Perioperative ischaemia in aortic surgery: combined epidural/ general anaesthesia and epidural analgesia vs general anaesthesia andiv analgesia

Purpose

The goal of this randomized study was to determine whether combined general and epidural anaesthesia with postoperative epidural analgesia, compared with general anaesthesia and postoperative intravenous analgesia, reduced the incidence of perioperative myocardial ischaemia in patients undergoing elective aortic surgery.

Method

Patients were randomly assigned to one of two groups. One group (EPI, n = 48) received combined general and epidural anaesthesia and postoperative epidural analgesia for 48 hrs. The other group (GA, n = 51) received general anaesthesia followed by postoperative intravenous analgesia. Anaesthetic goals were to maintain haemodynamic stability (± 20% of preoperative values), and a stroke volume > 1 ml · kg^?1. A Holter monitor was attached to each patient the day before surgery. Leads 11, V₂, and V₅ were monitored. Myocardial ischaemia was defined as ST segment depression > 1 mm measured at 80 millisec beyond the J point or an elevation of 2 mm 60 millisec beyond the J point which lasted > 60 sec. An event that lasted > 60 sec but returned to the baseline for > 60 sec and then recurred, was counted as two separate events. The Holter tapes were reviewed by a cardiologist blind to the patient’s group.

Results

There were no demographic differences between the two groups. Myocardial ischaemia was common; it occurred in 55% of patients. In hospital, preoperative ischaemia was uncommon (CA = 3, EP1 = 8). Intraoperative ischaemia was common (GA = 18, EP1 = 25). Mesenteric traction produced the largest number of ischaemic (GA = 11, EP1 =11) events. Postoperative ischaemia was most common on the day of surgery. Termination of epidural analgesia produced a burst of ischaemia (60 events in 9 patients)

Conclusion

Combined general and epidural anaesthesia and postoperative epidural analgesia do not reduce the incidence of myocardial ischaemia or morbidity compared with general anaesthesia and postoperative intravenous analgesia.     

Immediate extubation after aortic valve surgery using high thoracic epidural analgesia or opioid-based analgesia

OBJECTIVE: Fast-track anesthesia has gained widespread use in cardiac centers around the world. No study has been published focusing on immediate extubation after aortic valve surgery. This study examines the feasibility and hemodynamic stability of immediate extubation after simple or combined aortic valve surgery using either thoracic epidural analgesia or opioid-based analgesia. DESIGN: Prospective audit, pilot study. SETTING: Single-institution university medical center. PARTICIPANTS: Adult patients undergoing aortic valve replacement (N = 45). INTERVENTIONS: Forty-five patients undergoing aortic valve surgery with an ejection fraction of more than 30% were included in this prospective audit. Induction of anesthesia was done using fentanyl, 2 to 4 mug/kg, propofol, 1 to 2 mg/kg, and endotracheal intubation facilitated by rocuronium; anesthesia was maintained using sevoflurane titrated according to bispectral index (BIS [BIS target: 50]). Perioperative analgesia was provided by high thoracic epidural analgesia (TEA group, bupivacaine 0.125%, 6 to 14 mL/h) or fentanyl, up to 10 microg/kg, followed by patient-controlled analgesia with morphine (OPIOID group). MEASUREMENTS AND MAIN RESULTS: Success of extubation within 30 minutes after surgery was recorded. Hemodynamic data during surgery were compared by using an analysis of variance test; p < 0.05 was considered as showing a significant difference. Data presented as median (25th-75th percentile). In the TEA group, patients underwent simple aortic valve replacement (N = 21) or combined aortic valve surgery (N = 14), with additional coronary artery bypass grafting (N = 10) and replacement of the ascending aorta (Bentall, N = 4). In the OPIOID group, patients underwent simple aortic valve replacement (N = 5) or combined aortic valve surgery (N = 5), with additional aortocoronary bypass grafting (N = 2), replacement of the ascending aorta (Bentall, N = 2), and reconstruction of the mitral valve (N = 1). All 45 patients were extubated within 15 minutes after surgery. There was no need for reintubation; pain scores were lower in the TEA group than in the OPIOID group immediately after surgery and at 6 hours, 24 hours, and 48 hours after surgery. For the TEA group and OPIOID group, the pain scores were 0 (0-2), 0 (0-2), 0 (0-1.5), and 0 (0-0) and 5 (4-5.75), 4 (3-4.5), 4 (3.25-4), and 1 (0-2.5), respectively. During and up to 6 hours after surgery, there was no significant hemodynamic difference between the TEA and OPIOID groups. Eighteen of 45 patients needed temporary pacemaker activation. There were no epidural hematoma or neurologic complications related to TEA. CONCLUSION: Immediate extubation is feasible after aortic valve surgery using either high thoracic epidural analgesia or opioid-based analgesia; both techniques maintain hemodynamic stability throughout surgery. TEA provides superior pain control.     

