A randomized comparison of intravenous versus lumbar and thoracic epidural fentanyl for analgesia after thoracotomy

To Study the Efficacy of Ultrasound Guided Pecto-Intercostal Fascial Plane Block in Patients Undergoing Midline Sternotomy in Open Cardiac Surgery: A Randomized Prospective Comparative Study

BACKGROUND

The incidence of acute poststernotomy pain after cardiac surgery is 80%1. Pecto-intercostal fascial plane block (PIFB) adjacent to the sternum anesthetizes the anterior cutaneous branches of the intercostal nerves and may provide effective analgesia after sternotomy.

METHODOLOGY

A randomized controlled, double-blinded, prospective comparative trial was conducted at a tertiary care center on patients of midline sternotomy between 18 and 65 years and NYHA Class 2 and 3 for open cardiac surgery with the primary aim to evaluate analgesia on deep breathing after 3 hours of PIFB block bilaterally. A total of 60 patients were enrolled and randomly divided into three groups. PIFB was administered bilaterally before extubation, with 15 ml 0.125% bupivacaine plain (Group B), and bupivacaine+ clonidine 0.25 mcg/kg (Group B+C). Group C did not receive any intervention. All patients received acetaminophen 1 gram three times a day and injectable tramadol 1 mg/kg as a rescue analgesic.

RESULTS

Baseline characteristics were similar among all the groups. The Numeric Rating Scale (NRS) for pain was statistically lower (P < 0.05) in Groups B and B+C compared to Group C at rest, deep breathing, and coughing at 3, 6, and 12 hours after extubation. NRS on deep breathing in Groups B, B+C, and C was {(2.3, 1.5, 4.4) at 3 hours, (2.3, 1.6, 4.3) at 6 hours, (2.8, 2.1, 3.9) at 12 hrs, and {(4.3, 3.5, 3.6)} at 24 hours after extubation. The peak expiratory flow rate was the highest in Group B. Rescue analgesia was not required in Group B.

CONCLUSION

PIFB reduces sternotomy pain compared to the control group on deep breathing at 3 hours after block, with delayed requirement of rescue analgesia and improved respiratory mechanics in terms of peak expiratory flow rate at all time points. There is no benefit from adding clonidine.

American Society of Regional Anesthesia and Pain Medicine 2021 John J. Bonica Award Lecture

I am as deeply inspired and humbled to receive this prestigious award, as I am profoundly indebted to the Bonica Award selection committee and the American Society of Regional Anesthesia and Pain Medicine Board of Directors for recognizing my contributions to the development, teaching, and practice of pain medicine in the tradition of Dr John J Bonica. I would also like to recognize my parents, Aura and Tito for providing me with the support and the environment to fulfill my professional goals. Moreover, the support that I have gotten from my team at the hospital, and the Chair of my Department, Dr Mark Lema needs to be underscored.

Epidural Oxycodone for Acute Pain

Epidural analgesia is commonly used in labour analgesia and in postoperative pain after major surgery. It is highly effective in severe acute pain, has minimal effects on foetus and newborn, may reduce postoperative complications, and enhance patient satisfaction. In epidural analgesia, low concentrations of local anaesthetics are combined with opioids. Two opioids, morphine and sufentanil, have been approved for epidural use, but there is an interest in evaluating other opioids as well. Oxycodone is one of the most commonly used opioids in acute pain management. However, data on its use in epidural analgesia are sparse. In this narrative review, we describe the preclinical and clinical data on epidural oxycodone. Early data from the 1990s suggested that the epidural administration of oxycodone may not offer any meaningful benefits over intravenous administration, but more recent clinical data show that oxycodone has advantageous pharmacokinetics after epidural administration and that epidural administration is more efficacious than intravenous administration. Further studies are needed on the safety and efficacy of continuous epidural oxycodone administration and its use in epidural admixture.

Neuraxial anesthesia and postoperative opioid administration for cesarean delivery in patients with placenta accreta spectrum disorder: a retrospective cohort study

BACKGROUND

There is no consensus on optimal anesthetic and analgesic management of patients presenting for cesarean delivery with suspected placenta accreta spectrum disorder. Neuraxial anesthesia is preferred for uncomplicated procedures, but general anesthesia may be indicated for those at risk of hemorrhage and hysterectomy. We compared the effect of anesthesia techniques on postoperative maternal opioid administration and neonatal respiratory distress.

METHODS

A single-center retrospective study from 2016 to 2019 using electronic records to identify singleton pregnancies with a high index of suspicion of placenta accreta spectrum disorder. Patients were categorized by the anesthetic technique they received: general, neuraxial, or neuraxial with conversion to general anesthesia following delivery. Postoperative maternal opioid administration (oral morphine in mg equivalents) and risk of neonatal respiratory distress were compared using linear mixed models.

RESULTS

Thirty-nine records were analyzed. Mean-adjusted oral morphine mg equivalents were 192 for patients receiving general anesthesia vs. 90 for neuraxial anesthesia only (P=0.009) and 104 for neuraxial with conversion to general anesthesia (P=0.052). Neonates delivered under general anesthesia had a 3.5 times relative risk (95% CI 1.3 to 9.8, P=0.017) of respiratory distress compared with those exposed to neuraxial anesthesia alone.

CONCLUSION

Patients receiving general anesthesia alone were administered more opioids than those undergoing neuraxial anesthesia or neuraxial with conversion to general anesthesia. This finding was maintained when accounting for whether or not the patient underwent hysterectomy. Deciding on anesthetic management requires consideration of patient comorbidities, severity of placenta accreta spectrum pathology, and surgical requirements.

