Effects of electroacupuncture on pain sensation in a rat model of hyperalgesia with nicotine dependence.

Tobacco smoking is considered to be one of the main risk factors in the development of chronic pain. Long-term chronic exposure to nicotine and other forms of tobacco have been shown to be associated with an increased incidence of pain. Studies have shown that acupuncture can help smokers to reduce their desire to smoke, reduce their withdrawal symptoms, and avoid a relapse after treatment. However, little has been reported about the effects of acupuncture on pain sensitivity caused by long-term smoking. Models of hyperalgesia were established in rats exposed to nicotine for 6 weeks. After 6 weeks of continuous nicotine exposure, electroacupuncture at bilateral acupoints Zusanli (ST36) and Taichong (LR3) was performed 20 minutes per day for 6 days at a continuous wave with a frequency of 2 Hz and a stimulus intensity of 1 mA. The results revealed that electroacupuncture treatment increased the mechanical response threshold of hind paw of nicotine-dependent rats with hyperalgesia and up-regulated the protein expression of pain-related factors µ-opioid receptor, ß-endorphin and glutamic acid decarboxylase 65 in the spinal cord and midbrain periaqueductal gray and the protein expression of glutamic acid decarboxylase 67 in the spinal cord. These findings suggest that electroacupuncture treatment has positive analgesic effects on pain sensitivity caused by long-term chronic nicotine exposure. One possible mechanism for the improved analgesia is that electroacupuncture increases the expression of pain-related factors in the spinal cord and midbrain periaqueductal gray. This study was approved by Institutional Animal Care and Use Committee (IACUC) of the University of Miami (#18-167) on December 12, 2018.

The role of α7-nicotinic acetylcholine receptor in a rat model of chronic nicotine-induced mechanical hypersensitivity.

Smokers have a higher incidence of chronic pain than non-smokers, but the neural mechanism is not yet fully understood. Nicotine is the main component of tobacco and acts as an agonist for nicotinic cholinergic receptors (nAChRs) in the nervous system. This study was approved by the IACUC of UM. The effects of chronic nicotine administration on mechanical sensitivity were studied using a rat model. The changes in the expression levels of the α7 isoform of nAChR (α7-nAChR), inflammatory cytokines TNFα and COX-2, as well as the density of neuro-immune cells (astrocytes and microglia) were measured concurrently. The results indicate that long-term nicotine administration induces hypersensitivity to mechanical stimuli, as demonstrated by a significant reduction in the pain perception threshold. In response to nicotine, the expression levels of α7-nAChR increased in the periaqueductal gray matter (PAG) and decreased in the spinal cord. Acute administration of the selective α7-nAChR agonist CDP-Choline reversed this hypersensitivity. Chronic nicotine administration led to an increase of microglial cells in the dorsal horn of the spinal cord and increased expression levels of the cytokines TNFα and COX-2. This study suggests that decreased α7-nAChR expression in the spinal cord, as a result of long-term exposure to nicotine, may be causatively linked to chronic pain. Simultaneously, the increase of neuro-immune factors in the spinal cord is also a potential factor leading to chronic pain.

Policy Implications for the COVID-19 Pandemic in Light of Most Patients (≥72%) Spending at Most One Night at the Hospital After Elective, Major Therapeutic Procedures.

A large number of inpatients with Coronavirus disease 2019 (COVID-19) in some regions of the United States may interfere with the ability of hospitals to take care of patients requiring treatment for other conditions. Nonetheless, many patients need surgery to improve their quality of life and to prevent deterioration in health. Curtailment of services also negatively affects the financial health of hospitals and health systems. Broad policies to prohibit all "elective" surgical procedures to ensure that there is sufficient hospital capacity for pandemic patients may be unnecessarily restrictive because, for many such procedures, patients are rarely admitted following surgery or only stay overnight. We studied all elective inpatient and ambulatory cases involving major therapeutic procedures performed in the state of Florida in 2018. We mapped the primary procedure to the corresponding Clinical Classification Software (CCS) category. We determined the distributions of lengths of stay overall and as stratified by CCS category, then calculated the percentage of cases that had a hospital length of stay of ≤1 night (i.e., 0 or 1 day). A threshold of one night was selected because patients discharged home on the day of surgery have no effect on the inpatient census, and those staying overnight would either have a transient effect or no effect if observed overnight in the postoperative care unit. Among the 1,852,391 elective cases with one or more major therapeutic procedures, 65.2% (95% lower confidence limit [LCL] = 65.1%) of cases had a length of stay of 0 days and 72.9% (95% LCL = 72.8%) had stay ≤1 day. There were 38 different CCS categories for which at least 95% of patients had a length of stay of ≤1 day. There were 28 CCS codes that identified 80% of the patients who were discharged with a length of stay ≤1 day, showing representation of multiple surgical specialties. Our results show that even in the face of constraints imposed by a high hospital census, many categories of major therapeutic elective procedures could be performed without necessarily compromising hospital capacity. Most patients will be discharged on the day of surgery. If overnight admission is required, there would be an option to care for them in the postanesthesia care unit, thus not affecting the census. Thus, policies can reasonably be based on allowing cases with a substantial probability of at most an overnight stay rather than a blanket ban on "elective" surgery or creating a carve-out for specified surgical subspecialties. Such policies would apply to at least 72% of elective, major therapeutic surgical procedures.

