Thoracic Epidural Anesthesia Group Research Articles

Thoracic epidural anaesthesia reduces insulin resistance and inflammatory response in experimental acute pancreatitis

Aims: The activity of the sympathetic nervous system (SNS) is crucial at an early stage in the development of an inflammatory reaction. A study of metabolic events globally and locally in the early phase of acute pancreatitis (AP), implying hampered SNS activity, is lacking.We hypothesized that thoracic epidural anaesthesia (TEA) modulates the inflammatory response and alleviates the severity of AP in pigs.Material and methods: The taurocholate (TC) group (n = 8) had only TC AP. The TC + TEA group (n = 8) had AP and TEA. A control group (n = 8) underwent all the preparations, without having AP or TEA. Metabolic changes in the pancreas were evaluated by microdialysis and by histopathological examination.Results: The relative increase in serum lipase concentrations was more pronounced in the TC group than in TC + TEA and control groups. A decrease in relative tissue oxygen tension (PtiO2) levels occurred one hour later in the TC + TEA group than in the TC group. The maintenance of normoglycaemia in the TC group required a higher glucose infusion rate than in the TC + TEA group. The relative decrease in serum insulin concentrations was most pronounced in the TC + TEA group.Conclusion: TEA attenuates the development of AP, as indicated by changes observed in haemodynamic parameters and by the easier maintenance of glucose homeostasis. Further, TEA was associated with attenuated insulin resistance and fewer local pathophysiological events.

Efficacy and safety of transversus abdominis plane blocks versus thoracic epidural anesthesia in patients undergoing major abdominal oncologic resections: A prospective, randomized controlled trial

BackgroundThe purpose of this study was to compare patient outcomes for thoracic epidural anesthesia (TEA) with transversus abdominis plane (TAP) blocks. MethodsA prospective, randomized trial was performed for patients undergoing abdominal oncologic surgeries. ResultsThere were 32 TAP and 35 TEA subjects. The TEA group demonstrated increased episodes of hypotension in the first 24 h (3 v 0.6, p = 0.02). There was no difference in 24–48 h fluid balance between the groups. Overall parenteral morphine equivalents of opioids administered for the TEA group were higher for each postoperative day (p < 0.05). The post-operative survey did not demonstrate any difference in subjective pain between the TAP and TEA groups (6 v 6 p = 0.35). There was no attributable morbidity associated with either technique. ConclusionsTAP block use was associated with lower parenteral morphine equivalent usage and decreased incidence of hypotension in the early post-operative period compared to TEA.

Comparison between continuous thoracic epidural block and continuous thoracic paravertebral block in the management of thoracic trauma

BackgroundPostoperative pain is thought to be the single most important factor leading to ineffective ventilation and impaired secretion clearance after thoracic trauma. Effective pain relief can be provided by thoracic epidural analgesia but may have side effects or contraindications. Paravertebral block is an effective alternative method without the side effects of a thoracic epidural. We did this study to compare efficacy of thoracic epidural and paravertebral block in providing analgesia to thoracic trauma patients. MethodsAfter ethical clearance, 50 patients who had thoracic trauma were randomized into two groups. One was a thoracic epidural group (25), and second was a paravertebral group (25). Both groups received 10ml of bolus of plain 0.125% bupivacaine and a continuous infusion of 0.25% bupivacaine at the rate of 0.1ml/kg/h for 24h. Assessment of pain, hemodynamic parameters, and spirometric measurements of pulmonary function were done before and after procedure. Visual analog scale (VAS) scores were accepted as main outcome of the study and taken for power analysis. ResultsThere was significant decrease in postoperative pain in both the groups as measured by VAS score. However, the degree of pain relief between the groups was comparable. There was a significant improvement in pulmonary function tests in both the groups post-procedure. The change in amount of inflammatory markers between both the groups was not significantly different. ConclusionParavertebral block for analgesia is comparable to thoracic epidural in thoracic trauma patients and is associated with fewer side effects.

High thoracic anesthesia offers no major benefit over general anesthesia in on-pump cardiac surgery patients: a retrospective study.

