Mads U. Werner

A clinical pathway to accelerate recovery after colonic resection.

OBJECTIVE To investigate the feasibility of a 48-hour postoperative stay program after colonic resection. SUMMARY BACKGROUND DATA Postoperative hospital stay after colonic resection is usually 6 to 12 days, with a complication rate of 10% to 20%. Limiting factors for early recovery include stress-induced organ dysfunction, paralytic ileus, pain, and fatigue. It has been hypothesized that an accelerated multimodal rehabilitation program with optimal pain relief, stress reduction with regional anesthesia, early enteral nutrition, and early mobilization may enhance recovery and reduce the complication rate. METHODS Sixty consecutive patients undergoing elective colonic resection were prospectively studied using a well-defined postoperative care program including continuous thoracic epidural analgesia and enforced early mobilization and enteral nutrition, and a planned 48-hour postoperative hospital stay. Postoperative follow-up was scheduled at 8 and 30 days. RESULTS Median age was 74 years, with 20 patients in ASA group III-IV. Normal gastrointestinal function (defecation) occurred within 48 hours in 57 patients, and the median hospital stay was 2 days, with 32 patients staying 2 days after surgery. There were no cardiopulmonary complications. The readmission rate was 15%, including two patients with anastomotic dehiscence (one treated conservatively, one with colostomy); other readmissions required only short-term observation. CONCLUSION A multimodal rehabilitation program may significantly reduce the postoperative hospital stay in high-risk patients undergoing colonic resection. Such a program may also reduce postoperative ileus and cardiopulmonary complications. These results may have important implications for the care of patients after colonic surgery and in the future assessment of open versus laparoscopic colonic resection.

Does an acute pain service improve postoperative outcome

ain relief after surgical procedures continues tobe a major medical challenge. Alleviation of painhas been given a high priority by the medicalprofession and the health authorities. Improvement inperioperative analgesia not only is desirable for hu-manitarian reasons, but is also essential for its poten-tial to reduce postoperative morbidity (1–4) and mor-tality (2).Inadequacies in postoperative pain relief have beenevident for decades (5,6). The importance of establish-ing an organization for the management of postoper-ative pain relief, with special attention to a team ap-proach, was proposed more than 40 yr ago (7).Although several editorials (8–10) from 1976 to 1980again advocated the introduction of an analgesia teamto supervise and administer pain relief and to takeresponsibility for teaching and training in postopera-tive pain management, almost a decade passed beforea specialized in-hospital postoperative pain serviceemerged. Thus, in 1985 the first acute pain services(APSs) were introduced in the United States (11,12)and in Germany (13). Immediate and sustained formalsupport and authoritative recommendations from var-ious medical and health care organizations promoteda widespread introduction of APSs (14–22). One doc-ument explicitly stated “that this service should beintroduced in all major hospitals performing surgeryin the UK” (15); this is in agreement with recommen-dations from the Agency for Health Care Policy andResearch (United States) and the National Health andMedical Research Council (Australia), which state thatall major acute care centers should have an APS(14,18).Furthermore, provision of an APS is presently aprerequisite for accreditation for training by the RoyalCollege of Anaesthetists (23) and the Australian andNew Zealand College of Anaesthetists. A Canadiansurvey from 1991, including 47 university-affiliatedteaching hospitals, showed that 25 hospitals (53%)operated an APS and that an additional 17 (35%) wereattempting to organize one (24) (Table 1). A survey inAustralia and New Zealand in 1992–1993 from 111larger institutions showed that 37 (33%) had an APSand 58 (53%) would have liked to or had plans toimplement the service (25). Repeated surveys in 1994and 1996 from New Zealand indicated in 22 largerinstitutions an increase from 12 to 17 APSs (29). In aEuropean survey from 1993, including 105 represen-tative hospitals from 17 countries, 34% of the hospitalshad a formal APS (26). Forty-two percent to 73% of UShospitals, depending on size and academic affiliation,had an APS in 1995 (31,32). In the United Kingdom,the number of hospitals providing APSs increasedfrom 3% in 1990 to 43% in 1994 (27,28,36), to 47% in1996 (37), and to 49% in 1999 (35). In a recent surveyfrom Germany, 36% of hospitals operated an APS, butthe quality of criteria for the service was very variable(34).The introduction of APSs has led to an increase inthe use of specialized pain relief methods, such aspatient-controlled analgesia (PCA) and epidural infu-sions of local anesthetic/opioid mixtures, in surgicalwards. Implementation of these methods may repre-sent real advances in improving patient well-beingand in reducing postoperative morbidity (38).However, a pertinent question is whether the exten-sive resources allocated to these commitments havebeen successful and cost-effective. The objective of thisstudy, therefore, was to critically review the literatureon APSs regarding outcome: pain relief, side effects ofthe postoperative pain treatment, patient satisfaction,therapy-related adverse events, morbidity, hospitalstay, and cost issues.

