22 research outputs found
Performance and quality of tall fescue (Festuca arundinacea Schreb.) and perennial ryegrass (Lolium perenne L.) and mixtures of both species grown with or without white clover (Trifolium repens L.) under cutting management
There is increasing interest in tall fescue (Festuca arundinacea Schreb.) in Western Europe and elsewhere, mainly because of its better drought resistance and yield potential compared with perennial ryegrass (Lolium perenne L.). Important drawbacks of tall fescue, compared with perennial ryegrass, are its lower digestibility and voluntary intake. Mixtures of both species might combine the advantages of each, and species interactions may eventually lead to transgressive overyielding. We compared the agronomic performance of tall fescue, perennial ryegrass and tall fescue-perennial ryegrass mixtures, as pure-grass swards or in association with white clover (Trifolium repens L.). Tall fescue-perennial ryegrass mixtures differed in the proportion and ploidy of the perennial ryegrass component. Yield, feed quality and botanical composition were measured in the 3years after the sowing year. We found significant effects of ploidy of the ryegrass variety and of the proportion of ryegrass in the initial seed mixture on the botanical composition of the swards. Nevertheless, all swards were dominated by tall fescue at the end of the experiment. No overyielding of the mixtures compared with that of single-species swards was found, but feed quality was intermediate between that of the single-species swards. Mixed swards had better drought resistance than L.perenne and higher feeding quality than F.arundinacea swards
Wound dressings for a proteolytic-rich environment
Wound dressings have experienced continuous and significant changes over the years based on the knowledge of the biochemical events associated with chronic wounds. The development goes from natural
materials used to just cover and conceal the wound to interactive materials that can facilitate the healing process, addressing specific issues in non-healing wounds. These
new types of dressings often relate with the proteolytic wound environment and the bacteria load to enhance the healing. Recently, the wound dressing research is focusing on the replacement of synthetic polymers by natural protein materials to delivery bioactive agents to the wounds. This
article provides an overview on the novel protein-based wound dressings such as silk fibroin keratin and elastin.
The improved properties of these dressings, like the release of antibiotics and growth factors, are discussed. The different types of wounds and the effective parameters of
healing process will be reviewed
Dehydration improves biomechanical strength of bioartificial vascular graft material and allows its long-term storage
We have recently reported about a novel technique for the generation of bioartificial vascular grafts based on the use of a compacted fibrin matrix. In this study, we evaluated the effects of a dehydration process on the biomechanical properties of compacted fibrin tubes and whether it allows for their long-term storage
Vascular procedures in patients with left ventricular assist devices: single-center experience
Objective!#!A growing number of patients suffering from heart failure is living with a left ventricular assist device (LVAD) and is in the need for non-cardiac surgery. Vascular procedures due to ischemia, bleeding, or other device-related complications may be required and pose a challenge to the caregivers in terms of monitoring and management of these patients. Therefore, we reviewed our experience with LVAD patients undergoing vascular surgery.!##!Methods!#!From January 2010 until March 2017, a total of 54 vascular procedures were performed on 41 LVAD patients at our institution. Patient records were reviewed retrospectively in terms of incidence of LVAD-related complications, including thrombosis, stroke, bleeding, wound healing, and survival associated with vascular surgery. The type of surgery was recorded, as well as various clinical demographic variables.!##!Results!#!Vascular procedures were performed in 35 men (85.4%) and 6 women (14.6%) with LVADs. There were no perioperative strokes, device thromboses, or device malfunctions. Thirty-day mortality overall was 26.8% (eleven patients), with most patients dying within 30 days after LVAD implantation due to multi-organ failure. In 25 procedures (46.3%), a blood transfusion was necessary.!##!Conclusion!#!Patients on LVAD support are a complex cohort with a high risk for perioperative complications. In a setting where device function and anticoagulation are monitored closely, vascular surgery in these patients is feasible with an acceptable perioperative risk
Prospective evaluation of preoperative lung ultrasound for prediction of perioperative outcome and myocardial injury in adult patients undergoing vascular surgery (LUPPO study)
BACKGROUND
Myocardial injury after non-cardiac surgery (MINS) is a frequent perioperative event in vascular surgery, associated both with worse outcome and subsequent cardiovascular events. Current guidelines advocate troponin (hs-cTnT) and NT-proBNP measurements in selected patients before surgery, but accurate preoperative identification of patients at risk for MINS is an unmet clinical need. Focused lung ultrasound (LUS) might help to select patients at increased risk for MINS, because it can visualize B-line artifacts correlating to cardiopulmonary disease. Therefore, we investigated whether quantification of B-line artifacts improves perioperative risk predictive accuracy for MINS.
