Percutaneous Ultrasound-Guided Coracohumeral Ligament Release for Refractory Adhesive Capsulitis: A Prospective, Randomized, Controlled, Crossover Trial Demonstrating One-Year Efficacy.

BACKGROUND: Adhesive capsulitis (AC) is a painful and disabling condition with restricted range of motion (ROM) that affects 2% to 3% of the population and up to 20% of patients with diabetes. AC can be idiopathic, iatrogenic, or secondary to shoulder injuries. Some associated conditions include diabetes mellitus, thyroid disorders, dyslipidemia, stroke, prolonged immobilization, and autoimmune conditions. Management ranges from analgesics to physical therapy, local injections, hydrodilatation, and advanced surgical interventions. This study examines percutaneous coracohumeral ligament (PCHL) sectioning with the hypothesis that interruption would improve pain and ROM in patients with AC refractory to conservative management. OBJECTIVES: To use sonographically guided percutaneous interruption of the CHL for the treatment of refractory AC. STUDY DESIGN: A prospective, randomized, controlled, cross-over trial. SETTING: Academic medical center. METHODS: Patients were identified based on inclusion and exclusion criteria under the supervision of the Principal Investigator. After primary screening, research staff explained the study, risks, and benefits to the patients, and consent was obtained. Patients' pain score and shoulder ROM were assessed before and after the procedure, at one month, and one year. The Oxford Shoulder Scoring (OSS) questionnaire was also completed before the procedure and in the one-year follow-up visit.Forty patients were enrolled with refractory AC. Forty-six shoulders were treated; 6 patients underwent a bilateral procedure. Block 2:1 randomization was performed for the 2 groups (PCHL release [PCHLR] and local anesthetic CHL [LACHL]). The LACHL group received a lidocaine injection at CHL, and the PCHLR group received the CHL using a Tenex® (Tenex Health, Lake Forest, CA) needle. ROM, Numeric Rating Scale (NRS-11), and OSS were evaluated at baseline, immediate postprocedure, and long term. RESULTS: Among 46 shoulders included in the study, 7 were excluded due to lost to follow-up, total shoulder replacement, and shoulder manipulation. Twenty-six were randomized to the PCHLR group and 13 to LACHL group. ROM (external rotation and abduction), pain, NRS-11 score, and OSS score were measured at baseline and long term, confirmed by a nonbiased health care personnel. There was no statistically significant difference in ROM, NRS-11, and OSS between the 2 cohorts at the baseline visit. Nine patients in LACHL group crossed over to the PCHLR arm at one month. Data analysis in the long term revealed durability of the PCHLR group with a statistically significant difference in ROM, NRS-11, and OSS. External rotation improved by double, and abduction improved by almost 30% (P value < .001). NRS-11 decreased from 8 (IQR 8, 9) at baseline to 3 (IQR 2, 7) at long term among those who received PCHLR. The baseline mean OSS in the PCHLR group increased from 7.44 to 31.86 at one-year follow-up and was statistically significant (P value < .001). LIMITATIONS: This study represents a small population of patients with a CHL-related ROM deficit. Patients were not excluded for osteoarthritis or other motion-disabling shoulder conditions. We submit that the strength of the study could have been improved if the physician performing the procedure was blinded and if the patient was blinded as well to minimize operator and patient bias. CONCLUSIONS: We demonstrate that our technique for PCHLR is a safe, effective, and durable procedure that improved ROM, pain, and shoulder function in our patient population when compared to the control. KEY WORDS: Tenex, frozen shoulder, pain, range of motion, function, shoulder, minimally invasive, durable.

Defining Personas of People Living with Chronic Pain: An Ethnographic Research Study.

Introduction: Pain is the leading reason for which people seek medical care in the United States, and chronic pain (CP) affects approximately 50 million people in the US Pain perception is deeply personal, is highly correlated with behavioral and emotional disorders, and is greatly influenced by physiological and environmental factors. The patient-provider relationship can have profound implications for clinical outcomes within the context of treating CP. However, limited access to pain specialists, the complex nature of many CP-causing conditions, the absence of instruments for objective pain measurement, and the need to foster a trust-based patient-provider relationship throughout treatment pose unique challenges. Objective: To support a more optimal CP care delivery system that leverages a healthy therapeutic patient-provider relationship, we systematically gathered deeper knowledge of the behaviors, interpersonal dynamics, home environment, values, and mindsets of people who experience CP. Methods: We employed ethnographic research methods to collect and analyze data on views, habits, strategies, attitudes, and life circumstances of a range of participants living with CP. We aggregated, analyzed, and summarized participant data to identify trends and similarities. Results: Our findings suggest that patients can be broadly categorized into five predominant pain typologies, or "personas", which are characterized by respective symptom durations, care management preferences, values, communication styles, and behaviors. Conclusion: Identifying CP personas may enhance the ability to personalize CP care and help foster more robust therapeutic relationships, which may lead to greater trust, improved patient satisfaction, and better clinical outcomes.