Sufentanil postoperative analgesia reduce the increase of T helper 17 (Th17) cells and FoxP3+ regulatory T (Treg) cells in rat hepatocellular carcinoma surgical model: A randomised animal study.

BACKGROUND: Surgery-related pain and opioids might exacerbate immune defenses in immunocompromised cancer patients which might affect postoperativd overall survival. Sufentanil is a good postoperative pain control drug,the present study aimed to figure out whether it effect T cell immunity in rat hepatocellular carcinoma surgical model. METHODS: A rat hepatocellular carcinoma (HCC) models was established by N-nitrosodiethylamine. Forty-eight of them were randomly divided into 3 equal groups: surgery without postoperative analgesia (Group C), surgery with morphine postoperative analgesia (Group M), surgery with sufentanil postoperative analgesia (Group S). Each animal underwent a standard left hepatolobectomy, and intraperitoneally implanted with osmotic minipumps filled with sufentanil, morphine or normal saline according to the different group. The food and water consumptions, body weight changes, locomotor activity and mechanical pain threshold (MPT) were observed. The ratio of CD4+/CD8+, proportions of Th1, Th2, Th17 and Treg cells in blood were detected using flow cytometry. The liver function and the rats' survival situation of each group were observed. RESULTS: The food and water consumption, locomotor activity and MPT of group C declined than those of group S and M on d1, d2, d3 (P < 0.05). The CD4+/CD8+ ratio and the proportion of Th1 cells were significantly higher while the proportion of Th2, Th17 and Treg cells were significantly lower in group S and group M compared with group C. The rats of group S have higher CD4+/CD8+ ratio on d3, while lower proportion of Treg cells on d7 compared with group M. The plasma ALT and AST values in group C were significantly higher than that of group S and group M on both d3 and d7. There were not significant differences in mortality rate between 3 groups. CONCLUSIONS: Sufentanil and morphine postoperative analgesia in HCC rats accepted hepatectomy could relieve postoperative pain, promote the recovery of liver function after surgery, alleviate the immunosuppressive effect of pain. Furthermore, Compared to morphine, sufentanil might have a slighter effect on CD4+/CD8+ ratio and Treg frequencies. Therefore, sufentanil postoperative analgesia is better than morphine in HCC hepatectomy rats.

The mechanism of chronic nicotine exposure and nicotine withdrawal on pain perception in an animal model.

It has been demonstrated that smoking is associated with an increase in postoperative and chronic pain. The changes in the pain-related neural pathways responsible for these effects are unknown. Additionally, the effects of nicotine withdrawal, resulting from smoking abstinence preoperatively, has not been evaluated in terms of its impact on pain sensation. In this study, an animal model has been used to assess these effects. A rat model of long-term nicotine exposure was used. Von Frey mechanical sensory tests were performed. Western Blot and immunohistological analysis were conducted on spinal cord samples. Mechanical sensory thresholds increased in the initial period (1-3 weeks), indicating hyposensitivity. Long-term (410 weeks) and under nicotine withdrawal, the mechanical sensory thresholds decreased, indicating hyperalgesia. During short-term nicotine exposure, glutamate decarboxylase 67 (GAD67), GAD65, and µ-opioid receptors (MOR) up-regulated. Beta-endorphins down-regulated. Increased γ -aminobutyric acid (GABA) and MOR appear responsible for the hyposensitivity since the GABA receptor antagonist, bicuculline and opioid receptor antagonist, naloxone decreased the mechanical thresholds of nicotine-induced hyposensitivity. In long-term nicotine exposure, the expression of GAD67, MOR, and GABA decreased. Baclofen, a derivative of GABA, reversed the hyperalgesia seen with nicotine withdrawal. Therefore, nicotine acts as an analgesic when used acutely or short-term. Long-term exposure or nicotine withdrawal (similar to smoking cessation) results in hyperalgesia. Nicotine appears to alter pain sensitivity by affecting the expression of GAD65, GAD67, MOR, endorphins, and GABA. This may partially explain the increased pain and opioid use seen in chronic smokers in the postoperative period.

