depression, atelectasis, pneumonia, ileus, and postoperative nausea and vomiting, and also improved recovery of bowel function, but significantly increased the risk of arterial hypotension, pruritus, urinary retention, and motor blockade. Technical failures occurred in 6.1% of patients.

CONCLUSIONS

In adults having surgery under general anesthesia, concomitant epidural analgesia reduces postoperative mortality and improves a multitude of cardiovascular, respiratory, and gastrointestinal morbidity endpoints compared with patients receiving systemic analgesia. Because adverse effects and technical failures cannot be ruled out, individual risk-benefit analyses and professional care are recommended.

Etiology and use of the "hanging drop" technique: a review

Background. The hanging drop (HD) technique presumably relies on the presence of subatmospheric epidural pressure. It is not clear whether this negative pressure is intrinsic or an artifact and how it is affected by body position. There are few data to indicate how often HD is currently being used. Methods. We identified studies that measured subatmospheric pressures and looked at the effect of the sitting position. We also looked at the technique used for cervical and thoracic epidural anesthesia in the last 10 years. Results. Intrinsic subatmospheric pressures were measured in the thoracic and cervical spine. Three trials studied the effect of body position, indicating a higher incidence of subatmospheric pressures when sitting. The results show lower epidural pressure (−10.7 mmHg) with the sitting position. 28.8% of trials of cervical and thoracic epidural anesthesia that documented the technique used, utilized the HD technique. When adjusting for possible bias, the rate of HD use can be as low as 11.7%. Conclusions. Intrinsic negative pressure might be present in the cervical and thoracic epidural space. This effect is more pronounced when sitting. This position might be preferable when using HD. Future studies are needed to compare it with the loss of resistance technique.

Epidural analgesia for cardiac surgery

BACKGROUND

A combination of general anaesthesia (GA) with thoracic epidural analgesia (TEA) may have a beneficial effect on clinical outcomes by reducing the risk of perioperative complications after cardiac surgery.

OBJECTIVES

The objective of this review was to determine the impact of perioperative epidural analgesia in cardiac surgery on perioperative mortality and cardiac, pulmonary or neurological morbidity. We performed a meta-analysis to compare the risk of adverse events and mortality in patients undergoing cardiac surgery under general anaesthesia with and without epidural analgesia.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2012, Issue 12) in The Cochrane Library; MEDLINE (PubMed) (1966 to November 2012); EMBASE (1989 to November 2012); CINHAL (1982 to November 2012) and the Science Citation Index (1988 to November 2012).

SELECTION CRITERIA

We included randomized controlled trials comparing outcomes in adult patients undergoing cardiac surgery with either GA alone or GA in combination with TEA.

DATA COLLECTION AND ANALYSIS

All publications found during the search were manually and independently reviewed by the two authors. We identified 5035 titles, of which 4990 studies did not satisfy the selection criteria or were duplicate publications, that were retrieved from the five different databases. We performed a full review on 45 studies, of which 31 publications met all inclusion criteria. These 31 publications reported on a total of 3047 patients, 1578 patients with GA and 1469 patients with GA plus TEA.

MAIN RESULTS

Through our search (November 2012) we have identified 5035 titles, of which 31 publications met our inclusion criteria and reported on a total of 3047 patients. Compared with GA alone, the pooled risk ratio (RR) for patients receiving GA with TEA showed an odds ratio (OR) of 0.84 (95% CI 0.33 to 2.13, 31 studies) for mortality; 0.76 (95% CI 0.49 to 1.19, 17 studies) for myocardial infarction; and 0.50 (95% CI 0.21 to 1.18, 10 studies) for stroke. The relative risks (RR) for respiratory complications and supraventricular arrhythmias were 0.68 (95% CI 0.54 to 0.86, 14 studies) and 0.65 (95% CI 0.50 to 0.86, 15 studies) respectively.

AUTHORS' CONCLUSIONS

This meta-analysis of studies, identified to 2010, showed that the use of TEA in patients undergoing coronary artery bypass graft surgery may reduce the risk of postoperative supraventricular arrhythmias and respiratory complications. There were no effects of TEA with GA on the risk of mortality, myocardial infarction or neurological complications compared with GA alone.

