Thursday, October 17, 2019

Roger Fenton Essay Example | Topics and Well Written Essays - 500 words

Roger Fenton - Essay Example Although his pictures only depicted the "acceptable" parts of the conflict, they were the first to capture the mundane aspects of warfare† (Roger Fenton Biography). He was died on August 8, 1869. This paper analyses the pictures taken by Roger Fenton with respect to subject matter, composition, framing, and intent. Even though Roger Fenton has taken more than 360 war photographs, he deliberately avoided the pictures of dead, injured or mutilated soldiers. At the same time, he was successful in portraying or revealing the atrocities of war with the help of the photographed landscapes at or near the war front. Crimean War between Britain and Russia was portrayed beautifully by Roger Fenton. One of the most famous war photographs taken during Crimean War by Fenton is known as the Valley of the Shadow of Death. British soldiers faced lot of humiliating defeats in the place shown in the above photograph. Even though, dead bodies or injured people are not visible in this picture, the viewers will get a haunting experience after watching this picture. â€Å"Borrowing from the Twenty-third Psalm of the Bible, the Valley of Death was named by British soldiers who came under constant shelling there† (Valley of the Shadow of Death). Valley of the Shadow of Death is considered to be the master piece of Roger Fenton. It is still considered as an important piece of war photography. The theme of this picture is the view of a cannonball-strewn road near Sevastopol. This photograph appears to be a simple at the first look; however close analysis of this picture may present a haunting experience to the viewers. â€Å"The image offers a kind of visual equivalent to Tennysons poem The Charge of the Light Brigade. In it, the poet pays tribute to the six hundred British cavalrymen who died in this s ame valley on 25 October 1854† (Roger Fenton: The Valley of the Shadow of Death) Fenton believed that the perceptive eye of the camera could record "all

STRATEGIC ANALYSIS assignment Example | Topics and Well Written Essays - 500 words

STRATEGIC ANALYSIS - Assignment Example The evaluation helps them to know in which program to concentrate their effort to maximize their productivity. As the organization grew, the need for this assessment became critical. This made the sustainability of the organizational growth a problem. The organization faced the management and strategy issue, which also plagues other non-profit organizations. Any organization that lacks machinery to evaluate its programs, cannot know how effective those programs are or how productive they are in terms of delivering their objectives. This means that it cannot clearly demonstrate the commitment it has to its mission and it will be difficult for such an organization to secure long term funding from the funders. An organization such as HCZ with a mission to educate a poor child in Harlem, must know the long-term goals it has and should be in a position to explain clearly to the funders how they are planning to meet their objectives. This will convince the funder to give it the support it requires to continue growing. Fundamentally, the organization should find a way to manage their setups to a success level. It needed an instrument to assess the working programs and discover areas to work more in the organization to increase productivity. Finding a long term funding will enable them grow and achieve their mission and objectives. How to solve the resource problem is of essence especially at this time when some of Hcz’s primary funders such as various clients of Bernie Madoff and Lehman Brothers Holdings are going through financial crisis. (Spector, 98). Canada laid off staff members because of this issue. This is an obstacle to expanding services of the organization. HCZ is a good social asset. The problem that rocks it is how to protect funding from private sectors. For instance, when HCZ was planning 2003 budget, it allocated $11,300 annual spending per student in the promise academy. Funding crises forced the

Wednesday, October 16, 2019

Prescription drugs Research Paper Example | Topics and Well Written Essays - 2750 words