Opioid prescriptions for acute pain after outpatient surgery at a large public university-affiliated hospital: Impact of state legislation in Florida.

BACKGROUND: In response to the growing opioid crisis, Florida recently implemented a law restricting the duration of opioid prescriptions for acute pain. Little is known about the impact of such legislation on opioid prescription practices at the time of discharge after surgery. The objective of this study was to determine whether Florida's new legislation changed opioid prescription practices for analgesia after surgery. METHODS: Adults 18 years of age and older undergoing cholecystectomy, appendectomy, hernia repair, hysterectomy, mastectomy, or lymph node dissection were included in this retrospective cohort study at a large public university-affiliated hospital. We analyzed opioid prescriptions on discharge after these common outpatient surgical procedures between June 1, 2017, and December 31, 2018. Florida House Bill 21 was passed on March 2, 2018, and subsequent implementation of this law took place on July 1, 2018. The law restricts the duration of opioid prescriptions for acute pain to 3 days, which can be extended up to a maximum of 7 days with additional documentation. The outcomes studied included the following: the proportion of patients receiving opioid prescriptions on discharge, total opioid dose prescribed, daily opioid dose prescribed, and the proportion of patients receiving more than a 3-day supply of opioids. We colledted data on emergency department cumulative visits within 7 and 30 days after discharge. Drug doses were converted to morphine milligram equivalents and calculated for each selected procedure. RESULTS: A total of 1,467 surgical encounters were included. The cohort was predominantly female (963 [65.6%]) with a mean (SD) age of 49.6 (14.4) years. At 6 months after implementation of HB 21, the proportion of patients receiving opioid prescriptions decreased by 21% (95% CI 16.8% to 25.3%, P < .001), mean total opioid dose prescribed decreased by 64.2 morphine milligram equivalents (95% CI 54.7 to 73.7, P < .001) from a baseline mean (SD) of 172.5 (78.9) morphine milligram equivalents. The mean daily opioid dose prescribed increased by 3.5 morphine milligram equivalents (95% CI 1.8 to 5.1, P < .001) from a baseline mean (SD) of 30.5 (9.4) morphine milligram equivalents. The proportion of patients receiving opioid prescriptions for longer than a 3-day supply decreased by 68% (95% CI 63.4% to 72.7%, P < .001). We observed no change in the number of postoperative emergency department visits before and after implementation of the law. CONCLUSION: Opioid prescriptions for patients undergoing common outpatient surgical procedures at a large public university-affiliated hospital in Florida were substantially reduced within 6 months after implementation of state legislation limiting the duration of opioid prescriptions. This reduction was not associated with an increase in the number of postoperative emergency department visits. The legislation should significantly decrease the amount of unused opioid pills potentially available for diversion and abuse. Secondary effects from the enactment of this law remain to be evaluated.

A Phase 3, Randomized, Placebo-Controlled Evaluation of the Safety of Intravenous Meloxicam Following Major Surgery.

An intravenous (IV) formulation of meloxicam is being studied for moderate to severe pain management. This phase 3, randomized, multicenter, double-blind, placebo-controlled trial evaluated the safety of once-daily meloxicam IV 30 mg in subjects following major elective surgery. Eligible subjects were randomized (3:1) to receive meloxicam IV 30 mg or placebo administered once daily. Safety was evaluated via adverse events, clinical laboratory tests, vital signs, wound healing, and opioid consumption. The incidence of adverse events was similar between meloxicam IV- and placebo-treated subjects (63.0% versus 65.0%). Investigators assessed most adverse events as mild or moderate in intensity and unrelated to treatment. Adverse events of interest (injection-site reactions, bleeding, cardiovascular, hepatic, renal, thrombotic, and wound-healing events) were similar between groups. Over the treatment period, meloxicam IV was associated with a 23.6% (P = .0531) reduction in total opioid use (9.2 mg morphine equivalent) compared to placebo-treated subjects. The results suggest that meloxicam IV had a safety profile similar to that of placebo with respect to numbers and frequencies of adverse events and reduced opioid consumption in subjects with moderate to severe postoperative pain following major elective surgery.

Amisulpride for the Rescue Treatment of Postoperative Nausea or Vomiting in Patients Failing Prophylaxis: A Randomized, Placebo-controlled Phase III Trial.