BackgroundThoracic epidural anesthesia (TEA) has been proposed to improve and facilitate early postoperative outcome in cardiac surgery. The aim of our study was to analyze early postoperative outcome data of patients undergoing cardiac surgery under general anesthesia (GA) with comparison to patients receiving combined TEA and GA.MethodsMedical records data from 288 patients who underwent elective on-pump cardiac surgery were retrieved and analyzed. Patients were divided into two study groups according to the type of anesthesia used: GA group (n = 141) and TEA group (n = 147). Early postoperative outcome data including quality of analgesia and major organ outcome parameters were compared between the study groups.ResultsThere was no major difference in early postoperative outcome data between the study groups, except for shorter time to extubation (6.0 ± 10.0 vs. 6.9 ± 8.8 h, respectively, P < 0.05) and hospital stay (10.7 ± 5.9 vs. 12.9 ± 8.8 days, respectively, P < 0.05) in TEA group compared to GA group. Also TEA group as compared to GA group had lower pain numeric rating scale scores (1 ± 1.1 vs. 1.4 ± 1.5 at 24 h, respectively, P < 0.05) and morphine requirements during the first 24 h after surgery (148.2 vs. 193 ± 85.4 μg/kg, respectively, P < 0.05).ConclusionBoth anesthetic methods were equivalent in most postoperative outcome measures. Thoracic epidural analgesia provided superior pain relief, shorter time to extubation and earlier hospital discharge.

Comparison between thoracic epidural anaesthesia &amp; general anaesthesia for open cholecystectomy in adult patients

Background & Objectives: This study was done to assess the feasibility of thoracic epidural anaesthesia in open cholecystectomy. Laproscopic cholecystectomy is the standard now a days but in developing countries open cholecystectomy is still commonly performed. Methods: Our study was carried out on 60 adult, non-pregnant patients ASA grade I, II between 18 – 60 years of age for elective open cholecystectomy under thoracic epidural anaesthesia & general anaesthesia. Haemodynamic parameters(BP, heart rate), oxygenation were observed for 60 minutes. Sensory & motor blockade were observed in thoracic epidural group. Results: In our study both group T and group G were statistically comparable in terms of their gender, mean age and mean weight. Base line pulse rate, SBP, DBP, MAP was comparable in both groups. However, there was significant statistical difference in the two groups in hemodynamic parameters in the study period but it was not clinically significant. Interpretation & conclusions: Thoracic epidural anaesthesia can be used for open cholecystectomy in ASA 1, 2 patients. It provides hemodynamic stability, minimal respiratory distress (as per spo2 values). General anaesthesia still remains the anaesthetic technique of choice for open cholecystectomy. However, an experienced anaesthetist can use thoracic epidural anaesthesia for open cholecystectomy. Key words: Thoracic epidural, General anaesthesia, Open cholecystectomy

Post-thoracotomy pain relief in pediatric patients epidural versus inter-pleural analgesia

Background For controlling post-thoracotomy pain, thoracic epidural (TE) analgesia is considered a gold standard technique. However, it may be associated with serious complications. Interpleural (IP) analgesia is thought to be a simpler technique. Therefore, the current study aimed to compare the efficacy of simple IP with TE bupivacaine in controlling post-thoracotomy pain in pediatrics. Patients and methods A total of 80 pediatric patients undergoing elective thoracotomy were randomly assigned to either the TE or the IP group. In the TE group, epidural catheter was threaded through the caudal space and the tip was placed at the fourth intercostal space. In the IP group, the surgeon inserted the IP catheter through the IP space under direct vision and directed its tip towards the fourth intercostal space on the paravertebral line. Bupivacaine 1.5 mg/kg in 25% concentration was administered through either TE or IP catheters as intermittent boluses every 6 h, starting from the beginning of skin closure, for 24 h postoperatively. Fentanyl 1 mg/kg intravenous bolus was administered as rescue analgesia to keep the pain score less than 0.4. Hemodynamic parameters and pain scores were recorded at 1, 6, 12, 18, and 24 h. In addition, interleukin-6 was measured at 1, 6, and 24 h beginning from the first injected local anesthetic dose. Total postoperative 24 h fentanyl requirements and time to first postoperative rescue analgesia were recorded. Results CRIES pain score showed no significant difference between the studied groups. Time to first rescue analgesia was significantly shorter in the IP group (2.75 ± 0.93) compared with the TE group (4.17 ± 1.07). Patients of the IP group required higher doses of intravenous fentanyl than did those in the TE group (12.83 ± 3.83 vs. 8.16 ± 3.4μg) (P Conclusion For post-thoracotomy pain in pediatrics, equipotent analgesia can be achieved through TE blockade and the simpler IP technique, but with higher postoperative intravenous fentanyl supplementation to the latter technique.