Cross-Sectional Study Evaluating Clinical & Psychological Impact of Limited Access to Healthcare in Chronic Pain Patients During the COVID-19 Pandemic.

BACKGROUND: COVID-19 quarantine measures have created new challenges in the delivery of medical care, especially in the realm of medical and interventional chronic pain management. This study evaluated the effect of COVID-19 social distancing and quarantine measures on symptoms of pain and anxiety, as well as substance abuse and health care engagement in patients with chronic pain and the role of the clinic's virtual assessment initiatives in managing these patients. METHODS: A 24-question cross-sectional survey was conducted with patients with chronic pain seen at the Montefiore Medical Center Comprehensive Pain Clinic from June 2020 through July 2020. The survey was administered to 552 high-utilizer patients via telephone, evaluating domains such as pain, anxiety, substance use, and health care engagement. The questions were quantitively assessed on a Likert scale or a numerical rating scale. We used descriptive statistics to report our results. RESULTS: Of the 1,023 patients identified as high utilizers of the pain clinic, 552 patients participated in the survey. The median (25th-75th percentile) pain score reported was 7 (5-9) for all responders. Approximately 50% of the patients reported that they were anxious about their pain and somewhat or very concerned that their pain would be uncontrolled during the pandemic. Further, the severity of the pain reported was associated with sleep, appetite, and mood changes. In our cohort, 95% of all patients denied using alcohol, 92% denied using marijuana, and 98% denied using other recreational drugs to manage their pain during the pandemic. In addition, just more than three-fourths (79%) of all patients reported needing to speak with their health care provider during the pandemic. CONCLUSIONS: The survey conducted among high-utilizers demonstrated that patients who remained engaged with their health care team reported minimal concerns regarding chronic pain and associated symptoms during the COVID-19 quarantine period. In addition, the early implementation of virtual consults in the pain clinic may have contributed to mitigating patient concerns. Finally, the study also identified the importance of outreach and patient education on the availability and utilization of telemedicine services. Consequently, it is reasonable to implement virtual assessments and visits alongside other education outreach methods to engage patients with chronic pain who frequently utilize chronic pain health care resources.

The Use of a New Device-Assisted Needle Guidance versus Conventional Approach to Perform Ultrasound Guided Brachial Plexus Blockade: A Randomized Controlled Study.

Purpose: Ultrasound guidance during nerve blockade poses the challenge of maintaining in-plane alignment of the needle tip. The needle guidance device maintains needle alignment and assists with in-plane needle visualization. The purpose of this study is to evaluate the utility of this device by comparing procedure performance during brachial plexus blockade with the conventional approach. Methods: After the Institutional Review Board approval and obtaining informed consent, 70 patients receiving either interscalene or supraclavicular nerve blocks were randomly assigned into 2 groups, a conventional approach versus utilizing the needle guidance device. An independent observer recorded: total procedure time; needle insertion time; number of unplanned redirections; and number of reinsertions. Additionally, physician satisfaction and ease of needle visualization were assessed. Results: Data from seventy patients were analyzed. The median [25th percentile-75th percentile] time to complete the block by the device assisted needle guidance group was 3 (2-3.75) minutes and 4 (3-6) minutes in the conventional approach group (p < 0.001). Additionally, subgroup analyses were performed in the supraclavicular block and interscalene block. Supraclavicular blockade, needle insertion time (median [25th percentile-75th percentile] in seconds) (106 [92-162] vs 197 [140-278]), total procedure time (3 [2-3] vs 4.5 [4-6] in minutes) and unplanned needle redirections (2 [1-5] vs 5.5 [3-9]) were significantly lower in needle guidance group (p < 0.001). With interscalene blockade, needle insertion time (86 [76-146] vs 126 [94-295]) and unplanned needle redirections (2 [1-3] vs 4 [2-8.5]) were significantly lower with needle guidance (p < 0.001), but total procedure time was similar. All the physicians reported that they would use the needle guidance again, and 90% would prefer it for in-plane blocks. Conclusion: Performing regional blocks using the needle guidance device reduces needle insertion time and unplanned needle redirections in brachial plexus blockade. Moreover, physician satisfaction also improved compared to the use of the conventional technique.

Point To Area of Pain: A Clinically Useful Telehealth Physical Exam Technique for Focal Nociceptive and Neuropathic Pain.