BACKGROUND: Although antiemetics are commonly used to prevent postoperative nausea or vomiting, the failure rate is appreciable and there is currently no generally accepted standard for rescue treatment of postoperative nausea or vomiting after failed prophylaxis. This prospective, randomized, double-blind, parallel-group, placebo-controlled, multicenter study was designed to test the hypothesis that intravenous amisulpride, a dopamine D2/D3-antagonist, is superior to placebo at treating established postoperative nausea or vomiting after failed prophylaxis. METHODS: A total of 2,285 adult patients undergoing surgery under general inhalational anesthesia and receiving standard antiemetic prophylaxis were enrolled at 23 sites in Canada, France, Germany, and the United States. Of these, 702 patients experienced postoperative nausea or vomiting in the 24-h period after surgery and were randomized to receive a single dose of 5 or 10 mg intravenous amisulpride or matching placebo. The primary endpoint was complete response, defined as no emesis or rescue antiemetic use for 24 h after study drug administration, excluding emesis in the first 30 min. Secondary endpoints included incidence of emesis and rescue medication use, nausea burden, time to treatment failure, and length of stay in postanesthesia care unit and hospital. RESULTS: Complete response occurred in significantly more patients receiving 10 mg amisulpride (96 of 230, 41.7%) than placebo (67 of 235, 28.5%), a 13.2% difference (95% CI, 4.6 to 21.8; odds ratio, 1.80; P = 0.006). A 5-mg dose of amisulpride did not show a significant benefit (80 of 237, 33.8%); the difference from placebo was 5.2% (95% CI, 3.1 to 13.6; odds ratio, 1.24; P = 0.109). The total number of adverse events recorded and proportion of patients with at least one adverse event were comparable between the placebo and amisulpride groups. No clinically relevant toxicities were observed. CONCLUSIONS: A single 10-mg dose of intravenous amisulpride was safe and more effective than placebo at treating established postoperative nausea or vomiting in patients failing postoperative nausea or vomiting prophylaxis.

Survey of anesthesiologists' practices related to steep Trendelenburg positioning in the USA.

BACKGROUND: Steep Trendelenburg during surgery has been associated with many position-related injuries. The American Society of Anesthesiology practice advisory recommends documentation, frequent position checks, avoiding shoulder braces, and limiting abduction of upper extremities to avoid brachial plexopathy. We conducted a web-based survey to assess anesthesiologists' practices, institutional policies, and complications encountered when using steep Trendelenburg. METHODS: Two thousand fifty randomly selected active members of the American Society of Anesthesiology were invited via email to participate in a 9-item web-based survey. Results are reported as absolute numbers and proportions with 95% confidence interval (CI). RESULTS: Survey response rate was 290 of 2050 (14.1%). 44.6% (95% CI, 38.9-50.3) of the respondents documented anesthesia start and finish, 73.9% (95% CI, 68.8-79) frequently checked positioning during surgery, 30.8% (95% CI, 25.4-36.2) reported using shoulder braces, 66.9% (95% CI, 61.5-72.3) tucked patients' arms to the side, 54.0% (95% CI, 48.2-59.8) limited fluid administration, and more than two-thirds did not limit the duration or inclination angle. Notably, 63/290 (21.7%) reported a complication and only 6/289 (2.1%) had an institutional policy. The most common complication was airway and face edema, second was brachial plexus injury, and third was corneal abrasions. Most institutional policies, when present, focused on limiting duration of steep Trendelenburg and communication with surgical team. Only 1/6 policies required avoiding use of shoulder braces. CONCLUSION: Based on survey results, practices related to steep Trendelenburg varied among USA anesthesiologists. Differences included protective measures, documentation, positioning techniques, fluid management, and institutional guidelines. The singular commonality found among all respondents was lack of institutional policies. Survey results highlighted the need for institutional policies and more education.

Amisulpride Prevents Postoperative Nausea and Vomiting in Patients at High Risk: A Randomized, Double-blind, Placebo-controlled Trial.

BACKGROUND: Postoperative nausea and vomiting causes distress for patients and can prolong care requirements. Consensus guidelines recommend use of multiple antiemetics from different mechanistic classes as prophylaxis in patients at high risk of postoperative nausea and vomiting. The prophylactic efficacy of the dopamine D2/D3 antagonist amisulpride in combination with other antiemetics was investigated. METHODS: This double-blind, randomized, placebo-controlled, international, multicenter trial was conducted in 1,147 adult surgical patients having three or four postoperative nausea and vomiting risk factors. Patients were randomized to receive either intravenous amisulpride (5 mg) or matching placebo at induction of general anesthesia, in addition to one standard, nondopaminergic antiemetic, most commonly ondansetron or dexamethasone. Vomiting/retching, nausea, and use of rescue medication were recorded for 24 h after wound closure. The primary endpoint was complete response, defined as no emesis or rescue medication use in the 24-h postoperative period. RESULTS: Complete response occurred in 330 of 572 (57.7%) of the amisulpride group and 268 of 575 (46.6%) of the control group (difference 11.1 percentage points; 95% CI, 5.3 to 16.8; P < 0.001). The incidences of emesis (13.8% vs. 20.0%, P = 0.003), any nausea (50.0% vs. 58.3%, P = 0.002), significant nausea (37.1% vs. 47.7%, P < 0.001), and rescue medication use (40.9% vs. 49.4%, P = 0.002) were significantly lower in the amisulpride group. Adverse events and laboratory and electrocardiogram abnormalities occurred no more frequently with amisulpride than with placebo. CONCLUSIONS: Intravenous amisulpride was safe and effective as prophylaxis of postoperative nausea and vomiting when given in combination with an antiemetic from another class to adult patients at high risk for suffering postoperative nausea and vomiting undergoing elective surgery under inhalational general anesthesia. VISUAL ABSTRACT: An online visual overview is available for this article at http://links.lww.com/ALN/B727.

