Home About us Contact
|
Home About us Contact | ||
|
|
||
Optimal Management Strategies (optimal + management_strategy)
Selected AbstractsFetal macrosomia and pregnancy outcomesAUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 5 2009Hong JU Background:, Pregnancies with a macrosomic fetus comprise a subgroup of high-risk pregnancies. There is uncertainty in the clinical management and outcomes of such pregnancies. Aim:, We sought to examine clinical management and maternal and fetal outcomes in pregnancies with macrosomic infants at Royal Brisbane and Women's Hospital (RBWH). Methods:, Data from 276 macrosomic births (weighing , 4500 g) and 294 controls (weighing 3250,3750 g) delivered during 2002,2004 at RBWH were collected from the hospital database. Univariate and logistic regression analyses were performed for maternal risk factors and maternal and neonatal outcomes that were associated with fetal macrosomia. Results:, Macrosomia was more than two times likely in women with body mass index (BMI) of > 30 kg/m2 (odds ratio (OR) 2.41, 95% confidence interval (CI) 1.26,4.61) and in male infant sex (OR 2.05, 95% CI 1.35,3.12), and four times more likely in gestation of > 40 weeks (OR 3.93, 95% CI 1.99,7.74). Maternal smoking reduced the risk of fetal macrosomia (OR 0.27, 95% CI 0.14,0.51). Macrosomia was associated with nearly two times higher risk of emergency caesarean section (OR 1.75, 95% CI 1.02,2.97) and maternal hospital stay of > 3 days (OR 1.66, 95% CI 1.11,2.50), and four times higher risk of shoulder dystocia (OR 4.08, 95% CI 1.62,10.29). Macrosomic infants were twice as likely to have resuscitation (OR 2.21, 95% CI 1.46,3.34) and intensive care nursery admission (OR 1.89, 95% CI 1.03,3.46). Conclusion:, Macrosomia was associated with an increased risk of adverse maternal and neonatal health outcomes. Optimal management strategies of macrosomic pregnancies need evaluation. [source] Patterns in current anaesthesiological peri-operative practice for colonic resections: a survey in five northern-European countriesACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 9 2006P. Hannemann Background:, For colorectal surgery, evidence suggests that optimal management includes: no pre-operative fasting, a thoracic epidural analgesia continued for 2 days post-operatively, and avoidance of fluid overload. In addition, no long-acting benzodiazepines on the day of surgery and use of short-acting anaesthetic medication may be beneficial. We examined whether these strategies have been adopted in five northern-European countries. Methods:, In 2003, a questionnaire concerning peri-operative anaesthetic routines in elective, open colonic cancer resection was sent to the chief anaesthesiologist in 258 digestive surgical centres in Scotland, the Netherlands, Denmark, Sweden and Norway. Results:, The response rate was 74% (n = 191). Although periods of pre-operative fasting up to 48 h were reported, most (> 85%) responders in all countries declared to adhere to guidelines for pre-operative fasting and oral clear liquids were permitted until 2,3 h before anaesthesia. Solid food was permitted up to 6,8 h prior to anaesthesia. In all countries more than 85% of the responders indicated that epidural anaesthesia was routinely used. Except for Denmark, long-acting benzodiazepines were still widely used. Short-acting anaesthetics were used in all countries except Scotland where isoflurane is the anaesthetic of choice. With the exception of Denmark, intravenous fluids were used unrestrictedly. Conclusion:, In northern Europe, most anaesthesiologists adhere to evidence-based optimal management strategies on pre-operative fasting, thoracic epidurals and short-acting anaesthetics. However, premedication with longer-acting agents is still common. Avoidance of fluid overload has not yet found its way into daily practice. This may leave patients undergoing elective colonic surgery at risk of oversedation and excessive fluid administration with potential adverse effects on surgical outcome. [source] Long-term follow-up of impulse control disorders in Parkinson's diseaseMOVEMENT DISORDERS, Issue 1 2008Eugenia Mamikonyan MS Abstract Recent studies have linked dopamine agonist (DA) usage with the development of impulse control disorders (ICDs) in Parkinson's disease (PD). Little is known about optimal management strategies or the long-term outcomes of affected patients. To report on the clinical interventions and long-term outcomes of PD patients who developed an ICD after DA initiation. Subjects contacted by telephone for a follow-up interview after a mean time period of 29.2 months. They were administered a modified Minnesota Impulse Disorder Interview for compulsive buying, gambling, and sexuality, and also self-rated changes in their ICD symptomatology. Baseline and follow-up dopamine replacement therapy use was recorded and verified by