918 resultados para vascular access infection
Resumo:
Thrombophilia (TF) predisposes both to venous and arterial thrombosis at a young age. TF may also impact the thrombosis or stenosis of hemodialysis (HD) vascular access in patients with end-stage renal disease (ESRD). When involved in severe thrombosis TF may associate with inappropriate response to anticoagulation. Lepirudin, a potent direct thrombin inhibitor (DTI), indicated for heparin-induced thrombocytopenia-related thrombosis, could offer a treatment alternative in TF. Monitoring of narrow-ranged lepirudin demands new insights also in laboratory. The above issues constitute the targets in this thesis. We evaluated the prevalence of TF in patients with ESRD and its impact upon thrombosis- or stenosis-free survival of the vascular access. Altogether 237 ESRD patients were prospectively screened for TF and thrombogenic risk factors prior to HD access surgery in 2002-2004 (mean follow-up of 3.6 years). TF was evident in 43 (18%) of the ESRD patients, more often in males (23 vs. 9%, p=0.009). Known gene mutations of FV Leiden and FII G20210A occurred in 4%. Vascular access sufficiently matured in 226 (95%). The 1-year thrombosis- and stenosis-free access survival was 72%. Female gender (hazards ratio, HR, 2.5; 95% CI 1.6-3.9) and TF (HR 1.9, 95% CI 1.1-3.3) were independent risk factors for the shortened thrombosis- and stenosis-free survival. Additionally, TF or thrombogenic background was found in relatively young patients having severe thrombosis either in hepatic veins (Budd-Chiari syndrome, BCS, one patient) or inoperable critical limb ischemia (CLI, six patients). Lepirudin was evaluated in an off-label setting in the severe thrombosis after inefficacious traditional anticoagulation without other treatment options except severe invasive procedures, such as lower extremity amputation. Lepirudin treatments were repeatedly monitored clinically and with laboratory assessments (e.g. activated partial thromboplastin time, APTT). Our preliminary studies with lepirudin in thrombotic calamities appeared safe, and no bleeds occurred. An effective DTI lepirudin calmed thrombosis as all patients gradually recovered. Only one limb amputation was performed 3 years later during the follow-up (mean 4 years). Furthermore, we aimed to overcome the limitations of APTT and confounding effects of warfarin (INR of 1.5-3.9) and lupus anticoagulant (LA). Lepirudin responses were assessed in vitro by five specific laboratory methods. Ecarin chromogenic assay (ECA) or anti-Factor IIa (anti-FIIa) correlated precisely (r=0.99) with each other and with spiked lepirudin in all plasma pools: normal, warfarin, and LA-containing plasma. In contrast, in the presence of warfarin and LA both APTT and prothrombinase-induced clotting time (PiCT®) were limited by non-linear and imprecise dose responses. As a global coagulation test APTT is useful in parallel to the precise chromogenic methods ECA or Anti-FIIa in challenging clinical situations. Lepirudin treatment requires multidisciplinary approach to ensure appropriate patient selection, interpretation of laboratory monitoring, and treatment safety. TF seemed to be associated with complicated thrombotic events, in venous (BCS), arterial (CLI), and vascular access systems. TF screening should be aimed to patients with repeated access complications or prior unprovoked thromboembolic events. Lepirudin inhibits free and clot-bound thrombin which heparin fails to inhibit. Lepirudin seems to offer a potent and safe option for treatment of severe thrombosis. Multi-centered randomized trials are necessary to assess the possible management of complicated thrombotic events with DTIs like lepirudin and seek prevention options against access complications.
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Introduction
Nursing and midwifery students often struggle to engage with bioscience modules because they lack confidence in their ability to study science (Fell et al., 2012). Consequently many have difficulty applying anatomical and physiological information, essential to providing safe and effective patient care (Rogers, 2014; Rogers and Sterling, 2012); therefore a need exists for nurse educators to explore different methods of delivery of these important topics to enhance current curricula (Johnston, 2010). Inspired by the reported success of creative methods to enhance the teaching and learning of anatomy in medical education (Noel, 2013; Finn and McLachlan, 2010), this pilot study engaged nursing students in anatomy through the art of felt. The project was underpinned by the principles of good practice in undergraduate education, staff-student engagement, cooperation among students, active learning, prompt feedback, time on task, high expectations and respect for diverse learning styles (Chickering and Gamson, 1987).
