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Education  |   September 2002
Epidural Analgesia Enhances Functional Exercise Capacity and Health-related Quality of Life after Colonic Surgery: Results of a Randomized Trial
Author Affiliations & Notes
  • Franco Carli, M.D., M.Phil.
    *
  • Nancy Mayo, Ph.D.
  • Kristine Klubien, M.D.
  • Thomas Schricker, M.D., Ph.D.
  • Judith Trudel, M.D., M.Sc.
    §
  • Paul Belliveau, M.D.
    §
  • * Professor and Chairman, ‡ Assistant Professor, Department of Anesthesia, † Professor, Division of Clinical Epidemiology, § Assistant Professor, Department of Surgery.
  • Received from the Department of Anesthesia, McGill University Health Centre, Montreal, Canada.
Article Information
Education
Education   |   September 2002
Epidural Analgesia Enhances Functional Exercise Capacity and Health-related Quality of Life after Colonic Surgery: Results of a Randomized Trial
Anesthesiology 9 2002, Vol.97, 540-549. doi:
Anesthesiology 9 2002, Vol.97, 540-549. doi:
SURGICAL stress occurs before, during, and after an operative procedure. 1 Postoperative fatigue is encountered in approximately one third of patients for at least 4–6 weeks following uncomplicated major surgery, and its duration is proportional to the intensity of the stress. 2 The pathogenic mechanisms contributing to stress-induced organ dysfunction in the postoperative period and the associated fatigue experienced by many patients include the endocrine and inflammatory response, the restricted mobilization, and the impaired nutritional intake. 3 Several therapeutic interventions have been suggested to minimize this metabolic upset, such as nutritional support, hormonal supplementation, epidural anesthesia and analgesia, and exercise. 4 
The current literature shows that single interventions are of limited value in modifying the catabolic consequences of surgery, possibly because cointerventions are not standardized. 3 An integrated approach to perioperative care, comprising minimally invasive surgical access, optimal pain relief provided by epidural analgesia, early oral nutrition, and active mobilization, has been shown through observational studies to decrease time to discharge, readmission rate, and postoperative morbidity. 5–8 However, these observational studies are limited in their ability to control for important confounding variables impacting on the indications for use of the various components of care.
There is a need for randomized trials that standardize those components of care known to impact on recovery and that have well-defined patient relevant endpoints of functional outcome. 9 However, in evaluating multifactorial interventions, it must be recognized that the effects produced could impact on the integrating subsequent components. An appropriate measurement strategy for short- and long-term outcomes has been proposed. 10 While there is scanty evidence that perioperative interventions have long-term impact, it is reasonable to hypothesize a relation. For example, there is growing evidence that the lower inflammatory response caused by endoscopic surgery is associated with shorter length of hospital stay. 11 
Epidural analgesia has been recognized as a satisfactory method of pain relief control for abdominal surgery, but it is not necessarily the standard of care. Evidence that use of epidural analgesia also enhances the recovery process would lead to wider adoption of this method and better quality of care for surgical patients.
Thus, the purpose of this study was to evaluate the effect of epidural analgesia on the recovery processes and outcomes following colorectal surgery, during controlled conditions where perioperative care is standardized. Pain relief in the immediate postoperative period (4 days) would facilitate a greater degree of postoperative mobilization and nutritional intake, leading to restoration of functions.
Therefore, it is hypothesized that, in comparison to patients randomized to patient controlled analgesia (PCA) with intravenous morphine, patients randomized to epidural analgesia will have better functional exercise capacity at 3 and 6 weeks after hospital discharge, time when patients recover from surgical stress.
Subjects and Methods
The target population for this study was adult patients undergoing elective colorectal surgery for nonmetastatic conditions. Patients with malnutrition (serum albumin < 35 g/l), severe cardiopulmonary disease (American Society of Anesthesiologists physical status IV), sepsis (febrile on antibiotics), inflammatory bowel disease, chemotherapy or radiotherapy within the 6 months preceding surgery, and an inability to communicate or understand the aim of the project (questionnaire and consent form would need to be translated) were excluded. The study population was drawn from two adult hospital sites within the McGill University Health Centre from April 1998 and April 2000. The study was approved by the institutional ethics committees of the sites, and all 64 eligible patients agreed to participate in the study.
Procedures
All patients meeting eligibility criteria were approached 1 or 2 weeks before surgery when the project was explained in detail by the investigators. The patients were not blinded, but both PCA and epidural groups were equally attractive to them. Patients agreeing to the study were evaluated for baseline variables by two study nurses specially trained in these assessments. On the morning of the surgical procedure, the group to which the subject had been randomly assigned was revealed. Two surgeons (P. B. and J. T.) with fellowship training in colorectal surgery performed the procedures in all patients. Both groups received a daily postoperative regimen whereby protein drinks and semisolid food were offered as well as assisted mobilization out of bed starting the morning after surgery. A total of 32 patients were randomized to the PCA group and 32 to the epidural group.