Post-thoracotomy pain: three different analgesic modalities

Background Pain following chest surgery is often underestimated and under treated which may lead to pulmonary dysfunction, prolonged stay, higher cost, potential development of chronic pain, and decreased patient satisfaction. Purpose The aim of this article is to compare thoracic paravertebral versus epidural thoracic block in the control of post-thoracotomy pain. Patients and methods Ninety patients subjected to thoracic surgery were enrolled in this study. They were randomly divided into three equal groups (30 patients each). In the control group (C group) we used intravenous analgesia (fentanyl). In both the thoracic epidural group (TEP group) and the thoracic paravertebral group (TPV group), bupivacaine (0.25%) in a dose of 0.5 mg/kg supplemented with fentanyl 1 μg/kg was used for perioperative analgesia. Assessment included the visual analogue scale for pain, number of patients who needed postoperative analgesia, and the total analgesic dose. Also pulmonary functions represented by forced vital capacity and forced expiratory volume in 1 s were recorded as baseline and at 24 and 48 h postoperatively. Results Visual analogue scale for pain was significantly lower in the TPV group compared with the other two groups, and at the same time it was lower in the TEP group compared with the control group. TEP analgesia was associated with significant hypotension compared with the other two groups. The number of patients who needed postoperative analgesia was lower in the TPV group than the other groups. Respiratory functions represented by forced vital capacity and forced expiratory volume in 1 s were better in TEP and TPV groups in comparison with the control group. Conclusion Thoracic paravertebral block (TPV) provides a higher quality control of postoperative pain than thoracic epidural (TEP) and systemic opioids.

Effects of thoracic epidural anesthesia on cardiac function and myocardial cell apoptosis in isoproterenol-induced chronic heart failure rats.

This study aimed to investigate the effects of thoracic epidural anesthesia (TEA) on cardiac function and myocardial cell apoptosis in isoproterenol (ISO) induced chronic heart failure (CHF) rats. Rats were classified into 4 groups: the healthy control, ISO-induced CHF, ISO + TEA, and sham-treated groups. After 4 weeks, the animals in each group were examined by echocardiography. Invasive hemodynamic measurements were also preformed. Echocardiographic findings suggested that rats in the ISO + TEA group exhibited decreased left ventricular end-systolic (LVES) and left ventricular end-diastolic (LVED), and increased left ventricular ejection fraction (LVEF) and left ventricular shortening fraction (LVFS) compared with rats in the ISO-induced CHF group. Rats in the ISO + TEA group showed improved left ventricular systolic pressure (LVSP) and left ventricular end-diastolic pressure (LVEDP) compared with rats in the ISO-induced CHF group. Additionally, rats in the ISO + TEA group had significant decrease in LV and RV mass indexes (LVMI and RVMI) compared with rats in the ISO-induced CHF rats. Myocardial ultrastructure in the ISO + TEA group significantly improved compared with the ISO-induced CHF group. TEA significantly reduced the percent of TUNEL-positive cells in the ISO + TEA group compared with the ISO-induced CHF group. Compared with the ISO-induced CHF group, Bcl-2 expression of rats in the ISO + TEA group was significantly increased, while Bax expression was significantly attenuated. Our findings suggest that TEA may reduce myocardial apoptosis and decrease extent of structural damage and abnormalities in the myocardium.