Prescription drugs - Research Paper Example The large numbers of emergency room admissions from prescription drug abuse in the US are a compelling argument against DTC advertising. There is the need for pharma companies to show a higher degree of restraint in such DTC advertising, keeping in mind that the messages are viewed by people with varying levels of understanding of possible side effects from improper use of prescription drugs. Key words: Prescription Drugs, DTC advertising 1. Introduction The US is the only country in the world (apart from New Zealand) that permits Television advertisements for prescription drugs. The US Federal Drugs Administration (FDA) relaxed its requirements for information content needed in such advertising in 1997. The pharma industry’s spending on DTC (direct-to-customer) advertisements has grown rapidly since the FDA rule change and reached a peak of over $ 6 billion in 2006 and 2007 before falling off due to the global economic crisis. The spending in 2012 was still a high $ 3.47 bill ion (Mack, 2013). The European Union does not permit DTC advertising by pharma companies. This was reaffirmed in December 2010 when 22 of the 27 EU countries voted against the proposal despite lobbying by the pharma industry. Instead, the new ad regulations have become even tougher with the focus â€Å"on the rights of the patient to get the information he needs and not on the rights of pharma companies to spread information† (Golby, 2010). This paper examines the arguments in favor and against DTC advertising prescription drugs. PhRMA, the pharma industry association, in its 2008 guidelines for DTC advertising lists the benefits of DTC advertising as increased patient awareness about disease and the treatment options. The ads motivate patients to contact their doctors and engage in a dialogue about health concerns and increases likelihood of receiving care for conditions that get under-diagnosed or under treated. The advertisements also help patients to continue taking the prescribed medication (PhRMA, 2008). The beneficial effects of DTC advertising based on surveys of patients and doctors are shown in the chart below (Shaw, 2008). The chart shows that 95% of the benefit is from patient awareness and better discussion the doctor can have with the patient. The question clearly is whether these benefits outweigh potential negative effects of DTC advertising. 3. Top pharma companies advertising budgets in 2012 The table below shows the 2012 advertising budgets of the top 10 global pharma companies. The tabula tion has been made from data published on 26 February 2013 in FiercePharma.com (Palmer, 2013) Pharma Ad Spend 2012 ( in $ million)                   TV Magazine Other Total   Products       Pfizer 342.7 240 39.6 622.3 Celebrex- pain drug, Viagra, Lyrica - pain drug Eli Lilly 367.3 43.4 22.7 433.4 Cymbalta for pain, Cymbalta for depression, Cialis Abbott 264 35 2.7 301.7 Humira for arthritis, AndroGel, Humira for Crohn's disease Merck 133.7 87.8 64 285.5 Shingles awareness, Nasonex, Zostavax Amgen 164 52.1 13.2 229.3 Enbrel for arthritis, Prolia, Enbrel for psoriasis Astra Zeneca 156.5 41 11.8 209.3 Nexium - stomach , Symbicort, Crestor - cholesterol Allergan 85.9 107.2 0.23 193.3 Restasis, Botox for wrinkles, Botox for migbraine Boehringer 119.6 54.7 0.36 174.7 Spiriva, Pradaxa Glaxo SmithKline 70.3 84.8 15.5 170.6 Advair Diskus - respiratory , Lovaza - cholesterol , Jalyn Otsuka 73.9 41.2 0 115.1

STRATEGIC ANALYSIS assignment Example | Topics and Well Written Essays - 500 words

STRATEGIC ANALYSIS - Assignment Example The evaluation helps them to know in which program to concentrate their effort to maximize their productivity. As the organization grew, the need for this assessment became critical. This made the sustainability of the organizational growth a problem. The organization faced the management and strategy issue, which also plagues other non-profit organizations. Any organization that lacks machinery to evaluate its programs, cannot know how effective those programs are or how productive they are in terms of delivering their objectives. This means that it cannot clearly demonstrate the commitment it has to its mission and it will be difficult for such an organization to secure long term funding from the funders. An organization such as HCZ with a mission to educate a poor child in Harlem, must know the long-term goals it has and should be in a position to explain clearly to the funders how they are planning to meet their objectives. This will convince the funder to give it the support it requires to continue growing. Fundamentally, the organization should find a way to manage their setups to a success level. It needed an instrument to assess the working programs and discover areas to work more in the organization to increase productivity. Finding a long term funding will enable them grow and achieve their mission and objectives. How to solve the resource problem is of essence especially at this time when some of Hcz’s primary funders such as various clients of Bernie Madoff and Lehman Brothers Holdings are going through financial crisis. (Spector, 98). Canada laid off staff members because of this issue. This is an obstacle to expanding services of the organization. HCZ is a good social asset. The problem that rocks it is how to protect funding from private sectors. For instance, when HCZ was planning 2003 budget, it allocated $11,300 annual spending per student in the promise academy. Funding crises forced the