BACKGROUND: Chronic pain is a leading cause of disease burden and disability globally. The COVID-19 pandemic catalyzed a major paradigm shift in health care delivery with the universal adoption of telemedicine. Telehealth physical examination is particularly challenging and little guidance is available on this topic. OBJECTIVES: We attempt to describe the Point To the Area of Pain (PTAP) test and establish a consensus regarding its utility for musculoskeletal examination (MSK) via telehealth. STUDY DESIGN: The authors drafted an online survey. SETTING: The survey was sent to physicians and nurse practitioners within the authors' respective departments and institutions who routinely use telemedicine to treat pain METHODS: Respondents (n = 61) were asked about their primary specialty, comfort level in evaluating patients in pain, use of the PTAP test and its perceived clinical relevance to patient management, and other relevant questions. RESULTS: Respondents were predominantly trained in Physiatry (47.5%), Anesthesiology (23%), Neurology (13.1%) and Family Medicine (11.5%); 67.2% of providers treat pain related diseases > 75% of the time; 50.8% of respondents were "somewhat comfortable" at performing a virtual MSK exam and 29.5% were "not comfortable"; 65.5% utilize the PTAP test and 88.5% agree or strongly agree that this test provides extrinsic clinically relevant information. LIMITATIONS: The relatively small number of respondents. CONCLUSION: PTAP tests should not replace the standard accepted in-person or virtual physical examination in practice, but in the absence of a hands-on exam, the PTAP test is a clear and concise test that can easily be performed in conjunction with other techniques via telehealth, and in the context of assessing pain provides useful clinical information that can help guide medical decision making.

Comparison of Dexmedetomidine and Dexamethasone as Adjuvants to Ultra-Sound Guided Interscalene Block in Arthroscopic Shoulder Surgery: A Double-Blinded Randomized Placebo-Controlled Study.

BACKGROUND: Interscalene block is one of the popular methods for decreasing pain and analgesic consumption after shoulder arthroscopic surgeries. OBJECTIVES: The objective is to compare the analgesic duration of effects of dexmedetomidine and dexamethasone as adjuvants to 0.5% ropivacaine in ultrasound-guided interscalene blocks for arthroscopic shoulder surgery in an ambulatory setting. METHODS: In this randomized controlled trial, 117 adult patients candidate for ambulatory arthroscopic shoulder surgery under general anesthesia were divided into three groups to perform an ultra-sound guided interscalene block before the surgery. The ropivacaine (control) group received ropivacaine 0.5% 20 mL, group Dexamethasone received ropivacaine 0.5% 20 mL plus 4mg dexamethasone, and group dexmedetomidine received ropivacaine 0.5% 20 mL plus 75 mcg of dexmedetomidine. Time to return of sensory function, of motor function, of first pain sensation, amount of opioid medication consumed at 24 hours and 48 hours post-operatively were measured. RESULTS: The 24-hour median (25th- 75th percentile) opioid consumption in morphine equivalents was similar between groups 22.5 mg (10 - 30), 15 mg (0 - 30), and 15 mg (0 - 20.6) in the ropivacaine, dexmedetomidine, and dexamethasone groups, respectively (P = 0.130). The median (25th- 75th percentile) 48 hours post-operatively, the median opioid consumption in morphine equivalents was 40 mg (25 - 67.5) in the ropivacaine group, 30 mg (22 - 50.6) in the dexamethasone group, and 52.5 mg (30 - 75) in the dexmedetomidine group (P = 0.278). The median 24-hour pain scores were 6 (5 - 8) in the ropivacaine control group, 7 (5.5 - 8) in the dexamethasone group, and 7 (4 - 9) in the dexmedetomidine group (P = 0.573). CONCLUSIONS: There was no statistical difference in opioid consumption at 24 and 48 hours post-operatively when comparing dexmedetomidine, dexamethasone, and no adjuvant. However, intraoperative opioid use was significantly lower with dexmedetomidine compared to dexamethasone and plain 0.5% ropivacaine. The safe side effect profile of dexmedetomidine makes it a reasonable alternative as an adjuvant for peripheral nerve blockade when dexamethasone use may be contraindicated.

Expanding frontiers in telehealth: Video assisted at-home application of capsaicin 8% patch.

