Faculty Bibliography

Widespread hyperalgesia, characterized by pain sensitivity beyond the primary pain site, is a common yet under-characterized feature across chronic pain conditions, including chronic pancreatitis (CP). In this exploratory study, we identified a candidate neural biosignature of widespread hyperalgesia using high-density electroencephalography (EEG) in patients with chronic low back pain (cLBP). Specifically, stimulus-evoked delta, theta, and alpha oscillatory activity in the bilateral medial orbitofrontal cortex (mOFC) differentiated cLBP patients with widespread hyperalgesia from healthy controls. To examine cross-condition generalizability and advance predictive biomarker development for CP, we applied this mOFC-derived EEG biosignature to an independent cohort of patients with CP. The biosignature distinguished CP patients with widespread hyperalgesia and predicted individual treatment responses to peripherally targeted endoscopic therapy. These preliminary findings provide early support for a shared cortical signature of central sensitization across pain conditions and offer translational potential for developing EEG-based predictive tools for treatment response in CP.

INTRODUCTION/UNASSIGNED:This study aims to investigate the interregional functional connectivity in chronic back pain patients with widespread hyperalgesia, patients with localized back pain, and pain-free controls using stimulus-evoked high-density EEG recordings. METHODS/UNASSIGNED:We conducted high-density EEG recordings to compare the functional connectivity and betweenness centrality between these groups. RESULTS/UNASSIGNED:Compared with controls, chronic pain patients showed altered functional connectivity between regions that process cognitive information and regions that process sensory or affective information. Widespread hyperalgesia, however, is further differentiated from localized pain by decreased inter-hemispheric connectivity of sensory and affective areas and increased intra-hemispheric connectivity between sensory and cognitive cortices. Graph-theoretic analysis showed that whereas chronic pain is associated with decreased centrality of prefrontal, orbitofrontal, and cingulate areas, widespread hyperalgesia is distinguished by increased centrality of prefrontal and insular areas. DISCUSSION/UNASSIGNED:Together, our results show that although widespread hyperalgesia shares certain features with localized pain, it is further characterized by distinct cortical mechanisms.

BACKGROUND:Centrally inserted central catheters (CICCs) are indispensable in modern healthcare, but unfortunately, come with complications. Catheter-related thrombosis is a well-known complication reported to occur in 5-30% of patients with CICC. There is a paucity of studies that report the incidence of catheter-related thrombosis after the introduction of real-time ultrasound insertion guidance as clinical practice. This study aimed to demonstrate any pathological macro- or microscopic changes in the vein wall associated with CICCs. METHODS:The study was approved by the Swedish Ethical Review Authority and was conducted at a large university hospital. The study included 12 patients with a short-term CICC who were subject to autopsies. Vessels with inserted catheters were macroscopically and microscopically examined. RESULTS:In total, seven female and five male patients with a median age of 70 (interquartile range 63-76) were included. With one exception, all patients received routine thromboprophylaxis throughout the period with CICC. Most inserted CICCs were 9.5 French (54%) and were inserted in the internal jugular vein (92%). The median time with CICC was seven days (interquartile range 1.8-20). At autopsy, thrombi were observed in all cases (100%), macroscopically and microscopically, attached to the distal portion of the CICC and/or the adjacent vessel wall. Inflammatory changes in the vessel walls were seen in all cases, and varying degrees of fibrosis were demonstrated in eight cases (67%). CONCLUSIONS:This autopsy study demonstrated that catheter-related thrombus formation with adjacent inflammatory and fibrotic vessel wall thickening was very common, despite a limited period of catheter use. The consequences of these findings are important, as thrombi may cause pulmonary embolism and possibly lead to catheter-related infections, and since inflammatory and fibrotic vessel wall thickening may evolve into chronic venous stenosis. Furthermore, the findings are a cause of concern, as CICCs are indispensable in modern healthcare and complications may be masked by the general disease that was the indication for CICC insertion.

