Thoracic epidural anesthesia as an adjunct to general anesthesia for cardiac surgery: effects on ventilation-perfusion relationships

The Effects of Various Approaches to Lobectomies on Respiratory Muscle Strength, Diaphragm Thickness, and Exercise Capacity in Lung Cancer

BACKGROUND

The most common surgery for non-small cell lung cancer is lobectomy, which can be performed through either thoracotomy or video-assisted thoracic surgery (VATS). Insufficient research has examined respiratory muscle function and exercise capacity in lobectomy performed using conventional thoracotomy (CT), muscle-sparing thoracotomy (MST), or VATS. This study aimed to assess and compare respiratory muscle strength, diaphragm thickness, and exercise capacity in lobectomy using CT, MST, and VATS.

METHODS

The primary outcomes were changes in respiratory muscle strength, diaphragm thickness, and exercise capacity. Maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) were recorded for respiratory muscle strength. The 6-min walk test (6MWT) was used to assess functional exercise capacity. Diaphragm thickness was measured using B-mode ultrasound.

RESULTS

The study included 42 individuals with lung cancer who underwent lobectomy via CT (n = 14), MST (n = 14), or VATS (n = 14). Assessments were performed on the day before surgery and on postoperative day 20 (range 17-25 days). The decrease in MIP (p < 0.001), MEP (p = 0.003), 6MWT (p < 0.001) values were lower in the VATS group than in the CT group. The decrease in 6MWT distance was lower in the MST group than in the CT group (p = 0.012). No significant differences were found among the groups in terms of diaphragmatic muscle thickness (p > 0.05).

CONCLUSION

The VATS technique appears superior to the CT technique in terms of preserving respiratory muscle strength and functional exercise capacity. Thoracic surgeons should refer patients to physiotherapists before lobectomy, especially patients undergoing CT. If lobectomy with VATS will be technically difficult, MST may be an option preferable to CT because of its impact on exercise capacity.

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.

Current Status of Neuraxial and Paravertebral Blocks for Adult Cardiac Surgery

Cardiac surgeries are known to produce moderate to severe pain. Pain management has traditionally been based on intravenous opioids. Poorly controlled pain can result in increased incidence of respiratory complications such as atelectasis and pneumonia leading to prolonged intubation and intensive care unit length of stay and subsequent prolonged hospital stay. Adequate perioperative analgesia improves hemodynamics and immunologic responses, which would result in better outcomes after cardiac surgery. Opioid sparing "Enhanced Recovery After Surgery" protocols are increasingly being incorporated into cardiac surgeries. This will reduce opioid requirements and opioid-related side effects and facilitate fast-tracking of patients. Regional analgesia can be provided by neuraxial blocks, fascial plane blocks, peripheral nerve blocks, or simply by the infiltration of the wound with local anesthetics for cardiac surgery. Neuraxial analgesia is provided through epidural, spinal, and paravertebral routes. Though they are being replaced by peripheral fascial plane blocks, epidural and spinal analgesia are still being used in some centers. In this article, neuraxial forms of analgesia are focused. We sought to review epidural analgesia and its impact in suppressing hemodynamic stress response, reducing pulmonary complications, and development of chronic pain. The relationship between intraoperative heparinization and potential neuraxial hematoma is discussed. Other neuraxial options such as spinal and paravertebral analgesia and their usefulness, benefits, and limitations are also reviewed.

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.

Fast-Track Cardiac Anesthesia: Choice of Anesthetic Agents and Techniques

Fast-track cardiac anesthesia (FTCA) incorporates early tracheal extubation, decreased length of intensive care unit (ICU) and hospital stay, and (ideally) should avoid or reduce complications to safely achieve cost-savings. A growing body of evidence from randomized trials has identified many anesthetic interventions that can improve outcome after cardiac surgery. These include new short-acting hypnotic, opioid, and neuromuscular blocking drugs. An effective FTCA program requires the appropriate selection of suitable patients, a lowdose opioid anesthetic technique, early tracheal extubation, a short stay in the ICU, and coordinated perioperative care. It is also dependent on the avoidance of postoperative complications such as excessive bleeding, myocardial ischemia, low cardiac output state, arrhythmias, sepsis, and renal failure. These complications will have a much greater adverse effect on hospital length of stay and healthcare costs. A number of clinical trials have identified interventions that can reduce some of these complications. The adoption of effective treatments into clinical practice should improve the effectiveness of FTCA.