In recent years, the delivery of health services has undergone a major paradigm shift towards expanded outpatient services and widespread use of telemedicine. Post-herpetic neuralgia (PHN) is a treatment recalcitrant neuropathic pain condition referring to pain persisting more than three months from the initial onset of an acute herpes zoster. QUTENZA® (capsaicin 8% patch) is a single 1-hr localized treatment for PHN and can provide several months of pain relief per application. However, patient access to capsaicin 8% patch is limited due to sensitive handling protocols that require the patch application to occur under physicians or healthcare professionals under the close supervision of a physician. Herein, we describe a successful treatment of PHN at-home, using capsaicin 8% patch, performed under full supervision and instruction from a physician using video telehealth services. SIGNIFICANCE: This is a case report of the successful treatment of post-herpetic neuralgia at-home using Capsaicin 8% patch. The procedure was performed under full supervision and instruction from a physician using video telehealth services. Not only did the patient tolerate the procedure and have significant efficacy, she voiced preference to repeat treatment in this manner versus going back to the office.

A Randomized Comparison of Pain Control and Functional Mobility between Proximal and Distal Adductor Canal Blocks for Total Knee Replacement.

BACKGROUND: Adductor canal blocks (ACBs) have become a popular technique for postoperative pain control in total knee arthroplasty patients. Proximal and distal ACB have been compared previously, but important postoperative outcomes have yet to be assessed. AIMS: The primary objective of this study is to compare postoperative analgesia between proximal and distal ACB. Secondary outcomes include functional mobility, length of stay (LOS), and adverse events. SETTINGS AND DESIGN: This study was a single-center, assessor-blinded, randomized trial. SUBJECTS AND METHODS: Fifty-seven patients were randomly assigned to receive a proximal (n = 28) or distal (n = 29) ACB. A 20 mL bolus of 5 mg/mL ropivacaine was injected at the respective location followed by 2.0 mg/mL ropivacaine infusion for 24 h. STATISTICAL ANALYSIS: The primary outcome was intra- and postoperative 24-h opioid consumption in intravenous (IV) morphine equivalents. Secondary outcomes include percentage change in timed "Up and Go" (TUG) times, LOS, and average postoperative pain scores. Continuous variables were compared using Student's t-test. RESULTS: The mean (±standard deviation) 24-h intra-and postoperative opioid consumption showed no difference between the proximal and distal groups (39.72 ± 23.6 and 41.28 ± 19.6 mg IV morphine equivalents, respectively, P = 0.793). There was also no significant difference in the median [minimum, maximum] percentage change in TUG times relative to preoperative performance comparing proximal and distal ACB (334.0 [131, 1084] %-change and 458.5 [169, 1696] %-change, respectively, P = 0.130). In addition, there were no differences in postoperative pain scores or LOS. CONCLUSIONS: ACB performed at either proximal or distal locations shows no difference in postoperative pain measured by opioid consumption or pain scores. Better TUG performance seen in the proximal group was not statistically significant but might represent a clinically important difference in functional mobility.

Equivalent analgesic effectiveness between perineural and intravenous dexamethasone as adjuvants for peripheral nerve blockade: a systematic review and meta-analysis.

PURPOSE: Dexamethasone is commonly used as an adjuvant to local anesthetics for peripheral nerve blockade; however, uncertainty persists regarding its optimal route of administration and safety. A systematic review and meta-analysis of randomized-controlled trials (RCTs) was conducted to compare the incremental benefits of intravenous (IV) vs perineural (PN) dexamethasone when used as adjuvants for peripheral nerve blockade to improve analgesia. SOURCES: A search strategy was developed to identify eligible articles from the Cochrane and National Library of Medicine databases from inception until June 2017. The National Center for Biotechnology Information Medical Subject Headings browser thesaurus was used to identify search terms and combinations of keywords. Any clinical trial that randomly allocated adult patients (≥ 18 yr old) to receive either IV or PN dexamethasone for peripheral nerve blockade was considered for inclusion. PRINCIPAL FINDINGS: After full-text screening of potentially eligible articles, 14 RCTs were included in this review. Overall, the use of PN dexamethasone did not provide a significant incremental benefit to the duration of analgesia [ratio of means (ROM), 1.23; Hartung-Knapp-Sidik-Jonkman (HKSJ) 95% confidence interval (CI), 0.85 to 1.85; P = 0.23] or to motor block duration (ROM, 1.14; HKSJ 95% CI, 0.98 to 1.31; P = 0.07). Also, at 24-hr follow-up, there was no significant difference between the two groups regarding pain scores (standardized mean difference, 0.36; HKSJ 95% CI, -0.08 to 0.80; I2 = 75%; P = 0.09) and cumulative opioid consumption (mean difference, 5.23 mg; HKSJ 95% CI, -4.60 to 15.06; P = 0.15). Lastly, no long-term nerve-related complications were observed with the use of PN dexamethasone. CONCLUSIONS: The results of our meta-analysis suggest that PN and IV dexamethasone provide equivalent analgesic benefits and have similar safety profiles, when used as adjuvants, for peripheral nerve blockade.