chart review. Of 18 subjects, 15 (83.3%) participated in the follow-up interview. At follow-up, patients were receiving a significantly lower DA levodopa equivalent daily dosage (LEDD) (Z = ,3.1, P = 0.002) and a higher daily levodopa dosage (Z = ,1.9, P = 0.05), but a similar total LEDD dosage (Z = ,0.47, P = 0.64) with no changes in Unified Parkinson's Disease Rating Scale motor score (Z = ,1.3, P = 0.19). As part of ICD management, 12 (80.0%) patients discontinued or significantly decreased DA treatment, all of whom experienced full or partial remission of ICD symptoms by self-report, and 10 (83.3%) of whom no longer met diagnostic criteria for an ICD. For PD patients who develop an ICD in the context of DA treatment, discontinuing or significantly decreasing DA exposure, even when offset by an increase in levodopa treatment, is associated with remission of or significant reduction in ICD behaviors without worsening in motor symptoms. © 2007 Movement Disorder Society [source] SOLVING DYNAMIC WILDLIFE RESOURCE OPTIMIZATION PROBLEMS USING REINFORCEMENT LEARNINGNATURAL RESOURCE MODELING, Issue 1 2005CHRISTOPHER J. FONNESBECK ABSTRACT. An important technical component of natural resource management, particularly in an adaptive management context, is optimization. This is used to select the most appropriate management strategy, given a model of the system and all relevant available information. For dynamic resource systems, dynamic programming has been the de facto standard for deriving optimal state-specific management strategies. Though effective for small-dimension problems, dynamic programming is incapable of providing solutions to larger problems, even with modern microcomputing technology. Reinforcement learning is an alternative, related procedure for deriving optimal management strategies, based on stochastic approximation. It is an iterative process that improves estimates of the value of state-specific actions based in interactions with a system, or model thereof. Applications of reinforcement learning in the field of artificial intelligence have illustrated its ability to yield near-optimal strategies for very complex model systems, highlighting the potential utility of this method for ecological and natural resource management problems, which tend to be of high dimension. I describe the concept of reinforcement learning and its approach of estimating optimal strategies by temporal difference learning. I then illustrate the application of this method using a simple, well-known case study of Anderson [1975], and compare the reinforcement learning results with those of dynamic programming. Though a globally-optimal strategy is not discovered, it performs very well relative to the dynamic programming strategy, based on simulated cumulative objective return. I suggest that reinforcement learning be applied to relatively complex problems where an approximate solution to a realistic model is preferable to an exact answer to an oversimplified model. [source] Gastrointestinal stromal tumors (GIST) in children and adolescents: A comprehensive review of the current literaturePEDIATRIC BLOOD & CANCER, Issue 7 2009Martin Benesch MD Abstract Standards for the management of gastrointestinal stromal tumors (GIST) in children do presently not exist. Thus a systematic review and summary of the current literature was conducted serving as a basis for the further development of optimal management strategies for childhood GIST within a cooperative network. Presently 21 cases with familial GIST, and more than 100 pediatric cases each with Carney triad or sporadic GIST have been published so far. An international prospective registration based on national registries has recently started to acquire more clinical and molecular data and to develop appropriate management strategies for children and adolescents with GIST. Pediatr Blood Cancer 2009; 53:1171,1179. © 2009 Wiley-Liss, Inc. [source] Managing obstruction of the central airwaysINTERNAL MEDICINE JOURNAL, Issue 6 2010J. P. Williamson Abstract Lung cancer is the most common cause of cancer death in Australia, Europe and the USA. Up to 20,30% of these cancers eventually affect the central airways and result in reduced quality of life, dyspnoea, haemoptysis, post-obstructive pneumonia and ultimately death. Non-malignant processes may also lead to central airway obstruction and can have similar symptoms. With the development of newer technologies, the last 20 years have seen the emergence of the field of interventional pulmonology to deal specifically with the diagnosis and management of thoracic malignancy, including obstruction of the central airways. This review discusses the pathology, pre-procedure work-up and management options for obstructing central airway lesions. Several treatment modalities exist for dealing with endobronchial pathology with local availability and expertise guiding