Regional anesthesia and co-existing chronic pain

Antinociceptive Effect of Intravenous Regional Analgesia in Horses Underwent Selected Short-Time Distal Limb Surgeries

The aim of the present study was to establish appropriate doses for both lidocaine hydrochloride (Hcl) and mepivacaine in intravenous regional analgesia (IVRA) and to assess their intraoperative and postoperative analgesic effects in horses with distal limb surgeries. A total of 55 draft horses were included in the present study. Six clinically healthy horses were selected randomly for establishing the doses of lidocaine Hcl and mepivacaine in IVRA in horse limbs. After selection, 32 horses suffered from various distal limb surgical affections were randomly allocated into three groups: thiopental group (n = 6), animals were operated under general anesthesia using thiopental sodium; IVRA-LID group (n = 12), animals were operated under both general anesthesia and IVRA using lidocaine Hcl; and IVRA-MEP group (n = 14), horses were operated under both general anesthesia and IVRA using mepivacaine. Postoperative pain was measured using both Horse Grimace Pain Scale and multifactorial numerical rating composite pain. The results showed that conjunction of IVRA along with thiopental general anesthesia using either lidocaine or mepivacaine significantly decreased the total required doses of thiopental sodium during the operations and significantly increased the duration of postoperative analgesia to 60 and 150 minutes using lidocaine and mepivacaine, respectively. In conclusion, the uses of local IVRA before distal limb surgery improve the depth of general anesthesia and reduced postoperative pain, despite thiopental anesthesia alone. Mepivacaine is superior to lidocaine in IVRA, with a longer duration of action.

A Population-based Comparative Effectiveness Study of Peripheral Nerve Blocks for Hip Fracture Surgery

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New

Background

Adverse outcomes and resource use rates are high after hip fracture surgery. Peripheral nerve blocks could improve outcomes through enhanced analgesia and decreased opioid related adverse events. We hypothesized that these benefits would translate into decreased resource use (length of stay [primary outcome] and costs), and better clinical outcomes (pneumonia and mortality).

Methods

The authors conducted a retrospective cohort study of hip fracture surgery patients in Ontario, Canada (2011 to 2015) using linked health administrative data. Multilevel regression, instrumental variable, and propensity scores were used to determine the association of nerve blocks with resource use and outcomes.

Results

The authors identified 65,271 hip fracture surgery patients; 10,030 (15.4%) received a block. With a block, the median hospital stay was 7 (interquartile range, 4 to 13) days versus 8 (interquartile range, 5 to 14) days without. Following adjustment, nerve blocks were associated with a 0.6-day decrease in length of stay (95% CI, 0.5 to 0.8). This small difference was consistent with instrumental variable (1.1 days; 95% CI, 0.9 to 1.2) and propensity score (0.2 days; 95% CI, 0.2 to 0.3) analyses. Costs were lower with a nerve block (adjusted difference, −$1,421; 95% CI, −$1,579 to −$1,289 [Canadian dollars]), but no difference in mortality (adjusted odds ratio, 0.99; 95% CI, 0.89 to 1.11) or pneumonia (adjusted odds ratio, 1.01; 95% CI, 0.88 to 1.16) was observed.

Conclusions

Receipt of nerve blocks for hip fracture surgery is associated with decreased length of stay and health system costs, although small effect sizes may not reflect clinical significance for length of stay.

Analgesic efficacy and safety of ketamine after total knee or hip arthroplasty: a meta-analysis of randomised placebo-controlled studies

OBJECTIVE

To examine the analgesic efficacy and safety of ketamine after total knee or hip arthroplasty.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, EMBASE and Cochrane Library from inception to 22 May 2019.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Randomised controlled trials comparing the efficacy and safety of ketamine with placebo for postoperative pain relief in patients undergoing total knee or hip arthroplasty.

DATA EXTRACTION AND SYNTHESIS

Data (ie, pain intensity, morphine consumption, gastrointestinal and psychotic adverse effects) were extracted by two reviewers independently. The Cochrane Collaboration's recommended tool was used to determine the methodological quality of included studies.

RESULTS

A total of 10 studies were included. One of them was rated as low quality. Compared with placebo, intravenous ketamine was effective for pain relief during 0-8-hour (weighted mean difference (WMD) -1.21, 95% CI -1.45 to -0.98, p<0.001; three studies, 149 participants) but not during 8-24-hour postoperative periods, and effective for reduction of cumulative morphine consumption during both 0-24-hour (WMD -17.76, 95% CI -31.25 to -4.27, p=0.01; five studies, 366 participants) and 0-48-hour (WMD -21.79, 95% CI -25.46 to -18.11, p<0.001; four studies, 252 participants) postoperative periods, without increasing risks of gastrointestinal or psychotic adverse effects. The limited data available for intra-articular (WMD -0.49, 95% CI -0.70 to -0.29, p<0.001; two studies, 83 participants) and epidural (WMD -2.10, 95% CI -3.30 to -0.90, p<0.001; one study, 20 participants) ketamine pointed to a significant reduction in pain intensity during 8-24-hour postoperative period.