The Anatomic Relationship of the Tibial Nerve to the Common Peroneal Nerve in the Popliteal Fossa: Implications for Selective Tibial Nerve Block in Total Knee Arthroplasty.

Background. A recently described selective tibial nerve block at the popliteal crease presents a viable alternative to sciatic nerve block for patients undergoing total knee arthroplasty. In this two-part investigation, we describe the effects of a tibial nerve block at the popliteal crease. Methods. In embalmed cadavers, after the ultrasound-guided dye injection the dissection revealed proximal spread of dye within the paraneural sheath. Consequentially, in the clinical study twenty patients scheduled for total knee arthroplasty received the ultrasound-guided selective tibial nerve block at the popliteal crease, which also resulted in proximal spread of local anesthetic. A sensorimotor exam was performed to monitor the effect on the peroneal nerve. Results. In the cadaver study, dye was observed to spread proximal in the paraneural sheath to reach the sciatic nerve. In the clinical observational study, local anesthetic was observed to spread a mean of 4.7 + 1.9 (SD) cm proximal to popliteal crease. A negative correlation was found between the excess spread of local anesthetic and bifurcation distance. Conclusions. There is significant proximal spread of local anesthetic following tibial nerve block at the popliteal crease with possibility of the undesirable motor blocks of the peroneal nerve.

Investigating the Efficacy of Dexmedetomidine as an Adjuvant to Local Anesthesia in Brachial Plexus Block: A Systematic Review and Meta-Analysis of 18 Randomized Controlled Trials.

BACKGROUND AND OBJECTIVES: Dexmedetomidine has been thought to be an effective adjuvant to local anesthetics in brachial plexus blockade. We sought to clarify the uncertainty that still exists as to its true efficacy. METHODS: A meta-analysis of randomized controlled trials was conducted to assess the ability of dexmedetomidine to prolong the duration and hasten the onset of motor and sensory blockade when used as an adjuvant to local anesthesia for brachial plexus blockade versus using local anesthesia alone (control). A search strategy was created to identify eligible articles in MEDLINE, EMBASE, and The Cochrane Library. The methodological quality for each included study was evaluated using the Cochrane Tool for Risk of Bias. RESULTS: Eighteen randomized controlled trials were included in this meta-analysis (n = 1092 patients). The addition of dexmedetomidine significantly reduced sensory block time onset time by 3.19 minutes (95% confidence interval [CI], -4.60 to -1.78 minutes; I = 95%; P < 0.00001), prolonged sensory block duration by 261.41 minutes (95% CI, 145.20-377.61 minutes; I = 100%; P < 0.0001), reduced the onset of motor blockade by 2.92 minutes (95% CI, -4.37 to -1.46 minutes; I = 96%, P < 0.0001), and prolonged motor block duration by 200.90 minutes (CI, 99.24-302.56 minutes; I = 99%; P = 0.0001) as compared with control. Dexmedetomidine also significantly prolonged the duration of analgesia by 289.31 minutes (95% CI, 185.97-392.64 minutes; I = 99%; P < 0.00001). Significantly more patients experienced intraoperative bradycardia with dexmedetomidine (risk difference [RD], 0.06; 95% CI, 0.00-0.11; I = 72%; P = 0.03); however, there was no difference in the incidence of intraoperative hypotension (RD, 0.01; 95% CI, -0.02 to 0.04; I = 3%; P = 0.45). It is important to note that all studies reported that intraoperative bradycardia was either transient in nature or reversible, when needed, with the administration of intravenous atropine. CONCLUSIONS: Dexmedetomidine has the ability to hasten the onset and prolong the duration of blockade when used as an adjuvant to local anesthesia for brachial plexus blockade. Considering an analgesic effect to be either decreased pain, a longer duration of analgesic block, or decreased opioid consumption, the addition of dexmedetomidine to local anesthetics for brachial plexus blockade was found to significantly improve analgesia in all 18 included studies. However, patients receiving dexmedetomidine should be continuously monitored for the potentially harmful but reversible adverse effect of intraoperative bradycardia. LEVEL OF EVIDENCE: Therapeutic, level I.

The Use of Electrical Impedance to Identify Intraneural Needle Placement in Human Peripheral Nerves: A Study on Amputated Human Limbs.