INTRODUCTION/UNASSIGNED:Older adults undergoing surgery are at risk of postoperative neurocognitive disorders, prompting the need for preoperative cognitive screening in this population. Traditionally, cognitive screening has been conducted in-person using brief assessment tools such as the Montreal Cognitive Assessment (MoCA) or the Mini-Mental State Examination (MMSE). More comprehensive test batteries, such as the Uniform Data Set (UDS) Neuropsychological Battery, and its remote testing version, the Uniform Data Set version 3 tele-adapted test battery (UDS v3.0 T-cog), have been developed to assess cognitive decline in normal aging and disease conditions, but have not been applied in the perioperative setting. METHODS/UNASSIGNED:We assessed the feasibility of using this remote UDS v3.0 T-cog battery for preoperative cognitive assessment in 81 older adults 65+ scheduled for lower extremity joint replacement surgery. RESULTS/UNASSIGNED:Our results indicate that the UDS v3.0 T-cog achieves 99% completion rates and demonstrates high patient satisfaction. Further, we found 28% of subjects were cognitively impaired in this patient cohort. DISCUSSION/UNASSIGNED:These findings suggest that the UDS v3.0 T-cog is a feasible tool for assessing cognitive function in the older adult perioperative population. To our knowledge, this is the first study to apply this comprehensive remote test battery in the preoperative setting.

BACKGROUND/UNASSIGNED:To maintain a low incidence of Catheter Related Infections (CRI) and Catheter Related Bloodstream Infections (CRBSI), continuous follow-up studies on catheter management are necessary. The aims of the present study were to investigate the incidence of catheter tip colonisation, CRI and CRBSI in the Region, to further explore the feasibility of automatic data collection and to investigate associations between independent variables and CRI. METHODS/UNASSIGNED:Data from electronic patient charts on all documented central venous catheter (CVC) insertions from multiple hospitals in southern Sweden, between March 2019 and August 2020, were automatically extracted. Multivariable regression analyses were used to identify associated risk factors. RESULTS/UNASSIGNED:) with incidences of 1.2/1000 catheter days and 0.3/1000 catheter days, respectively. CONCLUSIONS/UNASSIGNED:We found a sustained low incidence of CRI and CRBSI in the Region. Catheter tips were less likely to be colonised when the subclavian route was used compared to the internal jugular route and male sex as well as increased number of catheter lumens were associated with both catheter tip colonisation and CRI. By using automated scripts, data extraction was efficient and feasible but also demonstrated that real-time quality assurance should be recommended, since this is superior to current standard.

Machine learning is becoming an increasingly common component of routine data analyses in clinical research. The past decade in pain research has witnessed great advances in human neuroimaging and machine learning. With each finding, the pain research community takes one step closer to uncovering fundamental mechanisms underlying chronic pain and at the same time proposing neurophysiological biomarkers. However, it remains challenging to fully understand chronic pain due to its multidimensional representations within the brain. By utilizing cost-effective and non-invasive imaging techniques such as electroencephalography (EEG) and analyzing the resulting data with advanced analytic methods, we have the opportunity to better understand and identify specific neural mechanisms associated with the processing and perception of chronic pain. This narrative literature review summarizes studies from the last decade describing the utility of EEG as a potential biomarker for chronic pain by synergizing clinical and computational perspectives.

INTRODUCTION/UNASSIGNED:Chronic pain negatively impacts a range of sensory and affective behaviors. Previous studies have shown that the presence of chronic pain not only causes hypersensitivity at the site of injury but may also be associated with pain-aversive experiences at anatomically unrelated sites. While animal studies have indicated that the cingulate and prefrontal cortices are involved in this generalized hyperalgesia, the mechanisms distinguishing increased sensitivity at the site of injury from a generalized site-nonspecific enhancement in the aversive response to nociceptive inputs are not well known. METHODS/UNASSIGNED: = 15) by analyzing behavioral and electroencephalographic (EEG) data. RESULTS/UNASSIGNED:As expected, participants with chronic pain endorsed enhanced pain with mechanical stimuli in both back and hand. We further analyzed electroencephalographic (EEG) recordings during these evoked pain episodes. Brain oscillations in theta and alpha bands in the medial orbitofrontal cortex (mOFC) were associated with localized hypersensitivity, while increased gamma oscillations in the anterior cingulate cortex (ACC) and increased theta oscillations in the dorsolateral prefrontal cortex (dlPFC) were associated with generalized hyperalgesia. DISCUSSION/UNASSIGNED:These findings indicate that chronic pain may disrupt multiple cortical circuits to impact nociceptive processing.

