Thoracic epidural analgesia as an adjunct to general anaesthesia for cardiac surgery. Effects on pulmonary mechanics

Rescue analgesia with a transversus abdominis plane block alleviates moderate-to-severe pain and improves oxygenation after abdominal surgery: a randomized controlled trial

Background

Abdominal surgery is a common surgical procedure that is frequently associated with substantial postoperative pain. However, rescue analgesia using opioids is associated with several adverse effects. The transversus abdominis plane block (TAPB) has been demonstrated to be effective as part of multimodal analgesia. This study aims to evaluate the effects of rescue analgesia using the TAPB following abdominal surgery.

Methods

Ninety patients undergoing abdominal surgery and reporting a numeric rating scale (NRS) score of cough pain ≥4 on the first postoperative day were randomized to receive either sufentanil or TAPB for rescue analgesia. Pain scores and arterial oxygen pressure (PaO2) were evaluated before and after the administration of rescue analgesia. Sleep quality and gastrointestinal function were assessed postoperatively. The primary outcome was the degree of pain relief on coughing 30 min after the administration of rescue analgesia.

Results

Patients of both groups reported a significantly reduced NRS score on coughing 30 min after receiving rescue analgesia (P paired < 0.001 for both groups). Notably, the degree of pain relief was significantly higher in the TAPB group than in the sufentanil group [median (interquartile range), -3 (-4 to -2) vs. -2 (-2 to -1), median difference = -1; 95% confidence interval, -2 to -1; P < 0.001]. Moreover, patients in the TAPB group experienced less pain than those in the sufentanil group during the following 24 h. When evaluated, PaO2 increased significantly after rescue analgesia was administered in the TAPB group (P paired < 0.001); however, there were no significant intragroup differences in the sufentanil group (P paired = 0.129). Patients receiving the TAPB experienced better quality of sleep than those receiving sufentanil (P = 0.008), while no statistical differences in gastrointestinal function were observed between the two groups.

Conclusion

Rescue analgesia with the TAPB on the first postoperative day alleviated pain, enhanced oxygenation, and improved sleep quality in patients undergoing abdominal surgery; however, its effect on gastrointestinal function requires further research.

Clinical Trial Registration

This study was registered in the Chinese Clinical Trial Registry (https://www.chictr.org.cn/showproj.html?proj=170983, ChiCTR2200060285) on 26 May 2022: Patients were recruited during the period between 30 May 2022 and 14 February 2023, and a follow-up of the last enrolled patient was completed on 16 March 2023.

Comparison of Early Postoperative Diaphragm Muscle Function after Lobectomy via VATS and Open Thoracotomy: A Sonographic Study

Although a growing body of evidence emphasizes the superiority of VATS over conventional thoracotomy, little is still known about early postoperative diaphragm muscle function after lobectomy via these two approaches. To fill the gap in existing literature, we conducted a comparative study between VATS and conventional thoracotomy in terms of postoperative diaphragm muscle function, assessing its contractility, strength, the magnitude of effort and potential risk of dysfunction such as atrophy and paralysis. A total of 59 patients (30 after VATS), who underwent anatomical pulmonary resection at our institution, were enrolled in this study. The control group consisted of 28 health subjects without medical conditions that could contribute to diaphragm dysfunction. Diaphragm muscle was assessed before and after surgery using ultrasonography. We found that both surgical approaches were associated with postoperative impairment of diaphragm muscle function-compared to baseline data. Postoperative reduction in diaphragm contraction was demonstrated in most of the 59 patients. In the case of the control group, the differences between measurements were not observed. We noted that lobectomy via thoracotomy was linked with a greater percentage of patients with diaphragm paralysis and/or atrophy than VATS. Similar findings were observed in referring to diaphragm magnitude effort, as well as diaphragm contraction strength, where minimally invasive surgery was associated with better diaphragm function parameters-in comparison to thoracotomy. Disturbance of diaphragm work was reported both at the operated and non-operated side. Upper-right and left lobectomy were connected with greater diaphragm function impairment than other segments. In conclusion, the VATS technique seems to be less invasive than conventional thoracotomy providing a better postoperative function of the main respiratory muscle.

