Faculty Bibliography

Spontaneous intracranial hypotension is an uncommon disorder with symptoms including postural headache that can be debilitating to patients. Diagnosis is mainly clinical, aided by imaging of the brain and spine with or without diagnostic procedures. Treatment can vary depending on severity, but most cases involve an epidural blood patch. We describe a case of a patient with clinical findings of spontaneous intracranial hypotension but with normal brain imaging. The patient responded to lumbar epidural blood patches and did not require additional tests to confirm the diagnosis.

BACKGROUND:When administered as a continuous infusion, ketamine is known to be a potent analgesic and general anaesthetic. Recent studies suggest that a single low-dose administration of ketamine can provide a long-lasting effect on mood, but its effects when given in the postoperative period have not been studied. OBJECTIVE:We hypothesised that a single low-dose administration of ketamine after bariatric surgery can improve pain and mood scores in the immediate postoperative period. DESIGN/METHODS:We performed a randomised, double-blind, placebo-controlled study to compare a single subanaesthetic dose of ketamine (0.4 mg kg) with a normal saline placebo in the postanaesthesia care unit after laparoscopic gastric bypass and gastrectomy. SETTING/METHODS:Single-centre, tertiary care hospital, October 2014 to January 2018. PATIENTS/METHODS:A total of 100 patients were randomised into the ketamine and saline groups. INTERVENTION/METHODS:Patients in the ketamine group received a single dose of ketamine infusion (0.4 mg kg) in the postanaesthesia care unit. Patients in the placebo groups received 0.9% saline. OUTCOME MEASURES/METHODS:The primary outcome was the visual analogue pain score. A secondary outcome was performance on the short-form McGill's Pain Questionnaire (SF-MPQ). RESULTS:There were no significant differences in visual analogue pain scores between groups (group-by-time interaction P = 0.966; marginal group effect P = 0.137). However, scores on the affective scale of SF-MPQ (secondary outcome) significantly decreased in the ketamine group as early as postoperative day (POD) 2 [mean difference = -2.2 (95% bootstrap CI -2.9 to 1.6), Bonferroni adjusted P < 0.001], compared with placebo group in which the scores decreased only by POD 7. Scores on the total scale of SF-MPQ for the ketamine group were smaller compared with the placebo group (P = 0.034). CONCLUSION/CONCLUSIONS:Although there was no significant difference between ketamine and placebo for the primary outcome measure, patients who received ketamine experienced statistically and clinically significant improvement in their comprehensive evaluation of pain, particularly the affective component of pain, on POD 2. However, future studies are needed to confirm the enduring effects of ketamine on the affective response to postoperative pain. CLINICAL TRIAL REGISTRATION/BACKGROUND:NCT02452060.

OBJECTIVE:In the context of the current opioid epidemic, there has been a renewed interest in the use of ketamine as an analgesic agent. METHODS:We have reviewed ketamine analgesia. RESULTS:Ketamine is well-known as an antagonist for N-methyl-D-aspartate receptors. In addition, it can regulate the function of opioid receptors and sodium channels. Ketamine also increases signaling through α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors. These myriad of molecular and cellular mechanisms are responsible for a number of pharmacological functions including pain relief and mood regulation. Clinically, a number of studies have investigated the role of ketamine in the setting of acute and chronic pain, and there is evidence that ketamine can provide analgesia in a variety of pain syndromes. DISCUSSION/CONCLUSIONS:In this review, we have examined basic mechanisms of ketamine and its current clinical use as well as potential novel use in pain management.

BACKGROUND:Previous surveys have identified variations in practice patterns related to epidural steroid injections. Since then, the United States Food and Drug Administration (FDA) has required the addition of drug warning labels for injectable corticosteroids. Updated evidence, as well as scrutiny from regulatory agencies, may affect practice patterns. OBJECTIVE:To provide an update on interlaminar epidural steroid injection (ILESI) practice patterns, we surveyed interventional pain management (IPM) physicians in the United States. STUDY DESIGN AND SETTING/METHODS:This was a cross-sectional survey of IPM physicians in the United States. METHODS:A web-based survey was distributed to IPM physicians in the United States selected from the Accreditation Council for Graduate Medical Education accredited pain medicine fellowship program list as well as the American Society of Interventional Pain Physicians membership database. Physicians were queried about ILESI practices, including needle size, use of image guidance, level of injection, identification of the epidural space, and preference for injectate. RESULTS:A total of 249 responses were analyzed. All respondents used image guidance for ILESI. There were variations in needle size, use of contrast, number of fluoroscopic views utilized, technique for identifying the epidural space, and choice of injectate. LIMITATIONS/CONCLUSIONS:The response rate is a limitation, thus the results may not be representative of all United States IPM physicians. CONCLUSIONS:Though all respondents used image guidance for ILESI, variations in other ILESI practices still exist. Since the closure of this survey, a multi-society pain workgroup published recommendations regarding ESI practices. Our survey findings support the need for more evidence-based guidelines regarding ESI. KEY WORDS/UNASSIGNED:Epidural injection, epidural steroids, survey, low back pain, neck pain, technique.

