Nicholas Joseph

Opioid-induced hyperalgesia in chronic pain patients and the mitigating effects of gabapentin.

Chronic pain patients receiving opioid drugs are at risk for opioid-induced hyperalgesia (OIH), wherein opioid pain medication leads to a paradoxical pain state. OIH involves central sensitization of primary and secondary afferent neurons in the dorsal horn and dorsal root ganglion, similar to neuropathic pain. Gabapentin, a gamma-aminobutyric acid (GABA) analog anticonvulsant used to treat neuropathic pain, has been shown in animal models to reduce fentanyl hyperalgesia without compromising analgesic effect. Chronic pain patients have also exhibited lower opioid consumption and improved pain response when given gabapentin. However, few human studies investigating gabapentin use in OIH have been performed in recent years. In this review, we discuss the potential mechanisms that underlie OIH and provide a critical overview of interventional therapeutic strategies, especially the clinically-successful drug gabapentin, which may reduce OIH.

Ketamine-Based Anesthetic Protocols and Evoked Potential Monitoring: A Risk/Benefit Overview

Since its discovery, ketamine, a non-competitive N-methyl D-aspartate (NMDA) receptor antagonist related to phencyclidine, has been linked to multiple adverse reactions sometimes described as “out of body” and “near death experiences,” including emergence phenomena, delusions, hallucinations, delirium, and confusion. Due to these effects, ketamine has been withdrawn from mainstream anesthetic use in adult patients. Evoked potentials (EPs) are utilized to monitor neural pathways during surgery, detect intraoperative stress or damage, detect and define the level of neural lesions, and define abnormalities. Unfortunately, many of the volatile anesthetics commonly used during spinal and neurologic procedures suppress EP amplitude and monitoring. Ketamine has been found in several preclinical and clinical studies to actually increase EP amplitude and thus has been used as an analgesic adjunct in procedures where EP monitoring is critical. Once the gap in our knowledge of ketamines risks has been sufficiently addressed in animal models, informed clinical trials should be conducted in order to properly incorporate ketamine-based anesthetic regimens during EP-monitored neurosurgeries.

Extracorporeal life support for refractory ventricular tachycardia

Extracorporeal life support (ECLS) is a very effective bridging therapy in patients with refractory ventricular tachycardia (VT) associated with cardiogenic shock. A moribund patient in extremis, is not amenable to optimization by standard ACC/AHA guidelines. New approaches and novel salvage techniques are necessary to improve outcomes in patients with refractory clinical settings such as malignant ventricular arrhythmias, cardiac arrest, cardiogenic shock and/or pulmonary failure until further management options are explored. Data base searches were done using key words such as ECLS, VT, cardiac arrest, VT ablation, venoarterial extra-corporeal membrane oxygenation (VA-ECMO). The use of ECLS has been described in a few case reports to facilitate VT ablation for incessant VT refractory to medical therapy. For patients with, out-of- hospital ventricular fibrillation (VF) and VT, Minnesota Resuscitation Consortium has implemented emergent advanced perfusion and reperfusion strategy, followed by coronary angiography and primary coronary intervention to improve outcome. The major indications for ECLS are cardiogenic shock related to acute myocardial infarction, myocarditis, post embolic acute cor pulmonale, drug intoxication and post cardiac arrest syndrome with the threat of multi-organ failure. ECLS permits the use of negative inotropic antiarrhythmic drug therapy, facilitates the weaning of catecholamine administration, thereby ending the vicious cycle of catecholamine driven electric storm. ECLS provides hemodynamic support during ablation procedure, while mapping and induction of VT is undertaken. ECLS provides early access to cardiac catheterization laboratory in patients with cardiac arrest due to shockable rhythm. The current evidence from literature, supports the use of ECLS to ensure adequate vital organ perfusion in patients with refractory VT. ECLS is a safe, feasible and effective therapeutic option when conventional therapies are insufficient to support cardiopulmonary function. A highly driven multidisciplinary team approach is essential to accomplish this task.

Alternative Therapies for the Prevention of Postoperative Nausea and Vomiting

Postoperative nausea and vomiting (PONV) is a complication affecting between 20 and 40% of all surgery patients, with high-risk patients experiencing rates of up to 80%. Recent studies and publications have shed light on the uses of alternative treatment for PONV through their modulation of endogenous opioid neuropeptides and neurokinin ligands. In addition to reducing PONV, hypnosis was reported to be useful in attenuating postoperative pain and anxiety, and contributing to hemodynamic stability. Music therapy has been utilized to deepen the sedation level and decrease patient anxiety, antiemetic and analgesic requirements, hospital length of stay, and fatigue. Isopropyl alcohol and peppermint oil aromatherapy have both been used to reduce postoperative nausea. With correct training in traditional Chinese healing techniques, acupuncture (APu) at the P6 acupoint has also been shown to be useful in preventing early PONV, postdischarge nausea and vomiting, and alleviating of pain. Electro-acupuncture (EAPu), as with APu, provided analgesic and antiemetic effects through release and modulation of opioid neuropeptides. These non-pharmacological modalities of treatment contribute to an overall patient wellbeing, assisting in physical and emotional healing.

Preoperative Prevalence of Staphylococcus aureus in Cardiothoracic and Neurological Surgical Patients.

Methicillin-resistant Staphylococcus aureus (MRSA) is a global cause of both hospital and community-acquired infection. This retrospective, observational study determined the prevalence of MRSA carriers in cardiothoracic and neurological surgical patients presenting to an outpatient preoperative assessment center in Columbus, OH. Aggressive skin and soft-tissue infection may be caused by MRSA with potentially fatal complications. Cardiothoracic and neurological surgical patients are at high risk for surgical-site infection. Results indicated that 4.25% of the sample carried MRSA and 25.25% carried methicillin-sensitive S. aureus.