Assessment Procedures
Assessments involved measurement of health-related outcomes, physiologic parameters, sociodemographic characteristics, compliance to regimen, adverse events, and hospitalization data. The measurement strategy varied according to the time interval from surgery (table 1).
Table 1. Outcome Measures during the Immediate and Late Postoperative Periods
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Table 1. Outcome Measures during the Immediate and Late Postoperative Periods
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Anesthesia Management
Patients in the PCA group received general anesthesia consisting of thiopentone, 250 μg fentanyl, vecuronium, and 1–1.5% end-tidal isoflurane, nitrous oxide, and oxygen. Postoperative pain relief was with PCA morphine started at the end of surgery and continued for 4 days after surgery. The rate of infusion of intravenous morphine was set up at 1–2 mg every 5 min with no background infusion and increased if the visual analog scale (VAS; 0–100 mm) at rest was greater than 50. PCA was discontinued on days 3–4 after surgery if VAS on moving was less than 30.
In the epidural group, an epidural catheter was inserted before general anesthesia in the eighth or ninth thoracic interspace, and bupivacaine 0.5% was injected in divided doses to a maximum of 15–20 ml in the epidural space to produce a bilateral segmental sensory block to ice and pinprick between T4and S5 dermatomes. The neural blockade was maintained during surgery with additional 5 ml bupivacaine 0.5% administered hourly. A light general anesthesia included induction with thiopentone, 100 μg fentanyl, and vecuronium, and maintenance with 0.4% end-tidal isoflurane, nitrous oxide, and oxygen. An epidural infusion of bupivacaine 0.1% with 2 μg/ml fentanyl at a rate between 4 and 15 ml/h was started at the end of surgery and continued for up to 4 postoperative days.
The segmental sensory level of analgesia was assessed twice a day by the acute pain team using a blunted needle and ice, and the infusion was adjusted to maintain a sensory block between T7 and L3. The quality of pain relief was assessed using a VAS (0–100 mm; where 0 represents no pain and 100 the worst imaginable pain). If VAS at rest was greater than 50, the rate of infusion was increased to a maximum of 15 ml/h or the concentration of bupivacaine increased to 0.2% with the infusion rate decreased to 8 ml/h. If pain still persisted, the epidural catheter was resited and the block tested. If the surgical incision extended beyond the dermatome area covered by the block, epidural fentanyl was replaced by morphine (0.1 mg/ml). The epidural infusion was decreased on the third day after surgery and discontinued on day 4 if VAS on moving was less than 30. A neurologic profile was performed on a daily basis to assess sensory and motor deficit, and the epidural site was inspected for signs of infection. If the epidural block did not provide adequate analgesia, the patient continued to be included in the intention-to-treat analysis, but was excluded from analysis addressing efficacy.
Both groups also received 500 mg Naproxen either orally or rectally twice a day for 4 days. The discontinuation of epidural and PCA was decided on the following criteria: tolerance of oral diet, absence of complications, and active mobilization. Then, oral acetaminophen up to 4 g/day and codeine up to 60 mg/day were prescribed as required until discharge. The acute pain team was unaware of the results of the clinical assessment.
Perioperative Care
Bowel preparation and antibiotic prophylaxis were started the day before surgery. Nasogastric tube and abdominal drains were not inserted. The surgical incision was either a midline vertical or horizontal. All patients received an intravenous infusion of 0.9% normal saline at a rate of 6 ml · kg−1· h−1. No blood was transfused unless blood loss was more than 20% of the patient's circulating blood volume. Hypotension (arterial blood pressure < 80 mmHg) was treated with intravenous bolus doses of phenylephrine. A thermal blanket set up at 40°C was positioned on the exposed parts of the body to attenuate the heat loss during surgery. A bladder catheter was inserted before surgery to monitor urine output and was removed 48 h after surgery. Oxygen therapy (30% oxygen mask) was provided to all patients during the first 24 h. All patients underwent surgery during the morning hours. The patients were visited by the surgical team that was responsible for patients’ postoperative care and that was unaware of the results of the clinical or objective assessments. This team diagnosed and recorded daily gastrointestinal function (presence of abdominal sounds, passage of flatus, abdominal distension and tenderness, presence of bowel movements) and also determined the readiness for discharging patients from the hospital according to standard criteria (patients fully mobile without assistance, tolerance of semisolid and solid food, absence of infection and pain, and passage of stool). Length of hospital stay and readmission rate were also recorded. Postoperative complications were fully documented and diagnosed according to clinical and laboratory criteria. Postoperative complications to be recorded were intraabdominal sepsis, clinically apparent anastomotic leakage, wound infection, wound dehiscence, proven pulmonary emboli, pneumonia, urinary infection, myocardial infarction, cerebrovascular accidents, paralytic ileus, urinary retention necessitating bladder catheterization, and bowel obstruction. Daily assessments of VAS at rest, on coughing, and on moving were recorded by the research nurses, who were unaware of the results of the objective assessment and did not know the explicit hypothesis to be tested. Similarly, fatigue VAS response (0–5; where 0 represents no tiredness and 5 greatest tiredness) was recorded daily throughout the study.