Comparison of low dose intravenous fentanyl and morphine infusion for postoperative analgesia in spine fusion surgeries - a randomized control trial

BACKGROUND AND AIMS

Post-operative analgesia for Spine surgeries is difficult without patient control analgesia (PCA) and inadequate monitoring facilities. The objective was to study the effectiveness of analgesia of intravenous administration of low dose fentanyl and morphine for postoperative analgesia following spine fusion surgeries.

METHODS

One hundred adult patients undergoing spine instrumentation surgeries were randomly allotted into two groups: Group M (morphine) or Group F (fentanyl). The patients received either 0.02 mg.kg^-1.h^-1 of morphine or 0.3 mcg.kg^-1.h^-1 of fentanyl infusion postoperatively. If the patient had pain, additional bolus dose of 0.04 mg.kg^-1 and 0.6 mcg. kg^-1 bolus for morphine and fentanyl respectively were given and noted. The additional analgesic consumption was recorded. The Ramsay sedation score (RSS), visual analogue score (VAS), vital parameters and complications were observed.

RESULTS

The demographic characteristics did not reveal significant difference among the two groups. In morphine group, 32 patients did not require any additional bolus dose, 15 patients needed one bolus dose and one patient each required two and three boluses. In fentanyl group, two, 24, 20 and four patients required 0, 1, 2 and 3 bolus doses respectively. There were no statistically significant variations in hemodynamic features like heart rate, blood pressure and oxygen saturation, RSS and VAS. The complication rate was not significant among the groups.

CONCLUSION

Low dose continuous infusion of morphine is more effective than fentanyl with fewer requirements of rescue analgesics for postoperative analgesia. Both drugs are safe without any serious complications.

Segmental thoracic epidural anaesthesia in a dog undergoing intercostal thoracotomy and lung lobectomy

A seven-year-old, 25-kg female crossbreed dog received segmental thoracic epidural anaesthesia for left lateral thoracotomy and lung lobectomy. At presentation mild exercise intolerance and weight loss were reported. A chest CT scan revealed a solitary soft tissue mass in the left caudal lobe. Lung lobectomy surgery was scheduled. Under isoflurane anaesthesia, an epidural catheter was threaded through T13–L1 and advanced 50 mm cranially. Bupivacaine and morphine were administered 30 minutes before incision and at 12-hour intervals thereafter. To minimise side effects, the postoperative dose was titrated to guarantee segmental analgesia. Purposeful movements and signs of sympathetic stimulation in response to surgery were not observed. Intraoperatively, a transient 13% increase in arterial blood pressure occurred, while heart rate remained stable compared with baseline. Although the intended postoperative dose was decreased to prevent side effects, pain scores were below the analgesic intervention score. The catheter was removed on the fourth postoperative day. Complications and neurological sequelae were not noticed.

Evaluation of the cardiopulmonary and antinociceptive effects of bupivacaine administered epidurally at the first lumbar vertebra in awake dogs

ABSTRACT The aim of this study was to evaluate the effect of epidural bupivacaine administration at the first lumbar vertebra on cardiopulmonary variables, arterial blood gases and anti-nociception. Sixteen healthy female dogs were randomly assigned into two groups based on bupivacaine dose: G1 group, 1mg kg-1 or G2 group, 2mg kg-1, diluted in the same final volume (1mL4kg-1). Cardiopulmonary variables were measured and arterial blood gas was collected (T0), it was repeated 10 minutes after intravenous administration of butorphanol 0.4mg kg -1 (T1). Anesthesia was induced with intravenous etomidate at 2mg kg-1 and the epidural catheter was introduced and placed at the first lumbar vertebra. Thirty minutes later, bupivacaine was administered epidurally. Cardiopulmonary measurements and arterial blood gas analysis were recorded at 10 minute intervals (T2 to T6). Evaluation of pre surgical anti-nociception was performed at 5 minute intervals for 30 minutes by clamping the hind limbs, anus, vulva, and tail with the dogs awake. Subsequently, ovariohysterectomy was performed and adequacy of surgical anti-nociception was evaluated at 5 time points. Parametric data were analyzed using the F test with a <0.05 significance. After bupivacaine administration, there were differences between groups just for bicarbonate means (HCO3 -) on T6 (P=0.0198), with 18.7±1.3 and 20.4±0.8 for G1 and G2, respectively. After T1, before bupivacaine administration, both groups presented a slightly lower pH, base excess (BE), the end-tidal carbon dioxide tension (PECO2), and partial pressure of carbon dioxide (PaCO2), suggesting mild metabolic acidosis. G2 showed better antinociceptive effect both before and during surgery. It was possible to perform ovariohysterectomy in 87.5% of the G2 bitches and 25% of the G1 bitches. The two doses of bupivacaine evaluated do not cause important alterations in the studied parameters and the dose of 2mg kg-1 results in a better antinociceptive effect.

Thoracic Epidural Analgesia

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

The Use of Regional Anesthesia in Combination With General Anesthesia for Cardiac Surgery in Children

The use of regional anesthesia in combination with general anesthesia for children undergoing cardiac surgery is the subject of a growing number of publications and presenta tions. Benefits of regional anesthesia in patients having car diac surgery include attenuation of the neuroendocrine response to surgical stress, improved postoperative pulmo nary function, enhanced cardiovascular stability, and im proved postoperative analgesia. To the extent that regional anesthesia facilitates early tracheal extubation in cardiac surgical patients, complications and costs associated with postoperative mechanical ventilation may be reduced. These benefits must, however, be weighed against the ad verse effects that may accompany the use of regional anes thesia, including hypotension, postoperative respiratory de pression, and epidural hematoma formation. In this article, the benefits and risks of regional anesthesia in infants and children undergoing open heart surgery are reviewed. In addition, specific spinal and epidural techniques currently in use are described, including management of side effects. Copyright © 2001 by W.B. Saunders Company.