Prediction of Postoperative Pain by Preoperative Nociceptive Responses to Heat Stimulation

BackgroundDespite major advances in the understanding of the neurobiologic mechanisms of pain, the wide variation in acute pain experience has not been well explained. Therefore, the authors investigated the potential of a preoperatively induced heat injury to predict subsequent postoperative pain ratings in patients undergoing knee surgery. MethodsTwenty patients were studied. The burn injury was induced 6 days before surgery with a contact thermode (12.5 cm2, 47°C for 7 min). The sensory testing, before and 1 h after the injury, included pain score during induction of the burn, secondary hyperalgesia area, thermal and mechanical pain perception, and pain thresholds. Postoperative analgesia consisted of ibuprofen and acetaminophen. Pain ratings (visual analog scale) at rest and during limb movement were followed for 10 days after surgery. ResultsThe burn injury was associated with development of significant hyperalgesia. There was a significant correlation between preoperative pain ratings during the burn injury and early (0–2 days, area under the curve) and late (3–10 days, area under the curve) postoperative dynamic pain ratings during limb movement. ConclusionThe results of this study suggest that the pain response to a preoperative heat injury may be useful in research in predicting the intensity of postoperative pain. These findings may have important implications to identify patients at risk for development of chronic pain and to stratify individuals for investigations of new analgesics.

Prediction of postoperative pain: a systematic review of predictive experimental pain studies.

Quantitative testing of a patients basal pain perception before surgery has the potential to be of clinical value if it can accurately predict the magnitude of pain and requirement of analgesics after surgery. This review includes 14 studies that have investigated the correlation between preoperative responses to experimental pain stimuli and clinical postoperative pain and demonstrates that the preoperative pain tests may predict 4–54% of the variance in postoperative pain experience depending on the stimulation methods and the test paradigm used. The predictive strength is much higher than previously reported for single factor analyses of demographics and psychologic factors. In addition, some of these studies indicate that an increase in preoperative pain sensitivity is associated with a high probability of development of sustained postsurgical pain.

Pain and sensory dysfunction 6 to 12 months after inguinal herniotomy

Inguinalherniarepairisassociatedwitha5%–30%incidence of chronicpain, but the pathogenesis remains unknown. We therefore evaluated pain and sensory dysfunction by quantitative sensory testing 6–12 mo after open herniorrhaphy. Before sensory testing, all patients (n = 72) completed a short-form McGill Pain Questionnaire and a functional impairment questionnaire. Sensory dysfunction in the incisional area was evaluated by quantification of thermal and mechanical thresholds, by mechanical pain responses (von Frey/pressure algometry), and by areas of pinprick hypoesthesia and tactile allodynia. The incidence of chronic pain was28%(20of72). Quantitative sensory testing and pressure algometry did not demonstrate differences between the pain and nonpain groups, except for a small but significant increase in pain response to von Frey hair and brush stimulation in the pain group. Hypoesthesia, or tactile allodynia, in the incisional area was observed in 51% (37 of 72) of the patients, but the incidence did not differ significantly between the pain group and the nonpain group (14 of 20 versus 23 of 52; P >0.3). We concluded that cutaneous hypoesthesia, or tactile allodynia, is common after inguinal herniotomy but has a low specificity for chronic postherniotomy pain. Factors other than nerve damage may be involved in the development of chronic postherniotomy pain.

Balanced analgesia : What is it and what are its advantages in postoperative pain?

The concept of balanced analgesia was introduced to improve analgesic efficacy and reduce adverse effects. A large amount of clinical data has documented improved analgesia by combining different analgesics, but data on reducing adverse effects are inconclusive. Balanced analgesia should be used whenever possible, and future studies should be directed to define optimal combination regimens in individual surgical procedures.

Effects of gabapentin in acute inflammatory pain in humans

Background and Objectives The aim of the study was to examine the analgesic effects of the anticonvulsant, gabapentin, in a validated model of acute inflammatory pain. Methods Twenty-two volunteers were investigated in a double-blind, randomized, placebo-controlled cross-over study. Gabapentin 1,200 mg or placebo was given on 2 separate study days. Three hours after drug administration, a first-degree burn injury was produced on the medial aspect of the nondominant calf (12.5 cm2, 47°C for 7 minutes). Quantitative sensory testing (QST) included pain ratings to thermal and mechanical stimuli (visual analog scale [VAS]), assessments of thermal and mechanical detection thresholds, and areas of secondary hyperalgesia. Side effects drowsiness and postural instability were assessed by subjective ratings (VAS). Results The burn injury induced significant primary and secondary hyperalgesia (P < .0001). Gabapentin diminished the decrease in mechanical pain threshold in the burn area (P = .04) and reduced secondary hyperalgesia, but the reduction was not significant (P = .06). Heat pain thresholds, pain during the burn, and mechanical pain in the area of secondary hyperalgesia were not significantly changed by gabapentin (P < .2). Ratings of drowsiness and unsteadiness during walking were significantly higher for gabapentin than for placebo (P < .05). Conclusions The study indicates that gabapentin has no analgesic effect in normal skin, but may reduce primary mechanical allodynia in acute inflammation following a thermal injury. These observations suggest a clinical potential of gabapentin in the treatment of postoperative pain.