Tuesday, October 15, 2019

Higher education Essay Example for Free

Higher education Essay In â€Å"Some Lessons from the Assembly Line† Andrew Braaksma writes about his experiences working for factories during his summer breaks and his education. His experiences let him realizes that he works so hard and get little pay. It’s totally different from his college life. So he appreciates his education. I agree with what Andrew Braaksma says about how college life is different from the â€Å"real world†. Have you already prepared to the real world? Andrew Braaksma is a college student. He compares and contrasts two aspects of his life: working at assembly line as a blue-collar during summer vacations and being a college student. He worked in the factories surrounding his hometown for two reasons: got overtime pay and saved money because lived at home is cheaper than campus.â€Å"Aftera particularly exhausting string of 12-hour days at a plastics factory,† Andrew Braaksma, as college student who has never been out in the real world, realized that college was better than the work he was doing. His life in college was relatively easy: he slept late; he was able to spend time studying. He also had time to relax with his friends. So he couldn’t wait for school to start again. I feel the same way with Andrew Braaksma. I couldn’t imagine my life in the real work before I graduated from college. During I went to college in 80’s in China, I wish I can get a job as soon as possible. While I was working at a TV factory as engineer,I saw many younger workers who worked there 16 hours a day for many years had no holiday and vacation because they had no education, and some didn’t finish high school. It was also very stressful for theworkers because they knew their job could disappear overnight for outsources. It’s really a dog eat dog world. Working in the assembly line caused Andrew to reflect on how fortunate he really was. This helped him appreciated his education. Those people without a proper education are often forced to take unstable and low pay jobs in order to support themselves and their families. However, poverty and backwardness of my hometown let me want to change lives through higher education. I realize that my education is more important when it comes to searching for a job for a long period of time.

