Lumbar versus thoracic epidural buprenorphine for postoperative analgesia following coronary artery bypass graft surgery

BACKGROUND: Thoracic epidural analgesia (TEA) is reported to provide effective analgesia following cardiac surgery. We compared the effect of buprenorphine (BN) through the lumbar and thoracic epidural routes for postoperative analgesia following coronary artery bypass graft surgery (CABG). METHODS: Forty patients with normal left ventricular ejection fraction scheduled for CABG were randomly divided into two groups, the TEA group (n = 19) and the lumbar epidural analgesia (LEA) group (n = 20). For postoperative pain relief they received epidural BN 0.15 mg at the first demand for pain relief following extubation. A top-up dose of BN 0.15 mg was administered in cases where visual analogue scale (VAS) score was > 3 at 1 h after first dose. Subsequent breakthrough pain was treated with 30 mg intramuscular ketorolac tromethamine (ketorolac). Pain assessed by VAS score on a 0-10 scale, respiratory rate, FEV1, FVC, mean arterial blood pressure, cardiac index, PaO2 and PaCO2 were measured at frequent intervals. Side effects of epidural opioids were noted. RESULTS: Both groups were comparable in demographic characteristics, had similar VAS scores from 1 to 24 h postoperatively, required similar amounts of intramuscular ketorolac for break-through pain and had comparable pulmonary functions and side effects. CONCLUSION: This study shows that BN by the lumbar epidural route for analgesia after CABG compares favourably with the same drug through the thoracic route in terms of quality of analgesia and incidence of side effects.     

Thoracic epidural anaesthesia and analgesia: United Kingdom practice

BACKGROUND: Thoracic epidural analgesia has become increasingly practised in recent years. Complications are rare but potentially serious and, consequently, careful evaluation is required before undertaking this technique. The practice surrounding this procedure varies widely amongst anaesthetists. METHODS: A postal survey to examine the practice of thoracic epidural analgesia was sent to all Royal College of Anaesthetists tutors in the United Kingdom. RESULTS: Responses were received from 240 tutors, representing a return rate of 83%. When obtaining consent for thoracic epidural cannulation, 42% of respondents mentioned risk of a dural tap complication and 11% mentioned neurological damage. Fifty percent of respondents performed epidural cannulation following induction of general anaesthesia. The practice of epidural insertion in patients with abnormal coagulation varied, although over 80% of respondents did not consider concurrent treatment with either aspirin or non-steroidal anti-inflammatory drugs a contraindication. Sterile precautions for epidural insertion also varied between anaesthetists. Postoperatively, 95% of respondents used an opioid-based bupivacaine solution for epidural infusions, and these were most commonly nursed on general surgical wards (63%). Seventy-eight percent of hospitals provided an acute pain team to review epidural analgesia. CONCLUSION: In the United Kingdom, there is little consensus in the practice of thoracic epidural analgesia relating to the issues of informed consent, epidural cannulation in patients with deranged clotting and the sterile precautions taken prior to performing epidural insertion. Most respondents use an opioid-based bupivacaine solution to provide postoperative epidural analgesia. Most hospitals in the UK now provide an acute pain service for thoracic epidural follow-up.     

Effects of preemptive epidural analgesia on post-thoracotomy pain

OBJECTIVE: The purpose of this study was to determine whether preemptive thoracic epidural analgesia (TEA) initiated before surgical incision would reduce the severity of acute post-thoracotomy pain and the incidence of chronic post-thoracotomy pain. METHOD: Meta-analysis of randomized controlled trials (RCTs). SEARCH STRATEGY: MEDLINE, the Cochrane Central Register of Controlled Trials (CENTRAL) and EMBASE were searched from 1966 to December 2004 for prospective RCTs published in all languages using the following MeSH terms: post-thoracotomy pain, epidural analgesia, chronic pain, and preemptive analgesia. SELECTION CRITERIA: All RCTs that compared thoracic epidural analgesia initiated before surgical incision (preemptive group) versus thoracic epidural analgesia initiated after completion of surgery (control group) in adult patients undergoing unilateral thoracotomy. MEASUREMENTS AND MAIN RESULTS: Three authors reviewed all citations and simultaneously extracted data on sample size, patient characteristics, surgical and analgesic interventions, methods of pain assessment, and pain scores at 24 hours, 48 hours, and 6 months postoperatively. Six studies were included with a total of 458 patients. Pooled analyses indicated that preemptive TEA was associated with a statistically significant reduction in the severity of acute pain on coughing at 24 and 48 hours (weighted mean difference -1.17 [95% confidence interval (CI) -1.50 to -0.83] and -1.08 [95% CI -1.17 to -0.99]), respectively. Acute pain was a good predictor of chronic pain. However, there was no statistically significant difference in the overall incidence of chronic pain at 6 months between the preemptive TEA group (39.6%) and the control group (48.6%). CONCLUSION: Preemptive TEA appeared to reduce the severity of acute pain but had no effect on the incidence of chronic pain.     