Thoracic Epidural Analgesia

Thoracic epidural analgesia (TEA) offers a unique oppor tunity for the anesthesiologist to enhance postopera tive recovery for the thoracic surgery patient. By deliver ing analgesics to a limited dermatomal distribution, TEA can provide profound segmental analgesia and also serves to modulate neural outflow to improve cardiac and pulmonary parameters. The notable side-effects of hypotension and respiratory depression can be mini mized by using synergistic combinations of local anes thetic and opioids, and by adopting a continuous infu sion strategy. With thoughtful patient selection, careful technique, and a proactive approach to the recognition of the known hemodynamic and respiratory effects of epidural drugs, TEA can be administered safely. The significant benefits of TEA include better pain relief, increased FEV1, earlier extubation, and, perhaps, de creased morbidity and mortality.

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.

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.

[Nonanalgesic effects of thoracic epidural anesthesia]

Thoracic epidural anesthesia, which has been performed since the 1950s, has progressed from being one analgesic technique among others to its present status as the technique of choice for managing pain after major abdominal and thoracic surgery. In addition to providing effective analgesia, the epidural infusion of local anesthetic agents produces a sympathetic block that offers advantages over other types of pain control, particularly with respect to the cardiovascular, respiratory, and gastrointestinal systems. Thoracic epidural anesthesia provides dynamic pain relief, allowing the patient to resume activity early. It also permits early extubation and is associated with fewer postoperative pulmonary complications, shorter duration of paralytic ileus, and a better response to the stress of anesthesia and surgery. However, meta-analyses have not yet demonstrated that postoperative outcomes are improved. This review describes the nonanalgesic effects of thoracic epidural anesthesia.

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.

MEASUREMENTS AND MAIN RESULTS

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.

[Coronary artery bypass grafting in conscious patients: a procedure with a perspective?]

Patients undergoing coronary artery bypass grafting increasingly show severe co-morbidities, which can negatively affect the outcome. Recent developments in cardiac surgery have therefore focused on minimizing the invasiveness of the procedure by revascularization on the beating heart without cardiopulmonary bypass, and by reducing surgical trauma using smaller surgical incisions. Progress in minimally invasive cardiac surgery has led to minimally invasive anesthesia, i.e. using high thoracic epidural anesthesia as the sole technique in the conscious patient (awake coronary artery bypass grafting, ACAB). Published data on ACAB procedures in smaller cohorts have demonstrated that the procedure is safe. Significant complications occurred in 7.1% of patients. A particular cause of concern during ACAB surgery is the development of spinal epidural hematoma the risk of which has been estimated to be as high as 1:1,000. A thorough risk-benefit analysis has therefore to be made. Currently, ACAB surgery remains limited to few specialized centers and highly selected patients.

[Combined general-epidural anesthesia compared to general anesthesia: a systematic review and meta-analysis of morbidity and mortality and analgesic efficacy in thoracoabdominal surgery]

OBJECTIVES

We performed a systematic review of randomized controlled trials to compare combined general-epidural anesthesia, followed by postoperative epidural analgesia, and general anesthesia followed by postoperative parenteral analgesia without epidural analgesia in patients undergoing thoracoabdominal surgery. Outcome measures considered were mortality, length of stay in hospital and in the intensive care unit, analgesia, and morbidity.