Method
Undergraduate student nurses from Queen’s University, Belfast, enrolled in the year one ‘Health and Wellbeing’ model were invited to participate in the project. Over a six week period the student volunteers worked in partnership with teaching staff to construct individual, unique, three dimensional felt models of the upper body. Students researched the agreed topic for each week in terms of anatomical structure, location, tissue composition and vascular access. Creativity was encouraged in relation to the colour and texture of materials used. The evaluation of the project was based on the four level model detailed by Kirkpatrick and Kirkpatrick (2006) and included both quantitative and qualitative analysis:• pre and post knowledge scores• self-rated confidence• student reflections on the application of learning to practice.
Results
At the end of the project students had created felt pieces reflective of their learning throughout the project and ‘memorable’ three dimensional mental maps of the human anatomy. Evaluation revealed not only acquisition of anatomical knowledge, but the wider benefits of actively engaging in creative learning with other students and faculty teaching staff.
The project has enabled nurse educators to assess the impact of innovative methods for delivery of these important topics.
Resumo:
PURPOSE: Arteriovenous fistulae (AVFs) are the preferred option for vascular access, as they are associated with lower mortality in hemodialysis patients than in those patients with arteriovenous grafts (AVGs) or central venous catheters (CVCs). We sought to assess whether vascular access outcomes for surgical trainees are comparable to fully trained surgeons.
METHODS: A prospectively collected database of patients was created and information recorded regarding patient demographics, past medical history, preoperative investigations, grade of operating surgeon, type of AVF formed, primary AVF function, cumulative AVF survival and functional patency.
RESULTS: One hundred and sixty-two patients were identified as having had vascular access procedures during the 6 month study period and 143 were included in the final analysis. Secondary AVF patency was established in 123 (86%) of these AVFs and 89 (62.2%) were used for dialysis. There was no significant difference in survival of AVFs according to training status of surgeon (log rank x2 0.506 p=0.477) or type of AVF (log rank x2 0.341 p=0.559). Patency rates of successful AVFs at 1 and 2 years were 60.9% and 47.9%, respectively.
CONCLUSION: We have demonstrated in this prospective study that there are no significant differences in outcomes of primary AVFs formed by fully trained surgeons versus surgical trainees. Creation of a primary AVF represents an excellent training platform for intermediate stage surgeons across general and vascular surgical specialties.
Resumo:
PURPOSE: Efforts to promote arteriovenous fistulas (AVFs) have been successful in increasing the prevalence of AVF use as the primary vascular access for haemodialysis (HD). Sustained preference for AVF use may not be the most appropriate vascular access choice for all patient groups. Arteriovenous grafts (AVGs) offer advantages of earlier use and lower primary failure rates compared to AVFs so may be preferable for patients where short-term vascular access is needed. This study was designed to assess comparative mortality in different age groups following AVF formation.
METHODS: A prospective cohort of patients having AVF creation was recruited. Patients were subdivided into three age groups: Group A: lt;50 years; Group B: 50-74 years and Group C: ≥75 years. Survival curves and Cox regression analysis were performed on each of these groups.
RESULTS: One hundred and thirty-four patients (n = 134) were recruited into the study. The prevalence of diabetes increased significantly with age. As expected, mortality was higher in older age groups (log rank (Mantel-Cox) 19.227; p = 0.0001). Mortality rates at 1 year were 0% in group A, 12.5% in group B and 29.1% in group C. Medium-term mortality at 4 years was 7.9% in group A, 39.1% in group B and 54.8% in group C.
CONCLUSIONS: We found a significantly higher mortality rate in patients ≥75 years in comparison to those lt;75 years. The choice of vascular access modality should be tailored to the individual with particular reference to the patient's expected survival.
Resumo:
It remains challenging to accurately predict whether an individual arteriovenous fistula (AVF) will mature and be useable for haemodialysis vascular access. Current best practice involves the use of routine clinical assessment and ultrasonography complemented by selective venography and magnetic resonance imaging. The purpose of this literature review is to describe current practices in relation to pre-operative assessment prior to AVF formation and highlight potential areas for future research to improve the clinical prediction of AVF outcomes.