Is urinary drainage necessary during continuous epidural analgesia after colonic resection

Background and Objectives Postoperative urinary retention may occur in between 10% and 60% of patients after major surgery. Continuous lumbar epidural analgesia, in contrast to thoracic epidural analgesia, may inhibit urinary bladder function. Postoperative urinary drainage has been common in patients with continuous epidural analgesia, despite the lack of scientific evidence for its indication after thoracic epidural analgesia. This study describes 100 patients who underwent elective colonic resection with 48 hours of continuous thoracic epidural analgesia and only 24 hours of urinary drainage. Methods This is a prospective, uncontrolled study with well-defined general anesthesia, postoperative analgesia, and nursing care programs in patients with a planned 2-day hospital stay, urinary catheter removal on the first postoperative morning, and epidural catheter removal on the second postoperative morning. Follow-up in the outpatient clinic was on days 8 and 30. Results Nine patients needed bladder recatheterization, 8 as a single procedure and 1 patient a second recatheterization with removal on day 7. This patient had urinary infection on day 10 and was readmitted for 5 days because of urosepsis and, subsequently, for cystitis and left-sided epididymitis. Three patients had uncomplicated urinary infection. No patients had urological complaints at 30 days follow-up (95% confidence limit, 0% to 3.6%). Conclusion The low incidence of urinary retention (9%) and urinary infection (4%) suggests that routine bladder catheterization beyond postoperative day 1 may not be necessary in patients with ongoing continuous low-dose thoracic epidural analgesia.

Ultrasound-guided ilioinguinal/iliohypogastric nerve blocks for persistent inguinal postherniorrhaphy pain: a randomized, double-blind, placebo-controlled, crossover trial.

BACKGROUND: Ilioinguinal and iliohypogastric nerve blocks are used in the clinical management of persistent inguinal postherniorrhaphy pain, but no controlled studies have been published on the subject. In this controlled study, we investigated the analgesic and sensory effects of ultrasound-guided blocks of the ilioinguinal and iliohypogastric nerves with lidocaine. METHODS: A randomized, double-blind, placebo-controlled, crossover trial in 12 patients with severe persistent inguinal postherniorrhaphy pain, including a control group of 12 healthy controls, was performed. Assessments included pain ratings under standardized conditions with numerical rating scale (0–10), sensory mapping to a cool roller, and quantitative sensory testing (QST), in the groin regions, before and after each ultrasound-guided block. A needle approach of 1 to 2 cm superior and medial to the anterior superior iliac spine was used. Outcomes were changes in pain ratings, sensory mapping, and QST compared with preblock values. Lidocaine responders were a priori defined by a pain reduction of ≥80% after lidocaine block and ⩽25% after placebo block, nonresponders by pain reduction of <80% after lidocaine block and ⩽25% after placebo block, and placebo responders by pain reduction of >25% after placebo block. RESULTS: One of 12 pain patients was a lidocaine responder, 6 patients were nonresponders, and 5 patients were placebo responders. No consistent QST changes were observed in patients after the lidocaine block. In 10 of 12 healthy controls, a cool hypoesthesia area developed in the groin after the lidocaine block. Furthermore, QST assessments demonstrated significantly decreased suprathreshold heat pain perception in the groin after lidocaine versus placebo blocks (95% confidence interval = −3.5 to −0.5, P = 0.008). CONCLUSION: Ultrasound-guided lidocaine blocks of the ilioinguinal and iliohypogastric nerves, at the level of the anterior superior iliac spine, are not useful in diagnosis and management of persistent inguinal postherniorrhaphy pain.

Dexamethasone Prolongs Local Analgesia after Subcutaneous Infiltration of Bupivacaine Microcapsules in Human Volunteers

Background The addition of small amounts of dexamethasone to extended-release formulations of bupivacaine in microcapsules has been found to prolong local analgesia in experimental studies, but no clinical data are available. Methods In a double-blinded study, 12 healthy male volunteers were randomized to receive simultaneous subcutaneous injections of bupivacaine microcapsules with dexamethasone and bupivacaine microcapsules without dexamethasone in each calf. Local analgesia was assessed with a validated human pain model; main parameters evaluated were thermal, mechanical, and pain detection thresholds and suprathreshold responses to heat and mechanical stimulation. Measurements were performed every 2 h for the first 8 h and daily for the week after injection. Primary endpoints were evaluation of maximal analgesic effect, time of onset, and duration of analgesia. Summary measures (area under curve [AUC]) were considered best estimate of analgesia. Safety evaluations were performed daily for the first week and at 2 weeks, 6 weeks, and 6 months after injection. Results The addition of dexamethasone significantly prolonged local analgesia of bupivacaine microcapsules without influence on maximal analgesic effect. AUC in all thermal measurements and the sensory mechanical threshold were significantly increased between 1–7 days after drug injection in the group given dexamethasone compared with the group not given dexamethasone. No serious side effects were observed. Conclusions Addition of small amounts of dexamethasone to bupivacaine incorporated in microcapsules prolonged local analgesia compared with microcapsules with plain bupivacaine after subcutaneous administration in humans.