160 research outputs found

    A model of the CO2 exchanges between biosphere and atmosphere in the tundra

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    A physical model of the soil thermal regime in a permafrost terrain has been developed and validated with soil temperature measurements at Barrow, Alaska. The model calculates daily soil temperatures as a function of depth and average moisture contents of the organic and mineral layers using a set of five climatic variables, i.e., air temperature, precipitation, cloudiness, wind speed, and relative humidity. The model is not only designed to study the impact of climate change on the soil temperature and moisture regime, but also to provide the input to a decomposition and net primary production model. In this context, it is well known that CO2 exchanges between the terrestrial biosphere and the atmosphere are driven by soil temperature through decomposition of soil organic matter and root respiration. However, in tundra ecosystems, net CO2 exchange is extremely sensitive to soil moisture content; therefore it is necessary to predict variations in soil moisture in order to assess the impact of climate change on carbon fluxes. To this end, the present model includes the representation of the soil moisture response to changes in climatic conditions. The results presented in the foregoing demonstrate that large errors in soil temperature and permafrost depth estimates arise from neglecting the dependence of the soil thermal regime on soil moisture contents. Permafrost terrain is an example of a situation where soil moisture and temperature are particularly interrelated: drainage conditions improve when the depth of the permafrost increases; a decrease in soil moisture content leads to a decrease in the latent heat required for the phase transition so that the heat penetrates faster and deeper, and the maximum depth of thaw increases; and as excepted, soil thermal coefficients increase with moisture

    Serum albumin is an early predictor of complications after liver surgery.

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    The morbidity associated with liver surgery remained substantially high despite considerable surgical and anesthetic improvements. The unmet need of accurate biomarkers to predict postoperative complications is widely accepted. This pilot study aimed to assess serum albumin as a surrogate marker of surgical stress and to test its potential predictive role for postoperative complications. This retrospective pilot study included 106 patients who underwent liver surgery between 2010 and 2014. Serum albumin levels were measured pre- and post-operatively. Maximal albumin decrease (AlbΔmin) was correlated with complications. Serum albumin rapidly dropped after surgery. AlbΔmin was significantly increased in patients with complications (14.5±6.0g/L vs. 10.3±7.2, p=0.009). On multivariate analysis, ASA III/IV (p=0.016) and AlbΔmin (p=0.037) were the only predictors of overall complications. Early postoperative drop of serum albumin reflects the intensity of the surgical stress and may predict complications after liver surgery. Serum albumin is a biomarker displaying precious features and deserving further prospective investigations

    Small bowel obstruction caused by a fast-growing desmoid tumor.

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    Desmoid tumors are rare tumors which can cause intestinal obstructions. Surgical wide excision is currently the treatment of choice, with the goal of achieving free resection margins

    Preoperative albumin level is a marker of alveolar echinococcosis recurrence after hepatectomy.

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    To identify a preoperative blood marker predictive of alveolar echinococcosis (AE) recurrence after hepatectomy. All consecutive patients who underwent operation for liver AE at the Lausanne University Hospital (CHUV) between January 1992 and December 2015 were included in this retrospective study. Preoperative laboratory values of leukocytes, mean corpuscular volume (MCV), red blood cell distribution width (RDW), thrombocytes, C-reactive protein (CRP) and albumin were collected and analyzed. Univariate and multivariate Cox regression analyses were performed to determine the risk factors for AE recurrence after liver resection. A receiver operating characteristic (ROC) curve was used to define the best discrimination threshold of the blood marker. Moreover, recurrence-free survival curves were calculated using the Kaplan-Meier method. The cohort included 68 adult patients (37 females) with median age of 61 years [interquartile range (IQR): 46-71]. Eight of the patients (12%) presented a recurrence over a median follow-up time of 76 mo (IQR: 34-128). Median time to recurrence was 10 mo (IQR: 6-11). Median preoperative leukocyte, MCV, RDW, thrombocyte and CRP levels were similar between recurrent and non-recurrent cases. Median preoperative albumin level was 43 g/L (IQR: 41-45) for non-recurrent cases and 36 g/L (IQR: 33-42) for recurrent cases (P = 0.005). The area under the ROC curve for preoperative albumin level to predict recurrence was 0.840 (95%CI: 0.642-1, P = 0.002). The cut-off albumin level value was 37.5 g/L for sensitivity of 94.5% and specificity of 75%. In multivariate analysis, preoperative albumin and surgical resection margins were independent predictors of AE recurrence (HR = 0.099, P = 0.007 and HR = 0.182, P = 0.045 respectively). Low preoperative albumin level was associated with AE recurrence in the present cohort. Thus, preoperative albumin may be a useful biomarker to guide follow-up

    Giant extra-hepatic thrombosed portal vein aneurysm: a case report and review of the literature.