Post-thoracotomy pain after thoracic epidural analgesia: a prospective follow-up study

BACKGROUND: Pain becomes chronic in 22-67% of patients who undergo a thoracotomy. Thoracic epidural analgesia (TEA) has replaced less invasive methods to manage postoperative pain. We wanted to find out if active use of TEA, combined with extended pain management at home, reduces the incidence of chronic post-thoracotomy pain. METHODS: All consecutive thoracotomy patients during a 16-month period were included. On the ward, pain was measured daily by VAS during rest and coughing and the consumption of analgesics was registered. The patients were interviewed one week after discharge by telephone and by a questionnaire after 3 and 6 months to find out how much pain they had. RESULTS: A total of 114 patients were recruited. The data were analysed from 89 patients who had had TEA and 22 who had had other methods. TEA was effective in alleviating pain at rest and during coughing. In the TEA patients the incidence of chronic pain of at least moderate severity was 11% and 12% at 3 and 6 months, respectively. One week after discharge 92% of all patients needed daily pain medication. CONCLUSIONS: TEA seems effective in controlling evoked postoperative pain, but technical problems occurred in 24% of the epidural catheters. The incidence of chronic pain was lower compared with previous studies where TEA was not used. The patients had significant pain and needed regular pain medication and instructions during the first week after discharge. Extended postoperative analgesia up to the first week at home is warranted.     

胸段硬膜外复合静脉全麻与全凭静脉麻醉在开胸手术中的比较

目的 比较胸段硬膜外复合静脉全麻与全凭静脉麻醉对开胸手术患者血流动力学、麻醉药维持剂量、术后苏醒、躁动及疼痛的影响.方法 64例择期行剖胸手术患者,ASA Ⅱ级～Ⅲ级,采用完全随机设计的方法分为2组.A组:胸段硬膜外复合静脉全麻组,患者预先用10 ml 0.25%布比卡因和0.1 mg芬太尼硬膜外给药.术中硬膜外0.25%布比卡因和芬太尼10μg/ml,5 ml/h复合丙泊酚维持.B组:全凭静脉麻醉组,丙泊酚-端芬太尼全凭静脉麻醉.观察并记录不同时间点2组心率(HR)、平均动脉压(MAP)、中心静脉压(CVP)、所需麻醉维持药量、术毕清醒及出现疼痛时间.结果 2组患者各观察点血流动力学变化比较,差异无统计学意义;胸段硬膜外复合静脉全麻组麻醉维持不需要静脉镇痛药瑞芬太尼和肌松药阿曲库铵,只需复合充分的丙泊酚镇静,就能满足手术需求;术后苏醒早;拔管时间(11±4)min,相对于全凭静脉麻醉组(23±16)min明显缩短(P<0.05):躁动例数显著减少;术后出现疼痛时间(7.4±2.6)min相对于全凭静脉麻醉组(0.5士0.3)min明显延长(P<0.01).结论 胸段硬膜外复合静脉全麻用于开胸手术快通道麻醉是一种安全、经济、有效并有利于患者术后恢复的麻醉方法.     

Can chronic poststernotomy pain after cardiac valve replacement be reduced using thoracic epidural analgesia?

BACKGROUND: The aim of our study was to evaluate the use of thoracic epidural analgesia (TEA) in acute pain management after cardiac valve replacement and determine if the incidence of chronic pain related to the sternotomy was reduced by the use of TEA. This patient group was chosen to exclude pain related to the use of the internal mammary artery and angina pectoris. METHODS: Patients scheduled for elective cardiac valve replacement were offered TEA. A match-control group was selected. Epidural catheter placement, complications and postoperative neurological state were noted for both groups. Eighteen months postoperatively, a questionnaire was sent out concerning pain management, wound discomfort and pain. RESULTS: Forty-nine patients were included. The TEA group consisted of 35 patients. At 18 months' follow up, 37% from the TEA group and 21% from the control group had pain or discomfort related to the sternum (NS). Two in the TEA group had severe pain. CONCLUSION: We found in our small material that TEA provided excellent analgesia in the peri- and postoperative period, but we did not find a protective effect of TEA on chronic poststernotomy pain, neither weak pain nor severe pain.     