Resumo:
OBJECTIVE: Over several decades, there has been an increase in the number of elderly patients requiring hemodialysis. These older patients typically have an increased incidence of comorbidities including diabetes, hypertension, and peripheral vascular disease. We undertook a systematic review of the current literature to assess outcomes of arteriovenous fistula (AVF) formation in the elderly and to compare the results of radiocephalic AVFs vs brachiocephalic AVFs in older patients.
METHODS: A literature search was performed using MEDLINE, Embase, PubMed, and the Cochrane Library. All retrieved articles published before December 31, 2014 (and in English) primarily describing the creation of hemodialysis vascular access for elderly patients were considered for inclusion. We report pooled AVF patency rates and a comparison of radiocephalic vs brachiocephalic AVF patency rates using odds ratios (ORs).
RESULTS: Of 199 relevant articles reviewed, 15 were deemed eligible for the review. The pooled 12-month primary and secondary AVF patency rates were 53.6% (95% confidence interval [CI], 47.3-59.9) and 71.6% (95% CI, 59.2-82.7), respectively. Comparison of radiocephalic vs brachiocephalic AVF patency rates demonstrated that radiocephalic AVFs have inferior primary (OR, 0.72; 95% CI, 0.55-0.93; P = .01) and secondary (OR, 0.76; 95% CI, 0.58-1.00; P = .05) patency rates.
CONCLUSIONS: This meta-analysis confirms that adequate 12-month primary and secondary AVF patency rates can be achieved in elderly patients. Brachiocephalic AVFs have both superior primary and secondary patency rates at 12 months compared with radiocephalic AVFs. These important data can inform clinicians' and patients' decision-making about suitability of attempting AVF formation in older persons.
Resumo:
Background: Arteriovenous fistula (AVF) failure to mature (FTM) rates contribute to excessive dependence on central venous catheters for haemodialysis. Choosing the most appropriate vascular access site for an individual patient is guided largely by their age, co-morbidities and clinical examination. We investigated the clinical predictors of AVF FTM in a European cohort of patients and applied an existing clinical risk prediction model for AVF FTM to this population.
Methods: A prospective cohort study was designed that included all patients undergoing AVF creation between January 2009 and December 2014 in a single centre (Belfast City Hospital) who had a functional AVF outcome observed by March 2015.
Results: A total of 525 patients had a functional AVF outcome recorded and were included in the FTM analysis. In this cohort, 309 (59%) patients achieved functional AVF patency and 216 (41%) patients had FTM. Female gender [P < 0.001, odds ratio (OR) 2.03 (CI 1.37–3.02)] and lower-arm AVF [P < 0.001, OR 4.07 (CI 2.77–5.92)] were associated with AVF FTM. The Lok model did not predict FTM outcomes based on the associated risk stratification in our population.
Conclusions: In this European study, female gender was associated with twice the risk of AVF FTM and a lower-arm AVF with four times the risk of FTM. The FTM risk prediction model was not found to be discriminative in this population. Clinical risk factors for AVF FTM vary between populations;we would recommend that units investigate their own clinical predictors of FTM to maximize AVF functional patency and ultimately survival in dialysis patients. Clinical predictors of AVF FTM may not be sufficient on their own to improve vascular access functional patency rates.
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Objective: Guidelines recommend the creation of a wrist radiocephalic arteriovenous fistula (RAVF) as initial hemodialysis vascular access. This study explored the potential of preoperative ultrasound vessel measurements to predict AVF failure to mature (FTM) in a cohort of patients with end-stage renal disease in Northern Ireland
.Methods: A retrospective analysis was performed of all patients who had preoperative ultrasound mapping of upper limb blood vessels carried out from August 2011 to December 2014 and whose AVF reached a functional outcome by March 2015.
Results: There were 152 patients (97% white) who had ultrasound mapping andan AVF functional outcome recorded; 80 (54%) had an upper arm AVF created, and 69 (46%) had a RAVF formed. Logistic regression revealed that female gender (odds ratio [OR], 2.5; 95% confidence interval [CI], 1.12-5.55; P = .025), minimum venous diameter (OR, 0.6; 95% CI, 0.39-0.95; P = .029), and RAVF (OR, 0.4; 95% CI, 0.18-0.89; P = .026) were associated with FTM. On subgroup analysis of the RAVF group, RAVFs with an arterial volume flow <50 mL/min were seven times as likely to fail as RAVFs with higher volume flows (OR, 7.0; 95% CI, 2.35-20.87; P < .001).
