Impact of Dobutamine in Patients With Septic Shock: A Meta-Regression Analysis.

Septic shock frequently requires vasopressor agents. Conflicting evidence exists for use of inotropes in patients with septic shock. Data from English studies on human adult septic shock patients were collected. A total of 83 studies were reviewed, while 11 studies with 21 data sets including 239 patients were pooled for meta-regression analysis. For VO2, pooled difference in means (PDM) was 0.274. For cardiac index (CI), PDM was 0.783. For delivery of oxygen, PDM was -0.890. For heart rate, PDM was -0.714. For left ventricle stroke work index, PDM was 0.375. For mean arterial pressure, PDM was -0.204. For mean pulmonary artery pressure, PDM was 0.085. For O2 extraction, PDM was 0.647. For PaCO2, PDM was -0.053. For PaO2, PDM was 0.282. For pulmonary artery occlusive pressure, PDM was 0.270. For pulmonary capillary wedge pressure, PDM was 0.300. For PVO2, PDM was -0.492. For right atrial pressure, PDM was 0.246. For SaO2, PDM was 0.604. For stroke volume index, PDM was 0.446. For SvO2, PDM was -0.816. For systemic vascular resistance, PDM was -0.600. For systemic vascular resistance index, PDM was 0.319. Meta-regression analysis was performed for VO2, DO2, CI, and O2 extraction. Age was found to be significant confounding factor for CI, DO2, and O2 extraction. APACHE score was not found to be a significant confounding factor for any of the parameters. Dobutamine seems to have a positive effect on cardiovascular parameters in patients with septic shock. Prospective studies with larger samples are required to further validate this observation.

Diagnoses and clinical features associated with high risk for unplanned readmission in vascular surgery. A cohort study.

BACKGROUND: Readmission rate is an established health quality indicator. Preventable readmissions bear an unnecessary, high cost on the healthcare system. An analysis performed by the National Centre for Health Outcomes Development (NCHOD) has demonstrated an increasing trend in emergency readmissions in the UK. Vascular surgery has been reported to have high readmission rates second only to congestive heart failure. This study aims to identify diagnoses and other clinical risk factors for high unplanned readmission rates. This may be the first step to sparing both the health care system and patients of unnecessary readmissions. RESULTS: The overall 30 day readmission rate for Leeds Vascular Institute was 8.8%. The two diagnoses with the highest readmission rates were lower limb ischaemia and diabetic foot sepsis. The readmission rate for medical reasons was overwhelmingly higher than for surgical reasons (6.5% and 2.3% respectively). The most common medical diagnoses were renal disease and COPD. The majority of the patients readmitted under the care of vascular surgery required further surgical treatment. CONCLUSION: Vascular units should focus on holistic and multidisciplinary treatment of lower limb ischaemia and diabetic foot sepsis, in order to prevent readmissions. Furthermore, the early involvement and input of physicians in the treatment of vascular patients with renal disease and COPD may be appropriate.

A four-step mechanism for the formation of supported-nanoparticle heterogenous catalysts in contact with solution: the conversion of Ir(1,5-COD)Cl/γ-Al2O3 to Ir(0)(∼170)/γ-Al2O3.

Product stoichiometry, particle-size defocusing, and kinetic evidence are reported consistent with and supportive of a four-step mechanism of supported transition-metal nanoparticle formation in contact with solution: slow continuous nucleation, A → B (rate constant k1), autocatalytic surface growth, A + B → 2B (rate constant k2), bimolecular agglomeration, B + B → C (rate constant k3), and secondary autocatalytic surface growth, A + C → 1.5C (rate constant k4), where A is nominally the Ir(1,5-COD)Cl/γ-Al2O3 precursor, B the growing Ir(0) particles, and C the larger, catalytically active nanoparticles. The significance of this work is at least 4-fold: first, this is the first documentation of a four-step mechanism for supported-nanoparticle formation in contact with solution. Second, the proposed four-step mechanism, which was obtained following the disproof of 18 alternative mechanisms, is a new four-step mechanism in which the new fourth step is A + C → 1.5C in the presence of the solid, γ-Al2O3 support. Third, the four-step mechanism provides rare, precise chemical and kinetic precedent for metal particle nucleation, growth, and now agglomeration (B + B → C) and secondary surface autocatalytic growth (A + C → 1.5C) involved in supported-nanoparticle heterogeneous catalyst formation in contact with solution. Fourth, one now has firm, disproof-based chemical-mechanism precedent for two specific, balanced pseudoelementary kinetic steps and their precise chemical descriptors of bimolecular particle agglomeration, B + B → C, and autocatalytic agglomeration, B + C → 1.5C, involved in, for example, nanoparticle catalyst sintering.