Continuous Paravertebral Nerve Blockade for Postoperative Analgesia after Video-Assisted Thoracoscopic Surgery and Chemical Pleurodesis in Children-A Case Series

Study Objective: It is to compare continuous thoracic paravertebral blockade and thoracic epidural catheters for postoperative pain after VATS and chemical pleurodesis in children. Design: Case series, retrospective chart review. Setting: Children’s Hospital of University of Pittsburgh Medical Center. Patients: We studied seventeen (17) pediatric patients who underwent VATS with chemical pleurodesis. Interventions: Fourteen children (14) had continuous thoracic paravertebral blockade and three children (3) had thoracic epidural catheters. Measurements and main results: Postoperative pain scores and consumption of analgesics were compared during the first 48 hours after surgery. Total length of hospital stay and complications secondary to analgesics and regional analgesia were analyzed and compared. Median pain scores were similar with P-values ranging from P = 0.13-0.76. Opioid consumption was not significantly different, with P-values for opioid morphine equivalency ranging from P= 0.13-0.96. Length of stay was significantly shorter for thoracic paravertebral group (3.86, SD±0.77) than for thoracic epidural group (5.00, SD±1.00) (P= 0.04). The rate of complications was low; frequency of nausea /emesis (P= 0.16) and itching (P= 0.60) was similar between groups.

High-dose remifentanil suppresses stress response associated with pneumoperitoneum during laparoscopic colectomy

Although laparoscopic surgery is minimally invasive, it produces stress responses to an extent similar to that of conventional laparotomy. Both epidural anesthesia and remifentanil intravenously (i.v.), combined with general anesthesia, provide stable hemodynamics during laparoscopic surgery. However, it has not been elucidated whether epidural anesthesia and remifentanil are associated with suppression of autonomic and neuroendocrine stress responses. This study aimed to clarify whether thoracic epidural anesthesia (TEA) or remifentanil suppresses stress responses during laparoscopic surgery. We assigned 60 patients undergoing laparoscopic colectomy to three groups anesthetized with 40% oxygen-air-sevoflurane plus either TEA (TEA group), continuous infusion of remifentanil 0.25μg/kg/min [low-dose (LD) group], or 1.0μg/kg/min [high-dose (HD) group] (n=20 each group). Plasma concentrations of adrenocorticotropic hormone (ACTH), cortisol, antidiuretic hormone (ADH), and catecholamines were measured immediately before anesthesia induction, and 30 and 90min after the start of pneumoperitoneum. All groups showed no significant changes in hemodynamics during the course of anesthesia. Compared with TEA, both high-dose and low-dose remifentanil significantly suppressed increases in ACTH, ADH, and cortisol during pneumoperitoneum. Plasma adrenaline showed no significant changes during pneumoperitoneum in any group. Compared with TEA, low-dose remifentanil produced significantly higher plasma concentrations of noradrenaline and dopamine during pneumoperitoneum. Notwithstanding similar hemodynamic responses in all groups, only high-dose remifentanil suppressed both sympathetic responses and the hypothalamus-pituitary-adrenal axis. This result indicates that of these three anesthesia regimens, high-dose remifentanil seems most suited for laparoscopic surgery.

Comparison of Effects of Thoracic Epidural and Intravenous Administration of Lidocaine on Target-Controlled Infusion of Propofol and Tracheal Intubation Response During Induction of Anesthesia