Monday, October 14, 2019

Permanent Vascular Access For Hemodialysis Health And Social Care Essay

Permanent Vascular Access For Hemodialysis Health And Social Care Essay Introduction: A progressive rise in the number of patients accepted for renal replacement therapy has been reported world wide . Permanent vascular access (VA) is the life-line for the majority of these patients, when hemodialysis is the treatment of choice. Thus, the successful creation of permanent vascular access and the appropriate management to decrease the complications is mandatory. A well functional access is also vital in order to deliver adequate hemodialysis therapy in end stage renal disease (ESRD) patients. Unfortunately, despite the advances in hemodialysis technology, in the field of vascular access in the last years the introduction of the polytetrafluoroethylene (PTFE) graft and the cuffed double lumen silicone catheter were the only changes. But the cost of vascular access related care was found to be more than fivefold higher for patients with arteriovenous graft (AVG) compared with patients with a functioning arteriovenous fistula (AVF) . It seems that the native arteriovenous fistula that Brescia and Cimino described in 1966 still remains the first choice VA . Thereafter, vascular access still remains the Achilles heel of the procedure and hemodialysis vascular access dysfunction is one of the most important causes of morbidity in this population . It has been estimated that vascular access dysfunction is responsible for 20% of all hospitalizations and the annual cost of placing and looking after dialysis vascular access in the United States exceeds 1 billion dollars per year . Nowadays, three types of permanent vascular access are used: arteriovenous fistula (AVF), arteriovenous grafts (AVG) and cuffed central venous catheters. They all have to be able to provide enough blood flow in order to deliver adequate hemodialysis, have a long use-life and low rate of complications. The native forearm arteriovenous fistulas (AVF) have the longest survival and require the fewest interventions. For this reason the forearm AV, is the first choice, fol lowing by the upper-arm AVF, the arteriovenous graft (AVG) and the cuffed central venous catheter as a final step . History of vascular access Vascular access for hemodialysis is closely associated with the history of dialysis. Glass needles were employed as vascular access when hemodialysis came into view in 1924. The first haemodialysis treatment in humans was carried out by Haas G who used glass cannulae to acquire blood from the radial artery and reverting it to the cubital vein . Venipuncture needles were used as means for blood acquisition from the femoral artery and its reinfusion to patient by vein puncture, in 1943 by Kolff W. . Regular hemodialysis treatments were possible in 1950s through the use of a medical apparatus ( Kolff s twin-coil kidney ), thus projecting the problem of a reliable, capable of repeated use vascular access. Today, the artery-side-to-vein-end-anastomosis has become a standard procedure . In 1952, Aubaniac had described the puncture of the subclavian vein . In the 60s, by using Alwalls experience, Quinton, Dillard and Scribner developed arteriovenous Teflon shunt . This procedure involved two thin-walled Teflon cannulas with tapered ends were inserted near the wrist in the forearm, one into the radial artery and the other into the adjacent cephalic vein. The external ends were connected by a curved Teflon bypass tube. Later, the Teflon tube was replaced by flexible silicon rubber tubing. After the advancement of permanent vascular access, the possibility of maintenance hemodialysis was a fact and therefore a groundbreaking procedure. In the subsequent years many variants of the AV shunt were used, with the majority of them concerning temporary vascular access from the onset of chronic dialysis treatment compensating for the time of AV fistulas absence or maturity. In 1961, Shaldon performed hemodialysis procedures by inserting catheters into femoral artery and vein, using the Seldinger-technique . Over time, vessels in different sites were used, including the subclavian vein jugular and femoral. In 1962 Cimino and Brescia described a simple venipuncture for hemodialysis . In 1963 Thomas J. Fogarty invented an intravascular catheter with an inflatable balloon at its distal tip designed for embolectomy and thrombectomy . The first surgically created fistula was placed in 1965, followed by further 14 operations in 1966. In 1966 Brescia, Cimino, Appel and Hurwich published their paper about arteriovenous fistula. Appell had performed a side-to-side-anastomosis between the radial artery and the cephalic antebrachial vein. One year later, in 1967, M. Sperling reported the successful creation of an end-to-end-anastomosis between the radial artery and the cephalic antebrachial vein in the forearm of 15 patients using a stapler . In the next few years this type of AV anastomosis received popular approval. However this procedure was cast aside as first choice AV, due to the increasing numbers of elderly, hypertensive and diabetic patients with demanding vessels and high risk of a stea l syndrome. End-to-end-anastomoses are still a common place technique in revision procedures. In 1968 Rà ¶hl L. published thirty radial-artery-side-to-vein-end anastomoses . After anastomosis was performed, the radial artery was ligated distal to the anastomosis, thus resulting in a functional end-to end-anastomosis. Today, the artery-side-to-vein-end-anastomosis has become a standard procedure . In 1970, Girardet R. and Brittinger W.D. described their experience with the femoral vein and artery for chronic hemodialysis. Experimental trials have been done by several authors in order to establish a permanent vascular access using