Value of prolonged epidural analgesia in thoracic surgery

The use of high thoracic epidurals for post-thoracotomy pain relief in 156 patients is reviewed. Analgesia was maintained with a continuous infusion of a local anaesthetic, bupivaca?ne 0.5% 40 ml, mixed with a narcotic, fentanyl 10 ml (perfusion rate between 3 and 7 ml/h). There was successful analgesia in 92%, with efficient ventilation, effective cough, no respiratory distress and only 8 cases of fibroaspiration. Only two significant respiratory complications occurred, due to incorrect management of the peridural route: the analgesic mixture was too concentrated and was injected by bolus instead of by continuous infusion. Other complications occurred, 8 cases of nausea or pruritus, 4 hallucinations, 10 cases of urinary retention lasting more than 24 h, 14 superior limb palsies and 22 Horner's oculopapillary syndrome. All of these complications were minor, easy to manage, and resolved after stopping peridural infusion. In conclusion, peridural analgesia is highly effective and improves the atmosphere in post-thoracotomy wards.     

Influence of thoracic epidural analgesia on cardiovascular autonomic control after thoracic surgery

Background. Thoracic epidural analgesia (TEA) is effective inalleviating pain after major thoracoabdominal surgery and mayalso reduce postoperative mortality and morbidity. This studyinvestigated cardiovascular autonomic control in patients undergoingelective thoracic surgery and its modulation by continuous TEA. Methods. Thirty-eight patients were randomly assigned to receivepatient-controlled analgesia (PCA group) or thoracic epiduralanalgesia (TEA group) with doses of bupivacaine (0.25% duringoperation, 0.125% after operation) and fentanyl (2 µg ml^–1).Heart rate variability (HRV), baroreflex function and pressureresponse to nitroglycerine and phenylephrine were assessed beforeoperation, 4 h after the end of surgery (POD 0) and on the firstand second postoperative days (POD 1 and POD 2). Results. Early after surgery, all HRV variables and baroreflexsensitivities were markedly decreased in both groups. In theTEA group, total HRV and its high-frequency components (HF)increased towards preoperative values at POD 1 and POD 2,whereas the ratio of low to high frequencies (LF/HF) was significantlyreduced (mean (SD), –44 (15)% at POD 0, –38 (17)%at POD 1, –37 (18%) at POD 2) and associatedwith blunting of the postoperative increase in heart rate andblood pressure. In the PCA group, the ratio of LF/HF remainedunchanged and the decrements in HRV variables persisted untilPOD 2. In the two groups, baroreflex sensitivities andpressure responses recovered preoperative values at POD 2. Conclusions. In contrast with PCA management, TEA using lowconcentrations of bupivacaine and fentanyl blunted cardiac sympatheticneural drive, resulting in vagal predominance, while HRV variableswere better restored after surgery. Br J Anaesth 2003; 91: 525–31     

Thromboembolic complications after major abdominal surgery: effect of thoracic epidural analgesia

In a prospective study of 50 patients subjected to major abdominal surgery, the frequencies of postoperative deep vein thrombosis and pulmonary embolism were analysed. The patients were randomized to one of two groups receiving either neurolept anaesthesia or neurolept anaesthesia combined with thoracic epidural analgesia. Five patients were excluded. No special anti-thrombotic prophylaxis was administered. Deep vein thrombosis was diagnosed with the 125I-fibrinogen test and pulmonary embolism with pre- and postoperative lung perfusion scintigraphy combined with lung X-ray. Patients with positive scintigraphy were subjected to pulmonary angiography for verification of the diagnosis. Deep vein thrombosis was treated when diagnosed. The frequency of deep vein thrombosis was equal in both groups (38%). No patient with pulmonary embolism was recorded during the first seven days after operation. It is concluded that the addition of thoracic epidural analgesia to neurolept anaesthesia does not alter the postoperative frequency of deep vein thrombosis in patients subjected to major abdominal surgery. Early diagnosis and treatment of postoperative deep vein thrombosis might prevent pulmonary embolism. Problems encountered in the diagnosis of postoperative pulmonary embolism are discussed.     