To compare the effects of thoracic epidural anesthesia (TEA) and intravenous (IV) lidocaine on the effect-site concentration (Ce) of propofol target-controlled infusion (TCI) and the intubation-induced stress responses during general IV anesthesia induction. A prospective, randomized trial. A university hospital. Sixty patients undergoing elective surgery for thoracotomies. Patients scheduled for thoracotomies were divided into 3 groups as group TEA, group IV, and control group. Group TEA or group IV received the same doses but not the same concentration of lidocaine via TEA (0.15 mL/kg of 1.35% lidocaine) or IV (2mg/kg of 2% lidocaine), respectively, 15 minutes before induction of anesthesia, and the control group received the same volume of 0.9% normal saline epidurally. Heart rate and mean arterial pressure as well as the time to loss of consciousness (LOC), total doses of propofol TCI, and Ce at LOC were recorded during anesthesia induction. Plasma lidocaine concentration detected was 1.9 (0.3) μg/mL in the IV group and 1.0 (0.3) μg/mL in the TEA group (p<0.001). The time to LOC, total doses of propofol TCI, and Ce at LOC were significantly lower in the IV group than in the TEA group and the control group (p<0.001). Both lidocaine groups showed significant decreases in the elevation of mean arterial pressure and heart rate and plasma concentrations of epinephrine and norepinephrine induced by intubation compared to the control group (p< 0.05). Lidocaine administered via both TEA and IV decreased the induction doses of propofol and suppressed cardiovascular and stress responses to tracheal intubation. Administration of 2mg/kg of 2% lidocaine IV was better, with no side effects of lidocaine toxicity.

Thoracic Epidural Anesthesia Improves Early Outcome in Patients Undergoing Cardiac Surgery for Mitral Regurgitation: A Propensity-Matched Study

There are no large studies that investigate the effect of thoracic epidural anesthesia (TEA) combined with general anesthesia (GA) in patients undergoing valvular surgery. The authors hypothesized that TEA might improve clinically relevant endpoints in patients with primary mitral regurgitation. Propensity-matched study. Cardiac surgery. Patients scheduled for mitral valve repair or replacement were studied. A propensity model was constructed to match 33 patients receiving TEA combined with GA with 33 patients receiving standard GA alone. Overall, the TEA group suffered fewer adverse events than the GA group: 10 (30%) v 23 (10%) with p = 0.002. In particular, the TEA group had a lower incidence of pulmonary events, 6 (18%) v 15 (45%) with p = 0.02, and of cardiac events, 8 (24%) v 16 (49%) with p = 0.04. Median (interquartile) time on mechanical ventilation was reduced in the TEA group, 11 (9-15) v 17 (12-36) with p = 0.007. This propensity-matched study suggested that TEA might be advantageous in patients undergoing surgery for mitral regurgitation.

Effects of Epidural Anesthesia on Acute and Chronic Pain After Coronary Artery Bypass Grafting

To evaluate the effects of thoracic epidural anesthesia (TEA) as an adjunct to general anesthesia (GA) on postoperative pain after coronary artery bypass grafting (CABG). Between April 2009 and March 2010, 40 patients with ischemic heart disease scheduled for elective CABG were prospectively randomized to receive either GA (n = 20) or GA + TEA (n = 20). Through epidural catheters, patients received an infusion of (10-20 mg/h) 0.25%-bupivacaine intraoperatively and during the first 24 hours after surgery. Study endpoints included assessment of postoperative pain at rest and with coughing, rescue analgesic need, and postoperative course. The differences in pain scores were decreased at rest during 6 (0.1 ± 0.3 vs. 2.4 ± 1.8; p < 0.05) and 12 hours (0.1 ± 0.3 vs. 3.9 ± 2.3; p < 0.05) and with coughing at 6 (0.1 ± 0.3 vs. 5.6 ± 2.2; p < 0.05), 12 (0.1 ± 0.3 vs. 5.9 ± 2.3; p < 0.05), and 24 hours (0.05 ± 0.2 vs. 4.6 ± 2.9; p < 0.05) in the GA + TEA group. At one-month follow-up, pain scores were decreased in GA + TEA group (0.3 ± 0.7 vs. 1.6 ± 1.3; p = 003). There was no significant difference at three and six months. Mechanical ventilation time (4.7 ± 1.2 vs. 2.9 ± 1.1 hours; p < 0.05), intensive care unit stay (28.4 ± 9.0 vs. 22.4 ± 3.4 hours; p < 0.05), and hospital stay (7.2 ± 1.1 vs. 6.1 ± 0.3 days; p = 0.001) were reduced in the GA + TEA group. TEA significantly reduced the intensity of postoperative pain and analgesic consumption in the early postoperative period following CABG. The delivery of effective analgesia along with conventional medications may prevent chronic pain after surgery.