MATERIAL AND METHODS

We performed a systematic search of online databases (MEDLINE, EMBASE, the Cochrane Controlled Trials Registry and the metaRegister of clinical trials at http://www.controlled-trials.com/mrct/ mrct info es.asp). We also hand-searched the literature. Authors were contacted when deemed necessary.

RESULTS

A total of 30 trials (4294 patients) were analyzed. Combined anesthesia showed significant advantages in relation to 2 variables: respiratory failure (odds ratio, 0.71; 95% confidence interval [CI], 0.58 to 0.87) and analgesia on the first day after surgery (weighted mean difference, -6.91 95% CI, -9.46 to -4.36). No significant differences were found in the other variables.

CONCLUSIONS

Combined anesthesia provides better analgesia and is associated with fewer cases of postoperative respiratory failure. No significant differences were found in mortality, length of stay in hospital, or other morbidity variables.

Intrathecal and Epidural Anesthesia and Analgesia for Cardiac Surgery

Adequate postoperative analgesia prevents unnecessary patient discomfort. It may also decrease morbidity, postoperative hospital length of stay and, thus, cost. Achieving optimal pain relief after cardiac surgery is often difficult. Many techniques are available, and all have specific advantages and disadvantages. Intrathecal and epidural techniques clearly produce reliable analgesia in patients undergoing cardiac surgery. Additional potential benefits include stress response attenuation and thoracic cardiac sympathectomy. The quality of analgesia obtained with thoracic epidural anesthetic techniques is sufficient to allow cardiac surgery to be performed in awake patients without general endotracheal anesthesia. However, applying regional anesthetic techniques to patients undergoing cardiac surgery is not without risk. Side effects of local anesthetics (hypotension) and opioids (pruritus, nausea/vomiting, urinary retention, and respiratory depression), when used in this manner, may complicate perioperative management. Increased risk of hematoma formation in this scenario has generated much of lively debate regarding the acceptable risk-benefit ratio of applying regional anesthetic techniques to patients undergoing cardiac surgery.

High thoracic epidural anesthesia and coronary artery disease in surgical and non-surgical patients

PURPOSE OF REVIEW

Even though high thoracic epidural anesthesia has been shown to be highly efficacious in the control of symptoms in refractory angina, its general use is still restricted. In patients who undergo coronary revascularization, however, the technique is becoming more and more popular. The present review outlines the use of high thoracic epidural anesthesia in patients with ischemic heart disease who underwent coronary revascularization in order to further reveal high thoracic epidural anesthesia's low complication rate and to analyze why physicians still refrain from using it more frequently.

RECENT FINDINGS

The incidence of severe hemodynamic complications after high thoracic epidural anesthesia is low in patients with coronary artery disease. The main advantage would be a myocardial sympathectomy leading to an improvement in the oxygen input-demand relationship. Likewise, a decrease in mortality due to respiratory complications could not be shown. In patients undergoing myocardial revascularization with full anticoagulation there is an increased risk of epidural hematoma formation. Its precise risk is difficult to evaluate. There is an overall low rate of epidural hematomas as a result of high thoracic epidural anesthesia. With the available data, the incidence has been estimated at between 1/1500 and 1/10,000.

SUMMARY

Epidural anesthesia does not decrease mortality or the incidence of myocardial infarction after coronary artery bypass grafting. It reduces the incidence of arrhythmias and respiratory complications and improves the quality of analgesia. High thoracic epidural anesthesia has been shown to be a safe and efficient technique for refractory angina that reduces the frequency of ischemic events and improves the clinical condition of patients.

Comparison of three anesthetic techniques for off-pump coronary artery bypass grafting: General anesthesia, combined general and high thoracic epidural anesthesia, or high thoracic epidural anesthesia alone

OBJECTIVE

This study compared general anesthesia (GA), combined GA plus thoracic epidural anesthesia (TEA), and TEA alone in patients scheduled for off-pump coronary artery bypass grafting.

DESIGN

Prospective, nonrandomized clinical study

SETTING

University hospital.