subcutaneous tunnel. Brittinger W. was the first to implant a plastic valve as a vascular access in an animal model but unfortunately his efforts did not proceed to a human one . Moreover during the early 70s, Buselmeier T.J. developed a U-shaped silastic prosthetic AV shunt with either one or two Teflon plugged outlets which communicated to the outside of the body. The U-shaped portion could be totally or partially implanted subcutaneously . Subsequ ently pediatric hemodialysis patients were extremely favored by this procedure. New materials for AV grafts were presented in 1972, one biologic and two synthetic.. In 1976, L.D. Baker Jr. presented the first results with expanded PTFE grafts in 72 haemodialysis patients . In the years to come several publications indicated the benefits and the shortcomings of the prosthetic material in question remaining the primary choice of graft for hemodialysis VA to date. The same year two authors, Mindich B. and Dardik H. had worked with a new graft material: the human umbilical cord vein. . Regrettably so, this material did not succeed in becoming a revolutionary graft material due to its inadequate resistance against the trauma of repeated cannulation and their complication (aneurysm and infection). After the subclavian route for haemodialysis access was firstly introduced by Shaldon in 1961, it was further processed in 1969 by Josef Erben, using the intraclavicular route . In the next 20 y ears or so, the subclavian vein was the preferred access for temporary vascular access by central venous catheterization. Today, due to phlebographic studies revealing a 50% stenosis or occlusion rate at the cannulation site, subclavian route has been discarded. The subclavian stenosis and occlusion predispose to oedema of the arm, especially after creation of an AV fistula . The first angioplasty described by Dotter et al who introduced a type of balloon, was immensely conducive to the resolution of one of the most significant predicaments in vascular surgery and vascular access surgery . In 1977 Gracz K.C. et al created the proximal forearm fistula for maintenance hemodialysis, a variant of an AV anastomosis . An adjustment of this AVF became quite significant in the old, hypertensive and diabetic patients on the grounds that it allows s a proximal anastomosis with a low risk of hypercirculation . In 1979 Golding A.L. et al developed a carbon transcutaneous hemodialysis access device (CATD), commonly known as button, as a blood access not requiring needle puncture . As a procedure of third choice, these devices were expensive and never gained widespread acceptance. Shapiro F.L. described another type of A.L. button, a device similar to that developed by Golding . Angioaccess classification Years after the initial efforts to create the appropriate vascular access in order to perform a safe hemodialysis, modern Nephrologists have now the possibility to select the appropriate access for their patients. So the first distinction is made between temporary and permanent VA . Temporary VA with expected half-life less than 90 days, peripheral arteriovenous shunts and non cuffed double lumen catheters are included . Mid-term VA with expected half life in 3 months to 3 years include veno-venous accesses (tunneled cuffed catheters and port catheter devices) and arteriovenous internal shunts, requiring vascular graft synthetic (PTFE) or biologic (saphenous vein, Procol, etc.) material ,or external shunt. Long-term VA with an expected half-life more than 3 years includes virtually the native arteriovenous fistulas and the new generation of PTFE grafts . Acute hemodialysis vascular access They are used for urgent hemodialysis and should be easy to insert and available for immediate use. Currently there are available two types of such accesses: Non-tunneled dialysis catheters and cuffed, tunnelled dialysis catheters. Double-lumen, non-cuffed, non-tunnelled hemodialysis catheters are the preferred method for immediate hemodialysis when a long term access is not available. They are made of polymers which are rigid at room temperature to facilitate insertion but soften at body temperature to minimize vessel injury and blood vessel laceration. The proximal and distal lumens should be separated by at least 2 cm to minimize recirculation . These catheters can be inserted into the central veins: femoral, jugular, or subclavian veins . The femoral artery can be used as an access central vein when all others central veins have been excluded. A modified Seldinger guide wire technique is used for their insertion. Image guided assistance in placing these catheters is recommended to avoid or minimize some of the immediate insertion complications, but non-cuffed catheters are also suitable for use at the bedside of the patient The 2006 National Kidney Foundation Dialysis Outcomes Quality Initiative (K/DOQI) guidelines recommend, after internal jugular or subclavian vein insertion, identifying radiographically any potential complications and confirming tip placement prior to either anticoagulation or catheter use . These guidelines also recommend ultrasound vessel identification prior to insertion. In general, now the subclavian catheters should be avoided because of the high incidence of vein stenosis and thrombosis. The maximum blood flow with this class of catheters is usually blood pump speeds of 300 mL/min, with an actual blood flow of 250 mL/min or less . Femoral catheters have to be at least 18 to 25 cm in length in order to have lower recirculation. The routine use-life of these catheters varies by site of insertion. In general, internal jugular catheters are suitable for two to three weeks of use, while femoral catheters are usually used for a single treatment (ambulatory patients) or for three to seven days in bed bound patients . However, the KDOQI