Cervical epidural analgesia via a thoracic approach using nerve-stimulation guidance in adult patients undergoing total shoulder replacement surgery

BACKGROUND: Continuous cervical epidural anesthesia can provide excellent peri- and post-operative analgesia, although several factors prevent its widespread use. Advancing catheters from thoracic levels to the cervical region may circumvent these barriers, provided they are accurately positioned. We hypothesize that guiding catheters from thoracic to cervical regions using low-current epidural stimulation will have a high success rate and enable excellent analgesia in adults undergoing total shoulder arthroplasty. METHODS: After Institutional Review Board approval, adult patients were studied consecutively. A 17-G Tuohy needle was inserted into the thoracic epidural space using a right paramedian approach with loss of resistance. A 20-G styletted epidural catheter, with an attached nerve stimulator, was primed with saline and a 1-10 mA current was applied as it advanced in a cephalad direction towards the cervical spine. Muscle twitch responses were observed and post-operative X-ray confirmed final placement. After a test dose, an infusion (2-8 ml/h) of ropivacaine 2 mg/ml and morphine 0.05 mg/ml (or equivalent) was initiated. Verbal analog pain scale scores were collected over 72 h. RESULTS: Cervical epidural anesthesia was performed on 10 patients. Average current required to elicit a motor response was 4.8 +/- 2.0mA. Post-operative X-ray of catheter positions confirmed all catheter tips reached the desired region (C4-7). The technical success rate for catheter placement was 100% and excellent pain control was achieved. Catheters were positioned two to the left, four to the right and four to the midline. CONCLUSION: This epidural technique provided highly effective post-operative analgesia in a patient group that traditionally experiences severe post-operative pain and can benefit from early mobilization.     

The effect of thoracic epidural analgesia on respiratory function after cholecystectomy

To assess the effect of thoracic epidural analgesia (TEA) on postoperative respiratory function and pulmonary complications, a prospective randomized trial was conducted in patients undergoing cholecystectomy. One hundred patients were allocated to TEA (n = 30), TEA + general anesthesia (TEA + GA) (n = 30), or general anaesthesia (GA) (n = 40) groups. Respiratory function was analysed by measuring forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), functional residual capacity (FRC), total lung capacity (TLC), peak expiratory flow (PEF) in the supine and sitting postures, and arterial blood gases. Postoperative pulmonary complications were carefully documented. TEA significantly prevented the postoperative deterioration of respiratory function as compared with general anaesthesia. FVC, FEV1 and PEF decreased by 20% in patients receiving TEA, in contrast to 55% in patients after GA on the day of operation. This improvement continued until the 2nd day after operation, when FVC, FEV1 and PEF and their recovery rates were equal in all groups. In the sitting posture the preoperative FVC, FEV1 and PEF were about 10% greater than in the supine position. After operation, this difference was further increased. The preoperative difference of 27% in FRC between the sitting and supine postures was maintained after operation. PaO2 decreased by 0.8 kPa after TEA, by 1.5 kPa after TEA + GA with the lowest value on the 2nd postoperative day and by 1.5 kPa after GA, with the lowest value immediately after operation. Simultaneous hypercarbia indicated hypoventilation, which may have contributed to impaired respiratory function on the following days.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of thoracic paravertebral block with bupivacaine versus combined thoracic epidural block with bupivacaine and morphine on pain and pulmonary function after cholecystectomy

Twenty patients undergoing elective cholecystectomy via a subcostal incision were randomized in a double-blind study to either thoracic paravertebral blockade with bupivacaine 0.5% (15 ml followed by 5 ml/h) or thoracic epidural blockade with bupivacaine 7 ml 0.5% + morphine 2 mg followed by 5 ml/h + 0.2 mg/h, respectively for 8 h postoperatively. Mean initial spread of sensory analgesia on the right side was the same (Th3,4-Th11 versus Th2,6-Th11), but decreased (P less than 0.05) postoperatively in the paravertebral group. All patients in the epidural group had bilateral blockade, compared with three patients in the paravertebral group. In both groups only minor insignificant changes in blood pressure and pulse rate were seen postoperatively. Pain scores were significantly higher in the paravertebral group, as was the need for systemic morphine (P less than 0.05). Pulmonary function estimated by forced vital capacity, forced expiratory volume and peak expiratory flow rate decreased about 50% postoperatively in both groups. In conclusion, the continuous paravertebral bupivacaine infusion used here was insufficient as the only analgesic after cholecystectomy. In contrast, epidural blockade with combined bupivacaine and low dose morphine produced total pain relief in six of ten patients.     