CONCLUSIONS

Intravenous administration of ketamine is effective and safe for postoperative pain relief in patients undergoing total knee or hip arthroplasty. Nevertheless, the analgesic efficacy and safety of ketamine in such patients seem to vary by different administration routes and still warrant further studies to explore.

Chronic Pain in Neurosurgery

This review includes a summary of contemporary theories of pain processing and advocates a multimodal analgesia approach for providing perioperative care. A summary of various medication classes and anesthetic techniques is provided that highlights evidence emerging from neurosurgical literature. This summary covers opioid management, acetaminophen, nonsteroidal antiinflammatories, ketamine, lidocaine, dexmedetomidine, corticosteroids, gabapentin, and regional anesthesia for neurosurgery. At present, there is not enough investigation into these areas to describe best practices for treating or preventing chronic pain in neurosurgery; but providers can identify a wider range of options available to personalize perioperative care strategies.

Management of the patient with chronic pain

Chronic pain is a significant complex problem in the perioperative environment. The management of patients with chronic pain has presented new challenges to anesthesia providers in the perioperative setting. The treatment of pain is often inadequate, and patients with preexisting chronic pain are not being managed properly. Although numerous techniques for intraoperative analgesia have been established, no official guidelines have been published for the growing population of patients with chronic pain. This article provides insight into and awareness of the various elements that should be addressed, along with interventions for the patient with chronic pain in the perioperative setting.

Which outcomes related to regional anesthesia are most important for orthopedic surgery patients?

An increasing body of evidence supports the benefits of regional anesthesia in orthopedic surgery. Compared with systemic anesthetic and analgesic approaches, these benefits include more focused and sustained pain control, less systemic side effects, improved patient comfort, earlier mobilization and hospital discharge, lower rates of advanced service requirements, and lower perioperative morbidity and mortality. However, there is discussion about the various outcomes as judged by patients and heath care practitioners. This article recapitulates the literature and presents an overview of endpoints.

Current cancer therapies - a guide for perioperative physicians

Cancer is expected to be the leading cause of death around the world. New cancer therapies have improved survival but they can also lead to complications and toxicity. In this article, the effects of modern anti-cancer therapies are reviewed. The perioperative effects of chemotherapy, radiotherapy and experimental therapies in relation to anaesthesia are discussed. Common and rare complications are summarised as is advice for optimal treatment of the cancer patient in the perioperative period.

Room for improvement: unmet needs in postoperative pain management

Postoperative pain treatment is an important healthcare issue. However, the management of pain in patients after surgery remains insufficient. In the present review, several key areas important for postoperative pain management are discussed. New findings about efficacy and side effects of nonopioid analgesics, such as paracetamol, NSAIDs and COX-2 inhibitors, are presented and discussed in light of acute, short-term application in the perioperative period. Second, new findings about postoperative pain management in patients with preoperative pain and chronic opioid consumption are reported. Third, feasibility of the transversus abdominal plane block as a new and promising regional anesthesia technique is discussed. Finally, potential predictors, mechanisms and preventive treatment strategies of persistent chronic pain after surgery are presented.

Perioperative management of the child on long-term opioids

The strategies used to manage children exposed to long-term opioids are extrapolated from adult literature. Opioid consumption during the perioperative period is more than three times that observed in patients not taking chronic opioids. A sparing use of opioids in the perioperative period results in both poor pain management and withdrawal phenomena. The child's pre-existing opioid requirement should be maintained, and acute pain associated with operative procedures should be managed with additional analgesia. This usually comprises short-acting opioids, regional or local anesthesia, and adjuvant therapies. Long-acting opioids, transdermal opioid patches, and implantable pumps can be used to maintain the regular opioid requirement. Intravenous infusion, nurse controlled analgesia, patient-controlled analgesia, or oral formulations are invaluable for supplemental requirements postoperatively. Effective management requires more than simply increasing opioid dose during this time. Collaboration of the child, family, and all teams involved is necessary. While chronic pain or palliative care teams and other staff experienced with the care of children suffering chronic pain may have helpful input, many pediatric hospitals do not have chronic pain teams, and many patients receiving long-term opioids are not palliative. Acute pain services are appropriate to deal with those on long-term opioids in the perioperative setting and do so successfully in many centers. Staff caring for such children in the perioperative period should be aware of the challenges these children face and be educated before surgery about strategies for postoperative management and discharge planning.