guidelines suggest that non-cuffed, non-tunnelled catheters be used for less than one week and that cuffed, tunnelled catheters be placed for those who require dialysis for longer than one week . More recently a non-cuffed, non-tunnelled triple-lumen dialysis catheter has been developed. The purpose for third lumen is for blood drawing and the intravenous administration of drugs and fluid. In a multicenter, prospective study, blood flow rates and infectious complications were similar with double lumen catheter . Infectious complications are the principal reason why the catheter must be removed. Permanent Vascular Access Taking into consideration patient factors such as life expectancy, comorbidities, and status of the venous and arterial vascular system is very important in order to prescribe the appropriate access. Other factors are determined by the type of access itself, as arteriovenous fistula (AVF), arteriovenous graft (AVG), or TC which have a different effect on circulatory system. Also the duration of their functionality and the risk for infection and thrombosis are important factors to consider. Each type of surgical anastomosis has advantages and disadvantages . In 2002 the American Association for Vascular Surgery and the Society for Vascular Surgery published reporting standards according to which three essential components of VA should be mentioned: conduit (autogenous, prosthetic), location and configuration (strait, looped, direct, etc.) . Arteriovenous fistula An AVF is the preferred type of vascular access; it has the lowest complication rates for thrombosis (~ one-sixth of AVGs) and infection (~ one-tenth of AVGs) . There are 3 types of AVF s: à ¢Ã¢â€š ¬Ã‚ ¢ First type when artery and vein are connected in their natural position, either with a side-to-side or a side-artery-to-vein-end anastomosis. à ¢Ã¢â€š ¬Ã‚ ¢ Second type, where a vein is moved to connect to an artery in end-to-side fashion to either bridge a larger anatomical distance, or to bring the vein to the surface where it is accessible for cannulation and requires a tunnel to position the vein in its new location. à ¢Ã¢â€š ¬Ã‚ ¢ Third type where a vein is removed from its anatomical location and, is connected to an artery and vein in end-to-end fashion. Both second and third type requires the formation of a tunnel . End-to-end anastomoses are now rarely performed, since the complete disruption of the artery imposes a risk for peripheral ischemia and thrombosis. The most common surgical technique today is the side-to-end anastomosis. However technical problems as cutting the end of the vein in an oblique angle may create functional problems due to stenosis. An anastomosis more proximal in the arterial system should be smaller to prevent steal and limit maximal fistula flow, with the inherent complication of ischemic steal or heart failure . Arteriovenous fistula creation is often performed under local anaesthesia, with low morbidity and requires time for maturation. Data from the Dialysis Outcomes and Practice Patterns Study (DOPPS) indicate that AVFs should mature at least 14 days before use . Fistula size and flow increase over time, of 8-12 weeks and the initial blood flow rates has a range of 200-300 mL/min. Placement of AVFs should be initiated when the patient reaches CKD stage 4, or within 1 year of the anticipated start of dialysis. A physical examination should document blood pressure differences between the upper extremities and an Allen test should be performed, the lack of a well-developed palmar arch predicts a higher risk for vascular steal symptoms if the dominant artery is used for forearm fistulas creation due to inadequate collateral circulation . Ultrasound must be done before surgical implantation because it can provide information for maximal surgical success by mapping arteries and veins; eg, a preoperative arterial lumen diameter >2 mm is associated with successful fistula maturation, while a diameter of 600 mL/min, a diameter >0.6 cm with discernible margins, and be at a depth of 0.6 cm (between 0.5 and 1.0 cm) from the surface 6 weeks after creation. In fistulas that are maturing successfully, flow increases rapidly post-surgery, from baseline values of 30-50 mL/min to 200-800 mL/min within 1 week, generally reaching flows >480 mL/min at 8 weeks .The AVFs must be evaluated 4-6 weeks after placement, and experienced examiners (eg, dialysis nurses) can identify non-maturing fistulas with 80% accuracy . Arteriovenous graft AVGs were the most commonly used type of dialysis access in the US however, they do not last as long as AVFs and have higher rates of infection and thrombosis . Grafts present a second choice of VA when AVF are not able to be performed because of vascular problems. They can be placed in the forearm, the upper arm, and the thigh, and can have a straight, curved, or loop configuration. They may offer a large surface area for cannulation. AVGs can be cannulated about 2-3 weeks after placement, although there are studies suggesting that immediate assessment after placement for PTFE AVGs is possible . This interval is needed in order to allow the surrounding tissue to adhere to the PTFE conduit, to reduce the postsurgical oedema and the risk for local complications such as perigraft hematoma and seroma . Tunnelled hemodialysis catheter TCs are used when AVFs or AVGs arent possible to be created for several reasons such as multiple vascular surgeries, that lead to vascular thrombosis or when patients have severe peripheral vascular disease or very low cardiac output. Its more often in paediatric and very old patients. Unfortunately they are associated with the highest infection rate and they are not a very long-term access option. Studies have revealed that central venous catheters are colonized within 10 days of placement; however, colonization