PARTICIPANTS

Ninety consenting patients undergoing beating-heart coronary artery revascularization with comparable coronary status and left ventricular function.

INTERVENTIONS

GA (n=30) was conducted with propofol, remifentanil, and cisatracurium or combined with TEA (GA+TEA, n=30) or TEA as the sole anesthetic with ropivacaine plus sufentanil (TEA, n=30).

MEASUREMENTS AND MAIN RESULTS

Groups were comparable regarding the surgical approaches and the number of anastomoses. Four patients (GA, n=2; GA+TEA, n=2) who required unplanned cardiopulmonary bypass, and 4 patients in the TEA group who underwent unexpected intubation because of pneumothorax (n=2), phrenic nerve palsy, or incomplete analgesia were excluded from further analysis. Intraoperative heart rate decreased significantly with both GA+TEA and TEA. None of the patients with TEA alone was admitted to the intensive care unit, they all were monitored on average for 6 hours postoperatively in the intermediate care unit and allowed to eat and drink as desired on admission. Postoperative pain scores were lower in both groups with TEA. There were no differences among groups in patients overall satisfaction.

CONCLUSION

Based on the authors data, all anesthetic techniques were equally safe from the clinicians standpoint. However, GA+TEA appeared to be most comprehensive, allowing for revascularization of any coronary artery, providing good hemodynamic stability and reliable postoperative pain relief. Nonetheless, the actual and potential risks of TEA during cardiac surgery should not be underestimated.

[High thoracic epidural anesthesia in coronary surgery]

INTRODUCTION

High thoracic epidural anesthesia and analgesia are being increasingly used for coronary artery bypass graft surgery. The reasons for this include excellent perioperative pain control with advantage of early tracheal extubation, improved postoperative pulmonary function, and cardiac protection due to sympthatetic blockade.

EFFECTS OF HIGH THORACIC EPIDURAL ANESTHESIA

Cardiac protection is the consequence of decreased heart rate, myocardial contractility and arterial blood pressure, without changes in coronary perfusion pressure. Therefore, high thoracic epidural analgesia beneficially alters major determinants of myocardial oxygen consumption, without jeopardizing coronary perfusion pressure. In addition, decrease of functional residual capacity, may reduce postoperative pulmonary morbidity.

RESULTS OF CLINICAL STUDIES

Patients with high thoracic epidural anesthesia revealed a more favourable perioperative hemodynamic profile, lower incidence of ischemia and better response to perioperative stress.

HIGH THORACIC EPIDURAL ANESTHESIA TECHNIQUE

The epidural catheter should be placed at the Th2/Th3 interspace at least one hour before administration of heparin. After local anesthetic bolus dose, a continuous epidural infusion is recommended.

CONCLUSION

There is strong evidence for beneficial effects of high thoracic epidural anesthesia in patients undergoing surgical myocardial revascularization. However, it is still underutilized in current clinical practice.

High thoracic epidural anesthesia for coronary artery bypass grafting using two different surgical approaches in conscious patients