A Prospective, Multicenter, Single-Blind Study Assessing Indices of SNAP II Versus BIS VISTA on Surgical Patients Undergoing General Anesthesia.

BACKGROUND: Traditionally, anesthesiologists have relied on nonspecific subjective and objective physical signs to assess patients' comfort level and depth of anesthesia. Commercial development of electrical monitors, which use low- and high-frequency electroencephalogram (EEG) signals, have been developed to enhance the assessment of patients' level of consciousness. Multiple studies have shown that monitoring patients' consciousness levels can help in reducing drug consumption, anesthesia-related adverse events, and recovery time. This clinical study will provide information by simultaneously comparing the performance of the SNAP II (a single-channel EEG device) and the bispectral index (BIS) VISTA (a dual-channel EEG device) by assessing their efficacy in monitoring different anesthetic states in patients undergoing general anesthesia. OBJECTIVE: The primary objective of this study is to establish the range of index values for the SNAP II corresponding to each anesthetic state (preinduction, loss of response, maintenance, first purposeful response, and extubation). The secondary objectives will assess the range of index values for BIS VISTA corresponding to each anesthetic state compared to published BIS VISTA range information, and estimate the area under the curve, sensitivity, and specificity for both devices. METHODS: This is a multicenter, prospective, double-arm, parallel assignment, single-blind study involving patients undergoing elective surgery that requires general anesthesia. The study will include 40 patients and will be conducted at the following sites: The Ohio State University Medical Center (Columbus, OH); Northwestern University Prentice Women's Hospital (Chicago, IL); and University of Miami Jackson Memorial Hospital (Miami, FL). The study will assess the predictive value of SNAP II versus BIS VISTA indices at various anesthetic states in patients undergoing general anesthesia (preinduction, loss of response, maintenance, first purposeful response, and extubation). The SNAP II and BIS VISTA electrode arrays will be placed on the patient's forehead on opposite sides. The hemisphere location for both devices' electrodes will be equally alternated among the patient population. The index values for both devices will be recorded and correlated with the scorings received by performing the Modified Observer's Assessment of Alertness and Sedation and the American Society of Anesthesiologists Continuum of Depth of Sedation, at different stages of anesthesia. RESULTS: Enrollment for this study has been completed and statistical data analyses are currently underway. CONCLUSIONS: The results of this trial will provide information that will simultaneously compare the performance of SNAP II and BIS VISTA devices, with regards to monitoring different anesthesia states among patients. CLINICALTRIAL: Clinicaltrials.gov NCT00829803; https://clinicaltrials.gov/ct2/show/NCT00829803 (Archived by WebCite at http://www.webcitation.org/6nmyi8YKO).

Octreotide Attenuates Acute Kidney Injury after Hepatic Ischemia and Reperfusion by Enhancing Autophagy.

Octreotide exerts a protective effect in hepatic ischemia-reperfusion (HIR) injury. However, whether octreotide preconditioning could also reduce acute kidney injury (AKI) after HIR is unknown. This study was designed to investigate the role of octreotide in AKI after HIR. Male Sprague-Dawley rats were pretreated with octreotide or octreotide combined with 3-methyladenine (autophagy inhibitor, 3MA). Plasma creatinine, inflammation markers (e.g., TNF-α and IL-6 etc.), apoptosis, autophagy and phosphorylation of protein kinase B/mammalian target of rapamycin/p70 ribosomal S6 kinase (Akt/mTOR/p70S6K) in the kidney were measured after 60 minutes of liver ischemia and 24 hours of reperfusion for each rat. Octreotide pretreatment significantly preserved renal function and reduced the severity of renal injury. Moreover, octreotide alleviated inflammation and apoptosis in the kidney after HIR. Additionally, octreotide induced autophagy and autophagy inhibition with 3MA markedly reversed the renoprotective, anti-inflammatory and anti-apoptotic effects of octreotide after HIR. Finally, octreotide abrogated the activation of phosphorylation of Akt, mTOR and p70S6K in the kidney after HIR. Our results indicate that octreotide reduced renal injury after HIR due to its induction of autophagy. The enhancement of autophagy may be potentially linked to the octreotide mediated Akt/mTOR/p70S6K pathway deactivation and reduction of kidney inflammation and apoptosis after HIR.