Current Status of Blood Transfusion and Antifibrinolytic Therapy in Orthopedic Surgeries

1 Department of Anesthesiology, Wexner Medical Center, Ohio State University, Columbus, OH, USA 2 Department of Neurological Surgery, Wexner Medical Center, Ohio State University, Columbus, OH, USA 3 Department of Neuroscience, Ohio State University, Columbus, OH, USA 4 Drexel University College of Medicine, Philadelphia, PA, USA 5 Temple University School of Medicine, Philadelphia, PA, USA 6 College of Medicine, Wexner Medical Center, Ohio State University, Columbus, OH, USA 7 Orthopedic One, Columbus, OH, USA *Correspondence: nicoleta.stoicea@osumc.edu

Effects of body mass index on parasympathetic nervous system reactivity and recovery following orthostatic stress

Vagally mediated heart rate variability (vmHRV), defined as the beat-to-beat fluctuations in a heart series mediated by the vagus nerve, serves as a non-invasive index of parasympathetic nervous system (PNS) activity. Lower resting state vmHRV is associated with greater body mass index (BMI), providing a psychophysiological pathway linking obesity with health and disease. However little research has been conducted to examine how BMI may influence PNS reactivity to orthostatic stress. The present study sought to explore this in a sample of 59 individuals (44 females, mean age = 24.37 years, age range 19–65 years). VmHRV was measured throughout the 5-minute baseline (sitting), orthostatic (standing), and recovery (sitting) conditions. Individuals were stratified into low (BMI < 20), moderate (BMI 20–25), and high (BMI > 25) BMI groups. Results indicate that the high BMI group had a greater decrease in vmHRV from baseline to standing in comparison to the moderate BMI group. Furthermore, the low BMI group showed lower vmHRV during recovery compared to baseline, suggesting that these individuals did not fully recover from the standing position. Taken together, these results extend previous literature showing that those with low and high BMI can show different yet maladaptive patterns of vmHRV in response to orthostatic stress..

Advanced Analgesic Drug Delivery and Nanobiotechnology

Transdermal administration of analgesic medications offers several benefits over alternative routes of administration, including a decreased systemic drug load with fewer side effects, and avoidance of drug degradation by the gastrointestinal tract. Transdermal administration also offers a convenient mode of drug administration over an extended period of time, particularly desirable in pain medicine. A transdermal administration route may also offer increased safety for drugs with a narrow therapeutic window. The primary barrier to transdermal drug absorption is the skin itself. Transdermal nanotechnology offers a novel method of achieving enhanced dermal penetration with an extended delivery profile for analgesic drugs, due to their small size and relatively large surface area. Several materials have been used to enhance drug duration and transdermal penetration. The application of nanotechnology in transdermal delivery of analgesics has raised new questions regarding safety and ethical issues. The small molecular size of nanoparticles enables drug delivery to previously inaccessible body sites. To ensure safety, the interaction of nanoparticles with the human body requires further investigation on an individual drug basis, since different formulations have unique properties and side effects.

Stereotype threat, trait perseveration, and vagal activity: evidence for mechanisms underpinning health disparities in Black Americans

ABSTRACT Objective: Black Americans (BAs) are at an elevated risk for morbidity and mortality in comparison to White Americans (WAs). Racial stressors are a common occurrence in American culture and is theorized to contribute to these disparities. When race-focused, stereotype threat (ST) is considered to be a factor that is detrimental to health in BAs; however few studies have directly investigated the impact of a ST manipulation on physiological function. Furthermore, it is proposed that racial stressors such as ST may have prolonged effects when more likely to perseverate (e.g. rumination) over the stressor and thus, those with greater trait perseveration may be more affected by ST. We sought to explore the impact of ST and trait perseveration on changes in vagus nerve activity – an indication of adaptive psychological and physiological well-being – as indexed by vagally mediated heart rate variability (vmHRV). Design: Forty-three (24 females, mean age of 20, standard deviation of 3 years) apparently healthy BA individuals were randomly assigned to one of three experimental conditions in which they received either implicit (subtle), explicit (blatant), or no ST priming (control condition), prior to completing a cognitive task. Resting vmHRV was assessed both at baseline (pre-task) and recovery (post-task). Results: BAs in the explicit ST condition exhibited the greatest decrease in vmHRV in comparison to the control group from pre- to post-task. BAs with moderate to high levels of trait perseveration showed the greatest decrease in vmHRV from pre- to post-task in comparison to those with lower levels of trait perseveration and BAs in the control group. Conclusion: These data suggest that racial ST, especially when explicit and coupled with trait perseveration, can decrease vagal activity, as indexed by decreased vmHRV, which when experienced frequently can have significant consequences for health and longevity in BAs.

Clevidipine-induced Dyspnea Relief in Acute Heart Failure Patients

Recently, EBioMedicine published a study proposing that clevidipines complex mechanism of action might be responsible for relieving dyspnea in acute heart failure (AHF) patients Dahl et al. (2016). Clevidipine was approved by Food and Drug Administration (FDA) (2008) as a third generation dihydropyridine (DHP) calcium channel blocker for the management of perioperative acute hypertension (Merry et al., 2014, Powroznyk et al., 2000, Aronson et al., 2008, Levy et al., 2007; Cleviprex (clevidipine butyrate) injectable emulsion for intravenous use [package insert], 2008). In 2014, Peacock et al. published the results of a randomized, open-label active control study (PRONTO) evaluating the efficacy of clevidipine versus standard of care (SOC) anti-hypertensive therapy and concluded that clevidipine was responsible for a rapid reduction in blood pressure and dyspnea improvement in hypertensive AHF patients (Peacock et al., 2010).