METHODS
In this prospective single-center observational study, 136 consecutive open vascular surgery patients underwent conventional preoperative assessment expanded by lung ultrasound. Lung ultrasound B-lines were counted in each of 28 bilateral scan fields of the anterior and lateral chest. Improvement of risk predictive accuracy was quantified with area under receiver operating characteristic (ROC) curve analysis and net reclassification improvement (NRI).
RESULTS
We included 118 patients into the final analysis. Twenty-three (19%) patients fulfilled the criteria for the primary endpoint MINS. Three or more bilateral positive B-line fields were calculated as the best ROC-derived cutoff associated with an increased incidence of MINS (odds ratio: 4.4; 95% confidence interval [CI]: 1.5 to 12.7; P=0.007). Adding LUS to hs-cTnT measurements improved risk predictive accuracy for MINS (NRI: 0.36, P=0.043).
CONCLUSIONS
Lung ultrasound in combination with hs-cTnT showed a better test accuracy than hs-cTnT alone and might guide clinicians to identify vascular patients at increased risk for MINS
Renal function interferes with copeptin in prediction of major adverse cardiac events in patients undergoing vascular surgery.
OBJECTIVE:Precise perioperative risk stratification is important in vascular surgery patients who are at high risk for major adverse cardiovascular events (MACE) peri- and postoperatively. In clinical practice, the patient's perioperative risk is predicted by various indicators, e.g. revised cardiac index (RCRI) or modifications thereof. Patients suffering from chronic kidney disease (CKD) are stratified into a higher risk category. We hypothesized that Copeptin as a novel biomarker for hemodynamic stress could help to improve the prediction of perioperative cardiovascular events in patients undergoing vascular surgery including patients with chronic kidney disease. METHODS:477 consecutive patients undergoing abdominal aortic, peripheral arterial or carotid surgery from June 2007 to October 2012 were prospectively enrolled. Primary endpoint was 30-day postoperative major adverse cardiovascular events (MACE). RESULTS:41 patients reached the primary endpoint, including 63.4% aortic, 26.8% carotid, and 9.8% peripheral surgeries. Linear regression analysis showed that RCRI (P< .001), pre- (P< .001), postoperative Copeptin (P< .001) and Copeptin level change (P= .001) were associated with perioperative MACE, but CKD remained independently associated with MACE and Copeptin levels. Multivariate regression showed that increased Copeptin levels added risk predictive information to the RCRI (P= .003). Especially in the intermediate RCRI categories was Copeptin significantly associated with the occurrence of MACE. (P< .05 Kruskal Wallis test). Subdivision of the study cohort into CKD stages revealed that preoperative Copeptin was significantly associated with CKD stages (P< .0001) and preoperative Copeptin measurements could not predict MACE in patients with more severe CKD stages. CONCLUSION:Preoperative Copeptin loses its risk predictive potential for perioperative MACE in patients with chronic kidney disease undergoing vascular surgery
ROC analysis comparing the RCRI alone or combined with Copeptin-derived parameters.
<p>Only preoperative Copeptin (blue dotted line) improved risk predictive accuracy of the RCRI (P = .0371, AUC .752). The RCRI-ROC Curve (black line) (AUC .714) indicates prediction of the occurrence of major adverse cardiovascular events (MACE). The combination of RCRI and postoperative Copeptin (red dashed line) (P = .0620, AUC .751) and RCRI and Copeptin changes (P = .1525, AUC .710) during the perioperative course (green dashed and dotted line) do not reach significantly larger AUCs. * marks significant values.</p
Analysis of Copeptin levels.
<p>Linear regression analysis of pre-, postoperative Copeptin levels and Copeptin change (pmol/L) and existing comorbidities as well as RCRI category and surgical procedure,</p><p>*marks significant confounders, abbreviations are used as follows: BMI (Body mass index), TIA (transitory ischemic attack), COPD (chronic obstructive pulmonary disease), CAD (coronary artery disease), RCRI (Revised cardiac index), surgical procedure (type of surgery performed subdivided into aortic, carotid and peripheral surgeries). Significance reveals results of linear regression analysis; significant results were additionally used in multivariate regression (significance multivariate) results are shown with P values.</p><p>Analysis of Copeptin levels.</p