Interventions for preventing post-operative atrial fibrillation in patients undergoing heart surgery

BACKGROUND

Atrial fibrillation is a common post-operative complication of cardiac surgery and is associated with an increased risk of post-operative stroke, increased length of intensive care unit and hospital stays, healthcare costs and mortality. Numerous trials have evaluated various pharmacological and non-pharmacological prophylactic interventions for their efficacy in preventing post-operative atrial fibrillation. We conducted an update to a 2004 Cochrane systematic review and meta-analysis of the literature to gain a better understanding of the effectiveness of these interventions.

OBJECTIVES

The primary objective was to assess the effects of pharmacological and non-pharmacological interventions for preventing post-operative atrial fibrillation or supraventricular tachycardia after cardiac surgery. Secondary objectives were to determine the effects on post-operative stroke or cerebrovascular accident, mortality, cardiovascular mortality, length of hospital stay and cost of treatment during the hospital stay.

SEARCH METHODS

We searched the Cochrane Central Register of ControlLed Trials (CENTRAL) (Issue 8, 2011), MEDLINE (from 1946 to July 2011), EMBASE (from 1974 to July 2011) and CINAHL (from 1981 to July 2011).

SELECTION CRITERIA

We selected randomized controlled trials (RCTs) that included adult patients undergoing cardiac surgery who were allocated to pharmacological or non-pharmacological interventions for the prevention of post-operative atrial fibrillation or supraventricular tachycardia, except digoxin, potassium (K(+)), or steroids.

DATA COLLECTION AND ANALYSIS

Two review authors independently abstracted study data and assessed trial quality.

MAIN RESULTS

One hundred and eighteen studies with 138 treatment groups and 17,364 participants were included in this review. Fifty-seven of these studies were included in the original version of this review while 61 were added, including 27 on interventions that were not considered in the original version. Interventions included amiodarone, beta-blockers, sotalol, magnesium, atrial pacing and posterior pericardiotomy. Each of the studied interventions significantly reduced the rate of post-operative atrial fibrillation after cardiac surgery compared with a control. Beta-blockers (odds ratio (OR) 0.33; 95% confidence interval) CI 0.26 to 0.43; I(2) = 55%) and sotalol (OR 0.34; 95% CI 0.26 to 0.43; I(2) = 3%) appear to have similar efficacy while magnesium's efficacy (OR 0.55; 95% CI 0.41 to 0.73; I(2) = 51%) may be slightly less. Amiodarone (OR 0.43; 95% CI 0.34 to 0.54; I(2) = 63%), atrial pacing (OR 0.47; 95% CI 0.36 to 0.61; I(2) = 50%) and posterior pericardiotomy (OR 0.35; 95% CI 0.18 to 0.67; I(2) = 66%) were all found to be effective. Prophylactic intervention decreased the hospital length of stay by approximately two-thirds of a day and decreased the cost of hospital treatment by roughly $1250 US. Intervention was also found to reduce the odds of post-operative stroke, though this reduction did not reach statistical significance (OR 0.69; 95% CI 0.47 to 1.01; I(2) = 0%). No significant effect on all-cause or cardiovascular mortality was demonstrated.

AUTHORS' CONCLUSIONS

Prophylaxis to prevent atrial fibrillation after cardiac surgery with any of the studied pharmacological or non-pharmacological interventions may be favored because of its reduction in the rate of atrial fibrillation, decrease in the length of stay and cost of hospital treatment and a possible decrease in the rate of stroke. However, this review is limited by the quality of the available data and heterogeneity between the included studies. Selection of appropriate interventions may depend on the individual patient situation and should take into consideration adverse effects and the cost associated with each approach.

Meta-analysis of randomized controlled trials on the efficacy of thoracic epidural anesthesia in preventing atrial fibrillation after coronary artery bypass grafting

Background

Postoperative atrial fibrillation (POAF) is one of the most common complications in patients undergoing coronary artery bypass grafting (CABG). The goal of this meta-analysis was to evaluate the efficacy of thoracic epidural anesthesia (TEA) in preventing POAF in adult patients undergoing CABG.

