Attenuation of Oxidative Stress by Ischemic Preconditioning in an Experimental Model of Intraabdominal Hypertension.

PURPOSE: Increased intra-abdominal pressure, as used in laparoscopic surgery or seen in intraabdominal hypertension (IAH), is associated with tissue ischemia and oxidative stress. Ischemic preconditioning (IP) is a method successfully used in liver and transplant surgery, in order to attenuate the detrimental effects of ischemia and reperfusion. In this experimental study, we tested the ability of IP to modify oxidative stress induced by extremely high intraabdominal pressures. METHODS: Twenty-five female pigs were studied and divided in three groups: a control group, a pneumoperitoneum group (with pressure of 30 mmHg), and an ischemic preconditioning group (initially subjected to preconditioning with pressure of 25 mmHg for 15 min and desufflation for 15 min and then to pneumoperitoneum as in pneumoperitoneum group). Blood samples were obtained at identical time intervals in the three groups. Total oxidative capacity, total antioxidative capacity and total nitric oxide (NO), nitrite and nitrate concentrations were measured and compared between groups. RESULTS: IP increased total antioxidative capacity (p = .045) and protective mediators like nitrite (p = .022). It was also associated with a trend toward lower levels of total oxidative capacity at the end of the abdominal desufflation period but statistical significance was not met. CONCLUSIONS: IP attenuated oxidative stress induced by IAH, mainly by increasing antioxidative capacity and the levels of protective mediators. The fact that IP was effective, even when used at extremely high levels of intraabdominal pressure, reinforces the interest on this method but further studies are needed to clarify its mechanism of action and potential clinical applications.

How does an undergraduate pain course influence future physicians' awareness of chronic pain concepts? A comparative study.

OBJECTIVE: Pain is one of the most undertreated medical complaints, with barriers to effective pain management lying in poor education of health professionals and misconceptions regarding patients in pain. The aim of this study was to assess whether an elective undergraduate course on chronic pain offered in Greek medical schools influences knowledge and attitudes of medical undergraduates about chronic pain and helps them clarify pain-related concepts. METHODS: An electronic questionnaire with 6 demographic and 21 pain-related items was uploaded on SurveyMonkey. The questionnaire was open to medical students in every Greek medical school for 1 month. Students were asked to respond to questions regarding various aspects of pain taught in the aforementioned course. In specific, they were asked to respond to questions regarding the definition, types, and adequacy of treatment of chronic cancer and non-cancer pain. They were queried about their knowledge of pain clinics, health practitioners who run them, and types of treatment available there. There were also questions about opioid use in cancer and non-cancer chronic pain patients and regarding the likelihood of opioid addiction. RESULTS: According to their responses, medical students had good knowledge about the definition and consequences of pain, and those who attended the pain course had greater knowledge regarding the adequacy of treatment of chronic pain and were more familiar with the recent classification of types of pain. Students who did not have exposure to the undergraduate pain course had little information regarding pain clinics and had poor knowledge regarding the use of opioids in cancer and in nonmalignant chronic pain. All students expressed concerns regarding addiction to opioids. CONCLUSIONS: Although students enter medical school with little knowledge about pain issues, pain awareness can be positively influenced by education. A curriculum about pain should not only teach the basic science of pain but also present treatment strategies available and address the socio-emotional dimensions of pain. Additionally, if misconceptions about opioid use and addiction are properly elucidated early in medical education, the future health practitioners will be one step forward in achieving the goal of alleviating suffering patients' pain.

Therapeutic management of chronic neuropathic pain: an examination of pharmacologic treatment.

Neuropathic pain is defined as pain caused by a lesion in the nervous system and is common in clinical practice. Diagnosis can be difficult. Recommendations for first-line pharmacologic treatments are based on positive results from multiple, randomized, controlled trials, and recommendations for second-line pharmacologic treatments are based on the positive result of a single, randomized, controlled trial or inconsistent results of multiple, randomized, controlled trials. The results of published trials and clinical experience provide the foundation for specific recommendations for first-line treatments, which include gabapentin, 5% lidocaine patch, opioid analgesics, tramadol hydrochloride, and tricyclic antidepressants (TCAs). Gabapentin (up to 3,600 mg/day) significantly reduced pain compared with placebo; improvements in sleep, mood, and quality of life were also demonstrated. Adverse effects of gabapentin include somnolence and dizziness, and, less commonly, gastrointestinal symptoms and mild peripheral edema. Thus, monitoring and dosage adjustment are required, without discontinuation of the drug. Gabapentin combined with morphine achieved better analgesia at lower doses of each drug than each drug alone, with only mild adverse effects. The first medication that proved effective for neuropathic pain in placebo-controlled trials was TCAs. Treatment decisions for patients with neuropathic pain can be difficult. Interest in the mechanisms and treatment of chronic neuropathic pain has increased during the past years, resulting in significant treatment advances in the future. In this article all recent knowledge on therapeutic management of chronic neuropathic pain is presented.