A prospective randomized study of intraoperative thoracic epidural analgesia in off-pump coronary artery bypass surgery

The purpose of this study was to test the hypothesis that general anesthesia (GA) plus thoracic epidural anesthesia (TEA) has no impact on the outcomes of off-pump coronary artery bypass surgery (OPCABs) compared to GA followed by patient-controlled TEA (PCTEA), while GA plus TEA leads to a higher requirement for vasoactive drug use. Sixty-four patients, American Society of Anesthesiologists physical status II and III, who were scheduled for elective OPCABs, were offered an epidural catheter inserted at the T2-3 interspace and then randomized into 1 of 2 groups according to whether TEA was applied intraoperatively. The TEA(perio) group received GA plus TEA, while the TEA(post) group received GA alone. All groups had postoperative PCTEA. The number of requirements for vasoactive drugs and the extubation times were recorded. The analgesic effect was monitored by visual analog scale (VAS) pain scores. Heart rate, blood pressure, and blood gases were also monitored. The data are presented as mean values±standard deviation, or medians with quartiles. The proportion of vasoactive drug use was significantly higher in the TEA(perio) group intraoperatively (before or during completion of anastomoses: 59.4 vs. 20.7%, p=0.004; after completion of anastomoses: 53.1 vs. 17.2%, p=0.007). There was no statistically significant difference in extubation times or VAS scores between the 2 groups. We conclude that GA plus TEA has no impact on the outcomes of OPCABs, while its use leads to a higher requirement for vasoactive drug use. GA followed by PCTEA facilitates the anesthesia administration, while it does not affect the extubation time and the postoperative analgesic effect.

The outcome of thoracic epidural anesthesia in elderly patients undergoing coronary artery bypass graft surgery.

Background:Thoracic epidural anesthesia (TEA) improves analgesia and outcomes after a cardiac surgery. As aging is a risk factor for postoperative pulmonary complications, TEA is of particular importance in elderly patients undergoing coronary artery bypass graft (CABG).Methods:Fifty patients aged 65–75 years; ASA II and III scheduled for elective CABG were included in the study. Patients were randomized to receive either general anesthesia (GA) group alone or GA combined with TEA group. Heart rate (HR), mean arterial pressure (MAP), and central venous pressure were recorded. Total dose of fentanyl μg/kg, aortic cross clamping, cardiopulmonary bypass (CPB) time, time to first awaking and extubation, arterial blood gases, visual analog scale (VAS) score in intensive care unit were reported. Postoperative pulmonary function tests were done.Results:TEA showed a significant HR and lower MAP compared with the GA group. The total dose of intraoperative fentanyl and nitroglycerine were significantly lower in the TEA. Patients in TEA group have statistically significantly higher PaO2, lower PaCO2, increase in Forced Vital Capacity (FVC) and Forced Expiratory Volume in one second (FEV1)Conclusions:TEA reduced severity of postoperative pulmonary function and restoration was faster in TEA group in elderly patients undergoing CABG. Also, it resulted in earlier extubation and awakening, better analgesia, lower VAS.

A Randomized, Double-Blind Trial Comparing Continuous Thoracic Epidural Bupivacaine With and Without Opioid in Contrast to a Continuous Paravertebral Infusion of Bupivacaine for Post-thoracotomy Pain