Methods

MEDLINE and EMBASE were searched to identify randomized controlled trails in adult patients undergoing CABG who were randomly assigned to receive general anesthesia plus thoracic epidural anesthesia (GA + TEA) or general anesthesia only (GA). Two authors independently extracted data using a standardized Excel file. The primary outcome measure was the incidence of POAF. We used DerSimonian-Laird random-effects models to compute summary risk ratios with 95% confidence intervals.

Results

Five studies involving 540 patients met our inclusion criteria. No significant difference in the incidence of POAF was observed between the two groups (risk ratio, 0.61; 95% confidence interval, 0.33 to 1.12; P = 0.11), with significant heterogeneity among the studies (I² = 73%, P = 0.005). Sensitivity analyses by primary endpoint, methodological quality and surgical technique yielded similar results.

Conclusions

The limited evidence suggests that TEA shows no beneficial efficacy in preventing POAF in adult patients undergoing CABG. However, the results of this meta-analysis should be interpreted with caution due to significant heterogeneity of the studies included. Thus, the potential infuence of TEA on the incidence of atrial fibrillation following CABG warrants further investigation.

Perioperative atrial fibrillation and epidural anesthesia: case report and review of the literature

A case of new-onset atrial fibrillation subsequent to activation of neuraxial anesthesia is presented. The development of atrial fibrillation was temporally related to placement and dosing of an epidural catheter, and may have been triggered by a vagal response to dosing of the anesthetic or the resulting treatment with fluid and an adrenergic agent. The literature on the acute preoperative management of atrial fibrillation and the implications of atrial fibrillation for the patient undergoing regional anesthesia are reviewed.

Examining the safety of amiodarone

INTRODUCTION

Amiodarone is the most widely used antiarrhythmic agent, with demonstrated effectiveness against all the spectrum of cardiac tachyarrhythmias. The risk of adverse effects acts as a limiting factor to its utilization especially in the long term. This article systematically reviews the published evidence on amiodarone versus placebo to examine its safety as an antiarrhythmic drug.

AREAS COVERED

Authors collected data on adverse effects reported in 49 randomized placebo-controlled trials with amiodarone. Adverse effects were classified according to the organ/system involved. Pooled estimates of the number needed to treat (NNT) and to harm (NNH) versus placebo were calculated.

EXPERT OPINION

Amiodarone is effective for both the acute conversion of atrial fibrillation (AF) (11 trials, NNT = 4 at 24 h; p = 0.003) and the prevention of postoperative AF (18 trials, NNT = 8; p < 0.001), although with an increased risk of bradycardia, hypotension, nausea or phlebitis (pooled NNH = 4; p < 0.001). Amiodarone administration for the maintenance of sinus rhythm has a favorable net clinical benefit (pooled NNT = 3; p < 0.001 versus pooled NNH for either thyroid toxicity, gastrointestinal discomfort, skin toxicity or eye toxicity = 11; p < 0.001). Treatment with amiodarone for the prophylaxis of sudden cardiac death has less favorable net clinical benefit (15 trials, NNT = 38; p < 0.001 versus NNH for either thyroid toxicity, hepatic toxicity, pulmonary toxicity or bradycardia = 14; p < 0.001). Amiodarone treatment in this setting should be used in only selected cases.

Epidural analgesia improves outcome in cardiac surgery: a meta-analysis of randomized controlled trials

OBJECTIVE

The authors conducted a review of randomized studies to determine whether there were any advantages for clinically relevant outcomes by adding epidural analgesia in patients undergoing cardiac surgery under general anesthesia.

DESIGN

Meta-analysis.

SETTING

Hospitals.

PARTICIPANTS

A total of 2366 patients from 33 randomized trials.

INTERVENTIONS

None.