BACKGROUND: Even as the use of peripheral nerve blockade in the perioperative setting is increasing, neural injury secondary to accidental intraneural injection remains a significant patient safety concern. Current modalities, including electrical stimulation and ultrasound imaging, still lack consistency and absolute reliability in both the detection and prevention of this complication. The measurement of electrical impedance (EI) could be an easy and valuable additional tool to detect intraneural needle placement. Our objectives in this study were to measure the change in EI with intraneural needle advancement in recently amputated human limbs. METHODS: The study was conducted within 45 minutes of amputation. The nerves that were studied were the sciatic nerve in the popliteal fossa in above-knee amputations or the tibial nerve below the calf in below-knee amputations. The amputated limb was placed on a tray and under ultrasound imaging guidance, an insulated peripheral block needle connected to a nerve stimulator was placed extraneurally and subsequently advanced intraneurally. The experiment was repeated on the same nerve after exposure by surgical dissection. The differences in impedance measurements between intraneural and extraneural needle placement were compared. RESULTS: In the below-knee amputated extremity (tibial nerve, n = 6) specimens based on the ultrasound methods, mean ± SD for ultrasound-guided intraneural impedance was 10 ± 2 kΩ compared with an extraneural impedance of 6 ± 1.6 kΩ (P = 0.005). The difference between intraneural and extraneural impedance after open dissection was also significant when we repeated the analysis based on the same specimens (P = 0.005). Similarly, in the above-the-knee amputated extremity (sciatic nerve, n = 5) specimens, mean intraneural impedance was 35.2 ± 7.9 kΩ compared with an extraneural impedance of 25.2 ± 5.3 kΩ (P = 0.037). The difference between intraneural and extraneural impedance obtained after open dissection was also significant when we repeated the analysis based on the same specimens (P = 0.0002). The impedance values were consistent and similar to those obtained after open dissection. CONCLUSIONS: There is no reliable "gold standard" to predict or prevent intraneural needle placement during peripheral nerve blockade. This small sample-sized study demonstrated that there is a change in EI with intraneural needle advancement. In clinical practice, measurement of the EI in conjunction with nerve stimulation may serve as another tool to use for identifying intraneural needle placement during peripheral nerve blockade.

Enolate-Forming Phloretin Pharmacophores: Hepatoprotection in an Experimental Model of Drug-Induced Toxicity.

Drug-induced toxicity is often mediated by electrophilic metabolites, such as bioactivation of acetaminophen (APAP) to N-acetyl-p-benzoquinone imine (NAPQI). We have shown that APAP hepatotoxicity can be prevented by 2-acetylcyclopentanone (2-ACP). This 1,3-dicarbonyl compound ionizes to form an enolate nucleophile that scavenges NAPQI and other electrophilic intermediates. In this study, we expanded our investigation of enolate-forming compounds to include analyses of the phloretin pharmacophores, 2',4',6'-trihydroxyacetophenone (THA) and phloroglucinol (PG). Studies in a mouse model of APAP overdose showed that THA provided hepatoprotection when given either by intraperitoneal injection or oral administration, whereas PG was hepatoprotective only when given intraperitoneally. Corroborative research characterized the molecular pharmacology (efficacy, potency) of 2-ACP, THA, and PG in APAP-exposed isolated mouse hepatocytes. For comparative purposes, N-acetylcysteine (NAC) cytoprotection was also evaluated. Measurements of multiple cell parameters (e.g., cell viability, mitochondrial membrane depolarization) indicated that THA and, to a lesser extent, PG provided concentration-dependent protection against APAP toxicity, which exceeded that of 2-ACP or NAC. The enolate-forming compounds and NAC truncated ongoing APAP exposure and thereby returned intoxicated hepatocytes toward normal viability. The superior ability of THA to protect is related to multifaceted modes of action that include metal ion chelation, free radical trapping, and scavenging of NAPQI and other soft electrophiles involved in oxidative stress. The rank order of potency for the tested cytoprotectants was consistent with that determined in a parallel mouse model. These data suggest that THA or a derivative might be useful in treating drug-induced toxicities and other conditions that involve electrophile-mediated pathogenesis.

The association between body mass index and outcome after coronary artery bypass grafting operations.