choice of treatment. While the literature lacks large, multicentre, randomized studies defining the optimal management strategy for a given problem, there is growing evidence from numerous case studies of improved physiology, of quality of life and possibly of survival with modern interventional techniques. [source] Defining the surgical management of suspected early-stage ovarian cancer by estimating patient numbers through alternative management strategiesBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 9 2009J Warwick Objective, To establish the optimal management strategy for women with suspected stage 1 ovarian cancer. Design, We created a flowchart to illustrate each of six hypothetical management strategies. These considered two surgical approaches (systematic lymphadenectomy versus no lymph node dissection at all) in combination with three different policies for giving adjuvant chemotherapy. Setting, Gynaecological cancer centre, London, UK. Data sources, Patient data and published papers. Methods, We developed a deterministic model that uses information from multiple sources to estimate patient flow through each level of a hypothesised decision tree. Results, We estimated that for every 100 cases of suspected early-stage ovarian cancer, there would be 37 cases with ,apparent' stage 1 disease and that of these, two (6%) would be denied potentially life-saving adjuvant treatment if systematic lymphadenectomy was not performed. The number of women given chemotherapy would not, according to our estimates, differ greatly between the two surgical approaches, the 7% increase with systematic lymphadenectomy being because of cases identified as having nodal metastases. Conclusions, We present a model of the intraoperative decision-making process that determines the extent of the staging procedure to be performed within our department when early-stage ovarian cancer is suspected. Unless adjuvant chemotherapy is prescribed for all, systematic pelvic and para-aortic node dissection is required to optimise survival. However, in our department, this would result in 32% of women with suspected early-stage ovarian cancer undergoing systematic node dissection. This flexible focused model may facilitate multidisciplinary team discussion when this part of the surgical staging procedure is considered within the context of the population presenting to the team, the morbidity of the procedure within the department and the predictive values of frozen section within that department. As the model is not disease-specific, it may be useful for decision making in other medical disciplines. [source] Pancreatic leak after left pancreatectomy is reduced following main pancreatic duct ligationBRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 2 2003M. M. Bilimoria Background: Although much is known about the long-term outcome of patients undergoing left (distal) pancreatectomy for malignancy, comparatively little is known about the optimal management strategy for the residual transected pancreatic parenchyma and the divided pancreatic duct. Clinicopathological and operative factors that may contribute to postoperative pancreatic leak were evaluated. Methods: A retrospective review of the medical records of 126 patients who underwent left pancreatectomy between June 1990 and December 1999 at the University of Texas M. D. Anderson Cancer Center was performed. Results: Indications for left pancreatectomy included pancreatic neoplasms (n = 42; 33·3 per cent), en bloc resection for management of retroperitoneal sarcoma (n = 21; 16·7 per cent), gastric adenocarcinoma (n = 14; 11·1 per cent), renal cell carcinoma (n = 11; 8·7 per cent) and other tumours or benign conditions (n = 38; 30·2 per cent). Pancreatic parenchymal closure was accomplished by a hand-sewn technique, mechanical stapling, or a combination of the two in 83, 20 and 15 patients respectively. No form of parenchymal closure was used in eight patients. Identification of the pancreatic duct and suture ligation was performed in 73 patients (57·9 per cent). Twenty-five patients (19·8 per cent) developed a pancreatic leak. For subgroups having duct ligation or no duct ligation, pancreatic leak rates were 9·6 per cent (seven of 73 patients) and 34·0 per cent (18 of 53 patients) respectively (P < 0·001). Multivariate analysis including clinicopathological and operative factors indicated that failure to ligate the pancreatic duct was the only feature associated with an increased risk for pancreatic leak (odds ratio 5·0 (95 per cent confidence interval 2·0 to 10·0); P = 0·001). Conclusion: Pancreatic leak remains a common complication after left pancreatectomy. The incidence of leak is reduced significantly when the pancreatic duct is identified and directly ligated during left pancreatectomy. Copyright © 2003 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source] | ||||||||||