Neuroleptanesthesia versus thoracic epidural anesthesia for abdominal aortic surgery

The hemodynamic consequences of abdominal aortic surgery with infrarenal cross-clamping were studied in 21 patients randomized in two groups. In Group I (11 patients), neuroleptanesthesia was utilized, while Group II (10 patients) received thoracic epidural anesthesia at the T8-9 level. Hemodynamic measurements were performed using Swan-Ganz catheters during the surgical procedures in all patients, with special attention to the periods of clamping and unclamping of the abdominal aorta. The thoracic epidural anesthesia group was characterized by greater hemodynamic stability during surgery, while patients in the neuroleptanesthesia group had significant lability of blood pressure, heart rate, and cardiac index. Nevertheless, in the two groups of patients, it is suggested that cardiac function was unfitted to the tissue oxygen demand after unclamping of the aortic prosthesis because the saturation in oxygen of the mixed venous blood and an increase in arteriovenous difference in oxygen were documented. These results point out that, whatever the anesthesia technique, the critical period in abdominal surgery could be aortic unclamping.     

The use of epidural anesthesia and analgesia in aortic surgery.

During a 3-year period, sixty-four consecutive patients, who had elective aortic reconstruction were investigated to determine whether epidural anesthesia and analgesia, combined with light general anesthesia, would lower the rate of perioperative complications in this high-risk group of patients. The epidural group comprised 32 consecutive patients who had surgery during the 20-month period from July 1986 to December 1987. These patients were compared with the previous 32 patients who had aortic reconstruction at Huntington Memorial Hospital (Pasadena, CA) using conventional general anesthetic techniques. Cardiovascular and respiratory morbidity, length of hospital stay, length of intensive care unit stay, and duration of endotracheal intubation were compared. There was no statistically significant difference in cardiovascular morbidity, length of hospital stay, or intensive care unit stay between the two groups. There was however, a striking decrease in respiratory complications and length of intubation in the epidural anesthesia group (P less than 0.005). The authors conclude that epidural anesthesia and analgesia, combined with a light general anesthetic may confer benefits over conventional general anesthesia in patients undergoing aortic surgery.     

Optimal dose of fentanyl for postoperative epidural analgesia after thoracic surgery

BACKGROUND: We investigated the dose of fentanyl in ropivacaine for epidural anesthesia that will provide effective analgesia with minimal side effects after thoracic surgery. METHODS: Sixty patients scheduled to undergo thoracic surgery were randomly allocated to four groups according to fentanyl dose in epidural analgesia: group R (0 microg x hr(-1); n = 15), group F1 (5 microg x hr(-1); n = 15), group F2 (10 microg x hr(-1); n = 15) and group F3 (15 microg x hr(-1); n = 15). Pain scores (visual analogue scale: VAS) were assessed at 1, 3, 6, 12, 24, and 48 hrs after surgery. Degrees of satisfaction regarding pain relief and complications during a period of 48 hrs after surgery were compared. RESULTS: Pain scores in group F3 were significantly lower than those in the other groups at 3, 6, and 12 hrs after surgery. The number of postoperative analgesics used in group R was significantly more than the numbers used in other groups. The incidences of side effects were similar in the four groups. CONCLUSIONS: We conclude that continuous epidural administration of more than 15 microg x hr(-1) of fentanyl in ropivacaine provides pain relief and few side effects after thoracic surgery.     

Perioperative epidural analgesia and outcome after major abdominal surgery in high-risk patients

In a primary analysis of a large recently completed randomized trial in 915 high-risk patients undergoing major abdominal surgery, we found no difference in outcome between patients receiving perioperative epidural analgesia and those receiving IV opioids, apart from the incidence of respiratory failure. Therefore, we performed a selected number of predetermined subgroup analyses to identify specific types of patients who may have derived benefit from epidural analgesia. We found no difference in outcome between epidural and control groups in subgroups at increased risk of respiratory or cardiac complications or undergoing aortic surgery, nor in a subgroup with failed epidural block (all P > 0.05). There was a small reduction in the duration of postoperative ventilation (geometric mean [SD]: control group, 0.3 [6.5] h, versus epidural group, 0.2 [4.8] h; P = 0.048). No differences were found in length of stay in intensive care or in the hospital. There was no relationship between frequency of use of epidural analgesia in routine practice outside the trial and benefit from epidural analgesia in the trial. We found no evidence that perioperative epidural analgesia significantly influences major morbidity or mortality after major abdominal surgery.     

High thoracic epidural analgesia for cardiac surgery: an audit of 874 cases

Despite clinical use for over 10 years, high thoracic epidural analgesia for cardiac surgery remains controversial, due to a perceived increased risk of epidural haematoma resulting from anticoagulation for cardiac pulmonary bypass. There are no sufficiently large randomised studies to address this question and few large case series reported. For this reason, we conducted an audit of neurological complications related to high thoracic epidural analgesia during cardiac surgery in our institution between 1998 and end 2005. During this period 874 patients received epidural analgesia. There were no neurological complications attributable to epidural use. Our findings suggest that major neurological complications related to high thoracic epidural use during cardiac surgery are rare.     