Intravenous Amisulpride for the Prevention of Postoperative Nausea and Vomiting: Two Concurrent, Randomized, Double-blind, Placebo-controlled Trials.

BACKGROUND: Two essentially identical, randomized, double-blind, placebo-controlled, parallel-group phase III studies evaluated the efficacy of intravenous amisulpride, a dopamine D2/D3 antagonist, in the prevention of postoperative nausea and vomiting in adult surgical patients. METHODS: Adult inpatients undergoing elective surgery during general anesthesia and having at least two of the four Apfel risk factors for postoperative nausea and vomiting were enrolled at 9 U.S. and 10 European sites. A single 5-mg dose of amisulpride or matching placebo was given at induction of anesthesia. The primary endpoint was complete response, defined as no vomiting/retching and no use of antiemetic rescue medication in the 24-h postoperative period. Nausea incidence was a secondary endpoint. RESULTS: Across the two studies, 689 patients were randomized and dosed with study medication, of whom 626 were evaluable per protocol. In the U.S. study, 46.9% (95% CI, 39.0 to 54.9) of patients achieved complete response in the amisulpride group compared to 33.8% (95% CI, 26.2 to 42.0) in the placebo group (P = 0.026). In the European study, complete response rates were 57.4% (95% CI, 49.2 to 65.3) for amisulpride and 46.6% (95% CI, 38.8 to 54.6) for placebo (P = 0.070). Nausea occurred less often in patients who received amisulpride than those who received placebo. There was no clinically significant difference in the safety profile of amisulpride and placebo; in particular, there were no differences in terms of QT prolongation, extrapyramidal side effects, or sedation. CONCLUSIONS: One of the two trials demonstrated superiority, while pooling both in a post hoc change to the plan of analysis supported the hypothesis that amisulpride was safe and superior to placebo in reducing the incidence of postoperative nausea and vomiting in a population of adult inpatients at moderate to high risk of postoperative nausea and vomiting.

Opioid-induced Hallucinations: A Review of the Literature, Pathophysiology, Diagnosis, and Treatment.

Despite their association with multiple adverse effects, opioid prescription continues to increase. Opioid-induced hallucination is an uncommon yet significant adverse effect of opioid treatment. The practitioner may encounter patient reluctance to volunteer the occurrence of this phenomenon because of fears of being judged mentally unsound. The majority of the literature concerning opioid-induced hallucinations arises from treatment during end-of-life care and cancer pain. Because the rate of opioid prescriptions continues to increase in the population, the rate of opioid-associated hallucinations may also conceivably increase. With a forecasted increase in the patient-to-physician ratio, opioid therapy is predicted to be provided by practitioners of varying backgrounds and medical specialties. Hence, knowledge of the pharmacology and potential adverse effects of these agents is required. This review seeks to increase awareness of this potential complication through a discussion of the literature, potential mechanisms of action, diagnosis, and treatment strategies.

Acute Hypoglycemia Induces Painful Neuropathy and the Treatment of Coenzyme Q10.

Diabetic neuropathic pain is reduced with tight glycemic control. However, strict control increases the risk of hypoglycemic episodes, which are themselves linked to painful neuropathy. This study explored the effects of hypoglycemia-related painful neuropathy. Pretreatment with coenzyme Q10 (CoQ10) was performed to explore the preventive effect of CoQ10 on hypoglycemia-related acute neuropathic pain. Two strains of mice were used and 1 unit/kg of insulin was given to induce hypoglycemia. Mechanical sensitivity of hindpaw withdrawal thresholds was measured using von Frey filaments. Blood glucose levels were clamped at normal levels by joint insulin and glucose injection to test whether insulin itself induced hypersensitivity. Results suggest that the increased mechanical sensitivity after insulin injection is related to decreased blood glucose levels. When blood glucose levels remained at a normal level by the linked administration of insulin and glucose, mice demonstrated no significant change in mechanical sensitivity. Pretreatment with CoQ10 prevented neuropathic pain and the expression of the stress factor c-Fos. These results support the concept that pain in the diabetic scenario can be the result of hypoglycemia and not insulin itself. Additionally, pretreatment with CoQ10 may be a potent preventive method for the development of neuropathic pain.