Nutrition
Nutritional supplement in liquid form containing up to 60 g of protein and 1,500 calories, based on patient's body weight and formulated to personal taste, was offered from the first day after surgery to both groups by a dietitian unaware of the study and group allocation. This was done to make the two groups as similar as possible on all interventions except for the mode of analgesia. The daily nutritional support (calorie count and protein intake) was monitored and measured accurately by the ward dietitian to ensure that the nutritional supplement was provided equally to both groups and was appropriately documented. The protein and calorie intake was increased on day 2 in either liquid or solid form as tolerated by the patient. If nausea and vomiting became troublesome, the diet was temporarily discontinued, and an antiemetic (metoclopramide) was administered. In case of distended abdomen and protracted vomiting and ileus, the diet was discontinued and intravenous fluids provided.
Mobilization
Patients in both groups were encouraged by the research nurse to mobilize in the morning and late afternoon as of the first postoperative day. Time out of bed, either sitting or walking, was reported by the patients in their own journal. Vital capacity was measured before surgery and for the first 4 postoperative days with the patient in a semisitting position.
Outcome Measurements
The primary outcome was functional exercise capacity as measured by the 6-minute walking test (6-MWT) before surgery and at 3 and 6 weeks after hospital discharge. The test has been shown to have a significant correlation with maximum oxygen consumption values obtained with other methods of exercise testing. 12 Patients were asked to walk on level indoor ground as far as possible using any aid that is usually used. They were instructed to walk at a pace that would make them tired at the end of the walk. They could, however, adjust their pace as necessary and stop if they felt too tired or breathless or if they experienced pain. In this study, all subjects walked for 6 min along a 10-m course, and the total distance covered was measured. The evaluator gave encouragement during the walk using set phrases such as “good, keep going” or “keep it up, you are doing well.” When tolerable, one practice walk was performed to minimize the learning effect. The reliability of the 6-MWT has been evaluated by a number of investigators directly and indirectly, and measurement error is approximately 10%. 12 
The secondary outcome was health-related quality of life (HRQL) as measured by the acute (1-week recall period) SF-36 health survey. The SF-36 is a generic measure of perceived health status that incorporates behavioral functioning, subjective well-being, and perceptions of health by assessing eight health concepts: (1) limitation in physical activities because of health problems; (2) limitations in role activities because of physical health problems; (3) pain; (4) limitations in social activities because of health problems; (5) general mental health; (6) limitations in usual role activities because of emotional problems; (7) vitality (energy and fatigue); and (8) general health perception. 13 It provides a comprehensive, validated, psychometrically sound and efficient way to measure health from the patient's point of view by scoring standardized responses to standardized questions. Reliability, both retested and internal consistency, has been extensively demonstrated, as have content, criterion, and construct validity and responsiveness to clinical changes. Recently, a method of scoring two components, physical and mental health, has been developed. The two subcomponents have been standardized to have a mean of 50 and a SD of 10. It is composed of 36 items and takes 10–15 min to complete. It can be self-administered or used by a trained interviewer in person or by telephone. This scale has been used in more than 200 studies in North America and in 40 surgical outcome studies. As part of an international initiative, the SF-36 has been applied to Canadian population and translated into Canadian French using a standard protocol. 14 Conceptually, better HRQL should arise secondary to better functional exercise capacity and, thus, the primary outcome was the 6-MWT, and the secondary outcome was the SF-36.
Intermediate outcomes, or those that the recovery regimen mediates to achieve measurable patient outcomes, such as respiratory muscle function, gastrointestinal function, pain, and fatigue, were assessed. For the purpose of this study, the vitality subscale of the SF-36 (energy and fatigue) was also used as a measure of the intermediate variable, fatigue.