Rescue analgesia with serratus anterior plane block improved pain relief after thoracic surgery

BACKGROUND

Video-assisted thoracic surgery (VATS) is frequently associated with substantial postoperative pain, which may lead to hypopnea. Rescue analgesia using opioids has adverse effects. We aimed to evaluate the effects of rescue analgesia with serratus anterior plane block (SAPB) on moderate-to-severe pain and oxygenation in patients undergoing VATS.

METHODS

Eighty patients undergoing VATS and reporting a numeric rating scale (NRS, ranging from 0-10) score of cough pain ≥4 on the first postoperative day were randomized to receive either sufentanil or SAPB for rescue analgesia. The primary outcome was the degree of relief in cough pain 30 min after rescue analgesia. Arterial oxygen pressure (PaO2), opioid consumption after rescue analgesia and the incidence of chronic pain were also assessed.

RESULTS

The NRS scores were significantly reduced after rescue analgesia in both groups (Ppaired <0.001). Notably, the degree of relief in cough pain was significantly higher in the SAPB group than that in the sufentanil group (medians [interquartiles]: -3 [-4, -2] vs. -2 [-3, -1], P<0.001). Moreover, patients receiving SAPB exhibited significantly higher PaO2 than those before receiving rescue analgesia (Ppaired=0.007). However, there were no significant differences in the PaO2 before and after receiving rescue analgesia in the sufentanil group. No significant differences in opioid consumption or the incidence of chronic pain were observed between groups.

CONCLUSIONS

Rescue analgesia with SAPB on the first postoperative day had a greater effect on pain relief and oxygenation after VATS. However, its long-term effect on chronic pain requires further research.

Effects of midline laparotomy on cough strength: a prospective study measuring cough pressure

BACKGROUND

Laparotomy is assumed to decrease cough strength due to three factors: abdominal muscle trauma, postoperative pain, and diaphragmatic dysfunction. However, the effect of trauma from laparotomy itself on strength (net of the other two factors) has not been measured to our knowledge. The aim of this study was to measure the effect of laparotomy on cough strength after first measuring the effect of epidural analgesia.

METHODS

In 11 patients scheduled for open midline laparotomy, cough pressure (PCOUGH), a proxy for strength, was measured with a rectal balloon at three moments: before the procedure, at baseline; before surgery, under epidural bupivacaine to T6; and postoperatively, under epidural bupivacaine to the same analgesic level (T6). Continuous variables were compared using the Wilcoxon signed-rank test. The repeatability of PCOUGH measurements was confirmed with the intraclass correlation coefficient (ICC). Pain on coughing, hand grip strength, and the Ramsay and modified Bromage scores were also recorded.

RESULTS

Median (interquartile range) PCOUGH decreased from a baseline of 103 (89-137) to 71 (56-116) cmH2O under presurgical epidural bupivacaine (P=0.003). Postoperative PCOUGH remained unchanged at 76 (46-85) cmH2O under epidural analgesia (P=0.131). The ICCs indicated excellent repeatability of the PCOUGH measurements (P<0.001). Pain on coughing was 0 to 1 in all subjects. Hand grip strength and the Ramsay and Bromage scores were unchanged.

CONCLUSIONS

Although thoracic epidural bupivacaine reduces cough strength as measured by PCOUGH, midline laparotomy does not further reduce strength in the presence of adequate epidural analgesia.