Epidural Analgesia after Rib Fractures

Pain associated with rib fractures impairs respiratory function and increases pulmonary morbidity. The purpose of this study was to determine how epidural catheters alter mortality and complications in trauma patients. We performed a retrospective study involving adult blunt trauma patients with moderate-to-severe injuries from January 1, 2004 to December 31, 2013. During the 10-year period, 526 patients met the inclusion criteria; 43/526 (8%) patients had a catheter placed. Mean age of patients with epidural catheter (CATH) was higher compared with patients without epidural catheter (NOCATH) (54 vs 48 years, P = 0.021), Injury Severity Score was similar (26 CATH vs 27 NOCATH, P = 0.84), and CATH had higher mean rib fractures (7.4 vs 4.1, P < 0.001). Mortality was lower in CATH (0% vs 13%, P = 0.006). Deep vein thrombosis (DVT) rate was higher in CATH (12% vs. 5%, P = 0.036). After regression analysis, we found catheter placement to be a predictor for DVT (adjusted odds ratios 2.80, P = 0.036). Our center noted increased use of epidural catheters in patients who present with moderate-to-severe injuries. Patients with catheters were older and had a mean of 7.4 ribs fractured. The epidural cohort had longer hospital LOS and decreased mortality. In contrast to other studies, DVT rates were increased in patients who received epidural catheters.

Epidural vs. intravenous fentanyl during colorectal surgery using a double-blind, double-dummy design

BACKGROUND

The overall therapeutic effectiveness of epidural fentanyl vs. the intravenous route is controversial. The present work describes a randomized, controlled, double-blind, double-dummy study of the intraoperative requirements of fentanyl administered by the intravenous or epidural routes during open colon surgery.

METHODS

Thirty patients were randomized to receive intraoperative analgesia with boluses of fentanyl administered by either the epidural or intravenous route (2 μg/kg). The first fentanyl bolus was administered 10 min before incision, and repeated boluses were given when mean arterial pressure or heart rate increased more than 20% over basal values. General anaesthesia was maintained with a propofol infusion. Intraoperative fentanyl and propofol requirements, time to awakening, time to analgesia request, and incidence of adverse effects were recorded.

RESULTS

Median [interquartile range (range)] fentanyl requirements in the epidural and intravenous groups were 0.81 [0.65 (0.47-2.61)] and 2.5 [1.08 (1.07-4.85)] μg/kg/h, respectively (P < 0.001). The epidural group had a shorter time to awakening, with a median of 8 min [4.5 (3-18)] compared with 20 min [12.5 (7-34)] for the intravenous group (P < 0.001). There were no significant differences in propofol requirements. The time to analgesia request was also delayed in the epidural group, with a median of 5 h [5.5 (1-16)] vs. 2 h [1 (1-5)] when fentanyl was administered intravenously (P < 0.001). The incidence of adverse effects was similar in both groups.

CONCLUSION

During major abdominal surgery, epidural administration requires lower doses of intraoperative fentanyl when compared with the intravenous route. Epidural fentanyl also facilitates early awakening and residual analgesia without increasing adverse events.

A randomized prospective evaluation of 3 techniques of postoperative pain management after posterior spinal instrumentation and fusion

STUDY DESIGN

Randomized prospective trial.

OBJECTIVE

To compare the efficacy of intravenous analgesia with single and dual continuous epidural analgesia (CEA) in patients with adolescent idiopathic scoliosis (AIS) undergoing posterior spinal fusion and instrumentation (PSIF).

SUMMARY OF BACKGROUND DATA

Pain management after posterior spinal fusion (PSF) for patients with AIS is challenging. Although intravenous patient-controlled analgesia (PCA) is used most commonly, CEA has been found to be safe and effective. Recently, the use of 2 epidural catheters has been thought to be more effective than a single catheter, although the efficacy of using 2 catheters has not been directly compared with a single catheter.

METHODS

Sixty-six patients with AIS were randomized into 3 groups prior to PSF; PCA, single CEA, and double CEA. Postoperative pain scores as well as side effects, complications, and use of breakthrough medication were collected. Recovery times were also recorded, including hospitalization, times to first bowel movement, and days to walk and climb stairs. Four patients were withdrawn due to the inability to maintain the pain management protocol.

RESULTS

Pain intensity was most effectively controlled with a double CEA when compared with PCA (P < 0.05) and a single CEA (P < 0.05). Pain control was equivalent in both the PCA and single CEA groups (P = 0.21). The pain control method with the fewest side effects trended toward the single CEA, with an average of 2.55 side effects per patient. The majority of the side effects included pruritis, constipation, and nausea. Late onset neurological events were absent in all patients.

CONCLUSION

These data document that the double CEA most effectively controls postoperative pain after surgery for AIS. The single CEA trended toward having the fewest side effects when compared with the other techniques. On the basis these findings, we now routinely use the double CEA technique for all patients having surgery for AIS.