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    BACKGROUND: Extrahepatic Portal vein aneurysm (EPVA) is a rare finding that may be associated with different complications, e.g. thrombosis, rupture, portal hypertension and compression of adjacent structures. It is being diagnosed more frequently with the advent of modern cross-sectional imaging. Our review of the English literature disclosed 13 cases of thrombosed EPVA. CASE PRESENTATION: A 50-years-old woman presented with acute abdominal pain but no other symptom. She had no relevant medical history. Palpation of the right upper quadrant showed tenderness. Laboratory tests were unremarkable. A computed tomography showed portal vein aneurysm measuring 88 × 65 mm with thrombosis extending to the superior mesenteric and splenic vein. The patient was treated conservatively with anticoagulation therapy. She was released after two weeks and followed on an outpatient basis. At two months, she reported decreased abdominal pain and her physical examination was normal. A computed tomography was performed showing a decreased thrombosis size and extent, measuring 80 × 55 mm. CONCLUSIONS: Although rare, surgeons should be made aware of this entity. Complications are various. Conservative therapy should be chosen in first intent in most cases. We reported the case of the second largest thrombosed extra-hepatic PVA described in the literature, treated by anticoagulation therapy with a good clinical and radiological response

    Metastasis to the rectum: A systematic review of the literature.

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    Metastatic spread to the rectum is a rare finding, and management of rectal metastases (RM) is not standardized. The aim of the present study was to review the evidence on diagnosis, management and outcomes of RM. A computerized literature search through MEDLINE/PubMed, Embase and the Cochrane databases was performed, applying a combination of terms related to RM. Articles and abstracts were screened and final selection was done after cross-referencing and by use of predefined eligibility criteria. Final analysis was based on 99 publications totaling 162 patients with RM from 16 different primary tumors. Most common origins of RM were breast (42 patients), stomach (38 patients), and prostate (16 patients). RM occurred metachronously in the majority of patients (77%). The main treatment was surgical resection (n = 32), followed by chemotherapy (n = 16). Median overall survival for breast RM, stomach RM, and prostate RM were 24 months (95% CI 9-39 months), 7 months (95% CI 0-14 months), and 24 months (95% CI 7-41 months), respectively. RM is a rare and highly heterogeneous condition. Surgical treatment appears to be a valuable treatment option in selected patients, while overall prognosis depends mainly on the primary tumor

    Patients satisfaction in an academic walk-in centre: a new model of residents training achieved by family doctors.

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    BACKGROUND: Walk-in centres may improve access to healthcare for some patients, due to their convenient location and extensive opening hours, with no need for an appointment. Herein, we describe and assess a new model of walk-in centre, characterised by care provided by residents and supervision achieved by experienced family doctors. The main aim of the study was to assess patients' satisfaction about the care they received from residents and their supervision by family doctors. The secondary aim was to describe walk-in patients' demographic characteristics and to identify potential associations with satisfaction. METHODS: The study was conducted in the walk-in centre of Lausanne. Patients who consulted between 11th and 31st April were automatically included and received a questionnaire in French. We used a five-point Likert scale, ranging from "not at all satisfied" to "very satisfied", converted from values of 1 to 5. We focused on the satisfaction regarding residents' care and supervision by a family doctor. The former was divided in three categories: "Skills", "Treatment" and "Behaviour". A mean satisfaction score was calculated for each category and a multivariable logistic model was applied in order to identify associations with patients' demographics. RESULTS: The overall response rate was 47% [184/395]. Walk-in patients were more likely to be women (62%), young (median age 31), with a high education level (40% of University degree or equivalent). Patients were "very satisfied" with residents' care, with a median satisfaction score between 4.5 and 5, for each category. Over 90% of patients were "satisfied" or "very satisfied" that a family doctor was involved in the consultation. Age showed the greatest association with satisfaction. CONCLUSION: Patients were highly satisfied with care provided by residents and with the involvement of a family doctor in the consultation. Older age showed the greatest positive association with satisfaction with a positive impact. The high level satisfaction reported by walk-in patients supports this new model of walk-in centre

    Cost-Benefit Analysis of the Implementation of an Enhanced Recovery Program in Liver Surgery.

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    BACKGROUND: Enhanced recovery after surgery (ERAS) programs have been shown to ease the postoperative recovery and improve clinical outcomes for various surgery types. ERAS cost-effectiveness was demonstrated for colorectal surgery but not for liver surgery. The present study aim was to analyze the implementation costs and benefits of a specific ERAS program in liver surgery. METHODS: A dedicated ERAS protocol for liver surgery was implemented in our department in July 2013. The subsequent year all consecutive patients undergoing liver surgery were treated according to this protocol (ERAS group). They were compared in terms of real in-hospital costs with a patient series before ERAS implementation (pre-ERAS group). Mean costs per patient were compared with a bootstrap T test. A cost-minimization analysis was performed. RESULTS: Seventy-four ERAS patients were compared with 100 pre-ERAS patients. There were no significant pre- and intraoperative differences between the two groups, except for the laparoscopy number (n = 18 ERAS, n = 9 pre-ERAS, p = 0.010). Overall postoperative complications were observed in 36 (49 %) and 64 patients (64 %) in the ERAS and pre-ERAS groups, respectively (p = 0.046). The median length of stay was significantly shorter for the ERAS group (8 vs. 10 days, p = 0.006). The total mean costs per patient were euro38,726 and euro42,356 for ERAS and pre-ERAS (p = 0.467). The cost-minimization analysis showed a total mean cost reduction of euro3080 per patient after ERAS implementation. CONCLUSIONS: ERAS implementation for liver surgery induced a non-significant decrease in cost compared to standard care. Significant decreased complication rate and hospital stay were observed in the ERAS group
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