Coronary Bypass Surgery in Patients with Previous Pneumonectomy

Introduction: Severe pulmonary dysfunction is a commonly occurring postoperative complication following cardiac surgery. Resection of a lung causes major anatomical and physiological changes. Shift of the mediastinum and reduction in respiratory function following pneumonectomy makes cardiac surgery challenging not only for the surgeon but also for the anaesthetist. The reported experience is sparse for patients with prior pneumonectomy who are undergoing surgery for ischemic or valvular heart disease. We report a case of cardiac surgery following pneumonectomy to highlight certain important features that we think are important while managing these patients. Case Presentation: The patient was a 56-year male who had undergone extra-pericardial pneumonectomy 30 years earlier for tuberculosis of the left lung. Echocardiography showed a left ventricular function of 50%. His coronary angiogram revealed severe triple vessle disease. Preoperative spirometry showed FVC 1.94 L (52% of predicted), FEV1 1.3 L (48% of predicted), FEV1/FVC ratio 70%. The pre-operative workup of this patient included computerised tomography of the chest to assess distortion of intra-thoracic anatomy. In an attempt to improve the pulmonary function this patient was admitted 10 days prior to surgery for intensive chest physiotherapy and incentive spirometry. He underwent coronary artery bypass grafting (CABG) using cardiopulmonary bypass and antegrade cold blood cardioplegia. Internal thoracic artery was used to graft left anterior descending artery (LAD), saphenous vein (SVG) was used to graft posterolateral branch of the right coronary artery, first diagonal and frist obtuse marginal arteries. Access to arteries in the circumflex region was difficult due to shift of heart to the left side. The patient was weaned from the ventilator 14 hours after and CPAP helmet was immediately applied for a period of 48 hours continuosly. After on it was applied at intervals for 5 days. The subsequent recovery was slow but progressive and the patient was discharged on the 11th postoperative day in good conditions. Conclusion: We conclude that with attention to the specific features of the preoperative, intraoperative, and postoperative management, open heart procedures can be performed successfully on patients after pneumonectomy.

Perioperative Pulmonary Atelectasis: Part II. Clinical Implications

The development of pulmonary atelectasis is common in the surgical patient. Pulmonary atelectasis can cause various degrees of gas exchange and respiratory mechanics impairment during and after surgery. In its most serious presentations, lung collapse could contribute to postoperative respiratory insufficiency, pneumonia, and worse overall clinical outcomes. A specific risk assessment is critical to allow clinicians to optimally choose the anesthetic technique, prepare appropriate monitoring, adapt the perioperative plan, and ensure the patient's safety. Bedside diagnosis and management have benefited from recent imaging advancements such as lung ultrasound and electrical impedance tomography, and monitoring such as esophageal manometry. Therapeutic management includes a broad range of interventions aimed at promoting lung recruitment. During general anesthesia, these strategies have consistently demonstrated their effectiveness in improving intraoperative oxygenation and respiratory compliance. Yet these same intraoperative strategies may fail to affect additional postoperative pulmonary outcomes. Specific attention to the postoperative period may be key for such outcome impact of lung expansion. Interventions such as noninvasive positive pressure ventilatory support may be beneficial in specific patients at high risk for pulmonary atelectasis (e.g., obese) or those with clinical presentations consistent with lung collapse (e.g., postoperative hypoxemia after abdominal and cardiothoracic surgeries). Preoperative interventions may open new opportunities to minimize perioperative lung collapse and prevent pulmonary complications. Knowledge of pathophysiologic mechanisms of atelectasis and their consequences in the healthy and diseased lung should provide the basis for current practice and help to stratify and match the intensity of selected interventions to clinical conditions.

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.

Off-pump coronary bypass grafting in a post-pneumonectomy patient: Challenges and management

Pulmonary complications are common in cardiac surgical patients. Limited respiratory reserves along with the pain associated with sternotomy add to the morbidity. Patients undergoing cardiac surgery who have had a pneumonectomy done before can be even more challenging to manage perioperatively due to a single-functioning lung. We present a case of a postpneumonectomy patient who underwent off-pump coronary artery bypass grafting. Perioperative optimization of lung function tests was stressed upon including the chest physiotherapy and early mobilization. Preoperative thoracic epidural catheter was inserted for postoperative pain and other proven benefits of thoracic epidural in coronary artery disease patients. We could conclude from our experience that proper optimization of lung function tests and meticulous pain management along with fast-tracking are keys to the management of such patients.

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.

Pulmonary Complications After Cardiac Surgery

Over the past two decades there has been a steady evolution in the practice of adult cardiac surgery with the introduction of “off-pump” surgery. However, respiratory complications remain a leading cause of postcardiac surgical morbidity and can prolong hospital stays and increase costs. The high incidence of pulmonary complications is in part due to the disruption of normal ventilatory function that is inherent to surgery in the thoracic region. Furthermore, patients undergoing such surgery often have underlying illnesses such as intrinsic lung disease (e.g., chronic obstructive pulmonary disease) and pulmonary dysfunction secondary to cardiac disease (e.g., congestive heart failure) that increase their susceptibility to postoperative respiratory problems. Given that many patients undergoing cardiac surgery are thus susceptiple to pulmonary complications, it is remarkable that more patients do not suffer from them during and after cardiac surgery. This is to a large degree because of advances in anesthetic, surgical and critical care that, for example, have reduced the physiological insults of surgery (e.g., better myocardial preservation techniques) and streamlined care in the immediate postoperative period (e.g., early extubation). Moreover, the development of minimally invasive surgery and nonbypass techniques are further evidence of the attempts at reducing the homeostatic disruptions of cardiac surgery. This review examines the available information on the incidences, consequences, and treatments of postcardiac surgery respiratory complications.