Spinal opioid bioavailability in postoperative pain

Opioids have been used for spinal analgesia for more than a century, and their injection epidurally and intrathecally has a key role in the control of postoperative pain. Since the discovery of the endogenous opioid system, 3 decades ago, their use has become more generalized in obstetric analgesia, the management of chronic pain, and acute postoperative pain. To use opioids effectively for this type of analgesia, it is important to understand the pharmacokinetics and clinical pharmacology of these drugs, specifically those that produce analgesia by an intrinsic spinal mechanism. Evidence from animal and human experiments indicates that hydrophilic opioids (such as hydromorphone and morphine) bind more strongly to specific receptors within the dorsal horn of the spinal cord than lipophilic opioids (such as alfentanil, fentanyl, and sufentanil). This can be understood by considering the spinal cord selectivity and bioavailability of these opioids. This difference is attributable to differences in the pharmacokinetic and pharmacodynamic properties of the 2 groups. It is more difficult for lipophilic opioids to reach and remain at sufficiently high concentrations at the site of action due to their sequestration in epidural fat and rapid plasma clearance from both epidural and intrathecal spaces, resulting in analgesia with a limited spread and duration, as well as the appearance of early supraspinal side effects. In contrast, morphine has very different properties, including greater spinal bioavailability and therefore administered neuraxially, it is suitable choice for the treatment of acute postoperative pain. However, when using morphine, a greater incidence of adverse effects can be expected, and it requires careful patient selection.

Techniques of Bronchial Sleeve Resection

A bronchial sleeve resection can be considered for lesions arising from a lobar bronchus so as to preclude a standard lobectomy, yet without enough distal involvement as to warrant a pneumonectomy. Limited bronchial resection allows maximal conservation of pulmonary function in patients with benign or malignant disease, without compromising oncologic outcome. This article defines the indications and preoperative management of candidate patients and discusses key anesthetic considerations and surgical techniques for this complex airway reconstruction. The essential component of a successful operation is a tension-free bronchial anastomosis. Open communication and careful discussion of airway management between anesthesiologist and surgeon will help ensure a good outcome.

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 PaO(2), lower PaCO(2), increase in Forced Vital Capacity (FVC) and Forced Expiratory Volume in one second (FEV(1))

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

OBJECTIVE

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.

DESIGN

A prospective, randomized, double-blinded trial.

SETTING

A teaching hospital.

PARTICIPANTS

Patients at a tertiary care teaching hospital undergoing throracotomy for lung cancer.

INTERVENTIONS

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.

METHODS AND MAIN RESULTS

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.

CONCLUSIONS

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.

Initial surgical and pain management outcomes after Nuss procedure

PURPOSE

The purpose of this article was to report surgical and pain management outcomes of the initial Nuss procedure experience at the Children's Hospital of Wisconsin (Milwaukee) and to place this experience in the context of the published literature.

METHODS

The initial 118 consecutive Nuss procedures in 117 patients were retrospectively reviewed with approval of the Children's Hospital of Wisconsin human rights review board. Patient, surgical, complication, and pain descriptors were collected for each case. Statistical methods for comparison of pain strategies included the Kolmogorov-Smirnov test for normality, 1-way repeated measures analysis of variance, and paired t tests.

RESULTS

Patient, surgical, and complication descriptors were comparable to other large series. Complication rates were 7% early and 25% late. Epidural success rate was 96.4%. There was 1 episode of recurrence 2 years postbar removal (n = 114).

CONCLUSIONS

The institution of the Nuss procedure provides a highly desired result with significant complication rates. The ideal approach would deliver this result with lower risk. A pain service-driven epidural administration of morphine or hydromorphone with local anesthetic provides excellent analgesia for patients after Nuss procedure. The success of epidural analgesia is independent of catheter site and adjunctive medications. Ketorolac was an effective breakthrough medication.

Epidural versus intravenous fentanyl for postoperative analgesia following orthopedic surgery: randomized controlled trial

CONTEXT AND OBJECTIVE

Controversy exists regarding the site of action of fentanyl after epidural injection. The objective of this investigation was to compare the efficacy of epidural and intravenous fentanyl for orthopedic surgery.

DESIGN AND SETTING

A randomized double-blind study was performed in Hospital São Paulo.

METHODS

During the postoperative period, in the presence of pain, 29 patients were divided into two groups: group 1 (n = 14) received 100 microg of fentanyl epidurally and 2 ml of saline intravenously; group 2 (n = 15) received 5 ml of saline epidurally and 100 microg of fentanyl intravenously. The analgesic supplementation consisted of 40 mg of tenoxicam intravenously and, if necessary, 5 ml of 0.25% bupivacaine epidurally. Pain intensity was evaluated on a numerical scale and plasma concentrations of fentanyl were measured simultaneously.

RESULTS

The percentage of patients who required supplementary analgesia with tenoxicam was lower in group 1 (71.4%) than in group 2 (100%): 95% confidence interval (CI) = 0.001-0.4360 (P = 0.001, Fisher's exact test; relative risk, RR = 0.07). Epidural bupivacaine supplementation was also lower in group 1 (14.3%) than in group 2 (53.3%): 95% CI = 0.06-1.05 (P = 0.03, Fisher's exact test; RR = 0.26). There was no difference in pain intensity on the numerical scale. Mean fentanyl plasma concentrations were similar in the two groups.

CONCLUSION

Intravenous and epidural fentanyl appear to have similar efficacy for reducing pain according to the numerical scale, but supplementary analgesia was needed less frequently when epidural fentanyl was used.

CLINICAL TRIAL REGISTRATION NUMBER

NCT00635986.