The integration of thoracic epidural anesthesia into anesthesia for intra-abdominal surgery]

Upper abdominal and thoracic surgeries require efficient pain management. The complications of postoperative analgesia include respiratory depression and--when choosing the epidural route--possible damage to the spinal cord by infection, trauma, or bleeding. Therefore, thoracic epidural analgesia may appear to be too risky and is frequently cancelled although many studies have shown its excellent efficacy. Controlled studies comparing thoracic epidural analgesia to lumbar epidural analgesia or intravenous analgetic regimens with special regard to the patient's outcome are contradictory. To make the preoperative decision on the method of pain control more rational, we studied catheter-related complications from 2056 thoracic epidural catheters used for intra- and postoperative analgesia retrospectively (n = 1002) and prospectively (n = 1054) over a 5 1/2-year period. In all patients the thoracic epidural catheter was inserted preoperatively using local anaesthesia, in most cases by the paramedian approach between level T 5/6 and T 8/9. During the clinical course of all patients there were no clinical signs of any epidural bleeding or infection. Neurological complications caused by the epidural catheter did not occur. Seven patients (0.035%) experienced radicular pain that disappeared after removal of the catheter or interruption of the puncture, respectively. A primary perforation of the dura mater was noticed in 0.5% of cases retrospectively and 1.23% prospectively. Respiratory depression following epidural application of 0.3 mg buprenorphine was seen in 1 patient (0.05%). Continuous analgesia with local anaesthetics and/or opioids applied epidurally by a thoracic catheter was performed on the peripheral ward (n = 829, 40%) if close monitoring of the neurological status as well as rapid diagnosis of any painful paraesthesia or paraplegia was possible.     

The influence of thoracic epidural analgesia on transcapillary fluid balance in subcutaneous tissue

Clinical observation and calculation of fluid balance have shown that patients undergoing aortocoronary bypass surgery with thoracic epidural analgesia (TEA) in addition to general anesthesia retain less fluid than patients having general anesthesia only. The present study was designed to investigate whether this effect could be explained by thoracic epidural analgesia influencing the transcapillary fluid balance, i.e. the transcapillary forces (COPpl, COPif, Pif). Interstitial fluid colloid osmotic pressure (COPif) and interstitial fluid pressure (Pif) were measured subcutaneously at heart level by the blister suction technique and the wick-in-needle technique, respectively. Simultaneously plasma colloid osmotic pressure (COPpl) was recorded. Sixteen male patients were allocated to two groups, one having general anesthesia only (controls, n = 8). The other group (TEA, n = 8) received, at the induction of anesthesia, bupivacaine 50 mg via an epidural catheter as an adjunct to general anesthesia. TEA was maintained by continuous infusion for 24 h postoperatively. Preoperatively no intergroup differences were observed in "the Starling forces" (COPpl, COPif, Pif). At the start of extracorporeal circulation COPpl was significantly lower in the TEA-group than in controls. During extracorporeal circulation the transcapillary COP-gradient (COPpl-COPif) was reversed in both groups. At the end of extracorporeal circulation Pif increased to a minor degree in the TEA-group and remained significantly lower than in controls from 3 to 24 h postoperatively. The subcutaneous interstitial tissue could be less expanded postoperatively in the TEA-group, also reflected by a lower increase in Pif.     

Epidural morphine and buprenorphine for postoperative pain relief after hepatectomy

Postoperative pain relief with epidural morphine and buprenorphine was studied in 33 patients following hepatectomy. Morphine 2mg or buprenorphine 0.06mg in 10ml of normal saline was administered through an epidural catheter inserted at the Th10-11 or L3-4 interspace. Morphine injected at the lumbar level, as well as that injected at the thoracic level produced excellent and long-lasting (20.8 +/- 8.6 hours) pain relief. Respiratory rate decreased significantly following epidural morphine at the L3-4, but PaCO2 did not change. Buprenorphine injected at the thoracic level produced good and long-lasting (22.6 +/- 9.9 hours) pain relief, although buprenorphine injected at the lumbar level produced incomplete analgesia. The epidural administration of morphine 2mg at L3-4 or buprenorphine 0.06mg at Th10-11 may be recommended for postoperative analgesia following hepatectomy.     