To compare the results of continuous epidural bupivacaine analgesia with and without hydromorphone to continuous paravertebral analgesia with bupivcaine in patients with post-thoracotomy pain. A prospective, randomized, double-blinded trial. A teaching hospital. Patients at a tertiary care teaching hospital undergoing throracotomy for lung cancer. Subjects were assigned randomly to receive a continuous thoracic epidural or paravertebral infusion. Patients in the epidural group were randomized to receive either bupivacaine alone or in combination with hydromorphone. Visual analog scores as well as incentive spirometery results were obtained before and after thoracotomy. Seventy-five consecutive patients presenting for thoracotomy were enrolled in this institutional review board-approved study. On the morning of surgery, subjects were randomized to either an epidural group receiving bupvicaine with and without hydromorphone or a paravertebral catheter-infused bupvicaine. Postoperative visual analog scores and incentive spirometry data were measured in the postanesthesia care unit, the evening of the first operative day, and daily thereafter until postoperative day 4. Analgesia on all postoperative days was superior in the thoracic epidural group receiving bupivacaine plus hydromorphone. Analgesia was similar in the epidural and continuous paravertebral groups receiving bupivacaine alone. No significant improvement was noted by combining the continuous infusion of bupivacaine via the paravertebral and epidural routes. Incentive spirometry goals were best achieved in the epidural bupivacaine and hydromorphone group and equal in the group receiving bupivacaine alone either via epidural or continuous paravertebral infusion. The current study provided data that fill gaps in the current literature in 3 important areas. First, this study found that thoracic epidural analgesia (TEA) with bupivacaine and a hydrophilic opioid, hydromorphone, may provide enhanced analgesia over TEA or continuous paravertebral infusion (CPI) with bupivacaine alone. Second, in the bupivacaine-alone group, the increased basal rates required to achieve analgesia resulted in hypotension more frequently than in the bupivacaine/hydromorphone combination group, underscoring the benefit of the synergistic activity. Finally, in agreement with previous retrospective studies, the current data suggest that CPI of local anesthetic appears to provide acceptable analgesia for post-thoracotomy pain.

Effects of Thoracic Epidural Anesthesia on Flow and Endothelium of Internal Thoracic Artery in Coronary Artery Bypass Graft Surgery

The internal thoracic artery (ITA) is the preferred conduit for coronary artery bypass graft (CABG) surgery. The authors investigated whether thoracic epidural anesthesia (TEA) as an adjunct to general anesthesia (GA) can increase the blood flow of the ITA. A prospective randomized study. A university hospital. Patients with ischemic heart disease. Thirty patients scheduled for elective CABG surgery were randomized to receive either GA (n = 15) or GA + TEA (n = 15) after receiving institutional review board approval. Demographics showed similarity between the groups. The epidural catheter was inserted in the thoracic region between T1 and T5 levels. In the GA + TEA group, the patients received a 20-mg bolus of 0.25% bupivacaine through epidural catheters 1 hour before surgery, and this was followed by the infusion (20 mg/h) of 0.25% bupivacaine. In all patients, ITA free blood flow was measured before cardiopulmonary bypass and without the administration of any vasodilatory agent. A short segment of ITA was excised for histologic examination; immunocytochemistry analysis was performed using antirabbit polyclonal VEGF antibody, rabbit polyclonal inducible nitric oxide synthase (i-NOS) antibody, and adenosine anti-A2B receptor antibody. The immunoreactivity rates then were evaluated. The mean ITA free flow in the GA + TEA group was significantly higher than in the GA group (56.0 ± 9.0 mL/min v 39.6 ± 14 mL/min, p = 0.001). Immunostaining intensity in the sections after incubation with each primary antibody increased in the GA + TEA group compared with the GA group. The results of this study indicated that TEA increased ITA free blood flow significantly via increased VEGF, i-NOS, and adenosine-A2B receptor expressions. Therefore, the use of TEA as an adjunct to GA might be considered as an alternative to vasoactive agents for increasing ITA flow in CABG surgery.

Thoracic Epidural Anesthesia for Cardiac Surgery: A Randomized Trial

The addition of thoracic epidural anesthesia (TEA) to general anesthesia (GA) during cardiac surgery may have a beneficial effect on clinical outcomes. TEA in cardiac surgery, however, is controversial because the insertion of an epidural catheter in patients requiring full heparinization for cardiopulmonary bypass may lead to an epidural hematoma. The clinical effects of fast-track GA plus TEA were compared with those of with fast-track GA alone. A randomized controlled trial was conducted in 654 elective cardiac surgical patients who were randomly assigned to combined GA and TEA versus GA alone. Follow-up was at 30 days and 1 yr after surgery. The primary endpoint was 30-day survival free from myocardial infarction, pulmonary complications, renal failure, and stroke. Thirty-day survival free from myocardial infarction, pulmonary complications, renal failure, and stroke was 85.2% in the TEA group and 89.7% in the GA group (P = 0.23). At 1 yr follow-up, survival free from myocardial infarction, pulmonary complications, renal failure, and stroke was 84.6% in the TEA group and 87.2% in the GA group (P = 0.42). Postoperative pain scores were low in both groups. This study was unable to demonstrate a clinically relevant benefit of TEA on the frequency of major complications after elective cardiac surgery, compared with fast-track cardiac anesthesia without epidural anesthesia. Given the potentially devastating complications of an epidural hematoma after insertion of an epidural catheter, it is questionable whether this procedure should be applied routinely in cardiac surgical patients who require full heparinization.