Preoperative evaluation for thoracic surgery

The goal of the preoperative evaluation for thoracic surgery is to assess and implement measures to decrease perioperative complications and prepare high-risk patients for surgery. Major respiratory complications, such as atelectasis, pneumonia, and respiratory failure, occur in 15% to 20% of patients and account for most of the 3% to 4% mortality rate. Development of pulmonary complications has been associated with higher postoperative mortality rates. Strategies aimed at preventing postoperative difficulties have the potential to reduce morbidity and mortality, decrease hospital stay, and improve resource use. One lung ventilation leads to a significant derangement of gas exchange, and hypoxemia can develop due to increased intrapulmonary shunting. Recent advances in anesthetic management, monitoring devices, improved lung isolation techniques, and improved critical care management have increased the number of patients who were previously considered inoperable. In addition, there is a growing tendency to offer surgery to patients with significant lung function impairment; hence a higher incidence of intraoperative gas-exchange abnormalities can be expected. The anesthesiologist must also consider the risks of denying or postponing a potentially curative operation in patients with lung cancer. Detailed consideration of the information provided by preoperative testing is essential to successful outcomes following thoracic surgery.

A systematic review of randomized trials evaluating regional techniques for postthoracotomy analgesia

BACKGROUND

Thoracotomy induces severe postoperative pain and impairment of pulmonary function, and therefore regional analgesia has been intensively studied in this procedure. Thoracic epidural analgesia is commonly considered the "gold standard" in this setting; however, evaluation of the evidence is needed to assess the comparative benefits of alternative techniques, guide clinical practice and identify areas requiring further research.

METHODS

In this systematic review of randomized trials we evaluated thoracic epidural, paravertebral, intrathecal, intercostal, and interpleural analgesic techniques, compared to each other and to systemic opioid analgesia, in adult thoracotomy. Postoperative pain, analgesic use, and complications were analyzed.

RESULTS

Continuous paravertebral block was as effective as thoracic epidural analgesia with local anesthetic (LA) but was associated with a reduced incidence of hypotension. Paravertebral block reduced the incidence of pulmonary complications compared with systemic analgesia, whereas thoracic epidural analgesia did not. Thoracic epidural analgesia was superior to intrathecal and intercostal techniques, although these were superior to systemic analgesia; interpleural analgesia was inadequate.

CONCLUSIONS

Either thoracic epidural analgesia with LA plus opioid or continuous paravertebral block with LA can be recommended. Where these techniques are not possible, or are contraindicated, intrathecal opioid or intercostal nerve block are recommended despite insufficient duration of analgesia, which requires the use of supplementary systemic analgesia. Quantitative meta-analyses were limited by heterogeneity in study design, and subject numbers were small. Further well designed studies are required to investigate the optimum components of the epidural solution and to rigorously evaluate the risks/benefits of continuous infusion paravertebral and intercostal techniques compared with thoracic epidural analgesia.

Recent insights into the pharmacokinetics of spinal opioids and the relevance to opioid selection

PURPOSE OF REVIEW

Spinal opioid administration was introduced into clinical practice nearly 25 years ago in the hope of producing intense spinal analgesia that was devoid of the dose-limiting side effects associated with systemic opioid administration. While spinal opioid administration can clearly be an effective analgesic technique, there is a widespread misconception that any opioid administered epidurally or intrathecally will produce analgesia by a selective spinal mechanism. This is simply not true; multiple opioids that are commonly administered spinally produce analgesia by uptake into the systemic circulation with subsequent redistribution to brainstem opioid receptors. In an effort to help clinicians understand why some opioids are not suitable for selective spinal analgesia, this review describes recent insights into the fate of intrathecally and epidurally administered opioids.

RECENT FINDINGS

A series of animal studies published over the last 4 or more years have provided the first measurements of opioid concentration in the epidural space, intrathecal space, spinal cord and peri-spinal tissues following intrathecal and epidural opioid administration. These studies characterize, for the first time, the factors governing the rate and extent to which different opioids redistribute from the epidural and intrathecal spaces to reach target opioid receptors in the spinal cord dorsal horn. The findings indicate that increasing lipid solubility decreases the spinal cord bioavailability of spinally administered opioids.

SUMMARY

These animal data help to explain multiple clinical studies that have demonstrated that the analgesic effect of spinally administered lipid-soluble opioids is due in part, if not exclusively, to uptake into plasma and distribution to brainstem opioid receptors.

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.

The effect of epidural sufentanil in ropivacaine on urinary retention in patients undergoing gastrectomy

BACKGROUND

Although epidural opioids have excellent analgesic property, their side-effects limit its use in patient-controlled epidural analgesia (PCEA). This study was designed to compare side-effects of epidural sufentanil in ropivacaine with that of morphine in ropivacaine focusing on lower urinary tract function after major abdominal surgery.

METHODS

In total 60 patients undergoing gastrectomy were randomly allocated to receive either sufentanil in ropivacaine (Group S, n=30) or morphine in ropivacaine (Group M, n=30) for their PCEA. Epidural catheter was inserted between the 7th and 8th thoracic spine. Visual analogue pain score and side-effects such as nausea, vomiting, pruritus, hypotension and urinary retention were evaluated during postoperative days (PODs) 1 and 2 in the postanaesthetic care unit.

RESULTS

The incidence of serious to major micturition problem in Group S was lower than that in Group M (P<0.001). The incidence of pruritus, nausea and vomiting was also lower in Group S than in Group M on POD 1.

CONCLUSIONS

The lower incidence of major/serious micturition problem in patients receiving sufentanil in ropivacaine thoracic epidural analgesia suggests that continuation of urinary drainage may not be necessary from POD 1 onwards.