PURPOSE/OBJECTIVE:Obstructive sleep apnea (OSA) is a risk factor for complications with postoperative opioid use, and in those patients with known or suspected OSA, minimization of postoperative opioids is recommended. We hypothesize that despite these recommendations, surgical patients with known or suspected OSA are prescribed postoperative opioids at hospital discharge at similar doses to those without OSA. METHODS:This was a retrospective analysis of the electronic health records of surgical patients from 1 November 2016 to 30 April 2017 at a single academic institution. Patients with a known diagnosis of OSA or a STOP-Bang score ≥ 5 were compared with those without OSA for the amount of postoperative discharge opioid medication using multivariable linear regression. RESULTS:Of the 17,671 patients analyzed, 1,692 (9.6%) had known or suspected OSA with 1,450 (86%) of these patients discharged on opioid medications. Of the 15,979 patients without OSA, 12,273 (77%) were discharged on opioid medications. The total median [interquartile range (IQR)] oral morphine equivalents (OME) for all patients was 150 [0-338] mg and for patients with known or suspected OSA was 160 [0-450] mg, an unadjusted comparison showing an 18% difference in OME (95% confidence interval [CI], 3% to 35%; P = 0.02). The analysis, after adjusting for confounders, showed no significant difference in the amount of opioids prescribed to OSA or non-OSA patients (8% difference in total OME; 95% CI, -6% to 25%; P = 0.26). CONCLUSION/CONCLUSIONS:This study shows that surgical patients at risk for OSA or confirmed OSA are prescribed opioids at similar rates and doses upon discharge despite guidelines that recommend minimizing opioid use in OSA patients. These findings indicate a need to implement different strategies to reduce the prescription of opioids to patients with OSA.

Introduction: In 2014, New York (NY) became the 23rd state to legalize medical marijuana (MMJ). The purpose of this survey was to collect data about practicing NY physicians' comfort level, opinions, and experience in recommending or supporting patient use of MMJ. Materials and Methods: An anonymous web-based survey was distributed to medical societies and to academic departments in medical schools within NY. Results: A total of 164 responses were analyzed. Physician participants were primarily located in New York City and surrounding areas. The majority (71%) agreed that MMJ should be an option available to patients. Most respondents were not registered to certify MMJ in NY, but were willing to refer patients to registered physicians. Common reasons for not registering included specialty and federal status of cannabis. More than 75% reported having patients who used cannabis for symptom control, and 50% reported having patients who inquired about MMJ within the past year. Most respondents are willing to discuss MMJ with their patients, but had little familiarity with the state program and a modest knowledge of the endocannabinoid system. Pain was a common symptom for which cannabis was recommended by registered physicians (69%) and purportedly used by patients (83%). Most respondents would consider MMJ as an adjuvant to opioids, and 84% believed opioids have greater risks than MMJ. Conclusion: Given that the majority of surveyed physicians support MMJ as an option for patients, few are registered and have adequate knowledge of MMJ. Although our study sample is small and geographically limited, our survey results highlight key physician issues that are likely applicable to practitioners in other states. Concerted efforts are needed at the federal, state, and academic levels to provide practitioners with evidence-based guidelines for the safe use of MMJ.

BACKGROUND AND AIMS: Pain is common in older adults but may be undertreated in part due to concerns about medication toxicity. Analgesics may affect cognition. In this retrospective cohort study, we used the Alzheimer's Disease Neuroimaging Initiative (ADNI) database to examine the interaction of cognitive status and medications, especially non-steroidal anti-inflammatory drugs (NSAIDs). We hypothesized NSAID use would be associated with cognition and that this could be mediated through changes in brain structure. METHODS: In this post hoc analysis of the ADNI database, subjects were selected by searching the "concurrent medications log" for analgesic medications. Subjects were included if the analgesic was listed on the medication log prior to enrollment in ADNI and throughout the study. Subjects taking analgesics, particularly NSAIDs, at each study visit were compared to control subjects taking no analgesics. Using descriptive statistics as well as univariate, multivariate and repeated measure ANOVA, we explored the relationship between NSAID use and scores for executive function and memory related cognitive activities. We further took advantage of the extensive magnetic resonance imaging (MRI) data available in ADNI to test whether cognitive change was associated with brain structure. The multitude of imaging variables was compressed into a small number of features (five eigenvectors (EV)) using principal component analysis. RESULTS: There were 87 NSAID users, 373 controls, and 71 taking other analgesics. NSAID use was associated with higher executive function scores for cognitively normal (NL) subjects as well as subjects with mild cognitive impairment (MCI). NSAID use was also associated with higher memory scores, but for NL females only. We analysed MRI data using principal component analysis to generate a set of five EVs. Examining NL and MCI subjects, one EV had significantly larger values in subjects taking NSAIDs versus control. This EV was one of two EVs which significantly correlated with composite executive function and memory scores as well as cognitive diagnosis. CONCLUSIONS: NSAID use was associated with higher executive function, and memory scores in certain subjects and larger cortical volumes in particular regions. Limitations of the study include secondary analysis of existing data and the possibility of confounding. IMPLICATIONS: These results suggest it is important to consider the secondary effects of medications when choosing a treatment regimen. Further prospective studies are needed to examine the role of analgesics on cognition and whether NSAIDs act through cortical dimension changes and how they are related to gender and cognitive diagnosis.