罗哌卡因复合芬太尼用于胸科患者术后硬膜外镇痛

目的 评估罗哌卡因复合不同浓度芬太尼用于胸科手术后硬膜外镇痛(PCEA)效果及不良反应.方法 选取择期胸科食管及贲门手术男性患昔72例,年龄18～65岁,随机分成三组,每组24例.术前T7～8行硬膜外穿刺留置导管,术后接硬膜外镇痛泵.分别用罗哌卡因复合芬太尼1μg/ml(A组)、2μg/ml(B组)或3μg/ml(C组),观察术后2、4、8、12、24、36、48 h的安静/咳嗽疼痛VAS评分、不良反应和追加使用吗啡剂量和PCEA按压情况.结果 术后2、4、8 h,B、C组安静和咳嗽时VAS评分均明显低于A组(P＜0.05);术后16 h,B、C组咳嗽时VAS评分仍低于A组(P＜0.05).B、C组PCEA按压次数显著少于A组(P＜0.01),追加吗啡量也明显低于A组(P＜0.01).结论 0.15%罗哌卡因合用1、2、3μg/ml芬太尼用于PCEA均可获得满意镇痛效果;但推荐以0.15%罗哌卡因合用2μg/ml为首选,镇痛效果好,不良反应低.     

Comparison of different concentrations of levobupivacaine for post-operative epidural analgesia

BACKGROUND: The relative effects of the mass, volume and concentration of local anaesthetic solution used for epidural anaesthesia and analgesia are still under debate. Clinical studies have shown discrepancies, probably because of limited consideration of total dose. METHODS: This prospective, randomized and blinded study evaluated the spread, the quality of post-operative analgesia and the incidence of side-effects of continuous thoracic epidural levobupivacaine 15 mg/h in three different concentrations: 1.5 mg/ml, 10 ml/h (n = 26), 5 mg/ml, 3 ml/h (n = 33) or 7.5 mg/ml, 2 ml/h (n = 31). The following variables were registered within 48 h: sensory block, pain scores, rescue morphine consumption, motor blockade, haemodynamics, sedation, nausea and vomiting, and patient satisfaction. RESULTS: The three groups were similar with regard to demographics, quality of analgesia, morphine consumption, and satisfaction rate. The upper level of sensory block was two segments higher in the 1.5 mg/ml group. Motor blockade in the lower limbs was low in the three groups. Haemodynamic profile was more stable in the higher concentration groups compared with the 1.5 mg/ml patient group (P < 0.001). Nausea was more frequent in the 1.5 mg/ml group (P = 0.02). CONCLUSION: The same dose of levobupivacaine provides an equal quality of analgesia in low or high volume continuous thoracic epidural infusion with reduced haemodynamic instability and nausea in the low volume/high concentration groups.     

Comparison of 2 concentrations of levobupivacaine in postoperative patient-controlled epidural analgesia

STUDY OBJECTIVES: To evaluate the quality of analgesia and the incidence of side effects of 2 different concentrations of levobupivacaine given as an equal milligram-bolus dose (5 mg) via patient-controlled epidural analgesia after abdominal surgery. DESIGN: Prospective, randomized, blinded study. SETTING: Postanesthesia care unit and surgical wards of a university hospital. PATIENTS: Forty-nine patients (41 with complete file) undergoing major lower abdominal surgery. INTERVENTIONS: The patients were randomly assigned to 2 groups: 1.5 mg/mL (bolus 3.3 mL, lockout 20 minutes, n = 26) and 5 mg/mL (bolus 1 mL, lockout 20 minutes, n = 23). The epidural catheter was inserted in the low thoracic level (T9-T12) before induction of a standardized general anesthesia technique. MEASUREMENTS: Demography, upper sensory block, visual analog scale scores at rest and after coughing, levobupivacaine and rescue morphine consumption, motor blockade, hemodynamics, postoperative nausea and vomiting, sedation, and patient satisfaction were recorded within the first 48 hours. MAIN RESULTS: Both groups were similar with regard to demographics, upper level of sensory blockade (T8), and visual analog scale pain scores at rest and after coughing, as well as levobupivacaine and subcutaneous rescue morphine consumption. Motor blockade in the lower limbs was very low in both groups. Arterial blood pressure was slightly lower in the 5 mg/mL group during the first 24 hours (P = 0.052). Five patients in the 1.5 mg/mL and 7 in the 5 mg/mL group had postoperative nausea and vomiting (P = 0.43). No other side effects were recorded, and all of the patients were satisfied. CONCLUSIONS: Administering the same dose of levobupivacaine in either a low or high concentration via patient-controlled epidural analgesia mode provides an equal quality of analgesia with no difference in the incidence of side effects.