The site of action of epidurally administered opioids and its relevance to postoperative pain management

The use of epidurally administered opioids to control postoperative pain is a well established and widely accepted technique. However, despite this longstanding use, there is still an ongoing debate concerning the site of action of the opioids used. Some argue that analgesia is mediated by a spinal mechanism and others that a supraspinal mechanism is responsible. On close inspection of the evidence it becomes apparent that epidural opioids act predominantly spinally when administered as a bolus, and predominantly supraspinally when administered as a continuous infusion. A concentration of 10 microg x ml(-1) appears to be the threshold at which epidurally administered fentanyl can elicit segmental analgesia, a value which may have significant clinical applications. The evidence supporting a synergistic relationship between epidural opioids and local anaesthetics is weak and unsupported by a plausible physiological mechanism. Thus the 'threshold concentration' of approximately 10 microg x ml(-1) is unlikely to be lowered by co-administering opioids with local anaesthetics.

Patient-controlled cervical epidural fentanyl compared with patient-controlled i.v. fentanyl for pain after pharyngolaryngeal surgery

BACKGROUND

Analgesia after pharyngolaryngeal surgery is commonly provided through the i.v. route. The aim of the study was to compare cervical epidural administration of fentanyl with the i.v. route for postoperative analgesia after pharyngolaryngeal surgery.

METHODS

In a randomized double-blind study 42 patients received fentanyl via patient-controlled analgesia (PCA) either through the i.v. route (PCA-IV group, n=22) or through the cervical epidural route (PCA-Epid group, n=20). Identical PCA settings were used in the two groups (bolus dose: 1.5 microg kg(-1), bolus: 25 microg, lockout interval: 10 min, maximum cumulative dose: 400 microg per 4 h). Analgesia at rest and during swallowing was evaluated using a visual analogue scale.

RESULTS

Analgesia at rest was better in the PCA-Epid group than in the PCA-IV group but only 2 and 6 h after surgery (P<0.02). There was no difference in analgesia during swallowing. Cumulative doses of fentanyl were similar {PCA-Epid group: 1412 microg (912), PCA-IV group: 1287 microg (1200) [median (IQR)]}. The Pa(o(2)) showed a significant decrease between the preoperative and postoperative period, but this decrease was identical in the two groups [PCA-IV-group: 11.47 (2.4) kPa vs 8.27 (0.9) kPa; PCA-Epid group: 11.33 (1.9) kPa vs 9.20 (2.4) kPa for preoperative and postoperative period respectively].

CONCLUSIONS

The study results show that cervical epidural analgesia provides marginally better pain relief at rest with no decrease in the fentanyl consumption. The use of the cervical epidural administration of fentanyl is questionable because of the possible complications of the technique.

Prospective, Randomized, Placebo-controlled Study of the Effect of TENS on Postthoracotomy Pain and Pulmonary Function

We investigated the efficacy of transcutaneous electrical nerve stimulation (TENS) for postthoracotomy pain control in a prospective, randomized, double-blind, placebo-controlled study. We studied two groups of patients undergoing posterolateral thoracotomy. In group 1, TENS was used postoperatively on 60 patients for 5 days. Group 2 contained 56 patients without TENS. In both groups a visual analog scale (VAS) was used to indicate if analgesia was needed. When the VAS was higher than 4, an analgesic was administered. We observed the forced expiratory volume in 1 second (FEV(1)), the forced vital capacity (FVC), partial arterial oxygen pressure (PaO2), partial arterial carbon dioxide pressure (PaCO2), and how many doses of analgesia were given at postoperative 0 (extubation time), 2, 6, 12, 24, 48, 72, and 120 hours. TENS was not employed in patients with cardiac or neurologic disease. In group 1, TENS reduced the need to administer opioids during the 5-day postoperative period. This result is statistically significant (P = 0.013). Additionally, following the sixth postoperative hour, TENS increased the spirometric breath function. The FEV1, FVC, and PaO2 were high and PaCO2 was low when the first group is compared to the second. All these results are statistically significant (P = 0.012, P = 0.01, P = 0.024, and P = 0.02 respectively). We observed that TENS produced no evidence of side effects or intolerance in the patients of group 1. TENS is thus beneficial for pain relief following thoracotomy and has no side effects. Consequently, the routine use of TENS following thoracic surgery is recommended.

Epidural Analgesia for Postoperative Pain

Epidural analgesia provides superior analgesia compared with other postoperative analgesic techniques. Additionally, perioperative epidural analgesia confers physiologic benefits, which may potentially decrease perioperative complications and improve postoperative outcome. However, there are many variables (eg, choice of analgesics, catheter-incision congruency, and duration of analgesia) that may influence the efficacy of epidural analgesia. In addition, the use of epidural analgesia should be evaluated on an individual basis because there are risks associated with this technique.

Impact of Acute Pain and Its Management for Thoracic Surgical Patients

Perioperative analgesia for thoracotomy has evolved in concert with increasing knowledge of the impact of pain on recovery, the origin of this pain, and new methods for treating it. Thoracic surgery is one of the few areas where there is more general agreement between surgeons and anesthesiologists as to the importance of aggressive pain management, often with an indwelling epidural catheter left in place until after thoracostomy tube removal. The reasons for this agreement is that it has become increasingly clear to both specialties that pain puts patients with decreased pulmonary reserve who undergo thoracotomy at greater risk for morbidity. Future studies need to examine drugs or drug combinations that can lead to further reductions in the often intense pain that patients receiving aggressive epidural analgesia still experience. Studies directed at finding interventions capable of reducing the rate of long-term postthoracotomy pain still need to be performed.

