Low-dose ketamine infusions for chronic pain management: Does this qualify as evidence-based practice?

Chronic pain is becoming increasingly prevalent and burdensome both worldwide and in the United Kingdom. Due to the complexity of chronic pain and the therapeutic challenge associated, management is often difficult and requires multidisciplinary care encompassing a combination of pharmacological and non-pharmacological strategies. Conventional analgesic treatments, such as opioids and anticonvulsants, are effective in less than half of chronic pain sufferers and are typically limited to short-term use to prevent complications associated with long-term use such as tolerance and dependence. Consequently, research and clinical interest in alternative management options for chronic pain have increased in recent years, with ketamine being one example under investigation. However, since ketamine has been licensed as an anaesthetic for decades, it has bypassed the traditional scrutinous drug development sequence that is typically seen for therapeutics marketed for pain. As such, data supporting the unlicensed administration of ketamine for chronic pain management is lacking and is being outpaced by the rates of off-label use in pain clinics. Recent limited evidence suggests that ketamine, when given as an intravenous infusion in subanaesthetic doses for refractory pain patients, may provide modest analgesic effects in nearly all aetiologies of chronic pain, with side effects common but typically mild. However, there are concerns over the safety of this practice due to the paucity of robust supportive evidence and the accompanying lack of clinical guidelines or standardised protocols. This review shall summarise the literature examining the use of subanaesthetic-dose ketamine infusions for chronic pain to comment on the current level of evidence, with limitations of existing research and future recommendations discussed.

Exploring incidence and risk factors for persistent postoperative opioid use in adult surgical patients: a systematic review protocol.

OBJECTIVE: The objective of this review is to determine the incidence of persistent postsurgical use of opioids in adult patients and the associated risk factors. INTRODUCTION: Surgery has been identified as an independent risk factor for unwarranted chronic opioid use, contributing to opioid-related harm in the community. Persistent opioid use after surgery is associated with morbidity and mortality from opioid-related adverse events, indicating a significant yet mitigable public health concern. There is substantial variation in the reported incidence and risk factors for postoperative opioid use, which require evaluation for future evidence-based risk-reduction strategies. INCLUSION CRITERIA: This review will include studies investigating the persistent use of opioids after 90 postoperative days in adult (≥18 y) patients undergoing surgery of any type, including patients with cancer pain. Selected evidence must report on opioid use prior to surgery. Analytical and descriptive observational studies, and experimental and quasi-experimental studies, published in the previous decade will be eligible for inclusion. METHODS: The proposed study methods follow the JBI methodology for systematic reviews of prevalence and incidence. A systematic search will be conducted in PubMed, Embase, CINAHL, Cochrane Central, and Web of Science, and a search of gray literature will include Google Scholar and ClinicalTrials.gov. Study selection, critical appraisal, and data extraction will be performed by 2 independent reviewers aided by the relevant JBI systematic review tools. We aim to produce a narrative synthesis of results and conduct a meta-analysis where feasible, in addition to subgroup analyses of suitable populations. The results are intended to promote safe, evidence-based postoperative opioid prescribing when considering risk factors for persistent postoperative opioid use. SYSTEMATIC REVIEW REGISTRATION NUMBER: PROSPERO CRD42022320691.

The excess insulin requirement in severe COVID-19 compared to non-COVID-19 viral pneumonitis is related to the severity of respiratory failure and pre-existing diabetes.

Introduction: Severe COVID-19 has been anecdotally associated with high insulin requirements. It has been proposed that this may be driven by a direct diabetogenic effect of the virus that is unique to SARS-CoV-2, but evidence to support this is limited. To explore this, we compared insulin requirements in patients with severe COVID-19 and non-COVID-19 viral pneumonitis. Methods: This is a retrospective cohort study of patients with severe COVID-19 admitted to our intensive care unit between March and June 2020. A historical control cohort of non-COVID-19 viral pneumonitis patients was identified from routinely collected audit data. Results: Insulin requirements were similar in patients with COVID-19 and non-COVID-19 viral pneumonitis after adjustment for pre-existing diabetes and severity of respiratory failure. Conclusions: In this single-centre study, we could not find evidence of a unique diabetogenic effect of COVID-19. We suggest that high insulin requirements in this disease relate to its propensity to cause severe respiratory failure in patients with pre-existing metabolic disease.