Standard blood flow rates of cardiopulmonary bypass are adequate in awake on-pump cardiac surgery☆

Standard blood flow rates for cardiopulmonary bypass have been assumed to be the same for awake cardiac surgery with thoracic epidural anesthesia (TEA) as for general anesthesia. However, compared with general anesthesia, awake cardiac surgery with epidural anesthesia may be associated with higher oxygen consumption and may result in lactic acidosis when standard blood flow rates were used. The aim of our study was to investigate if standard blood flow rates are adequate in awake cardiac surgery. Forty-five patients undergoing elective on-pump cardiac surgery were assigned to receive either epidural (Group TEA, n=15), combined (Group TEA-GA, n=15) or general (Group GA, n=15) anesthesia. To monitor the adequacy of standard blood flow rates, arterial lactate, acid base parameters, and central venous and jugular bulb saturation were measured at six time points (before, during, and after the surgery) in all groups. Blood flow rates were adjusted when needed. No lactic acidosis has developed in any group (p=NS). TEA as compared with TEA-GA and GA groups had lower central venous (67±4%, 75±11%, and 72±13%, respectively, p<0.05) and jugular bulb oxygen saturations during cardiopulmonary bypass (60±7%, 68±9%, and 75±12%, respectively, p<0.05) during the post-cardiopulmonary bypass period. The TEA group as compared with the TEA-GA and GA groups also had mild hypercapnic respiratory acidosis (56±10, 42±8, and 37±4 mmHg, respectively, p<0.05) and mild decrease of arterial oxygen saturation (93±4%, 97±2%, and 96±1%, respectively, p<0.05) at the end of surgery without any clinical consequences. Thus, no additional blood flow rates adjustments in any study group and no ventilatory support in TEA group were required. Under careful monitoring, the use of standard blood flow rates is adequate for patients undergoing awake on-pump normothermic cardiac surgery.

Differential effects of lumbar and thoracic epidural anaesthesia on the haemodynamic response to acute right ventricular pressure overload

The safety of epidural anaesthesia in patients at risk for right ventricular pressure overload remains controversial. We compared the haemodynamic effects of vascular and cardiac autonomic nerve block, induced by selective lumbar (LEA) and high thoracic epidural anaesthesia (TEA), respectively, in an animal model subjected to controlled acute right ventricular pressure overload. Eighteen pigs were instrumented with epidural catheters at the thoracic (T) and lumbar (L) level and received separate injections at T2 (1 ml) and L3 (4 ml) with saline (s) or bupivacaine 0.5% (b). Three groups of six animals were studied: (i) a control group (Ls+Ts), (ii) LEA group (Lb+Ts), and (iii) TEA group (Ls+Tb). Haemodynamic measurements including biventricular pressure-volumetry were performed. Right ventricular afterload was then increased by inflating a pulmonary artery (PA) balloon. Measurements were repeated after 30 min of sustained right ventricular afterload increase. LEA decreased systemic vascular resistance (SVR) and did not affect ventricular function. TEA had minor effects on SVR but decreased left ventricular contractility while baseline right ventricular function was not affected. Control and LEA-treated animals responded similarly to a PA balloon occlusion with an increase in right ventricular contractility and heart rate. Animals pretreated with a TEA did not show this positive inotropic response and developed low cardiac output in the presence of right ventricular pressure overload. In contrast to LEA, TEA reduced the haemodynamic tolerance to PA balloon occlusion by inhibiting the right ventricular positive inotropic response to acute pressure overload.