Pain management strategies for patients undergoing extrapleural pneumonectomy

The role of anesthetic or analgesic technique in outcome remains controversial. The choice of anesthetic and postoperative analgesic plan plays a small, albeit important, role in perioperative care and a multimodal rehabilitation program. Pulmonary complications are the most important cause of morbidity and mortality after EPP. There is increasing evidence that TEA with local anesthetic agents and opioids is superior for the control of dynamic pain, plays a key role in early extubation and mobilization, reduces postoperative pulmonary complications, and has the potential to decrease the incidence of PTPS.

Intrathecal morphine provides effective and safe analgesia in children after cardiac surgery

BACKGROUND

The purpose of this prospective, randomized, blinded to observer study was to assess the analgesic effect and safety of intrathecal morphine (ITM) in post-operative pain control in children after heart surgery with a sternotomy incision.

METHODS

Eighty children, 3-55 kg in body weight, undergoing elective cardiac surgery with opioid-based anaesthesia were randomly divided into two treatment groups to receive either 20 micrograms/kg ITM at induction of anaesthesia or control. To standardize the protocol for administration of post-operative rescue intravenous morphine boluses and infusion (20-60 micrograms/kg/h), the Cardiac Analgesic Assessment Scale (CAAS) was used.

RESULTS

Nine patients were excluded from the study after randomization. Thirty-five patients were enrolled to the ITM group and 36 to the control group. The groups were similar for demographics and intra-operative clinical characteristics. The mean time for the first intravenous morphine dose from ITM administration or equivalent time zero in the control group was significantly longer (P = 0.003) in the ITM group compared with the control group (12.3 vs. 8.7 h). Time from Paediatric Intensive Care Unit (PICU) admission to the start of intravenous morphine was also significantly longer (P = 0.01) in the ITM group (6.0 vs. 3.4 h). The total intravenous morphine consumption over the mean 19 post-operative hours was significantly lower (P = 0.03) in the ITM group. However, the use of ITM did not result in earlier extubation or earlier discharge from the PICU. Of the 35 patients who received ITM at induction of anesthesia, 20% (n = 7) did not require any additional morphine in the PICU compared with three out of 36 control group patients. This did not reach statistical significance. The incidence of adverse events was low in both groups.

CONCLUSIONS

An ITM dose of 20 micrograms/kg had a significant (P = 0.03) intravenous morphine-sparing effect after cardiac surgery. Effective analgesia was observed for 12 h after administration of intrathecal morphine.

Analgesia after thoracotomy: epidural fentanyl/bupivacaine compared with intercostal nerve block plus intravenous morphine

OBJECTIVES

Intercostal nerve blockade plus intravenous (IV) patient-controlled analgesia (PCA) could be an easier and safer alternative to epidural analgesia for postthoracotomy pain, but information about the efficacy of this technique is scarce. The objective of this randomized study was to compare the quality of analgesia and lung function in 2 groups of patients undergoing pulmonary surgery through a posterolateral thoracotomy.

METHODS

Two groups were studied: G1 (n = 16) patients received a 5-segment intercostal block plus IV PCA morphine, and G2 (n = 15) patients received a bupivacaine and fentanyl PCA infusion through a thoracic epidural catheter. Resting and dynamic visual analog pain scale (VAS) measurements, forced vital capacity, and forced expiratory volume in 1 second were measured basally, on arrival in the recovery room, then hourly up to 4 hours and then 12, 24 and 48 hours later. Results were analyzed with a 2-way analysis of variance, chi-square, or Fisher exact test. A p value < or =0.05 was considered significant.

RESULTS

Resting and dynamic VAS scores were slightly lower in G2 patients, although only resting scores were significant. After the first hour, mean scores were below 4 in both groups. No significant difference was observed between groups in relation to respiratory parameters or side effects.

CONCLUSION

The fact that the difference in pain scores is probably not clinically significant shows that an intercostal block with bupivacaine plus IV morphine PCA is a good alternative for postthoracotomy pain management.

The site of action of epidural fentanyl in humans: the difference between infusion and bolus administration

Most published studies suggesting that epidural fentanyl acts predominantly at spinal sites administered the drug as a bolus injection, whereas most studies suggesting that it acts predominantly at supraspinal sites administered the drug as an infusion. In this study we tested the hypothesis that the mode of administration (bolus versus infusion) of epidural fentanyl determines its site of action. Ten healthy volunteers were enrolled in this randomized, double-blinded, cross-over study. On separate study days fentanyl was administered into the epidural space as a bolus (0.03 mg followed by 0.1 mg 210 min later) and as an infusion (0.03 mg/h followed by 0.1 mg/hr 210 min later for 200 min). Using a thermal and electrical experimental pain model, the heat ( degrees C) and electrical current (mA) causing maximum tolerable pain were assessed repetitively over a period of 420 min. The analgesic efficacy measures were obtained at a lumbar and a cranial dermatome. Plasma fentanyl concentrations were determined throughout the study. Epidural bolus administration of fentanyl resulted in segmental analgesia (leg > head), whereas the epidural infusion of fentanyl produced nonsegmental analgesia (leg = head). There was a significant linear relationship between the analgesic effect and the plasma concentration of fentanyl for the epidural infusion but not for the epidural bolus administration of fentanyl. These findings support our hypothesis and might explain the apparent conflict in the literature regarding the site of action of epidural fentanyl.

