Tertiary Care Clinical Experience with Intravenous Lidocaine Infusions for the Treatment of Chronic Pain.

Objective: To evaluate the safety of and long-term pain relief due to intravenous lidocaine infusion for the treatment of chronic pain in a tertiary pain management clinic. Design: Retrospective chart review. Methods: Medical records were reviewed from 233 adult chronic pain patients who underwent one to three lidocaine infusions. The initial lidocaine challenge consisted of 1,000 mg/h administered intravenously for up to 30 minutes until infusion was complete, full pain resolution, the patient requested to stop, side effects (SEs) became intolerable, and/or if there were any safety concerns. Subsequent infusions were tailored to patient response. Data reviewed included pain diagnosis, lidocaine dose, SEs, and duration of pain relief documented at a follow-up visit. Results: Patients primarily had neuropathic pain (80%), were 94% white, 58% were female, and there was an average pain duration of 7.9 years. SEs were usually mild and transient, including perioral tingling, dizziness, tinnitus, and nausea/vomiting, and they were uncommon after the initial infusion. Overall, 41% of patients showed long-lasting pain relief, with positive response to the initial infusion associated with receiving and benefitting from subsequent infusions. Benefit by pain diagnoses varied from 32% to 58%. Conclusions: Our retrospective study in a heterogeneous population with chronic pain suggests that intravenous lidocaine is a safe treatment. Data also suggest long-term pain relief in a significant proportion of patients. Additional study is important in order to delineate patient selection, determine optimal dosing and treatment frequency, assess pain reduction and duration, and treatment cost-effectiveness.

Effect of Perioperative Opioid Use on Patients Undergoing Hip Arthroscopy.

Background: Opioids are commonly used to treat postoperative pain; however, guidelines vary regarding safe opioid use after hip arthroscopy. Purpose/Hypothesis: The purposes were to (1) identify risk factors for persistent opioid use, (2) assess the effect of opioid use on outcomes, and (3) describe common opioid prescribing patterns after hip arthroscopy. It was hypothesized that preoperative opioid use would affect complication rates and result in greater postoperative opioid use. Study Design: Case-control study; Level of evidence 3. Methods: The Utah State All Payer Claims Database was queried for patients who underwent hip arthroscopy between January 2013 and December 2017. Included were patients ≥14 years of age at index surgery with continuous insurance. Patients were separated into acute (<3 months) and chronic (≥3 months) postoperative opioid use groups. Primary outcomes included revision surgery, complications (infection, pulmonary embolism/deep venous thrombosis, death), emergency department (ED) visits, and hospital admissions. Multivariate logistic regression was utilized to identify factors associated with the outcomes. Results: Included were 2835 patients (mean age, 47 years; range, 14-64 years), of whom 2544 were in the acute opioid use and 291 were in the chronic opioid use group. Notably, 91% of the patients in the chronic group took opioid medications preoperatively, and they were more than twice as likely to carry a mental health diagnosis (P < .01). Patients in the acute group had a significantly shorter initial prescription duration, took fewer opioid pills, and had fewer refills than those in the chronic group (P < .01 for all). Patients in the chronic group had a significantly higher risk of postoperative ED visits (odds ratio [OR], 2.76; P = .008), hospital admission (OR, 3.02; P = .002), and additional surgery (P = .003), as well as infection (OR, 2.55; P < .001) and hematoma (OR, 2.43; P = .030). Patients who had used opioids before hip arthroscopy were more likely to need more refills (P < .01). A formal opioid use disorder diagnosis correlated significantly with postoperative hospital admissions (OR, 3.83; P = .044) and revision hip arthroscopy (OR, 4.72; P = .003). Conclusion: Mental health and substance use disorders were more common in patients with chronic postoperative opioid use, and chronic postoperative opioid use was associated with greater likelihood of postoperative complications. Preoperative opioid use was significantly correlated with chronic postoperative opioid use and with increased refill requests after index arthroscopy.

Levels of processing effects on recognition memory in patients with schizophrenia.

This study sought to characterize the performance of patients with schizophrenia, as compared with healthy participants, on a memory task that required encoding of items to different depths. Participants included 21 individuals with schizophrenia and 26 healthy controls. During the encoding phase of the study, participants processed successively presented words in two ways: perceptually (by making a decision as to whether the letter "a" was present in the word) or semantically (by making a living/nonliving decision for each word). During the recognition phase of the study, participants were presented with a list of words containing items that had been presented during the encoding phase (during either the letter decision task or the semantic decision task), as well as items that had not been seen before (foils). Though patients with schizophrenia performed more poorly overall on the recognition task, recognition was facilitated by semantic encoding to an equivalent degree in both groups. In other words, while significant main effects were present for group and encoding, no groupxencoding condition was present. This result is consistent with previous findings of a lack of qualitative differences in performance on learning and memory tasks between patients with schizophrenia and healthy controls. It also suggests that strategies that place constraints on the encoding processes used by patients may help improve the efficiency with which they learn and remember information.

Letter and category fluency in schizophrenic patients: a meta-analysis.

Patients with schizophrenia typically demonstrate impairments on semantic and letter fluency tasks but it is possible that these tests demand subtly different cognitive processing: a lexical search based on phonology or orthography or a semantic search based on organization of semantic networks by dimension or attribute. Differences in the performance between these two tasks may imply whether deficits involve difficulties in accessing or traversing connectivities in the semantic system, as opposed to those based on linguistic units. In this meta-analysis, we reviewed 13 studies (N=915) in an attempt to clarify whether schizophrenic patients are in fact differentially impaired in semantic fluency. Results from analyses indicated that schizophrenic patients are disproportionately deficient in category fluency (d=1.23 for semantic and 1.01 for letter fluency with minimal overlap of confidence intervals of weighted d's) suggesting that compromises the semantic system may be present in schizophrenia and perhaps play a role in the symptomatic anomalies exhibited in this patient population.