Power of the Study
For purpose of sample estimation, we identified that a difference of 36 m walked in 6 min produces a meaningful impact on the lives of the subject. 15 This magnitude of difference with an SD of approximately 50 m would require a total of 64 subjects for a 80% power and a risk of a type 1error of 5%. A pilot study of nine patients confirmed the feasibility of the investigation as a whole and provided estimates of variability for use in the power calculation.
Data Analysis
The impact of the treatment group on the main outcomes such as 6-MWT and HRQL were analyzed using repeated-measures analysis of variance (time, group, and group × time). With the type of analysis, a significant group effect was interpreted as the effect of group averaged over all assessments, and a significant group × time effect was interpreted as an effect of group that depends on time, which was the hypothesis under investigation. For variables that did not depend on time (length of stay, readiness for discharge), a two-group comparison was made depending on the measurement scale. The time to first passage of flatus and first bowel movement was compared using the log-rank test.
Results
The demographic characteristics and clinical data related to surgery, preoperative health status, and nutritional status of the two groups were comparable (table 2).
Table 2. Demographic Characteristics and Preoperative Clinical Data of the Two Groups Studied
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Table 2. Demographic Characteristics and Preoperative Clinical Data of the Two Groups Studied
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Perioperative Anesthesia and Surgical Care
There was no difference between the two groups as far as surgical diagnosis, types of surgery, type of surgical incision, need of colostomy, duration of surgery, amount of blood loss and blood transfused, number of postoperative complications, length of hospital stay, and number of hospital readmissions. In contrast, the epidural group met the criteria to be discharged from the hospital significantly earlier than the PCA group (table 3). One patient in the PCA group, although enrolled in the study, was excluded from further analysis as he did not undergo colonic resection as previously thought. There were four readmissions, one in the PCA group and three in the epidural group between days 7 and 30 after surgery. The duration of hospital stay after readmission was from 1 to 3 days. There was one readmission in the PCA group on postoperative day 23 for prostatic surgery. In the epidural group, there were three readmissions, one on the day 10 for incisional hernia and two on days 12 and 14 for perineal dressing and closure.
Table 3. Surgical and Hospital Processes of the Two Groups Studied
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Table 3. Surgical and Hospital Processes of the Two Groups Studied
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Postoperative Complications
There were a total of 27 postoperative complications within 1 month of surgery, with 13 in the PCA group and 14 in the epidural group (table 3). Four patients in the PCA group and three patients in the epidural group had postoperative ileus that resolved between 36 and 72 h. Perineal abscess occurred in 5 patients following low anterior resection between the 5th and 10th day after surgery. Wound infection occurred in 5 patients between the 5th and 17th day after surgery. Pleural effusion with progressive oxygen desaturation was treated conservatively and improved on day 7 after surgery. Distended abdomen with vomiting in 2 patients resolved within 72 h and did not require surgery. Two patients in the PCA group had an anastomotic leakage that was diagnosed on days 3 and 4 after surgery, while one patient in the epidural group was diagnosed at day 5. In one patient the leakage was treated conservatively, while in the other two (one in the PCA group and one in the epidural group) an ileostomy was performed. Two patients in the epidural group had urinary retention requiring bladder catheterization between days 4 and 5. A bleeding gastric ulcer was diagnosed and treated surgically in one patient in the epidural group on day 5, with a delayed discharge of 4 days. One patient in the epidural group returned to the hospital on day 10 for incisional hernia repair.
Impact on Functional Exercise Capacity and Health-related Quality of Life
The evolution of functional exercise capacity and HRQL over time is presented in table 4, according to the group assignment. The values for Physical Health and Mental Health are presented along with the SF-36 subscales. As expected, there was a dramatic decrease in these measures postoperatively with some recuperation by the last evaluation at 6 weeks.
Table 4. Data on Functional Exercise Capacity and Health-related Quality of Life in the Two Groups Studied
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Table 4. Data on Functional Exercise Capacity and Health-related Quality of Life in the Two Groups Studied
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Because of this pattern, the difference from preoperative values was calculated for each subject and used as the primary outcome for the analysis. These values are presented in table 5.
Table 5. Difference from Baseline Values of Functional Exercise Capacity and Health-related Quality of Life at 3 and 6 Weeks after Surgery
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Table 5. Difference from Baseline Values of Functional Exercise Capacity and Health-related Quality of Life at 3 and 6 Weeks after Surgery
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As can be seen in this table for the 6-MWT, at 3 weeks after discharge there was an average decrease from baseline of 62.9 m in the PCA group and 32 m in the epidural group. At 6 weeks the decrease was 21.7 and 5 m for the PCA and epidural groups, respectively. While both groups showed an expected deterioration, the decrease for the PCA group was consistently greater over time than the decrease seen in the epidural group (time × group effect = 0.0005).