Conclusions: In this cohort, a radial artery flow rate <50 mL/min was associated with a sevenfold increased risk of FTM in RAVF, which to our knowledge has not been previously reported in the literature. Preoperative ultrasound mapping adds objective assessment in the clinical prediction of AVF FTM.
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Purpose: In extreme situations, such as hyperacute rejection of heart transplant or major bleeding per-operating complications, an urgent heart explantation might be the only means of survival. The aim of this experimental study was to improve the surgical technique and the hemodynamics of an Extracorporeal Membrane Oxygenation (ECMO) support through a peripheral vascular access in an acardia model. Methods: An ECMO support was established in 7 bovine experiments (59±6.1 kg) by the transjugular insertion to the caval axis of a self-expanded cannula, with return through a carotid artery. After baseline measurements of pump flow and arterial and central venous pressure, ventricular fibrillation was induced (B), the great arteries were clamped, the heart was excised and right and left atria remnants, containing the pulmonary veins, were sutured together leaving an atrial septal defect (ASD) over the cannula in the caval axis. Measurements were taken with the pulmonary artery (PA) clamped (C) and anastomosed with the caval axis (D). Regular arterial and central venous blood gases tests were performed. The ANOVA test for repeated measures was used to test the null hypothesis and a Bonferroni t method for assessing the significance in the between groups pairwise comparison of mean pump flow. Results: Initial pump flow (A) was 4.3±0.6 L/min dropping to 2.8±0.7 L/min (P B-A= 0.003) 10 minutes after induction of ventricular fibrillation (B). After cardiectomy, with the pulmonary artery clamped (C) it augmented not significantly to 3.5±0.8 L/min (P C-B= 0.33, P C-A= 0.029). Finally, PA anastomosis to the caval axis was followed by an almost to baseline pump flow augmentation (4.1±0.7 L/min, P D-B= 0.009, P D-C= 0.006, P D-A= 0.597), permitting a full ECMO support in acardia by a peripheral vascular access. Conclusions: ECMO support in acardia is feasible, providing new opportunities in situations where heart must urgently be explanted, as in hyperacute rejection of heart transplant. Adequate drainage of pulmonary circulation is pivotal in order to avoid pulmonary congestion and loss of volume from the normal right to left shunt of bronchial vessels. Furthermore, the PA anastomosis to the caval axis not only improves pump flow but it also permits an ECMO support by a peripheral vascular access and the closure of the chest.
Transcatheter aortic valve implantation (TAVI): state of the art techniques and future perspectives.
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Transcatheter aortic valve therapies are the newest established techniques for the treatment of high risk patients affected by severe symptomatic aortic valve stenosis. The transapical approach requires a left anterolateral mini-thoracotomy, whereas the transfemoral method requires an adequate peripheral vascular access and can be performed fully percutaneously. Alternatively, the trans-subclavian access has been recently proposed as a third promising approach. Depending on the technique, the fine stent-valve positioning can be performed with or without contrast injections. The transapical echo-guided stent-valve implantation without angiography (the Lausanne technique) relies entirely on transoesophageal echocardiogramme imaging for the fine stent-valve positioning and it has been proved that this technique prevents the onset of postoperative contrast-related acute kidney failure. Recent published reports have shown good hospital outcomes and short-term results after transcatheter aortic valve implantation, but there are no proven advantages in using the transfemoral or the transapical technique. In particular, the transapical series have a higher mean logistic Euroscore of 27-35%, a procedural success rate above 95% and a mean 30-day mortality between 7.5 and 17.5%, whereas the transfemoral results show a lower logistic Euroscore of 23-25.5%, a procedural success rate above 90% and a 30-day mortality of 7-10.8%. Nevertheless, further clinical trials and long-term results are mandatory to confirm this positive trend. Future perspectives in transcatheter aortic valve therapies would be the development of intravascular devices for the ablation of the diseased valve leaflets and the launch of new stent-valves with improved haemodynamic, different sizes and smaller delivery systems.
