Low serum S100β protein levels following coronary artery surgery with or without cardiopulmonary bypass

Background: S100β protein has been used as a serum marker of brain injury during cardiac surgery. Previous studies may have been confounded by the re-transfusion of shed mediastinal blood, which has a high concentration of S100β.Aim: To examine serum S100β levels in coronary artery surgery patients in whom re-transfusion of shed mediastinal blood was avoided, and to compare levels with and without cardiopulmonary bypass (CPB).Methods: Serum S100β levels were measured preoperatively, pre-heparin, post-protamine and 24 h postoperatively in 31 patients undergoing elective coronary artery surgery with (n = 14) or without (n = 17) CPB. The postoperative values were compared to their preoperative controls using two-tailed paired t-tests.Results: There was a minor increase in serum S100β post-protamine in the CPB group only (0.41 ng/mL; P < 0.01). All other levels in both groups were within normal limits.Conclusions: Coronary artery surgery without CPB is not associated with an increase in serum S100β. The observed increase in the CPB group was four- to ninefold lower than levels previously reported. A possible explanation for the lower level was the avoidance of retransfusing shed mediastinal blood. If elevated S100β levels are thought to represent a cerebral insult caused by CPB, the magnitude of the insult might be less than previously assumed.     

Pain management and quality in healthcare

Management of pain in the acute peri-operative setting still leaves a significant number of patients suffering from moderate to severe pain. In order to improve this, it is important to understand the underlying mechanisms of pain perception, and be able to apply this to clinical settings. Effective assessment of pain is needed, with re-assessment to detect treatment efficacy. Meta-analyses and systematic reviews are available for many of the analgesic therapies used, and this can be used as a basis for formulating an effective management plan. By optimizing pain management in the peri-operative period, and utilizing this, it should be possible to minimize resultant disability and hospital stay.     

Stereoselective activity of local anesthetics

Most local anesthetic molecules contain an asymmetric carbon atom in their structure.Therefore, they provide excellent examples of chiral drugs that exist as two enantiomers, where each form may exhibit striking differences in its pharmacologic profile. Bupivacaine is currently marketed as a racemic mixture of both its S-(-)- and R-(+)-enantiomers. Fuelled by concerns about the cardiovascular toxicity of this preparation, research has focused on the pharmacology of the single enantiomers.The R-(+)-enantiomer has a higher potency as a sodium channel blocker than its “chiral twin” but correspondingly, also causes higher cardiovascular and central nervous system toxicity at lower doses.This work on bupivacaine has in turn driven the development and release of ropivacaine, an optically pure S-(-)-propyl homologue of bupivacaine.When compared with racemic bupivacaine, it demonstrates a significantly improved toxicity profile.This paper reviews some of the more recent literature on this subject in order to provide an account of current thinking on this important group of drugs.     

Does a Combination of Intensive Cognitive‐Behavioral Pain Management and a Spinal Implantable Device Confer any Advantage? A Preliminary Examination

Abstract:   Research suggests that a combination of a somatic and a psychosocial intervention for chronic noncancer pain should be associated with a better outcome than either alone. This study presents data on a series of 31 patients who underwent sequential treatment with an implantable device targeting pain relief and a cognitive-behavioral pain management program that targeted improved function. A combination of treatments was used as there was a suboptimal response to the initial treatment. There were improvements in a range of outcomes at a long-term follow-up. Significant improvements were found in disability, affective distress, self-efficacy, and catastrophizing, but not in average pain severity. Further analyses failed to demonstrate an order effect. These results support the view that combined somatic and psychosocial interventions can achieve better outcomes than either alone in selected chronic pain patients. This approach requires that psychological assessment is essential before the use of an implantable device. This may not only improve patient selection, but also identify psychosocial factors that may be modified to enhance the effectiveness of invasive interventions. In addition, consideration for an implantable device following a suboptimal response to treatment in a cognitive-behavioral pain management program should include a re-evaluation of the patients' beliefs and use of self-management (coping) strategies before deciding on further treatment options.