Effect of electro-acupuncture stimulation of Ximen (PC4) and Neiguan (PC6) on remifentanil-induced breakthrough pain following thoracal esophagectomy

The clinical analgesic effect of electro-acupuncture (EA) stimulation (EAS) on breakthrough pain induced by remifentanil in patients undergoing radical thoracic esophagectomy, and the mechanisms were assessed. Sixty patients (ASAIII) scheduled for elective radical esophagectomy were randomized into three groups: group A (control) receiving a general anesthesia only; group B (sham) given EA needles at PC4 (Ximen) and PC6 (Neiguan) but no stimulation; and group C (EAS) electrically given EAS of the ipsilateral PC4 and PC6 throughout the surgery. The EAS consisting of a disperse-dense wave with a low frequency of 2 Hz and a high frequency of 20 Hz, was performed 30 min prior to induction of general anesthesia and continued through the surgery. At the emergence, sufentanil infusion was given for postoperative analgesia with loading dose of 7.5 μg, followed by a continuous infusion of 2.25 μg/h. The patient self-administration of sufentanil was 0.75 μg with a lockout of 15 min as needed. Additional breakthrough pain was treated with dezocine (5 mg) intravenously at the patient's request. Blood samples were collected before (T1), 2 h (T2), 24 h (T3), and 48 h (T4) after operation to measure the plasma β-EP, PGE2, and 5-HT. The operative time, the total dose of sufentanil and the dose of self-administration, and the rescue doses of dezocine were recorded. Visual Analogue Scale (VAS) scores at 2, 12, 24 and 48 h postoperatively and the incidence of apnea and severe hypotension were recorded. The results showed that the gender, age, weight, operative time and remifentanil consumption were comparable among 3 groups. Patients in EAS group had the lowest VAS scores postoperatively among the three groups (P<0.05). The total dose of sufentanil was 115±6.0 μg in EAS group, significantly lower than that in control (134.3±5.9 μg) and sham (133.5±7.0 μg) groups. Similarly, the rescue dose of dezocine was the least in EAS group (P<0.05) among the three groups. Plasma β-EP levels in EAS group at T3 (176.90±45.73) and T4 (162.96±35.00 pg/mL) were significantly higher than those in control (132.33±36.75 and 128.79±41.24 pg/mL) and sham (136.56±45.80 and 129.85±36.14 pg/mL) groups, P<0.05 for all. EAS could decrease the release of PGE2. Plasma PGE2 levels in EAS group at T2 and T3 (41±5 and 40±5 pg/mL respectively) were significantly lower than those in control (64±5 and 62±7 pg/mL) and sham (66±6 and 62±6 pg/mL) groups. Plasma 5-HT levels in EAS group at T2 (133.66±40.85) and T3 (154.66±52.49 ng/mL) were significantly lower than those in control (168.33±56.94 and 225.28±82.03) and sham (164.54±47.53 and 217.74±76.45 ng/mL) groups. For intra-group comparison, plasma 5-HT and PGE2 levels in control and sham groups at T2 and T3, and β-EP in EAS group at T3 and T4 were significantly higher than those at T1 (P<0.05); PGE2 and 5-HT levels in EAS group showed no significant difference among the different time points (P>0.05). No apnea or severe hypotension was observed in any group. It was concluded that intraoperative ipsilateral EAS at PC4 and PC6 provides effective postoperative analgesia for patients undergoing radical esophagectomy with remifentanil anesthesia and significantly decrease requirement for parental narcotics. The underlying mechanism may be related to stimulation of the release of endogenous β-EP and inhibition of inflammatory mediators (5-HT and PGE2).

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 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.