IMPLICATIONS

In an experimental pain study in volunteers, epidural fentanyl caused segmental analgesia when administered as a bolus and nonsegmental systemic analgesia when administered as a continuous infusion. This finding may help resolve the long-standing controversy surrounding the site of action of epidural fentanyl.

Spinal Mechanisms Contribute to Analgesia Produced by Epidural Sufentanil Combined with Bupivacaine for Postoperative Analgesia

When used alone, lipid-soluble epidural opioids are thought to produce analgesia supraspinally via systemic absorption. However, spinal opioids and local anesthetics have been shown to act synergistically at the spinal level in animal studies. We, therefore, tested the hypothesis that sufentanil requirements will be less when given epidurally than IV in patients simultaneously given epidural bupivacaine after major abdominal surgery. Forty patients were anesthetized with isoflurane and epidural bupivacaine for major abdominal surgery. After surgery, each was given a continuous epidural infusion of bupivacaine at a rate of 5 mg/h and sufentanil patient-controlled analgesia (PCA). In a randomized, double-blinded fashion, the sufentanil was given either epidurally or IV. PCA settings were the same in each group. For 60 hrs after surgery, the following variables were measured: pain scores at rest, during mobilization, and during coughing; extension of sensory block; side effects; and sufentanil consumption. Pain scores, extension of sensory block, and the incidence of side effects did not differ between the two groups. Consumption of sufentanil in the epidural group was half that of the IV group (48 h after surgery: 107 +/- 57 microg versus 207 +/- 100 microg for the epidural and IV groups, respectively; P < 0.05). We conclude that spinal mechanisms contribute to the analgesia produced by epidural sufentanil in combination with a local anesthetic.

IMPLICATIONS

When combined with epidural bupivacaine, the sufentanil requirement was 50% less when given epidurally than IV. Epidural sufentanil thus appears to have a spinal mechanism of action.

Acute pain management for patients undergoing thoracotomy

Management of thoracotomy pain can be difficult, but the benefits of effective pain control are significant. A variety of modalities for treating postoperative pain after thoracotomy are available, including systemic opiates, regional analgesics, and new oral and parenteral agents. This work provides a review of the literature and recommendations for the clinician.

Understanding the physiology and pharmacology of epidural and intrathecal opioids

Epidural and intrathecal opioid administration has become an important part of contemporary medical practice in a variety of clinical settings. It has been widely assumed that any opioid placed in the epidural or intrathecal spaces will produce highly selective spinally mediated analgesia that is superior to that produced by other analgesic techniques. Unfortunately, this is simply not true. In fact, multiple opioids are currently employed for spinal use despite the fact that clinical evidence has shown that spinal administration does not produce analgesia with a selective spinal mechanism or that the analgesia produced is not superior to that produced by intravenous administration. This chapter presents the basic science and clinical data available to assist clinicians in identifying which opioids are appropriate for spinal use and which are not.

Implantable devices for pain control: spinal cord stimulation and intrathecal therapies

Untreated chronic pain is costly to society and to the individual suffering from it. The treatment of chronic pain, a multidimensional disease, should rely on the expertise of varying health care providers and should focus not only on the neurobiological mechanisms of the process but also on the psychosocial aspects of the disease. Implantable devices are costly and invasive, and such efficacious therapies should be used only when more conservative and less costly therapies have failed to provide relief of pain and suffering. Spinal cord stimulation provides neuromodulation of neuropathic, but not nociceptive, pain signals and when used for appropriate indications in the right individuals provides approximately 60-80% long-term pain relief in 60-80% of patients trialled for efficacy. Intrathecal therapies with opioids such as morphine, fentanyl, sufentanil or meperidine--or non-opioids such as clonidine or bupivacaine--provide analgesia in patients with nociceptive or neuropathic pain syndromes. Baclofen, intrathecally, provides profound relief of muscle spasticity due to multiple sclerosis, spinal cord injuries, brain injuries or cerebral palsy.

The primary action of epidural fentanyl after cesarean delivery is via a spinal mechanism

We tested the hypotheses that the primary mechanism of action of epidural fentanyl after cesarean delivery is spinal and that very small dose epidural bupivacaine with epinephrine enhances this effect. After elective cesarean delivery, 100 parturients were randomized in a double-blinded design to four groups. Group I and II patients received a continuous 12 mL/h epidural infusion of bupivacaine 0.015% with epinephrine 1 microg/mL for 48 h and Groups III and IV received a 12 mL/h saline epidural infusion instead. Fentanyl 20 microg/mL was administered via a patient-controlled analgesia device either into the epidural infusion (Groups I and IV) or IV (Groups II and III). When compared to patients receiving epidural fentanyl, those receiving IV fentanyl required larger mean infused and total dose of fentanyl (P < 0.0001), reported more pain (P < 0.001), and had a more frequent incidence of excessive sedation (P < 0.01), nausea (P < 0.01), and vomiting (P < 0.01). Plasma concentrations of fentanyl were larger for Group II and III than for Groups I and IV (P < 0.001) at 24 and 48 h. Our results support the hypothesis that the primary mechanism of analgesia of epidural fentanyl after cesarean delivery is spinal. Our data also show that the total required dose of epidural, but not IV, fentanyl is reduced by very small dose epidural bupivacaine and epinephrine (Group I versus Group IV, P < 0.02 and Group II vs Group III, not significant).

IMPLICATIONS

Fentanyl administered epidurally to parturients after cesarean delivery has a primarily spinal mechanism of action and this effect is enhanced by very small dose epidural bupivacaine and epinephrine.