Soft-tissue chondroma.

Soft-tissue chondromas are rare and benign soft-tissue tumors. Over 95% occur in the hands and feet. They are seen in both sexes equally and mainly occur in patients aged 30-60 years. If excised fully, they do not reoccur, and no cases in the literature have reported malignant transformations.

Radiologic case study. Spontaneous osteonecrosis of the knee reclassified as insufficiency fracture.

Three questions need to be answered. First, does spontaneous osteonecrosis of the knee in fact exist? The answer is "probably," but much more rarely than initially believed. In five of the authors' most recent MRIs in patients with clinically diagnosed or radiographically suggested spontaneous osteonecrosis of the knee, only one patient's images fulfilled the criteria for spontaneous osteonecrosis (Figure 3). Three of the five had subchondral changes of either insufficiency fractures or true fractures, while one patient had equivocal findings. Second, will the actual diagnosis influence the treatment? The answer appears to be "no" because early subchondral fractures and early spontaneous osteonecrosis of the knee are treated conservatively and only the later changes of subchondral surface collapse are treated more aggressively with joint replacement. Third, is there any method of halting the progression of early subchondral changes before they progress into collapse, flattening, and loose-body formation? The answer appears to be "maybe" as non-weight-bearing conservative therapy has not consistently prevented progression of the disease. Whether new arthroscopic techniques can provide the necessary intervention to halt osteoarthritic sequelae remains unanswered. Thus, it appears most patients with what has been called spontaneous osteonecrosis of the knee actually have subchondral insufficiency fractures. The histologic findings of avascular areas in biopsy specimens appear to be a secondary phenomenon and not the primary cause. If diagnosed early enough, conservative therapy may lead to healing without subsequent collapse and fragmentation of the subchondral bone.

Stress injuries to bone in college athletes: a retrospective review of experience at a single institution.

BACKGROUND: No comprehensive studies have been published on stress injuries to bone in college athletes. PURPOSE: To review, in a college athlete population, the epidemiologic aspects of stress injuries to bone, and to examine a subset of patients who were treated with a uniform protocol for return to activities, with magnetic resonance imaging as the primary tool for diagnosis. STUDY TYPE: Retrospective review. METHODS: Ten years of medical records from a Division I college institution were reviewed. Location and grade of stress injury to bone and duration of disability were recorded. All injured athletes followed the same treatment program, with the exception of football players, who were excluded from the return to sport analyses. RESULTS: Seventy-four athletes had lower extremity symptoms consistent with stress injury to bone. Diagnosis was confirmed in 68 of these athletes, 61 via magnetic resonance imaging, 6 via positive radiographs only, and 1 via bone scan only. Distance runners accounted for the most stress injuries to bone for both men and women. The tibia (37%) was the most frequently involved bone; however, as an anatomic region, the foot (44%) was the site of the most stress injuries. There was a significant correlation between grade of injury and time to full return to activity. CONCLUSIONS: The grading system used at this institution is a standardized tool that can be used to predict time to return to sport. A standardized rehabilitation protocol allowed for an appropriate plan to return the athletes to pain-free competition.

Radiologic case study. Secondary hyperparathyroidism, osteomalacia with a pseudofracture, and amyloid deposition.

The advancement of medical management of chronic renal failure has helped eliminate secondary hyperparathyroidism and osteomalacia. However, if a patient is recalcitrant, florid forms of both conditions can develop. Secondary amyloidosis is poorly understood but occurs in patients who are on long-term dialysis. As the survival rates for patients on long-term dialysis improve, it will be seen more frequently.

Radiologic case study. Traumatic dislocation of the knee.

Imaging in knee dislocation requires multiple modalities and a comprehensive assessment of ligaments, cartilage, bone, nerve, and vascular anatomy. Magnetic resonance imaging is essential in the work-up of these patients and MRA is a promising modality for detecting vascular injury.