Analgesia best practice after cardiac surgery

Sources of pain after cardiac surgery include sternotomy, rib retraction, conduit harvest, and drain tubes sites. An analgesic regimen should consider individual patient characteristics, including age, preoperative history of pain and response to analgesics, comorbidities, and psychologic state. Intraoperative and postoperatively administered opioids remain the mainstay of therapy, but adjunctive analgesics such as paracetamol, nonsteroidal anti-inflammatory drugs and tramadol, and regional techniques, can reduce opioid consumption and opioid-induced respiratory depression. This may facilitate earlier tracheal extubation, mobilization, and recovery.

Cardiac surgery in patients with previous pneumonectomy

Severe pulmonary dysfunction is a commonly occurring postoperative complication following cardiac surgery. Resection of a lung causes major anatomical and physiological changes. Shift of the mediastinum and reduction in respiratory function following pneumonectomy makes cardiac surgery challenging not only for the surgeon but also for the anaesthetist. With improvement in life expectancy and better results following cardiac and pulmonary operations increasing number of patients are likely to be subjected to both of these operations during their lifetime.

There is paucity of data in the literature on the subject of cardiac surgery subsequent to previous pneumonectomy. We report our experience on performing cardiac surgery following pneumonectomy to highlight certain important features that we think are important while managing these patients.

Epidural anesthesia and pulmonary function

The epidural administration of local anesthetics can provide anesthesia without the need for respiratory support or mechanical ventilation. Nevertheless, because of the additional effects of epidural anesthesia on motor function and sympathetic innervation, epidural anesthesia does affect lung function. These effects, i.e., a reduction in vital capacity (VC) and forced expiratory volume in 1 s (FEV(1.0)), are negligible under lumbar and low thoracic epidural anesthesia. Going higher up the vertebral column, these effects can increase up to 20% or 30% of baseline. However, compared with postoperative lung function following abdominal or thoracic surgery without epidural anesthesia, these effects are so small that the beneficial effects still lead to an improvement in postoperative lung function. These results can be explained by an improvement in pain therapy and diaphragmatic function, and by early extubation. In chronic obstructive pulmonary disease (COPD) patients, the use of thoracic epidural anesthesia has raised concerns about respiratory insufficiency due to motor blockade, and the risk of bronchial constriction due to sympathetic blockade. However, even in patients with severe asthma, thoracic epidural anesthesia leads to a decrease of about 10% in VC and FEV(1.0) and no increase in bronchial reactivity. Overall, epidural administration of local anesthetics not only provides excellent anesthesia and analgesia but also improves postoperative outcome and reduces postoperative pulmonary complications compared with anesthesia and analgesia without epidural anesthesia.

The benefits of adding epidural analgesia to general anesthesia: a metaanalysis

The purpose of this metaanalysis was to determine the benefits of postoperative epidural analgesia in patients operated on under general anesthesia. By searching the American National Library of Medicine's Pubmed database from 1966 to July 10, 2004, 70 studies were identified. These included 5402 patients, of which 2660 had had epidural analgesia. Epidural analgesia reduces the incidence of arrhythmia, odds ratio (OR) = 0.59 (95%CI = 0.42, 0.81, P = 0.001); time to tracheal extubation, OR = -3.90 h (95%CI = -6.37, -1.42, P = 0.002); intensive care unit stay, OR = -2.94 h (95%CI = -5.66, -0.22, P = 0.03); visual analogical pain (VAS) scores at rest, OR = -0.78 (95%CI = -0.99, -0.57, P < 0.00001) and during movement, OR = -1.28 (95%CI = -1.81, -0.75, P < 0.00001); maximal blood epinephrine, OR = -165.70 pg.ml(-1) (95%CI = -252.18, -79.23, P = 0.0002); norepinephrine, OR = -134.24 pg.ml(-1) (95%CI = -247.92, -20.57, P = 0.02); cortisol, OR = -55.81 nmol.l(-1) (95%CI = -79.28, -32.34, P < 0.00001); and glucose concentrations achieved, OR = -0.87 nmol.l(-1) (95%CI = -1.37, -0.37, P = 0.0006). It also reduces the first 24-h morphine consumption, OR = -13.62 mg (95%CI = -22.70, -4.54, P = 0.003), and improves the forced vital capacity (FVC), OR = 0.23 l (95%CI = 0.09, 0.37, P = 0.001) at 24 h. A thoracic epidural containing a local anesthetic reduces the incidence of renal failure: OR = 0.34 (95%CI = 0.14, 0.81, P = 0.01). Epidural analgesia may thus offer many advantages over other modes of postoperative analgesia.