Epidural buprenorphine--a double-blind study of postoperative analgesia and side effects

Epidural buprenorphine was investigated as a postoperative analgesic in a randomized double-blind study of 158 patients given epidural analgesia with mepivacaine or bupivacaine for orthopedic surgery of the lower extremity. At the end of surgery, patients were given either 0.15 mg of epidural buprenorphine (n = 38), 0.3 mg (n = 37) in 15-ml saline, or no further epidural injections (n = 47, control group) after 2% mepivacaine for intraoperative anesthesia. A fourth group (n = 36) received 0.3 mg of buprenorphine in 15-ml saline, after the intraoperative use of 0.5% bupivacaine. The patients rated postoperative pain. The need for additional analgesics as well as side effects were recorded. Analgesia after 0.15 mg buprenorphine was superior to that after no reinjection for 6 hr after surgery (P less than 0.05). Buprenorphine (0.3 mg) was superior both to no reinjection and to 0.15 mg of buprenorphine until the twelfth hour (P less than 0.05). Analgesia after bupivacaine followed by 0.3 mg of buprenorphine was not significantly different than analgesia seen after mepivacaine followed by 0.3 mg of buprenorphine. There was an increase of PaCO2 of 2-5 mm Hg between 1.5-3.5 hr after 0.3 mg of buprenorphine without any evidence for late respiratory depression. Other side effects, e.g., disturbances of micturition, pruritus, nausea, vomiting, fatigue, and headache, were comparably common in all groups. The epidural administration of 0.3 mg buprenorphine may be recommended for postoperative analgesia following orthopedic surgery of the lower extremity.     

Intravenous patient controlled analgesia combined with continuous thoracic epidural analgesia for post-thoracotomy pain

We compared the efficacy of intravenous patient controlled analgesia of buprenorphine plus continuous thoracic epidural infusion of bupivacaine (IV-PCA group) with the efficacy of continuous thoracic epidural infusion of bupivacaine and buprenorphine (the TEA group). No patient in IV-PCA group required supplemental analgesics, while 90% of TEA group required supplemental intramuscular buprenorphine to relieve post-thoracotomy pain. In TEA group, 94% of the supplemental drugs were administered during night shifts. These results indicate that IV-PCA of buprenorphine combined with continuous thoracic epidural infusion of bupivacaine is more effective analgesic management than continuous TEA with buprenorphine and bupivacaine.     

Epidural anesthesia during upper abdominal surgery provides better postoperative analgesia

Since repeated noxious stimuli may sensitize neuropathic pain receptors of the spinal cord, we tested the hypothesis that the appropriate blockade of surgical stimuli with epidural anesthesia during upper abdominal surgery would be beneficial for postoperative analgesia. Thirty-six adult patients undergoing either elective gastrectomy or open cholecystectomy were randomly allocated to receive either inhalational general anesthesia alone (group G) or epidural anesthesia along with light general anesthesia (group E) throughout the surgery. Postoperative pain management consisted of patient-controlled analgesia (PCA) with bupivacaine accompanied by the continuous infusion of buprenorphine. To assess postoperative pain, a visual analogue scale (VAS) was employed at 2, 24, and 48 h postoperatively. While there was no significant difference in the bupivacaine dose, more patients undergoing gastrectomy in group G required supplemental analgesics than those in group E, and the VAS scores in group E demonstrated significantly better postoperative analgesia compared to group G after both types of surgery. Thus, an appropriate epidural blockade during upper abdominal surgery likely provides better postoperative pain relief.     

The optimum initial pediatric epidural bolus: a comparison of four local anesthetic solutions

BACKGROUND: There is no consensus on the concentration or type of local anesthetic used for initiation of epidural anesthesia. The aim of this randomized, double-blind, controlled trial was to compare the clinical effectiveness of epidural administration of both levobupivacaine and bupivacaine in 0.2% and 0.25% concentrations in pediatric patients undergoing abdominal and urological surgery. METHODS: One hundred and forty-one children scheduled for lower abdominal and urological surgery were randomized to receive 0.4-0.6 ml.kg(-1) epidural, 0.25% bupivacaine, 0.2% bupivacaine, 0.25% levobupivacaine or 0.2% levobupivacaine. Initial epidural volumes, onset times; hemodynamic consequences, postoperative pain scores and degree of residual postoperative motor block were all recorded. RESULTS: There were no significant differences in the proportion of children with effective analgesia after incision [0.20% bupivacaine 97%, 0.25% bupivacaine 94%, 0.20% levobupivacaine 91%, 0.25% levobupivacaine 92% (P=0.73)] when a median volume of 0.55 ml.kg(-1) was used. There was no association between the volume used for thoracic, lumbar, or sacral epidural anesthesia and the effectiveness of the agents used. There was a significantly greater incidence of pain on awakening with the 0.2% solutions compared with the 0.25% solutions, but no differences in the incidence of residual motor block between groups. CONCLUSIONS: While there is no difference in the proportion of effective surgical anesthesia, the lower incidence of pain and distress with the 0.25% solutions suggests that this concentration has clinical advantages over the 0.2% solutions for pediatric epidural anesthesia.     