A similar pattern was observed for change in SF-36 Physical Health. Both groups deteriorated and then returned to baseline, but the epidural group showed less deterioration. For mental health, the epidural group recuperated their baseline values and the PCA group did not (group effect P  = 0.002).
For completeness, the results of the subscales are also presented, but, as eight comparisons are being made, it is expected that there will be many significant associations.
Postoperative Pain Relief, Respiratory Function, Fatigue, and Gastrointestinal Function
Table 6presents the results for these intermediate outcomes. VAS rating of pain at rest, on coughing, and on moving was significantly lower in the epidural group compared with the PCA group, as was patients’ rating of fatigue. There was no impact of type of perioperative management on vital capacity nor on frequency of nausea and vomiting (data not presented).
Table 6. Data on Visual Analog Scale Pain and Fatigue and Forced Vital Capacity of the Two Groups Studied
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Table 6. Data on Visual Analog Scale Pain and Fatigue and Forced Vital Capacity of the Two Groups Studied
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Twenty-one patients (66%) in the epidural group passed gas and 13 (41%) had bowel movements in the first 48 h. This in contrast with the PCA group, where 8 patients (27%) passed gas and 1 (3%) had bowel movements in the first 48 h. By day 4, 97% of patients in the epidural group passed gas and 69% had bowel movements, whereas only 73 and 28% of patients in the PCA group passed gas and had bowel movements, respectively. This difference in time to recovery of gastrointestinal motility was significant according to the log-rank test (P  < 0.01).
Time Out of Bed and Intake of Proteins and Calories
There also was a positive impact of epidural analgesia on activity and oral intake. These data are presented descriptively in table 7. Although there were significant differences, a large number of comparisons were made, and thus many differences would have been expected by chance alone.
Table 7. Postoperative Activity Out of Bed and Oral Intake of Nutrients in the Two Groups Studied
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Table 7. Postoperative Activity Out of Bed and Oral Intake of Nutrients in the Two Groups Studied
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Discussion
The results of this prospective randomized study showed that patients undergoing elective colonic surgery recuperated functional exercise capacity and HRQL faster when managed with epidural analgesia than when managed with PCA. This was most likely a result of the positive effects of epidural analgesia on postoperative pain control, mobilization, gastrointestinal motility, and intake of protein and calories. These effects were not a result of differing postoperative protocols, as these were standardized for both surgical and nursing care. In addition, nutrition and assistance to mobilization were offered equally to the two groups.
For the outcome measure used, the 6-MWT, a change in 35 m is noticeable to the individual, and even a change as low as 12 m can be detected. 15 In this study, the decrease from baseline to 3 weeks in the 6-MWT was, on average, 63 m for persons in the PCA group and 32 m for those in the epidural group (table 5). In the PCA group, 61% of the 31 persons studied declined by this critical amount at the 3-week assessment compared with only 38% in the epidural group; at 6 weeks, the proportions were 39 and 31% for the PCA and epidural groups, respectively.
Again, the difference from baseline in physical health (PCS value;table 5), 13.5 points for PCA and 11.2 for the epidural group at 3 weeks and 5.5 and 3.8 for the two groups, respectively, at 6 weeks, is clinically important. At baseline, the sample studied here, on average 60 yr of age, was within the normal range for Canadians of this age group. 14 However, by 3 weeks the decline to 39 put the sample well below the norms for Canadians older than 75 yr; by 6 weeks, the sample had recovered to some degree but still remained at the values for persons more than a decade older. Although the absolute difference between the two groups was numerically small, a two-point change in PCS is associated with noticeable health effects in the general population. 13 
While the data on the changes on the different subscales of the SF-36 point out interesting patterns, it must be remembered that it is unwise to make inferences when many comparisons are made at the same time. Table 5shows that pain and vitality were two subscales where the epidural analgesia appeared to have lasting benefits. This type of information would be useful in designing future studies of surgical mechanisms and outcomes.