Recent developments in coronary artery bypass graft surgery (CABG) without cardiopulmonary bypass made the sole use of high thoracic epidural anesthesia (TEA) in conscious patients feasible. Previously, TEA has been reported only for single-vessel CABG via lateral thoracotomy. We investigated the feasibility and complications of sole TEA in 20 patients undergoing beating-heart arterial revascularization via partial lower sternotomy for single-vessel disease (minimally invasive direct coronary artery bypass grafting [MIDCAB] technique; n = 10) or complete median sternotomy for multivessel disease (off-pump coronary artery bypass grafting [OPCAB] technique; n = 10). An epidural catheter was inserted at the T1-2 or T2-3 interspace. An epidural infusion of ropivacaine 0.5% and sufentanil 1.66 micro g/mL was started to establish anesthetic levels at C5-6 for OPCAB and at T1-2 for MIDCAB. Nine OPCAB and eight MIDCAB procedures were completed while patients were awake and spontaneously breathing during the entire procedure. Because of surgical pneumothorax (OPCAB), insufficient anesthesia, or phrenic nerve palsy (both MIDCAB), three patients required intraoperative conversion to general anesthesia. The heart rate decreased significantly (P < 0.05) by 10%-15% in both groups during the procedure. Compared with baseline (B), mean arterial blood pressure (mm Hg) was decreased significantly only during coronary anastomosis (CA) (B(OPCAB), 95 +/- 11; CA(OPCAB), 68 +/- 9; B(MIDCAB), 86 +/- 10; CA(MIDCAB), 73 +/- 10; P not significant between groups). PaCO(2) increased from 42 +/- 2 mm Hg to 46 +/- 7 mm Hg (P < 0.05) throughout the perioperative course during OPCAB, whereas it remained almost unaltered during MIDCAB procedures. All patients rated TEA as "good" or "excellent." In conclusion, we demonstrated that the sole use of TEA for MIDCAB and OPCAB procedures was feasible and provided a high degree of patient satisfaction in our small and highly selected cohorts. IMPLICATIONS. The sole use of high thoracic epidural anesthesia was studied in 20 patients who underwent beating-heart coronary artery bypass grafting using either median or partial lower sternotomy while awake.

Anaesthesia for minimally invasive cardiac surgery

Minimally invasive cardiac surgery is used for both extracardiac and intracardiac procedures. Extracardiac procedures, such as coronary artery bypass grafting, are often performed on a beating heart. Intracardiac procedures are done with the aid of cardiopulmonary bypass. The surgery is performed via a minithoracotomy or a ministernotomy. Thoracoscopic video-assisted surgery, often with robotic assistance, necessitates prolonged one-lung ventilation to optimize exposure. Port-access surgery will require appropriate positioning of various catheters to establish cardiopulmonary bypass. Adequate flow during cardiopulmonary bypass may require suction augmentation of venous return and may increase the risk of air emboli. Limited exposure of the heart during surgery poses challenges with management of arrhythmia, haemostasis, myocardial protection and de-airing at the end of surgery. Patient selection is important to avoid intra-operative and post-operative complications. Prolonged single-lung ventilation, incomplete revascularization in hybrid procedures, and limited access for rapid intervention pose challenges with patient management. Conversion to sternotomy that may be required occasionally and extension of portals over several dermatomal segments mandate a versatile analgesic technique.

Thoracic epidural anesthesia for cardiac surgery: the effects on tracheal intubation time and length of hospital stay

Improvements in analgesia after major surgery may allow a more rapid recovery and shorter hospital stay. We performed a prospective randomized trial to study the effects of epidural analgesia on the length of hospital stay after coronary artery surgery. The anesthetic technique and postoperative mobilization were altered to facilitate early intensive care discharge and hospital discharge. Fifty patients received high (T1 to T4) thoracic epidural anesthesia (TEA) with ropivacaine 1% (4-mL bolus, 3-5 mL/h infusion), with fentanyl (100-microg bolus, 15-25 microg/h infusion) and a propofol infusion (6 mg x kg(-1) x h(-1)). Another 50 patients (the General Anesthesia group) received fentanyl 15 microg/kg and propofol (5 mg x kg(-1) x h(-1)), followed by IV morphine patient-controlled analgesia. The TEA group had lower visual analog scores with coughing postextubation (median, 0 vs 26 mm; P < 0.0001) and were extubated earlier (median hours [interquartile range], 3.2 [2.1-4.6] vs 6.7 [3.3-13.2]; P < 0.0001). More than half of all patients were discharged home on Postoperative Day 4 (24%) or 5 (33%), but there was no difference in the length of stay between the TEA group (median [interquartile range], Day 5 [5-6]) and the General Anesthesia group (median [interquartile range], Day 5 [4-7]). There were no differences in postoperative spirometry or chest radiograph changes or in markers for postoperative myocardial ischemia or infarction. No significant TEA-related complications occurred. In summary, TEA provided better analgesia and allowed earlier tracheal extubation but did not reduce the length of hospital stay after coronary artery surgery.

