The effect of perioperative beta-blockade on the pulmonary function of patients undergoing major arterial surgery.

INTRODUCTION: Concern about the potential detrimental side-effects of beta-blockade on pulmonary function often dissuades against their perioperative use in patients undergoing major arterial surgery (especially in those with chronic obstructive pulmonary disease (COPD)). In this study we aimed to establish prospectively the clinical relevance of these concerns. METHODS: After ethics committee approval and individual informed consent, the pulmonary function of twenty patients (mean age 68.7 years (range 43-82), 11 males) scheduled to undergo non-emergency major vascular surgery was studied by recording symptoms and spirometry before and after institution of effective beta-blockade. Fifteen patients (75%) had significant smoking histories (mean pack years/patient=50), while 12 (60%) had COPD. RESULTS: All patients tolerated effective beta-blockade satisfactorily without developing either subjective deterioration in symptoms or significant change on spirometry. The mean change in FEV1 following adequate beta-blockade was 0.05+/-0.24 liters (95% CI -0.06 to +1.61), p=0.35, giving a mean percentage change of 3.18%+/-11.66 (95% CI -2.26 to 8.62). CONCLUSIONS: Previously held concerns about worsening pulmonary function through the short-term use of beta-blockers should not dissuade their perioperative usage in patients with peripheral vascular disease. Furthermore, the accuracy of pulmonary function tests in preoperative assessment and risk stratification also appears unaffected by this therapy.     

A comparative analysis of radiological and surgical placement of central venous catheters

Purpose To compare the differences in practice and outcome of all radiologically and surgically placed central venous catheters retrospectively over a 2-year period simultaneously, at a single institution. Methods A total of 253 Hickman catheters were inserted in 209 patients; 120 were placed radiologically in 102 patients and 133 were placed surgically in 107 patients. The indication was chemotherapy in 76% of radiological and in 47% of surgical cases; the remainder were for total parenteral nutrition and venous access. Results There were 6 (4.5%) primary surgical failures and a further 17 (13%) surgical cases requiring multiple placement attempts. Pneumothorax occurred once (0.8%) surgically and four times (3.3%) radiologically. There were no radiological primary misplacements but there were five (3.7%) surgical ones. Catheter or central vein thrombosis occurred in four (3.3%) radiological and five (3.7%) surgical cases. The rate of infection per 1000 catheter-days was 1.9 in radiologically placed catheters and 4.0 in surgically placed ones (p<0.001). Average catheter life-span was similar for the two placement methods (100±23 days). Conclusion Radiological placement is consistently more reliable than surgical placement. There are fewer placement complications and fewer catheter infections overall.     

硫酸多糖对体外人脐静脉内皮细胞损伤的保护作用

研究表明,硫酸多糖体外对多聚阳离子和氧自由基损伤的人脐静脉内皮细胞有保护作用。肝素、硫酸软骨素A抗多聚阳离子损伤作用比同浓度低分子肝素和甘糖酯强。肝素、硫酸软骨素A、甘糖酯抗氧自由基损伤作用优于同浓度低分子肝素。结果显示硫酸多糖有保护血管内皮的作用,其作用可能与所带阴离子基团有关。     

Immune responses in kidney preservation and reperfusion injury.

Organ preservation and reperfusion injury have significant detrimental effects on both short- and long-term organ function. Ischemia reperfusion injury (IRI) underlies organ transplant dysfunction, myocardial infarction, stroke, and shock. Multiple molecular pathways are engaged in reactive oxygen production, apoptosis, signaling, and tissue regeneration. There has been an increased understanding of the important role of immune and inflammatory pathways in IRI, both in humans and in experimental models. Both cellular and soluble components of the immune system are directly activated during IRI, and there is evidence that immune mediators directly contribute to organ dysfunction. Immune activation during IRI likely underlies the enhanced immunogenicity of ischemic organs, with resultant increased rejection and fibrosis. Novel human therapies targeting T and B cells for classic immune diseases can now be considered to prevent and treat IRI. Organ preservation injury and cold ischemia could well have distinct pathophysiology from warm IRI and represent an opportunity to develop improved preservation methods.     

Recurrent stroke associated with thymoma and anticardiolipin antibodies

A 44-year-old woman developed recurrent thrombotic cerebral cortical infarctions. IgG and IgM anticardiolipin antibodies were found, as was a thymoma. To our knowledge, these antiphospholipid antibodies, which may inhibit prostacyclin formation and alter platelet function, have not been previously associated with this thymic neoplasm, an association we believe is not coincidental.     

Understanding what works--and why--in quality improvement: the need for theory-driven evaluation.

Clinicians who are asked to participate in quality improvementprogrammes in healthcare organizations are often heard to askfor the evidence that they ‘work’. By that, theyoften mean they want randomized controlled trials, which showthat accreditation, or credentialing, or criterion-based audit,or adverse event monitoring, or continuous quality improvementprogrammes, or whatever approach is being used cause meaningfuland worthwhile improvements in the quality of care [1]. Whenthey learn that there are relatively few experimental studiesof quality improvement interventions [2], and those which doexist often show weak or moderate effects at best, this stateof affairs is sometimes used to argue that it is not worthwhile