High thoracic epidural blockade increases myocardial oxygen availability in coronary surgery patients

BACKGROUND

High thoracic epidural techniques are increasingly being used in patients scheduled for cardiothoracic surgery, including coronary artery bypass grafting. In the present study, we evaluated the acute effects of the epidural blockade on myocardial oxygen availability by means of tissue oxygen pressure monitoring in patients submitted for surgical revascularization.

METHODS

Fifty adult patients were included in a prospective, randomized, double-blind study. After placement of an epidural catheter in thoracic space T1-T2, and under general anesthesia, 5-10 ml of either normal saline or 0.3% ropivacaine was injected through the epidural catheter. Hemodynamic parameters and the intramyocardial oxygen partial pressure were recorded before and 20 min after the epidural injection.

RESULTS

There were no demographic or hemodynamic differences between the groups before intervention. A significant increase in intramyocardial partial oxygen pressure was observed in the ropivacaine group (14.6 mmHg vs. 25.1 mmHg, P < 0.0005).

CONCLUSION

High thoracic epidural blockade with 5-10 ml of 0.3% ropivacaine increases myocardial oxygen availability in coronary diseased patients prior to surgical revascularization without deleterious hemodynamic disturbances.

New approaches and old controversies to postoperative pain control following cardiac surgery

OBJECTIVE

To evaluate the effect of postoperative pain control in cardiac surgical patients on morbidity, mortality and other outcome measures.

BACKGROUND

New approaches in pain control have been introduced over the past decade. The impact of these interventions, either alone or in combination, on perioperative outcome was evaluated in cardiac surgical patients.

METHODS

We searched Medline for the period of 1980 to the present using the key terms analgesics, opioid, non-steroidal anti-inflammatory drugs, cardiac surgery, regional analgesia, spinal, epidural, fast-track cardiac anaesthesia, fast-track cardiac surgery, myocardial ischaemia, myocardial infarction, postoperative care, accelerated care programmes, postoperative complications, and we examined and discussed the articles that were identified to be included in this review.

RESULTS

Pain management in cardiac surgery is becoming more important with the establishment of minimally invasive direct coronary artery bypass surgery and fast-track management of conventional cardiac surgery patients. Advances have been made in this area and encompass specific techniques, such as central neuraxial blockade or selective nerve blocks, and drugs (opioids, sedative-hypnotics and non-steroidal anti-inflammatory drugs). Ideally, these therapies provide not only patient comfort but also mitigate untoward cardiovascular responses, pulmonary responses, and other inflammatory and secondary sympathetic responses. The introduction of these newer approaches to perioperative care has reduced morbidity, but not mortality, in cardiac surgical patients.

CONCLUSIONS

Understanding perioperative pathophysiology and implementation of care regimes to reduce the stress of cardiac surgery, will continue to accelerate rehabilitation associated with decreased hospitalization and increased satisfaction and safety after discharge. Reorganization of the perioperative team (anaesthesiologists, surgeons, nurses and physical therapists) will be essential to achieve successful fast-track cardiac surgical programmes. Developments and improvements of multimodal interventions within the context of 'fast-track' cardiac surgery programmes represents the major challenge for the medical professionals working to achieve a 'pain and risk free' perioperative course.

Effect of obesity and thoracic epidural analgesia on perioperative spirometry

BACKGROUND

Lung volumes in obese patients are reduced significantly in the postoperative period. As the effect of different analgesic regimes on perioperative spirometric tests in obese patients has not yet been studied, we investigated the effect of thoracic epidural analgesia and conventional opioid-based analgesia on perioperative lung volumes measured by spirometry.

METHODS

Eighty-four patients having midline laparotomy for gynaecological procedures successfully completed the study. Premedication, anaesthesia and analgesia were standardized. The patients were given a free choice between epidural analgesia (EDA) (n=42) or opioids (n=42) for postoperative analgesia. We performed spirometry to measure vital capacity (VC), forced vital capacity, peak expiratory flow, mid-expiratory flow and forced expiratory volume in 1 s at preoperative assessment, 30-60 min after premedication and 20 min, 1 h, 3 h and 6 h after extubation.