Iliac artery occlusion with "oxbow lake" formation following stent deployment in a tortuous external iliac artery during EVAR: a case report.

In this case report, we describe a complication that we term the "oxbow lake" deformity. This phenomenon occurs when a tortuous elongated external iliac artery segment is artificially straightened by an iliac stent resulting in kinking and compression of a redundant loop with lumen compromise. We describe the anatomy, corrective treatment, and outcome. This occurrence is potentially foreseeable with tortuous vascular anatomy and recognition can allow appropriate management planning avoiding complications for the patient.

Lower respiratory tract infection and rapid expansion of an abdominal aortic aneurysm: a case report.

INTRODUCTION: The rate of abdominal aortic aneurysm expansion is related to multiple factors. There is some evidence that inflammation can accelerate aneurysm expansion. However, the association between pulmonary sepsis and rapid abdominal aortic aneurysm expansion is rarely reported. CASE PRESENTATION: Here we present a case of a rapidly expanding abdominal aortic aneurysm in a 68-year-old Caucasian man with a concomitant lower respiratory tract infection and systemic sepsis requiring intensive monitoring and urgent endovascular intervention. Our patient had an uncomplicated post-operative recovery and a follow-up computed tomography scan at one month demonstrated no evidence of an endoleak. CONCLUSION: This case highlights the potential association between pulmonary sepsis and rapid abdominal aortic aneurysm expansion. In such cases, a policy of frequent monitoring should be adopted to identify those patients requiring definitive management.

CT study of the relationship between the common iliac artery and vein and their juxtaposition: implications for conduit construction prior to endovascular stent-graft repair of aortic aneurysms.

The objective of this study was to determine the anatomical relationship and juxtaposition between the common iliac artery and vein in a population of patients with aortic aneurysmal disease and a population clinically and radiologically free of atheroma. It was a retrospective study of 100 consecutive patients undergoing computed tomographic assessment of abdominal aortic aneurysm prior to endovascular or open surgical repair and 100 patients undergoing computed tomographic assessment for other pathologies who did not have clinical or imaging signs of aorto-iliac atheroma. In both groups the anatomical relationship between the right and left iliac artery and vein was studied, and the thickness of the fat plane separating the artery from the vein measured. The right iliac vein was posterolateral to the artery at the level of the common iliac artery bifurcation in 95% of patients in both groups. At the same level the left iliac vein was posterior in 23% (p B 0.001). Eighty-three percent of patients in the aneurysm group had a fat plane between the right artery and vein that measured 0 mm (no visible fat plane = 52%) to 1 mm (= 31%). Ninety-eight percent of patients in the aneurysm group had a measurable fat plane between the left iliac artery and vein of up to 5 mm (p = 0.001). Six percent of the control group demonstrated no visible fat plane between the right iliac artery and vein (p B 0.001), while the fat plane measured more than 1 mm (1-5 mm) on the left in 100%. We conclude that in patients where conduit construction is required for aortic stent-graft access, the anatomical configuration and intimate relationship of the iliac arteries and veins should be assessed and taken into account at CT scan evaluation. The distal right common iliac artery should not be used, as venous damage can be predicted from the anatomical and intimate relationship of the iliac artery and vein at this level in patients with atheroma and the difficulties this relationship presents if venous repair is necessary.