The mechanism whereby perioperative care can produce short- and long-term effects is not fully understood. 10 What is known is that thoracic epidural local anesthetics have a direct effect on the gastrointestinal innervation, thereby facilitating restoration of motility. 16,17 The earlier restoration of gastrointestinal function shown in the epidural group of this study is in agreement with previous findings 18,19 and represents a clinically relevant achievement as it is one of the criteria used to decide the timing of discharge. 20 It could be hypothesized that enhanced gastrointestinal function reduced unpleasant symptoms such as nausea and vomiting, thereby facilitating feeding. In fact, the oral intake of protein and calories was greater in the epidural group, with a daily average of 15–26 g of proteins and 400–900 calories within the first 4 postoperative days (table 7). Early feeding following colonic surgery is delayed by many surgeons until resolution of postoperative ileus, as it might compromise the intestinal anastomosis. However, recent prospective randomized studies have demonstrated the safety and tolerability of early feeding. 21–23 
Another beneficial effect of epidural analgesia is the optimal pain relief provided not only at rest but also during mobilization out of bed. These results are in agreement with other investigations confirming the superiority of epidural local anesthetic and opioid mixture in the pain management of patients undergoing colonic surgery. 19 This intervention made it possible for the patients in the epidural group to be out of bed for a greater period of time. In fact, during the first 4 postoperative days, the patients in this group spent between 2 and 5 h out of bed, with most of the time spent walking. In contrast, patients in the PCA group spent much of their time out of bed, sitting rather than walking (table 7). It appears logical to attribute limited activity to the presence of pain on movement and, in fact, the VAS rating of pain on moving was significantly greater for patients in the PCA group than for those in the epidural group (table 6).
The potential benefits of activity have been demonstrated in many disabling conditions, 24,25 and one might infer from the current study that excellent pain relief, by facilitating mobilization, would contribute to a reduction of side effects associated with bed rest, such as muscle wasting 26 and impairment of homeostatic mechanisms. Unfortunately, little data are available on the effect of mobilization on the speed and quality of recuperation from surgery. Basse et al.  8 reported daily mobilization greater than 8 h on the second postoperative day; however, it is not clear from their study how much of this activity was sitting or walking.
The challenge in assessing outcome following surgery is in choosing an appropriate measurement strategy both for short- and long-term outcomes. 10 The outcomes must have a biologically plausible relation to the intervention being offered. In this study, the intervention was epidural analgesia, which is known to have an impact on pain. Because of the relation between pain and mobilization, measuring the time spent out of bed and walking was considered key in this study. We hypothesized that enhanced early mobilization would have a positive effect throughout the recuperation phase and translate into a better functional exercise capacity in the long term. The choice of the 6-MWT as the primary outcome was based on this premise. Although HRQL is increasingly being measured as an outcome following surgery, it is influenced by many factors (function, pain, social role, emotional role, physical role, mental health, energy, and general health). Of these, only a few are directly under the influence of our intervention, epidural analgesia.
The focus of this study was to evaluate whether the impact of the type of analgesia chosen would extend beyond the immediate short term and produce effects that would be noticeable to patients when they left the hospital and began their normal activities. This necessitated using outcome measures that were related to constructs relevant to people functioning in their own environments. The challenge in using these measures is in understanding what constitutes important change. When using physiologic measures, clinicians are familiar with values that indicate change.
Although criteria for discharge were achieved earlier in the epidural group, patients in this group went home at the same time as the PCA group (table 2). The reasons for keeping patients in hospital vary, and length of stay is influenced by the health care system, the administrative culture of the hospital, and patients’ expectations. While hospital stay is often used as an indicator of recovery, 9 it is a poor proxy measure of this complex outcome. The implementation of standardized perioperative care plans that eliminate variation in intraoperative and postoperative care have been shown to influence positively hospital stay and morbidity. 27,28 
A key contributor to postoperative outcome is the number of complications. The rate of postoperative complications in the current study was twice the rate reported by Basse et al.  in a similar population. 8 It has to be said that the study by Basse et al.  , in contrast to ours, adopted a standardized and multimodal approach to perioperative care, suggesting that both strategies need to be present to modulate surgical pathophysiology.
Several mechanisms can be proposed to explain how a perioperative intervention, such as epidural anesthesia and analgesia, could influence postoperative functional exercise capacity and vitality. Evidence is mounting that epidural anesthesia has a positive influence on protein and glucose metabolism, leading to preservation of muscle protein, 29 a decrease in whole body protein catabolism, 30 an improved use of nutritional substrate, 31,32 and amelioration of insulin sensitivity. 31 However, a direct relation between the metabolic changes and functional outcome has not yet been demonstrated.
While the mechanisms relating short-term surgical recovery to long-term function are not fully understood, this study has shown that a relation is plausible. By manipulating the mode of analgesia, an immediate impact on pain, bowel function, and ability to mobilize was observed. In addition, the effects on exercise capacity and HRQL were evident even as long as 6 weeks after surgery.
The authors thank Rose De Angelis, R.N., M.Sc., and Louise Lamb, R.N. (Research Nurses, Department of Anesthesia, McGill University Health Centre), for their valuable assistance with data collection, and Lyne Nadeau (Data Manager, Division of Clinical Epidemiology, McGill University Health Centre), for conducting the data analysis.