RESULTS

Baseline values were all within the normal range. All perioperative spirometric values decreased significantly with increasing body mass index (BMI). The greatest reduction in VC occurred directly after extubation, but was less in the EDA group than in the opioid group: mean of -23(sd 8)% versus -30(12)% (P<0.001). In obese patients (BMI>30) the difference in VC was significantly more pronounced than in patients of normal weight (BMI<25): -45(10)% versus -33(4)% (P<0.001). Recovery of spirometric values was significantly quicker in patients receiving EDA, particularly in obese patients.

CONCLUSION

We conclude that EDA should be considered in obese patients undergoing midline laparotomy to improve postoperative spirometry.

Epidural clonidine, bupivacaine and methadone as the sole analgesic agent after thoracotomy for lung resection

Thoracic epidural analgesia can effectively relieve post-thoracotomy pain but may also adversely affect pulmonary function. This randomised, prospective study compared the effects on pulmonary function of three different epidural analgesics (clonidine, bupivacaine and methadone). Forty-seven patients undergoing thoracotomy were treated postoperatively for 72 h with one of the study drugs. Doses were titrated to maintain visual analogue pain scale values below 4 out of 10. Throughout the postoperative period, reductions of up to 70% of the pre-operative value were observed in forced expiratory volume in 1 s, forced vital capacity and peak expiratory flow rate. Patients who received clonidine showed significantly faster recovery rates of forced expiratory variables compared to other patients, and by the third postoperative day significantly higher spirometry values (10-15%) were recorded in this group. As clonidine was the most effective drug in terms of preservation of pre-operative lung function, it may be clinically advantageous in post-thoracotomy patients.

High thoracic epidural anesthesia for off-pump coronary artery bypass surgery

OBJECTIVE

To assess the feasibility of high thoracic epidural anesthesia combined with sevoflurane for off-pump coronary artery bypass surgery and to evaluate the postoperative pain control, side effects, and perioperative hemodynamics.

DESIGN

Retrospective review of prospectively collected data.

SETTING

A university teaching hospital.

PARTICIPANTS

One hundred six consecutive patients receiving thoracic epidural combined with sevoflurane.

INTERVENTION

From November 1999, the patients undergoing off-pump coronary artery bypass grafting were offered the epidural-inhalation anesthetic approach.

MEASUREMENTS AND MAIN RESULTS

Insertion of the epidural catheter was successful in all but 2 patients; 1 bloody tap occurred and the dura was never punctured, although 1 patient presented with postoperative paraplegia. An emergency spinal cord nuclear magnetic resonance excluded signs of medullary compression caused by epidural or spinal hematoma. Visual analog scale scores for pain during the first 24-hour period were < 2 in all patients. Mean time to extubation was 4.6 +/- 2.9 hours. The average intensive care unit stay was 1.5 +/- 0.8 days. Incidences of perioperative myocardial infarction, myocardial ischemia, and atrial fibrillation were 2.8%, 7.5%, and 10.6%, respectively. Two patients died: 1 from multiorgan failure and the other from myocardial infarction. Heart rate, mean arterial pressure, cardiac index, and systemic vascular resistance were not affected by thoracic epidural alone. Mean arterial pressure and cardiac index decreased (p < 0.05) when general anesthesia was induced and remained stable thereafter. Neither heart rate nor systemic vascular resistance changed from baseline during operation.

CONCLUSIONS

Thoracic epidural as an adjunct to general anesthesia is a feasible technique in off-pump coronary artery bypass surgery. It induces intense postoperative analgesia and does not compromise central hemodynamics.

Operative techniques in awake coronary artery bypass grafting

BACKGROUND

Off-pump coronary artery bypass grafting was implemented to reduce trauma of surgical coronary revascularization by avoiding extracorporeal circulation. High thoracic epidural anesthesia further reduces intraoperative stress and postoperative pain. In addition, this technique even allows awake coronary artery bypass grafting, avoiding the drawbacks of mechanical ventilation and general anesthesia in high-risk patients.