PURPOSE/UNASSIGNED:The COVID-19 pandemic led to a drastic expansion in utilizing telemedicine, circumventing some of the geographical barriers to accessing pain care. However, uncertainties around the impact of telemedicine across various sociodemographic groups still exist, prompting further exploration. Therefore, this study aimed to evaluate the impact of sociodemographic factors in telemedicine utilization during and after the COVID-19 pandemic. PATIENTS AND METHODS/UNASSIGNED:All outpatient non-procedural visits at the pain medicine division of a large academic institution in the epicenter of the pandemic (New York, USA), between March 2019 and October 2021, were retrospectively included. Sociodemographic data including gender, age, ethnicity/race, postal code, and type of health insurance, across three time periods associated with the COVID-19 pandemic - pre-lockdown (in-office visits only), lockdown (telemedicine visits only) and post-lockdown (offering both in-office and telemedicine visits) - were analyzed and compared. RESULTS/UNASSIGNED:In total, 12,615 unique patients - The majority being women (58%) - were seen during the whole study period. In the post-lockdown period, telemedicine was utilized by 42% of all patients. Follow-up visits, younger patients, white patients, patients residing further away from the hospital, and privately insured patients were more likely to utilize telemedicine post-lockdown (p <0.05). Older patients, minorities, Manhattan residents, and Medicare/Medicaid recipients, were more likely to use in-office visits post-lockdown (p <0.05). CONCLUSION/UNASSIGNED:We identified disparities in the utilization of telemedicine in Pain Medicine, which may be due to socioeconomic factors such as lack of access to reliable internet access, cost of devices, and technological know-how. This emphasizes the need for further studies to better understand the reasons for and barriers to telemedicine use. This could help inform policymaking to safeguard equitable access to telemedicine use for pain care.

BACKGROUND:The frequency of central venous catheter (CVC)-related complications in hematologic patients has previously been studied but some uncertainty remains. Therefore, this observational cohort study was designed primarily to investigate mechanical and infectious complications related to CVC insertion in hematologic patients and secondarily to identify factors associated with these complications. METHODS:Documented data on CVC insertions in all adult hematologic patients who received a CVC from 2013 to 2019 at a University Hospital in Sweden were retrospectively collected. RESULTS:A total of 589 CVC insertions in 387 patients were included. The prevalence of moderate and severe mechanical complications, predominantly comprising grades 2-4 bleeding, was 11%. Preprocedural coagulopathy, number of needle passes, and arterial puncture were all independently associated with grades 2-4 bleeding. The incidence of suspected catheter-related infections (sCRI) was 3.7/1000 catheter days. Higher body mass index and male gender were independently associated with sCRI. CONCLUSIONS:Patients with hematologic malignancies have a high risk of both grades 2-4 bleeding and sCRI after CVC insertion. This underlines the importance of optimizing the conditions at the insertion and also of daily inspections, evaluation of future needs, and extra precautions to avoid sCRI in these susceptible patients.

BACKGROUND:Catheter-related infections (CRIs) and catheter-related bloodstream infections (CRBSIs) are among the most frequent hospital acquired infections. CRI/CRBSI studies in Scandinavian cohorts are scarce. The primary aim of this study was to investigate the CRI/CRBSI incidence and the association between potential risk factors, including the introduction of a simple hygiene insertion bundle and CRIs at a large university hospital in Sweden. METHODS:We retrospectively included all patients aged 12 and above who received a central venous catheter (CVC) or a central dialysis catheter during a 2-year period, 1 year before and 1 year after the implementation of a simple hygiene insertion bundle. Microbiological data, including catheter tip cultures and blood cultures, were merged with CVC insertion data. RESULTS:A total of 1722 catheter insertions in 1428 patients were included. CRI and CRBSI incidence were 1.86/1000 and 0.62/1000 catheter days, respectively. In a multivariable regression model, the implementation of a simple hygiene insertion bundle was the independent factor most strongly associated with significantly lower CRI-incidence (95% confidence interval [CI] of odds ratio [OR] 0.23-0.92, P = .029). Choosing multiple lumen catheters was associated with increasing CRI-incidence (95% CI of OR 1.11-2.39, P = .013). CONCLUSION:The incidence of catheter-related infections and catheter-related bloodstream infections in this Scandinavian cohort was low. The implementation of a simple hygiene insertion bundle seems to be an effective intervention for reducing catheter-related infections. The use of multiple-lumen catheters is associated with increased risk of catheter-related infections.