Opioid Induced Hyperalgesia.

OBJECTIVE: To discuss the phenomenon of opioid induced hyperalgesia (OIH) and investigate the data and clinical recommendations available on this topic. DESIGN: A literature search on the topic of OIH was performed. Relevant studies pertaining to OIH were included in this review. RESULTS: Existing studies and reviews on the pathophysiology, diagnosis, and clinical management of OIH are discussed with updated data and literature references. CONCLUSION: As more opioids are prescribed, especially to treat chronic nonmalignant pain, OIH becomes more of a relevant and significant issue. Although the exact mechanisms of OIH are not clearly understood further research is required to broaden and develop our knowledge of this topic.

Understanding whether chronic lower back pain patients with lumbar spinal stenosis benefit from multiple epidural steroid injections prior to the mild® Procedure.

Originally published in Pain Management, this article is a summary of a study performed to look at the benefit, if any, of more than one epidural steroid injection in the spine before the mild® Procedure. Minimally invasive lumbar decompression (commonly known as the mild Procedure) and epidural steroid injections are both common treatment options for lumbar spinal stenosis (commonly referred to as LSS), a condition that causes chronic lower back pain in older adults. To determine how to best treat LSS patients, healthcare professionals use a guide to help with the decision-making process (called an algorithm) to pass through non-medical to more invasive therapies that often includes one or more epidural steroid injections. An epidural steroid injection is medication inserted in the lower back to reduce swelling and provide relief from pain. Researchers wanted to look at a change to when in the treatment process the mild Procedure is carried out. In the study, researchers compared the medical records of participants who had received either just one or no steroid injection prior to the mild Procedure, to participants who received two or more epidural steroid injections prior to the mild Procedure. Similar outcomes in both treatment groups in this study proved that giving more than one epidural steroid injection prior to the mild Procedure did not improve how well patients did and may have delayed patient care. Based on the results of the study, it is recommended that the standard treatment process for LSS patients be changed to give the mild Procedure either as soon as LSS is diagnosed or after the failure of the first epidural steroid injection.

Minimally invasive direct decompression for lumbar spinal stenosis: impact of multiple prior epidural steroid injections.

Background: A modified algorithm for the treatment of lumbar spinal stenosis with hypertrophic ligamentum flavum using minimally-invasive lumbar decompression (mild®)was assessed, with a focus on earlier intervention. Patients & methods: Records of 145 patients treated with mild after receiving 0-1 epidural steroid injections (ESIs) or 2+ ESIs were retrospectively reviewed. Pain assessments as measured by visual analog scale (VAS) scores were recorded at baseline and 1-week and 3-month follow-ups. Results: Improvements in VAS scores at follow-ups compared with baseline were significant in both groups. No statistically significant differences were found between the two groups. Conclusion: Multiple ESIs prior to mild showed no benefit. A modified algorithm to perform mild immediately upon diagnosis or after the failure of the first ESI is recommended.

Lay abstract Physicians use a structured decision-making process (an algorithm) to decide how best to treat lumbar spinal stenosis (LSS) that results from abnormal thickening of the spinal ligaments that run the length of the spinal cord. Early treatments can include one or more epidural steroid injections (ESIs). This study evaluated a change to the algorithm that involves earlier intervention with a minimally invasive, short outpatient procedure that removes a major root cause of the abnormal thickening (lumbar decompression) and leaves no implants behind. Records of patients treated with minimally-invasive lumbar decompression (mild^®) after receiving either a single ESI procedure or none at all, were compared with the records of patients who underwent the mild procedure after receiving two or more ESIs (145 total patients). The patients' pain scores before surgery, at 1 week postsurgery and at 3 months postsurgery were reviewed. The improvements in pain scores following the mild procedure were compared within each group and between the two groups. The improvements in pain scores at both the 1-week and 3-month follow-up visits indicated that the mild procedure had a positive effect for both groups. Further, there were no significant differences in how much pain scores improved when the two groups were compared. Since neither group experienced significantly more pain relief than the other, there appears to be no benefit to having multiple ESI procedures before undergoing the mild procedure. The authors recommend that the algorithm be modified to perform the mild procedure either as soon as LSS is diagnosed or after the failure of the first ESI procedure.