Inhibition of Mitochondrial Fission Protein Reduced Mechanical Allodynia and Suppressed Spinal Mitochondrial Superoxide Induced by Perineural Human Immunodeficiency Virus gp120 in Rats.

BACKGROUND: Mitochondria play an important role in many cellular and physiologic functions. Mitochondria are dynamic organelles, and their fusion and fission regulate cellular signaling, development, and mitochondrial homeostasis. The most common complaint of human immunodeficiency virus (HIV)-sensory neuropathy is pain on the soles in patients with HIV, but the exact molecular mechanisms of HIV neuropathic pain are not clear. In the present study, we investigated the role of mitochondrial dynamin-related protein 1 (Drp1, a GTPase that mediates mitochondrial fission) in the perineural HIV coat glycoprotein gp120-induced neuropathic pain state. METHODS: Neuropathic pain was induced by the application of recombinant HIV-1 envelope protein gp120 into the sciatic nerve. Mechanical threshold was tested using von Frey filaments. The mechanical threshold response was assessed over time using the area under curves. Intrathecal administration of antisense oligodeoxynucleotide (ODN) against Drp1, mitochondrial division inhibitor-1 (mdivi-1), or phenyl-N-tert-butylnitrone (a reactive oxygen species scavenger) was given. The expression of spinal Drp1 was examined using western blots. The expression of mitochondrial superoxide in the spinal dorsal horn was examined using MitoSox imaging. RESULTS: Intrathecal administration of either antisense ODN against Drp1 or mdivi-1 decreased mechanical allodynia (a sensation of pain evoked by nonpainful stimuli) in the gp120 model. Intrathecal ODN or mdivi-1 did not change basic mechanical threshold in sham surgery rats. Intrathecal Drp1 antisense ODN decreased the spinal expression of increased Drp1 protein induced by peripheral gp120 application. Intrathecal phenyl-N-tert-butylnitrone reduced mechanical allodynia. Furthermore, both intrathecal Drp1 antisense ODN and mdivi-1 reversed the upregulation of mitochondrial superoxide in the spinal dorsal horn in the gp120 neuropathic pain state. CONCLUSIONS: These data suggest that mitochondrial division plays a substantial role in the HIV gp120-related neuropathic pain state through mitochondrial reactive oxygen species and provides evidence for a novel approach to treating chronic pain in patients with HIV.

The impact of anesthesia providers on major morbidity following screening colonoscopies.

BACKGROUND AND AIMS: Few studies evaluate the impact of anesthesia providers during procedures, such as colonoscopy, on low-risk patients. The objective of this study was to compare the effect of anesthesia providers on several outcome variables, including major morbidity, following screening colonoscopies. METHODS: A propensity-matched cohort study of 14,006 patients who enrolled with a national insurer offering health maintenance organization (HMO), preferred provider organization (PPO), and Medicare Advantage plans for a screening colonoscopy between July 1, 2005 and June 30, 2007 were studied. Records were evaluated for completion of the colonoscopy, new cancer diagnosis (colon, anal, rectal) within 6 months of the colonoscopy, new primary diagnosis of myocardial infarction (MI), new primary diagnosis of stroke, hospital admission within 7 days of the colonoscopy, and adherence to guidelines for use of anesthesia providers. RESULTS: The presence of an anesthesia provider did not affect major morbidity or the percent of completed exams. Overall morbidity within 7 days was very low. When an anesthesia provider was present, a nonsignificant trend toward greater cancer detection within 6 months of the procedure was observed. Adherence to national guidelines regarding the use of anesthesia providers for low-risk patients was poor. CONCLUSION: A difference in outcome associated with the presence or absence of an anesthesia provider during screening colonoscopy in terms of MI, stroke, or hospital admission within 7 days of the procedure was not observed. Adherence to published guidelines for the use of anesthesia providers is low. The incidence of completed exams was unaffected by the presence of an anesthesia provider. However, a nonstatistically significant trend toward increased cancer detection requires further study.

CYP3A4 * 1G Genetic Polymorphism Influences Metabolism of Fentanyl in Human Liver Microsomes in Chinese Patients.