References
Watters J, Clancey S, Moulton S, Briere K, Zhu J: Impaired recovery of strength in older patients after abdominal surgery. Ann Surg 1993; 218: 380–93Watters, J Clancey, S Moulton, S Briere, K Zhu, J
Christensen T, Kehlet H: Postoperative fatigue. World J Surg 1993; 17: 220–5Christensen, T Kehlet, H
Kehlet H, Moesgaard F: Prophylaxis against postoperative complications in gastroenterology. Scand J Gastroenterol Suppl 1996; 31: 218–24Kehlet, H Moesgaard, F
Carli F, Schricker T: Modulation of the catabolic response to surgery. Nutrition 2000; 16: 777–80Carli, F Schricker, T
Moniche S, Bulow S, Hesselfeldt P, Hestboek A, Kehlet H: Convalescence and hospital stay after colonic surgery with balanced analgesia, early oral feeding and enforced mobilisation. Eur J Surg 1995; 161: 283–8Moniche, S Bulow, S Hesselfeldt, P Hestboek, A Kehlet, H
Bardram L, Funch-Jensen PM, Jensen P, Crawford ME, Kehlet H, et al.: Recovery after laparoscopic colonic surgery with epidural analgesia, and early nutrition and mobilisation. Lancet 1995; 345: 763–4Bardram, L Funch-Jensen, PM Jensen, P Crawford, ME Kehlet, H
Kehlet H, Mogensen T: Two-day hospital stay after open sigmoidectomy with a multi-modal rehabilitation program. Br J Surg 1999; 86: 227–30Kehlet, H Mogensen, T
Basse L, Jakobsen DH, Billesbolle P, Werner M, Kehlet H: A clinical pathway to accelerate recovery after colonic resection. Ann Surg 2000; 232: 1–7Basse, L Jakobsen, DH Billesbolle, P Werner, M Kehlet, H
Wu CL, Fleisher LA: Outcomes research in regional anesthesia and analgesia. Anesth Analg 2000; 91: 1232–42Wu, CL Fleisher, LA
Carli F, Mayo N: Measuring the outcome of surgical procedures: What are the challenges. Br J Anaesth 2001; 87: 531–3Carli, F Mayo, N
Kehlet H: Surgical stress response: Does endoscopic surgery confer an advantage? World J Surg 1999; 23: 801–7Kehlet, H
Butland RJ, Pang J, Gross ER, Woodcock AA, Geddes DM: Two-, six-, and 12-minute walking tests in respiratory disease. BMJ 1982; 284: 1607–8Butland, RJ Pang, J Gross, ER Woodcock, AA Geddes, DM
Ware JE, Kosinski M, Keller SD: SF-36 Physical and Mental Health Summary Scales: A User's Manual. Boston, The Health Institute, New England Medical Centre, 1994
Hopman WM, Towheed T, Anastassiades T, Tenenhouse A, Poliquin S, Berger C, Joseph L, Brown JP, Murray TM, Adachi JD, Hanley DA, Papadimitropoulos E: Canadian normative data for the SF-36 Health Survey. CMAJ 2000; 163: 265–71Hopman, WM Towheed, T Anastassiades, T Tenenhouse, A Poliquin, S Berger, C Joseph, L Brown, JP Murray, TM Adachi, JD Hanley, DA Papadimitropoulos, E
O'Keefe ST, Lye M, Donnellan C, Carmichael DN: Reproducibility and responsiveness of quality of life assessment and six minute walk test in elderly heart failure patients. Heart 1998; 80: 377–82O'Keefe, ST Lye, M Donnellan, C Carmichael, DN
Hodgson PS, Liu S: Thoracic epidural anaesthesia and analgesia for abdominal surgery: Effect on gastrointestinal function and perfusion. Baillieres’ Clin Anaesthesiol 1999; 75: 13: 9–22
Carli F, Schricker T: Combined epidural/general anesthesia for gastrointestinal surgery. Techniques Reg Anesth Pain Manage 2000; 4: 1–7Carli, F Schricker, T
Scheinin A, Asantila R, Orko R: The effect of bupivacaine and morphine on pain and bowel function after colonic surgery. Acta Anaesthesiol Scand 1987; 31: 161–4Scheinin, A Asantila, R Orko, R
Liu SS, Carpenter RL, Mackey DC: Effect of perioperative analgesic technique on rate of recovery after colon surgery. A nesthesiology 1995; 83: 757–65Liu, SS Carpenter, RL Mackey, DC
Carli F, Trudel JL, Belliveau P: The effect of intraoperative thoracic epidural anesthesia and postoperative analgesia on bowel function after colorectal surgery: A prospective randomized trial. Dis Colon Rectum 2001; 44: 1083–9Carli, F Trudel, JL Belliveau, P
Reissman P, Teoh TA, Cohen SM: Is early oral feeding safe after elective colorectal surgery? Ann Surg 1995; 221: 327–8Reissman, P Teoh, TA Cohen, SM
Stewart BT, Woods RJ, Collopy BT, Fink RJ, Mackay JR, Kack JO: Early feeding after elective open colorectal resections: A prospective ramdomized trial. Aust N Z J Surg 1998; 68: 125–8Stewart, BT Woods, RJ Collopy, BT Fink, RJ Mackay, JR Kack, JO