DATA SOURCES AND STUDY SELECTION

PubMed, BioMedCentral, CENTRAL, EMBASE, Cochrane Central Register of Controlled Trials, and conference proceedings were searched (updated January 2008) for randomized trials that compared general anesthesia with an anesthetic plan including general anesthesia and epidural analgesia in cardiac surgery. Two independent reviewers appraised study quality, with divergences resolved by consensus. Overall analysis showed that epidural analgesia reduced the risk of the composite endpoint mortality and myocardial infarction (30/1125 [2.7%] in the epidural group v 64/1241 [5.2%] in the control arm, odds ratio [OR] = 0.61 [0.40-0.95], p = 0.03 number needed to treat [NNT] = 40), the risk of acute renal failure (35/590 [5.9%] in the epidural group v 54/618 [8.7%] in the control arm, OR = 0.56 [0.34-0.93], p = 0.02, NNT = 36), and the time of mechanical ventilation (weighted mean differences = -2.48 hours [-2.64, -2.32], p < 0.001).

CONCLUSIONS

This analysis suggested that epidural analgesia on top of general anesthesia reduced the incidence of perioperative acute renal failure, the time on mechanical ventilation, and the composite endpoint of mortality and myocardial infarction in patients undergoing cardiac surgery.

Prophylactic Amiodarone for Prevention of Atrial Fibrillation After Cardiac Surgery: A Meta-Analysis

Amiodarone has been proposed to decrease atrial fibrillation after cardiac surgery. The literature was systematically reviewed for randomized trials comparing amiodarone with control for prevention of atrial fibrillation. Data were extracted on study characteristics, quality, and incidence of atrial fibrillation, cardiovascular outcomes, and length of hospitalization. Nineteen trials were included. Amiodarone reduced the odds ratio of atrial fibrillation (0.50; 95% confidence interval [CI]: 0.43 to 0.59, p < 0.0001), ventricular tachyarrhythmias (0.39; 95% CI: 0.26 to 0.58, p < 0.0001), and strokes (0.53; 95% CI: 0.30 to 0.92, p = 0.02). Amiodarone reduced hospital stay (0.6 days; 95% CI: 0.4 to 0.8, p < 0.0001). Amiodarone decreased atrial fibrillation, reduced perioperative ventricular tachyarrhythmias and strokes, and reduced duration of hospitalization. The current evidence supports recommending the routine use of perioperative amiodarone for cardiac surgery.

Safety of amiodarone in the prevention of postoperative atrial fibrillation: A meta-analysis

PURPOSE

A meta-analysis was conducted to assess the safety of amiodarone in the prevention of postoperative atrial fibrillation.

METHODS

A search of the medical literature was conducted to identify randomized controlled trials of prophylactic amiodarone use in cardiothoracic surgery. Studies were independently reviewed by three investigators and selected for inclusion if they met the following three criteria: (1) randomized controlled trial of amiodarone versus placebo or routine treatment, (2) patients underwent coronary artery bypass graft or valvular surgery, and (3) reported data on the frequency of at least one of the following safety endpoints: bradycardia, hypotension, heart block, nausea, cerebral vascular accident, myocardial infarction, and death. Both random- and fixed-effects models were used to determine any significant associations between amiodarone and safety endpoints.

RESULTS

Eighteen trials were analyzed. A total of 3408 patients were enrolled in these trials (1736 received amiodarone and 1672 received placebo). Amiodarone increased the odds of developing bradycardia (odds ratio [OR], 1.70; 95% confidence interval [CI], 1.05-2.74) and hypotension (OR, 1.62; 95% CI, 1.04-2.54). The administration of i.v. amiodarone, an average daily dose exceeding 1 g, and postoperative amiodarone administration were each associated with a greater likelihood of hemodynamic adverse effects. Amiodarone did not appear to affect other safety endpoints.

CONCLUSION

Meta-analysis showed amiodarone to be associated with an increased risk of developing bradycardia and hypotension when used for the prophylaxis of postoperative atrial fibrillation. The greatest risk in the occurrence of these adverse events arose when using regimens containing i.v. amiodarone, initiating prophylaxis during the postoperative period, and using regimens with average daily doses exceeding 1 g.