IMPLICATIONS

We found that epidural analgesia was more effective than IV morphine for cardiac surgery. Epidural anesthesia also allowed earlier weaning from mechanical ventilation, but it did not affect hospital discharge time.

To ventilate or not after minimally invasive direct coronary artery bypass surgery: the role of epidural anesthesia

OBJECTIVE

To evaluate the effect of immediate postoperative extubation and postoperative ventilation after minimally invasive direct coronary artery bypass (MIDCAB) surgery and to assess the role of epidural anesthesia.

DESIGN

Randomized prospective study.

SETTING

University hospital, single institution.

PARTICIPANTS

Patients (n = 90) scheduled for elective MIDCAB surgery.

INTERVENTIONS

Patients were divided into 3 groups: 30 patients had general anesthesia and were extubated immediately after surgery (extubated group), 30 patients had a thoracic epidural and general anesthesia and were extubated immediately after surgery (epidural group), and 30 patients had general anesthesia and were ventilated after surgery (intubated group).

MEASUREMENTS AND MAIN RESULTS

With a similar cardiac index and less vasoactive medication, mean arterial blood pressure (77 plus minus 8 mmHg [mean plus minus SD]) and heart rate (76 plus minus 10 beats/min) in the epidural group were lower on the first postoperative day than in the intubated group (83 plus minus 10 mmHg and 81 plus minus 13 beats/min) and the extubated group (86 plus minus 10 mmHg and 83 plus minus 13) (p = 0.01 and p = 0.09). Oxygenation on the first postoperative day was better in the epidural group than in the intubated group (14.8 plus minus 3.8 kPa v 12.6 plus minus 3.2 kPa; p = 0.05). The epidural group and the extubated group had a transient respiratory acidosis postoperatively. Pain score in the epidural group was lower on the first postoperative day than in the extubated group with general anesthesia (3.0 plus minus 1.6 visual analog scale v 4.6 plus minus 1.8 visual analog scale; p = 0.01). Hospital stay was shorter in the epidural group than in the ventilated group (5.9 plus minus 2.4 days v 8.1 plus minus 5.3 days; p = 0.05)

CONCLUSION

Immediate postoperative extubation in patients with thoracic epidural anesthesia and supplemental general anesthesia provides the most favorable clinical circumstances after MIDCAB surgery.

Post-thoracotomy analgesia

Pain relief has come a long way in 20 years. Many aspects of the relief of pain of thoracic surgery must be rationalized and modernized to meet the demands placed on services and subject to new dynamics. To place the present state of practice and knowledge in the context of an anticipation that such attitudes will impact on and, ultimately, drive services for relief of pain, the key issues of safety, defining and measuring quality, and giving value for money must be addressed. Rationing is the impetus; the exercise to be conducted by those interested in the field of thoracic pain relief is to recognize that not all patients can have or require five-star services and gold standard techniques but are entitled to an equally high quality and measure of pain relief. Newer drugs, such as clonidine, ropivacaine, and modified local anesthetics, are on the horizon; old drugs, such as ketamine, are being revisited. Their place in the field will become apparent only if the ways that outcome measures are presented are more uniform and standard. Disaggregation analysis, pain profiling, a revisitiation of respiratory restoration factor, and optimization modeling are suggested ways forward to meet the clinical and organizationally holistic population forces being generated on the cusp of the third millennium. Increasingly, we live in a world defined by guidelines and protocols. The challenge is ensuring that these measure up to the watchwords--effective, safe, affordable.

Thoracic epidural anesthesia does not influence the occurrence of postoperative sustained atrial fibrillation

BACKGROUND

To evaluate whether thoracic epidural anesthesia (TEA) can reduce the incidence of atrial fibrillation (AF) after coronary artery bypass grafting (CABG).