METHODS

Thirty-four patients underwent awake coronary artery bypass grafting with left internal thoracic artery to left anterior descending coronary artery by partial lower ministernotomy (n = 20), H-graft technique (n = 2), or rib cage-lifting technique (n = 2). In 9 cases we performed double bypass grafting, and in 1 case we performed triple-vessel coronary artery revascularization through complete median sternotomy. In addition to clinical outcomes, visual analog scale pain scores were recorded on days 1, 2, and 3 after surgery.

RESULTS

Thirty-one patients remained awake throughout the whole procedure. Three patients required secondary intubation because of incomplete analgesia (n = 1) or pneumothorax (n = 2). Procedure time was 90 +/- 31 minutes, and recovery room stay was 4.2 +/- 0.6 hours. There were no in-hospital deaths or serious postoperative complications. In 1 case a graft occlusion was documented on predischarge angiography. Early postoperative pain was low (visual analog scale score of 30 +/- 6).

CONCLUSION

These data demonstrate the feasibility and safety of various surgical coronary revascularization techniques without general anesthesia. Continuation of thoracic epidural analgesia provides good pain control and fast mobilization postoperatively. Surprisingly, the awake coronary artery bypass grafting procedure was well accepted by the patients.

Awake coronary artery bypass grafting: utopia or reality?

BACKGROUND

Off-pump coronary artery bypass grafting (OPCAB) was implemented to reduce trauma during surgical coronary revascularization. High thoracic epidural anesthesia further reduced intraoperative stress and postoperative pain. This technique also supports awake coronary artery bypass (ACAB), completely avoiding the drawbacks of mechanical ventilation and general anesthesia in high-risk patients. We compared our first results of the ACAB procedure with the conventional OPCAB operation.

METHODS

Thirty-five patients underwent ACAB (group A) with left internal mammary artery to left anterior descending coronary artery grafting using a partial lower ministernotomy (n = 25) or double bypass grafting (n = 9) and even triple vessel coronary artery revascularization (n = 1) through complete median sternotomy. Thirty-four patients (group B), matched for age, sex, and comorbidity with group A, underwent either partial lower ministernotomy (n = 24) or OPCAB by complete sternotomy (n = 10). We recorded clinical outcomes and postoperative visual analog scale pain scores.

RESULTS

In group A, 32 patients remained awake throughout the entire procedure. Three patients required secondary intubation because of incomplete analgesia (n = 1) or pneumothorax (n = 2). Patients in group A had a recovery room stay of 6.0 +/- 3.2 hours. In group B, mechanical ventilation was implemented for 4.8 +/- 3.1 hours and intensive care unit stay lasted 12 +/- 6.8 hours. Group A had no in-hospital deaths, compared with 1 death in the conventional OPCAB group. Each group had 1 patient with graft stenosis detected on the predischarge angiogram. Early postoperative pain was significantly less in group A than in group B (visual analog scale of 32 +/- 8 compared with 58 +/- 11, p < 0.0001).

CONCLUSIONS

The present data demonstrate the feasibility and safety of surgical coronary revascularization without general anesthesia. Continuation of thoracic epidural analgesia provides better pain control and faster mobilization after such procedures. Surprisingly, the ACAB procedure was well accepted by the patients.

How to implement an acute pain service

To implement a successful acute pain service the following factors are the most important for success: anaesthesiologist-supervised pain nurses and an ongoing educational programme for patients and all health personnel involved in the care of surgical patients. The benefits in increased patient satisfaction and improved outcome after surgery will far outweigh the costs of running an acute pain service that raises standards of pain management throughout the hospital. Optimal use of basic pharmacological analgesia will improve relief of post-operative pain for most surgical patients. More advanced approaches, such as well-tailored epidural analgesia, are needed to relieve severe dynamic pain (e.g. when coughing). This may reduce markedly risks of complications in patients at high risk of developing post-operative respiratory infections and cardiac ischaemic events. More aggressive methods for post-operative pain management need robust routines that will discover the early symptoms and signs of potentially serious complications. High preparedness must be present for swift and correct handling of the rare but potentially catastrophic complications of bleeding and infection in the spinal canal. Chronic pain is common after surgery. Better acute pain relief may reduce this distressing long-term complication of surgery. Research into the long-term effects of optimal neuraxial analgesia and drugs that dampen glutamatergic hyperphenomena (hyperalgesia/allodynia) are urgently needed to verify whether these approaches can reduce the problem of intractable chronic post-operative pain.