Epidural buprenorphine for postoperative analgesia. A controlled comparison with epidural morphine.

In a double-blind controlled study, epidural buprenorphine 0.3 mg was compared with 4 mg of epidural morphine for postoperative pain relief the first 24 hours after major orthopaedic surgery. The degree of analgesia was equal and satisfactory in both groups. Duration of action was 620 minutes with buprenorphine and 580 minutes with morphine, which was not significantly different. The only serious side effects were recorded in the morphine group, with two patients complaining of pruritus and five of urinary retention. In conclusion, epidural buprenorphine did not offer any advantages in preference to morphine for postoperative pain relief following orthopaedic surgery.     

轻比重罗哌卡因单侧腰麻用于单侧下肢创伤手术对PCEA的影响

目的 观察轻比重罗哌卡因单侧腰麻用于下肢创伤手术患者的麻醉效果及其对硬膜外自控镇痛(PCEA)的影响.方法 ASA Ⅰ或Ⅱ级下肢创伤手术患者120例,随机均分为L1、L2、W1、W2四组.L1、L2组分别用轻比重罗哌卡因7.5～15.0 mg、15.0～22.5 mg,W1、W2组分别用重比重罗哌卡因7.5～15.0 mg、15.0～22.5 mg.术后用罗哌卡因150 mg+舒芬太尼0.05 mg+阿扎司琼10 mg+生理盐水至100 ml行PCEA.记录两组麻醉效果、不良反应,术始、术中及PCEA结束时双下肢的Bromage评分.结果 L1、L2、W2组麻醉效果优于W1组(P＜0.05).L1、L2组感觉、运动阻滞起效时间明显短于W1、W2组(P＜0.05).L1组各时点健肢Bromage评分明显低于患肢(P＜0.05).L1组低血压、尿潴留发生率明显低于L2、W2组(P＜0.05).结论 下肢创伤手术使用0.3％轻比重罗哌卡因7.5～15.0 mg单侧腰麻,麻醉效果满意,术后PCEA期间运动阻滞仅限于患肢,血流动力学稳定,不良反应发生率低,患者总体满意度高.     

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.     

Thoracic epidural analgesia improves pulmonary function in patients undergoing cardiac surgery

PURPOSE: Pulmonary dysfunction commonly occurs following coronary artery bypass graft (CABG) surgery, increasing morbidity and mortality. We hypothesized that thoracic epidural anesthesia (TEA) would improve pulmonary function and would decrease complications in patients undergoing CABG surgery. METHODS: This prospective, randomized, controlled trial was conducted with Ethics Board approval. Fifty patients, undergoing CABG surgery, were randomized to the epidural group or to the patient-controlled analgesia morphine group. Patients in the epidural group received a high, thoracic epidural, preoperatively. Intraoperatively, 0.75% ropivacaine was infused, followed postoperatively, by 0.2% ropivacaine for 48 hr. Outcome measurements included: visual analogue pain scores; spirometry; atelectasis scores on chest radiographs; and the incidence of atrial fibrillation. RESULTS: Twenty-five patients were enrolled in each group. Patients in the epidural group had significantly less pain on the operative day, and for the subsequent two days. Compared to baseline, the forced expiratory volume in one second was significantly higher in the epidural group, on the first and second postoperative days (43.7 +/- 12.2% vs 36.4 +/- 12.0%, p < 0.002, and 43.3 +/- 12.5% vs 38.4 +/- 11.0%, p <0.05). There was significantly more atelectasis in the control group, four hours postoperatively (p < 0.04); however, on the third, postoperative day, the groups were similar with regards to this outcome. The incidence of atrial fibrillation was similar in both groups, and there were no complications related to the epidural. CONCLUSIONS: High TEA decreases postoperative pain and atelectasis and improves pulmonary function in patients undergoing CABG surgery. Our results support the use of TEA in this group of patients.