METHODS

Forty-one patients undergoing CABG were treated with TEA intraoperatively and postoperatively. Another 80 patients served as the control group. The sympathetic and parasympathetic activities were evaluated by analysis of neuropeptides, catecholamines and heart rate variability (HRV), preoperatively and postoperatively.

RESULTS

Postoperative AF occurred in 31.7% of the TEA-treated patients and in 36.3% of the untreated patients (p = 0.77). TEA significantly suppressed sympathetic activity, as indicated by a less pronounced increase of norepinephrine and epinephrine (p = 0.03, p = 0.02) and a significant decrease of neuropeptide Y (p = 0.01) postoperatively in TEA-treated patients compared to untreated patients. The HRV variable expressing sympathetic activity was significantly lower and the postoperative increase in heart rate was significantly less in the TEA group than in the control group after surgery (p = 0.01, p < 0.001). Among patients developing AF, the maximal number of supraventricular premature beats per minute increased significantly in untreated patients postoperatively but remained unchanged in TEA-treated patients (p = 0.004 versus p = 0.86).

CONCLUSIONS

TEA has no effect on the incidence of postoperative sustained AF, despite a significant reduction in sympathetic activity.

Postoperative intensive care in cardiac surgery

Postoperative intensive care in cardiac surgery is a growing area, fuelled by the increase in the number of cardiac surgical procedures performed. An increase in the number of patients has resulted in increased resource utilization. Much of the recent research in this field is concerned with the early extubation of cardiac surgical patients, reducing the length of stay in the intensive care unit and predicting which patients will have delayed extubation and a prolonged length of stay. A number of recent studies have been published advocating 'off pump' cardiac surgery as a way of reducing the physiological insult of cardiopulmonary bypass and thereby improving the postoperative course. There is still insufficient evidence that this approach reduces morbidity and intensive care unit length of stay in multi-vessel off-pump coronary artery bypass surgery. The traditional design of post-cardiac surgical intensive care units and high dependency units has also recently been challenged. More flexible integrated units improve cost control and are more suited to modern cardiac surgery.

Combined regional and general anaesthesia

Combining regional and general anaesthesia can have many advantages, particularly in patients undergoing major thoracic, abdominal or orthopaedic surgery. The use of regional anaesthetic techniques in anaesthetized children is an accepted standard of care, because needle and procedure phobias are very common and can result in severe anxiety, an inability to cooperate and sudden unpredictable movement. Epidural local anaesthetics have the potential of attenuating sympathetic hyperactivity, maintaining bowel peristalsis, sparing the use of opioids, and facilitating postoperative feeding and out-of-bed activity. Catheter techniques allow excellent and prolonged postoperative analgesia using epidural or peripheral nerve blocks. However, the superiority of regional techniques for hip fracture surgery and carotid endarterectomy has been disputed in several recent studies. As part of the combination technique, epidural block may in fact decrease blood flow in free flap surgery by a steal phenomenon, and increase intrapulmonary shunting during one-lung ventilation. The present review focuses on the use of a combination of regional and general anaesthesia for a variety of surgical procedures. It also compares the two anaesthetic techniques in elderly patients. The review is based on studies published during the past year.

Target-controlled intravenous anaesthesia with bispectral index monitoring for thoracotomy in a patient with severely impaired left ventricular function

The anaesthetic management of an elderly patient with severely impaired left ventricular function undergoing thoracotomy and lobectomy is described. Total intravenous anaesthesia (TIVA) with remifentanil and target-controlled infusion of propofol titrated according to the bispectral index (BIS) was used, with thoracic epidural anaesthesia commenced at the end of surgery providing postoperative analgesia. Avoidance of intraoperative epidural local anaesthetics and careful titration and dose reduction of propofol using the BIS was associated with excellent haemodynamic stability. The rapid offset of action of remifentanil and low-dose propofol facilitated early recovery and tracheal extubation. The BIS was a valuable monitor in optimal titration of TIVA.