PURPOSE: This study aimed to investigate whether CYP3A4*1G genetic polymorphism influences the metabolism of fentanyl in human liver microsomes in Chinese patients. METHODS: The human liver microsomes were obtained from 88 hepatobiliary surgery patients who accepted liver resection surgery in this study. A normal liver sample (confirmed by the Department of Pathology) was taken from the outer edge of the resected tissue. The metabolism of fentanyl in human liver microsomes was studied. The concentration of fentanyl was measured by high performance liquid chromatography. The CYP3A4*1G variant allele was genotyped using the PCR restriction fragment length polymorphism method. RESULTS: The frequency of the CYP3A4*1G variant allele was 0.188 in the 88 Chinese patients who had received hepatobiliary surgery. The metabolic rate of fentanyl in patients homozygous for the *1G/*1G variant (0.85 ± 0.37) was significantly lower than that in patients bearing the wild-type allele *1/*1 (1.89 ± 0.58) or in patients heterozygous for the *1/*1G variant (1.82 ± 0.65; p < 0.05). There were no gender-related differences in the metabolic rate of fentanyl (p > 0.05) nor was there any correlation between age and metabolic rate of fentanyl (p > 0.05). Results from different hepatobiliary diseases showed no significant difference in the metabolic rate of fentanyl (p > 0.05). The difference of CYP3A4 mRNA among different CYP3A4*1G variant alleles was significant (p < 0.05). There was positive correlation between CYP3A4 mRNA and metabolic rate of fentanyl (p < 0.01). CONCLUSIONS: CYP3A4*1G genetic polymorphism decreases the metabolism of fentanyl. There is a positive correlation between CYP3A4 mRNA level and metabolism of fentanyl.

A Comparison of Fentanyl and Flurbiprofen Axetil on Serum VEGF-C, TNF-α, and IL-1ß Concentrations in Women Undergoing Surgery for Breast Cancer.

BACKGROUND: Vascular endothelial growth factor-C (VEGF-C), tumor necrosis factor-α (TNF-α), and interleukin-1ß(IL-1ß) have been shown to be associated with the recurrence and metastasis of breast cancer after surgery. This study tested the hypothesis that patients undergoing surgery for breast cancer, who received postoperative analgesia with flurbiprofen axetil combined with small doses of fentanyl (FA), exhibited reduced levels of VEGF-C, TNF-α, and IL-1ß compared with those patients receiving fentanyl alone (F). METHOD: Forty-women with primary breast cancer undergoing a modified radical mastectomy were randomized to receive postoperative analgesia with flurbiprofen axetil combined with fentanyl or fentanyl alone. Venous blood was sampled before anesthesia, at the end of surgery, and at 48 hours after surgery, and the serum was analyzed. The primary endpoint was changes in the VEGF-C concentrations in serum. RESULTS: Group FA patients reported similar analgesic effects as group F patients at 2, 24, and 48 hours. At 48 hours, mean postoperative concentrations of VEGF-C in group F patients were higher than in group FA patients, 730.9 versus. 354.1 pg/mL (P = 0.003), respectively. The mean postoperative concentrations of TNF-α in group F patients were also higher compared with group FA patients 27.1 vs. 15.8 pg/mL (P = 0.005). Finally, the mean postoperative concentrations of IL-1ß in group F were also significantly higher than in group FA 497.5 vs. 197.7 pg/mL (P = 0.001). CONCLUSION: In patients undergoing a mastectomy, postoperative analgesia with flurbiprofen axetil, combined with fentanyl, were associated with decreases in serum concentrations of VEGF-C, TNF-α, and IL-1ß compared with patients receiving doses of only fentanyl.

A matrix model for valuing anesthesia service with the resource-based relative value system.

BACKGROUND: The purpose of this study was to propose a new crosswalk using the resource-based relative value system (RBRVS) that preserves the time unit component of the anesthesia service and disaggregates anesthesia billing into component parts (preoperative evaluation, intraoperative management, and postoperative evaluation). The study was designed as an observational chart and billing data review of current and proposed payments, in the setting of a preoperative holing area, intraoperative suite, and post anesthesia care unit. In total, 1,195 charts of American Society of Anesthesiology (ASA) physical status 1 through 5 patients were reviewed. No direct patient interventions were undertaken. RESULTS: Spearman correlations between the proposed RBRVS billing matrix payments and the current ASA relative value guide methodology payments were strong (r=0.94-0.96, P<0.001 for training, test, and overall). The proposed RBRVS-based billing matrix yielded payments that were 3.0%±1.34% less than would have been expected from commercial insurers, using standard rates for commercial ASA relative value units and RBRVS relative value units. Compared with current Medicare reimbursement under the ASA relative value guide, reimbursement would almost double when converting to an RBRVS billing model. The greatest increases in Medicare reimbursement between the current system and proposed billing model occurred as anesthetic management complexity increased. CONCLUSION: The new crosswalk correlates with existing evaluation and management and intensive care medicine codes in an essentially revenue neutral manner when applied to the market-based rates of commercial insurers. The new system more highly values delivery of care to more complex patients undergoing more complex surgery and better represents the true value of anesthetic case management.