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Introducción: la insuficiencia renal crónica IRC ha aumentado su prevalencia en los últimos años pasando de 44.7 pacientes por millón en 1993 a 538.46 pacientes por millón en 2010, los pacientes quienes reciben terapia de remplazo renal hemodiálisis en Colombia cada vez tienen una mayor sobrevida. El incremento de los pacientes y el incremento de la sobrevida nos enfocan a mejorar la calidad de vida de los años de diálisis. Metodología: se comparó la calidad de vida por medio del SF-36 en 154 pacientes con IRC estadio terminal en manejo con hemodiálisis, 77 pacientes incidentes y 77 pacientes prevalentes, pertenecientes a una unidad renal en Bogotá, Colombia. Resultados: se encontró una disminución de la calidad de vida en los componentes físicos (PCS) y metales (MCS) de los pacientes de hemodiálisis en ambos grupos. En el modelo de regresión logística la incapacidad laboral (p=0.05), el uso de catéter (p= 0,000), el bajo índice de masa corporal (p=0.021), la hipoalbuminemia (p=0,033) y la anemia (p=0,001) fueron factores determinantes en un 78,9% de baja calidad de vida de PCS en los pacientes incidentes con respecto a los prevalentes. En el MCS de los pacientes incidentes vs. Prevalentes se encontró la hipoalbuminemia (p=0.007), la anemia (p=0.001) y el acceso por catéter (p=0.001) como factores determinantes en un 70.6% de bajo MCS Conclusiones: la calidad de vida de los pacientes de diálisis se encuentra afectada con mayor repercusión en el grupo de los pacientes incidentes, se debe mejorar los aspectos nutricionales, hematológicos y de acceso vascular en este grupo.
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Introducción: La evaluación de injertos vasculares de submucosa de intestino delgado para la regeneración de vasos sanguíneos ha producido una permeabilidad variable (0-100%) que ha sido concurrente con la variabilidad en las técnicas de fabricación. Metodología: Investigamos los efectos de fabricación en permeabilidad y regeneración en un diseño experimental de 22factorial que combino: 1) preservación (P) o remoción (R) de la capa estratum compactum del intestino, y 2) deshidratada (D) o hidratada (H), dentro de cuatro grupos de estudio (PD, RD, PH, RH). Los injertos fueron implantados en las Arterias Carótidas de porcinos (ID 4.5mm, N=4, 7d). Permeabilidad, trombogenicidad, reacción inflamatoria, vascularización, infiltración de fibroblastos, perfil de polarización de macrófagos y fuerza tensil biaxial fueron evaluadas. Resultados: Todos los injertos PD permanecieron permeables (4/4), pero tuvieron escasa vascularización e infiltración de fibroblastos. El grupo RD permaneció permeable (4/4), presentó una extensa vascularización e infiltración de fibroblastos, y el mayor número del fenotipo de macrófagos (M2) asociado a regeneración. El grupo RH presentó menor permeabilidad (3/4), una extensa vascularización e infiltración de fibroblastos, y un perfil dominante de M2. El grupo PH presentó el menor grado de permeabilidad, y a pesar de mayor infiltración celular que PD, exhibió un fenotipo de macrófagos dominante adverso. La elasticidad de los injertos R evolucionó de una manera similar a las Carótidas nativas (particularmente RD, mientras que los injertos P mantuvieron su rigidez inicial. Discusión: Concluimos que los parámetros de fabricación afectan drásticamente los resultados, siendo los injertos RD los que arrojaron mejores resultados.