Case report: Anti-N-methyl-D-aspartate receptor encephalitis and its anesthetic implications.

We describe the anesthetic management and implications of 2 patients with anti-N-methyl-D-aspartate (NMDA) receptor encephalitis. Anti-NMDA receptor encephalitis is a neurological disorder caused by production of antibodies to the NMDA receptor. The NMDA receptor is the target of many drugs used in anesthesia. It is important to understand the pharmacologic interactions these anesthetics have with a disabled NMDA receptor while preparing an anesthetic plan for patients with anti-NMDA receptor encephalitis. Symptoms of the disease such as psychosis, paroxysmal sympathetic hyperactivity, and central hypoventilation pose risks to the induction and maintenance of anesthesia in these patients.

Sublethal exposure to UV radiation affects respiration rates of the freshwater cladoceran Daphnia catawba.

We examined the effects of UV radiation (UVR) on metabolic rates of the freshwater cladoceran Daphnia catawba. We exposed D. catawba to UVB for 12 h in a lamp phototron at levels of 2.08 and 4.16 kJ m(-2) both with and without concomitant exposure to UVA and visible photorepair radiation (PRR). We also included a group that received PRR only and a dark control group. Respiration rates were measured for 6 h following exposure. Respiration rates increased by 31.8% relative to the dark control at the lowest level of UVB stress (2.08 kJ m(-2) UVB with PRR), whereas respiration was inhibited by 70.3% at the highest stress level (4.16 kJ m(-2) UVB without PRR). Survival rates in the group that received PRR only and the group exposed to 2.08 kJ m(-2) and PRR were not significantly different from that in the control group; however, the survival rate was reduced for all other UVR exposures. We hypothesize that enhanced respiration rates reflect energetic costs related to repair of cellular components damaged by sublethal levels of UVR. Increases in respiration rate of the magnitude we found in our experiment could significantly reduce energetic reserves available for growth and reproduction, especially in cases where these costs are incurred repeatedly during a series of days with high levels of UVR.

The Pain Medical Home: A Patient-Centered Medical Home Model of Care for Patients with Chronic Pain.

Chronic pain affects an estimated 100 million people a year in the United States and costs society anywhere from $560 to $635 billion annually. The patient-centered medical home and the patient-centered medical home-neighbor models of care have been advocated to improve patient outcomes. These models of care advocate improved coordination of care within the primary care and specialty care setting. The authors present the patient-centered medical home model of care and suggest how this model of care might be used to improve patient outcomes for patients with chronic pain.

Trichostatin A and 5 Aza-2' deoxycytidine decrease estrogen receptor mRNA stability in ER positive MCF7 cells through modulation of HuR.

Trichostatin A (TSA) and 5-Aza 2'deoxycytidine (AZA), two well characterized pharmacologic inhibitors of histone deacetylation and DNA methylation, affect estrogen receptor alpha (ER) levels differently in ER-positive versus ER-negative breast cancer cell lines. Whereas pharmacologic inhibition of these epigenetic mechanisms results in re-expression and increased estrogen receptor alpha (ER) levels in ER-negative cells, treatment in ER-positive MCF7 cells results in decreased ER mRNA and protein levels. This decrease is dependent upon protein interaction with the ER 3'UTR. Actinomycin D studies showed a 37.5% reduction in ER mRNA stability from 4 to 1.5 h in AZA/TSA treated MCF7 cell lines; an effect not seen in 231ER + cells transfected with the ER coding region but lacking incorporation of the 3'UTR. AZA/TSA do not appear to directly interact with the 3'UTR but rather decrease stability through altered subcellular localization of the RNA binding protein, HuR. siRNA inhibition of HuR expression reduces both the steady-state and stability of ER mRNA, suggesting that HuR plays a critical role in the control of ER mRNA stability. Our data suggest that epigenetic modulators can alter stability through modulation of HuR subcellular distribution. Taken together, these data provide a novel anti-estrogenic mechanism for AZA and TSA in ER positive human breast cancer cells.