OBJECTIVES: This investigation was undertaken to analyse the association between body mass index (BMI) and morbidity after coronary artery bypass graft (CABG) operations. METHODS: The setting was a cardiovascular intensive care unit (ICU) of a tertiary medical referral centre. This was a retrospective review; patients were classified according to their BMI into five groups: underweight <18.5 kg/m(2); normal weight 18.5-24.9 kg/m(2); overweight 25-29.9 kg/m(2); Class I obesity 3034.9 kg/m(2); and Class II/III obesity >35 kg/m(2). We included patients who underwent isolated CABG between January 3, 2006 and March 8, 2011. After including only the initial operation or admission in patients with more than one operation or hospital admission and excluding patients with any missing variable, 3470 patients remained in the analyses. The primary outcomes analysed were hospital mortality and pulmonary and infection morbidities. We secondarily assessed the association between BMI category and each of the three outcomes. RESULTS: Respective mortality, and pulmonary and infection morbidity occurrence rates were: 8.7, 13.0 and 13.0% for the underweight; 2.4, 8.0 and 4.8% for the overweight; 1.8, 10.9 and 5.6% for the Class I obesity group; and 2.7, 11.1 and 5.7% for the Class II/III obesity group, vs 2.3, 7.0 and 6.2% for the normal weight group. Class I and II/III obesity patients were more likely to have pulmonary morbidity compared with the normal weight group, after adjusting for the potential confounding variables. CONCLUSIONS: Class I and Class II/III obesity (BMI ≥30 kg/m(2)) was associated with increased pulmonary morbidity after CABG operations. There was no difference in mortality or infection morbidity in any BMI group compared with the normal group.

2-Acetylcyclopentanone, an enolate-forming 1,3-dicarbonyl compound, is cytoprotective in warm ischemia-reperfusion injury of rat liver.

We have previously shown that 2-acetylcyclopentanone (2-ACP), an enolate-forming 1,3-dicarbonyl compound, provides protection in cell culture and animal models of oxidative stress. The pathophysiology of ischemia-reperfusion injury (IRI) involves oxidative stress, and, therefore, we determined the ability of 2-ACP to prevent this injury in a rat liver model. IRI was induced by clamping the portal vasculature for 45 minutes (ischemia phase), followed by recirculation for 180 minutes (reperfusion phase). This sequence was associated with substantial derangement of plasma liver enzyme activities, histopathological indices, and markers of oxidative stress. The 2-ACP (0.80-2.40 mmol/kg), administered by intraperitoneal injection 10 minutes prior to reperfusion, provided dose-dependent cytoprotection, as indicated by normalization of the IRI-altered liver histologic and biochemical parameters. The 2-ACP (2.40 mmol/kg) was also hepatoprotective when injected before clamping the circulation (ischemia phase). In contrast, an equimolar dose of N-acetylcysteine (2.40 mmol/kg) was not hepatoprotective when administered prior to reperfusion. Our studies to date suggest that during reperfusion the enolate nucleophile of 2-ACP limits the consequences of mitochondrial-based oxidative stress through scavenging unsaturated aldehyde electrophiles (e.g., acrolein) and chelation of metal ions that catalyze the free radical-generating Fenton reaction. The ability of 2-ACP to reduce IRI when injected prior to ischemia most likely reflects the short duration of this experimental phase (45 minutes) and favorable pharmacokinetics that maintain effective 2-ACP liver concentrations during subsequent reperfusion. These results provide evidence that 2-ACP or an analog might be useful in treating IRI and other conditions that have oxidative stress as a common molecular etiology.

Resolution of long standing tinnitus following radiofrequency ablation of C2-C3 medial branches--a case report.

Tinnitus is described as an auditory phantom perception analogous to central neuropathic pain. Despite the high prevalence of this debilitating symptom, no intervention is recognized that reliably eliminates tinnitus symptoms; a cause has yet to be determined. A 65-year-old healthy man presented with a 3 year history of left-sided tinnitus. Full workup performed by the primary care physician including blood tests for electrolyte imbalance, consultations by 2 independent otholaryngologists, and imaging did not reveal abnormalities to provide etiology of the tinnitus. No other complaints were noted except for occasional minimal left sided neck pain. Cervical spine x-ray showed degenerative changes with facet hypertrophy more pronounced on the left side. Subsequently, the patient underwent diagnostic left-sided C2-C3 medial branch block, resulting in complete resolution of tinnitus for more than 6 hours. After successful radiofrequency ablation of left C2-C3 medial branches, the patient became asymptomatic. At one year follow-up, he continued to be symptom free. Sparce studies have shown interaction between the somatosensory and auditory system at dorsal cochlear nucleus (DCN), inferior colliculus, and parietal association areas. Upper cervical nerve (C2) electrical stimulation evokes potentials in the DCN, eliciting strong patterns of inhibition and weak excitation of the DCN principal cells. New evidence demonstrated successful transcutaneous electrical nerve stimulation (TENS) of upper cervical nerve (C2) for treatment of somatic tinnitus in 240 patients. This case indicates that C2-C3 facet arthropathy may cause tinnitus and radiofrequency ablation of C2-C3 medial branches can provide an effective approach not previously considered.

Early tracheostomy is associated with improved outcomes in patients who require prolonged mechanical ventilation after cardiac surgery.