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Marco conceptual: La enfermedad renal crónica es un serio problema de salud pública en nuestro país por la gran cantidad de recursos económicos que requiere su atención. La hemodiálisis es el tratamiento más usado en nuestro medio; el acceso vascular y sus complicaciones derivadas son el principal aspecto que incrementa los costos de atención en éstos pacientes. Materiales y métodos: Se realizó un estudio económico de los accesos vasculares en pacientes incidentes de hemodiálisis en el año 2012 en la agencia RTS-Fundación Cardio Infantil. Se estableció el costo de creación y mantenimiento del acceso con catéter central, fístula arteriovenosa nativa, fístula arteriovenosa con injerto; y el costo de atención de las complicaciones para cada acceso. Se determinó la probabilidad de ocurrencia de complicaciones. Mediante un árbol de decisiones se trazó el comportamiento de cada acceso en un período de 5 años. Se establecieron los años de vida ajustados por calidad (QALY) en cada acceso y el costo para cada uno de éstos QALY. Resultados: de 36 pacientes incidentes de hemodiálisis en 2012 el 100% inició con catéter central, 16 pacientes cambiaron a fístula arteriovenosa nativa, 1 a fístula arteriovenosa con injerto que posteriormente pasó a CAPD, 15 continuaron su acceso con catéter y 4 pacientes fallecieron. En 5 años se obtuvieron 2,36 QALY para los pacientes con catéter central que costarían $ 24.813.036,39/QALY y 2,535 QALY para los pacientes con fístula nativa que costarían $ 6.634.870,64/QALY. Conclusiones: el presente estudio muestra que el acceso vascular mediante fístula arteriovenosa nativa es el más costo-efectivo que mediante catéter
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Introducción: El desarrollo tecnológico permite efectuar procedimientos eficientes en pacientes críticos de urgencias como canalizar vasos centrales guiados por ecografía. Éste procedimiento comparado con la técnica a ciegas ofrece ventajas como disminución de complicaciones, mejor éxito y menor tiempo de procedimiento. Hay diferentes técnicas de abordaje: transversal, longitudinal y oblicua, lo que supone diferencias en la efectividad y éxito en cada una de ellas. Materiales y métodos: Se realizó un experimento en modelos simulados con especialistas y residentes de último año de medicina de emergencias. Posterior a estandarizar los conceptos y abordajes de cada una de las técnicas, se puncionaron los modelos para determinar cuál técnica presenta mayor éxito y efectividad para canalización yugular con guía ecográfica. Resultados: El procedimiento fue efectivo en 175 réplicas (97.2%) distribuidas así: éxito 133 (73.9%), redirección 37 (20.6%) y requerimiento de segunda punción en 5 (2.8%). En la técnica transversal la efectividad fue 96.7% (n=58), en longitudinal del 100% (n=60) y en oblicua del 95.0% (n=57), (p=0.377). En residentes la efectividad fue 95.6% (n=86) y en especialistas 98.9% (n=89), (p=0.184). La distribución de éxito mostró que en los especialistas fue mayor en un 18.9% que en los residentes (p=0.004), por género los hombres tienen un éxito mayor en un 18.7% que las mujeres (p=0.009, OR=3.12, IC 95%: 1.30, 7.52). Discusión: No se encontró diferencia significativa en el uso de cualquier técnica, pero la tendencia favorece la técnica longitudinal, quien obtuvo mayor porcentaje de efectividad y éxito.
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Introducción: El objetivo principal de la selección del donante es disminuir la posibilidad de transmisión de enfermedades infecciosas o neoplásicas en el receptor. De forma cruda se calcula que aproximadamente el 50% de los potenciales donantes son contraindicados, la mayoría por infección. La alta demanda de órganos obliga a revalorar las contraindicaciones que hasta hace poco eran absolutas, el reto es diferenciar el SIRS del donante por Muerte Encefálica con el SIRS por infecciones. Método: Estudio de cohorte retrospectivo; que busca evaluar la respuesta inflamatoria sistémica (SIRS) como predictor de infección en pacientes con trasplante renal en el primer mes pos trasplante. Resultados: El contraste de hipótesis proporciono una significancia bilateral (P= 0,071). La pruebas de hipótesis aceptaron la hipótesis nula (P= 0,071), que no existe asociación entre la presencia de SIRS en el donante con la incidencia de infección en el primer mes del pos trasplante renal. La estimación del riesgo de no reingreso por infección al primer mes pos trasplante renal es de 0.881 veces para los donantes con SIRS (IC 0.757 – 1.025). Conclusión: A pesar de no encontrar significancia estadística: el SIRS en el donante no se asocia con un aumento en la incidencia de infección en el primer mes postrasplante. Para encontrar la significancia se propone un estudio con un tamaño de muestra mayor.