DiFronzo LA, Cymerman J, O'Connell TX: Factors affecting early postoperative feeding following elective open colon resection. Arch Surg 1999; 34: 941–6DiFronzo, LA Cymerman, J O'Connell, TX
Simpson K, Kilian K, McCartney NM, Stubbing DG, Jones NL: Randomized controlled trial of weightlifting exercise in patients with chronic airflow limitation. Thorax 1992; 47: 70–5Simpson, K Kilian, K McCartney, NM Stubbing, DG Jones, NL
McCartney N, McKelvie RS, Haslam DR, Jones NL: Usefulness of weightlifting training in improving strength and maximal power output in coronary artery disease. Am J Cardiol 1991; 67: 939–45McCartney, N McKelvie, RS Haslam, DR Jones, NL
Ferrando AA, Lane HW, Stuart CA, Davis Street J, Wolfe WW: Prolonged bed rest decreases skeletal muscle an whole body proteins. Am J Physiol 1996; 270: E2627–33Ferrando, AA Lane, HW Stuart, CA Davis Street, J Wolfe, WW
Bradshaw BG, Liu S, Thirlby RC: Standardized perioperative care protocols and reduced length of stay after colon surgery. J Am Coll Surg 1998; 186: 501–6Bradshaw, BG Liu, S Thirlby, RC
Wexner SD: Standardized perioperative care protocols and reduced lengths of stay after colon surgery. J Am Coll Surg 1998; 186: 589–93Wexner, SD
Carli F, Halliday D: Continuous epidural blockade arrests the postoperative fall in muscle protein fractional synthetic rate in surgical patients. A nesthesiology 1997; 86: 1033–40Carli, F Halliday, D
Carli F, Webster J, Pearson M, Pearson J, Bartlett S, Bannister P, Halliday D: Protein metabolism after abdominal surgery: Effect of 24-h extradural block with local anesthetics. Br J Anaesth 1991; 67: 729–34Carli, F Webster, J Pearson, M Pearson, J Bartlett, S Bannister, P Halliday, D
Schricker T, Carli F, Wykes L: Epidural anesthesia improves substrate utilization after colonic surgery. Am J Physiol 2000; 279: E646–53Schricker, T Carli, F Wykes, L
Barratt SMcG, Smith RC, Kee AJ, Mather LE, Cousins MJ: Multimodal analgesia and intravenous nutrition preserves total body protein following major upper gastrointestinal surgery. Reg Anesth Pain Med 2002; 27: 15–22Barratt, SMcG Smith, RC Kee, AJ Mather, LE Cousins, MJ
Table 1. Outcome Measures during the Immediate and Late Postoperative Periods
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Table 1. Outcome Measures during the Immediate and Late Postoperative Periods
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Table 2. Demographic Characteristics and Preoperative Clinical Data of the Two Groups Studied
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Table 2. Demographic Characteristics and Preoperative Clinical Data of the Two Groups Studied
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Table 3. Surgical and Hospital Processes of the Two Groups Studied
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Table 3. Surgical and Hospital Processes of the Two Groups Studied
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Table 4. Data on Functional Exercise Capacity and Health-related Quality of Life in the Two Groups Studied
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Table 4. Data on Functional Exercise Capacity and Health-related Quality of Life in the Two Groups Studied
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Table 5. Difference from Baseline Values of Functional Exercise Capacity and Health-related Quality of Life at 3 and 6 Weeks after Surgery
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Table 5. Difference from Baseline Values of Functional Exercise Capacity and Health-related Quality of Life at 3 and 6 Weeks after Surgery
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Table 6. Data on Visual Analog Scale Pain and Fatigue and Forced Vital Capacity of the Two Groups Studied
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Table 6. Data on Visual Analog Scale Pain and Fatigue and Forced Vital Capacity of the Two Groups Studied
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Table 7. Postoperative Activity Out of Bed and Oral Intake of Nutrients in the Two Groups Studied
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Table 7. Postoperative Activity Out of Bed and Oral Intake of Nutrients in the Two Groups Studied
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