BACKGROUND: The best time to perform a tracheostomy in cardiac surgery patients who require prolonged postoperative mechanical ventilation remains unknown. The primary aim of this investigation was to determine if tracheostomy performed before postoperative day 10 improves patient outcomes. STUDY DESIGN: We conducted a retrospective review of prospectively collected patient information obtained from the Anesthesiology Institute Patient Registry on adult patients recovering from coronary artery bypass grafting and/or valve surgery. Demographic and comorbidity patient variables were obtained. Patients were divided into 2 groups based on the timing of their tracheostomy: early (less than 10 days) and late (14 to 28 days). The 2 patient groups were matched using propensity scores and compared on morbidity and in-hospital mortality outcomes. The primary outcomes measures were length of stay, morbidity, and in-hospital mortality. RESULTS: After propensity matching (n = 114 patients/group), early tracheostomy was associated with decreased in-hospital mortality (21.1% vs 40.4%, p = 0.002) and cardiac morbidity (14.0% vs 33.3%, p < 0.001), along with decreased ICU (median difference 7.2 days, p < 0.001) and hospital (median difference 7.5 days, p = 0.010) durations. The occurrence of sternal wound infection (6.0% vs 19.5%, p = 0.009) was less in the early tracheostomy group, but mediastinitis did not differ significantly (3.5% vs 7.0%, p = 0.24). CONCLUSIONS: Tracheostomy within 10 postoperative days in cardiac surgery patients who require prolonged mechanical ventilation was associated with decreased length of stay, morbidity, and mortality.

Ultrasound-guided placement of a permanent percutaneous femoral nerve stimulator leads for the treatment of intractable femoral neuropathy.

BACKGROUND: Femoral nerve injury is a rare complication of cardiac catheterization and is usually caused by direct trauma during femoral artery access, compression from a hematoma, or prolonged digital pressure for post-procedural hemostasis. Peripheral nerve stimulation has been used to treat different pain syndromes in the upper and lower extremities with variable success and it typically requires direct vision with open surgical approach. Since the femoral nerve can be readily seen with ultrasonography, an ultrasound-guided lead placement seemed practical. CASE REPORT: A 61-year-old morbidly obese male who sustained femoral nerve injury during cardiac catheterization continued to complain of intractable femoral neuropathy 18 months afterwords. He failed multiple treatment modalities and continued to complain of severe neuropathic pains that markedly interfere with his daily activities. Two percutaneous leads were placed under real-time ultrasonography and the placement was confirmed with fluoroscopy. One lead was placed along the longitudinal axis of the nerve and the patient had good coverage over the anterior thigh but not below the knee. So another lead was placed horizontally across the femoral nerve in order to stimulate all the branches and the patient reported good coverage along the saphenous nerve distribution down to the foot. RESULTS: The patient continues to be pain free 20 months after the implant. CONCLUSION: Here we described a novel non-invasive percutaneous approach for femoral nerve stimulation with ultrasound guidance which allowed precise placement of the stimulating lead very close to the femoral nerve without the need for surgical exploration.

Ultrasound-guided cervical selective nerve root block: a fluoroscopy-controlled feasibility study.

BACKGROUND AND OBJECTIVES: Reports of intravascular injection during cervical transforaminal injections, even after confirmation by contrast fluoroscopy, have led some to question the procedure's safety. As ultrasound allows for visualization of soft tissues, nerves, and vessels, thus potentially improving precision and safety, we evaluated its feasibility in cervical nerve root injections. METHODS: This is a prospective series of 10 patients who received cervical nerve root injections using ultrasound as the primary imaging tool, with fluoroscopic confirmation. Our radiologic target point was the posterior aspect of the intervertebral foramen just anterior to the superior articular process in the oblique view and at the midsagittal plane of the articular pillars in the anteroposterior (AP) view. RESULTS: The needle was exactly at the target point in 5 patients in the oblique view and in 3 patients in the AP views. The needle was within 3 mm in all patients in the lateral oblique view and in 8 patients in the AP view. In the remaining 2 patients, the needle was within 5 mm from the radiologic target. In 4 patients, we were able to identify vessels at the anterior aspect of the foramen, whereas 2 patients had critical vessels at the posterior aspect of the foramen, and in 1 patient, this artery continued medially into the foramen, most likely forming or joining a segmental feeder artery. In both cases, the vessels might well have been in the pathway of a needle correctly positioned under fluoroscopic control. CONCLUSIONS: Our case series shows the feasibility of using ultrasound imaging to guide selective cervical nerve root injections. It may facilitate identifying critical vessels at unexpected locations relative to the intervertebral foramen and avoiding injury to such vessels, which is the leading cause of the reported complications from cervical nerve root injections. A randomized controlled trial to compare the effectiveness and safety of ultrasound imaging against other imaging techniques seems warranted.