of the catheter biofilm does not correspond to positive blood cultures or clinical signs of bacteremia . Recently Power A. et al published their experience with 759 TCs. The survival rate at 1,2 and 5 years was 85%, 72% and 48% respectively. The infection rate was 0.34 per 1000 catheter day showing with careful and appropriate use of TCs, they can provide effective and adequate long term hemodialysis and rates of access related infection almost similar to AVGs . Hemodialysis vascular access in children The choice of replacement therapy in children is variable. The registry of the North American Pediatric Renal Trials and Collaborative Studies (NAPRTCS) reports that of patients initiating renal replacement therapy in paediatric centres : one quarter of children underwent preemptive renal transplantation, one half were started on peritoneal dialysis and one quarter were started on hemodialysis. Kidney transplantation remains the preferred therapy for paediatric patients therefore, many paediatric patients receive maintenance HD through an indwelling catheter in perspective of short HD period . In the United States less than 800 paediatric patients receive maintenance HD therapy, therefore surgical experience and clinical data for fistulae or grafts creation in small patients is limited due to rare need for such procedures. Smaller patients, especially those less than 10kg, are very demanding in surgical and nursing skill, this is significant reason the majority of smaller patients re ceive PD for their maintenance dialysis modality . Peritoneal dialysis is much more common in infants and younger children , significantly due to problems of vascular access. However, hemodialysis can be performed successfully in infants and very young children, as well . Children who will join in hemodialysis will need evaluation of their vasculature for placement of an arteriovenous (AV) fistula, arteriovenous graft, or cuffed double lumen catheter. The use of an AV fistula, the recommended type of vascular access in adults, is limited in children due to the size of their vessels. In the 2008 NAPRTCS annual report, vascular access for hemodialysis included external percutaneous catheter in 77.7 percent of patients, internal AV fistula in 12.3 percent, and internal and external AV shunt in 7.3 and 0.7 percent, respectively . K/DOQI has encouraged greater use of AV fistulas in larger children receiving hemodialysis who are not likely to receive a transplant within 12 months, with a goal of achieving more effective dialysis with fewer complications (eg, infection) than occurs with catheters. The choice of catheter size and configuration depends on the size of the patient. It is suggested by studies that in children as small as 4 to 5 kg a dual-lumen 8 Fr catheter can be well tolerated, and as the child becomes larger in size, a larger volume access can be placed . Vascular access should be able to provide sufficient blood flow and adequate dialysis with a Kt/V greater than 1.2. Kt/V is influenced further by the recirculation rate. Because flow rates in paediatrics vary by the size of catheter, which varies by the size of the patient, a recommended flow rate of 3 to 5 mL/kg/min is acceptable in most patients . Vascular access complications and Survival Studies have shown a mortality risk dependent on access type, with the highest risk associated with central venous dialysis catheters, followed by AVGs and then AVFs . The CHOICE study examined mortality based on access type in 616 hemodialysis patients for up to 3 years of follow-up. Central venous catheters and AVGs were associated with approximately 50% and 26% increased mortality, respectively, compared with AVFs with prevalence in men and elderly patients . Despite these findings and the KDOQI recommendations, dialysis access data from 2002-2003 showed that only 33% of prevalent hemodialysis patients in the US were being dialyzed via AVFs. Contrary in Europe and Canada, the majority of the patients (74% and 53% respectively) were being dialyzed via AVFs . Vascular access admissions continue to fall, with more procedures now performed in an outpatient setting, and are 45.1 percent below levels noted in 1993. By two-year time period, the adjusted relative risks of all- cause and cardiovascular hospitalization among hemodialysis patients vary little when compared to the reference period of 1997-1998; the risk of hospitalization for infection, however, is now 18 percent greater than in the reference period, while that of a vascular access hospitalization is 30 percent less. Among African American patients, the relative risk of an all-cause hospitalization or one related to infection is almost equal to that of white patients; the risk of a vascular access hospitalization, however, is 24 percent higher. In our previous work with 149 hemodialysis patients who had undergone 202 vascular access procedures (177 Cimino-Brescia fistulae and 25 PTFE grafts we found that the Cimino-Brescia fistula was used as the first choice of vascular access in all patients except one in the elderly group. PTFE grafts were the second or third choice in 7 patients younger than 65 and 15 in the elderly group (p: NS). The only reason for technique failure was vascular thrombosis in both groups (p: NS). Other complications were: aneurysms (10/48 and 14/101, p: NS), infections (0/48 and 2/101 p: NS) and oedema (0/48 and 6/101, p: NS). (Table à ¢Ã¢â€š ¬Ã‚ ¦.. Five-year technique survival of the first AV fistula in the two groups was 35% and 45% respectively (log-rank test, p: NS). (FIGUREà ¢Ã¢â€š ¬Ã‚ ¦..) Our findings suggested that there was no difference in vascular access complications across age groups and the survival of the first AV fistula is independent of age. Other encouraging results include a 22.9 percent fall in dialysis access admissions since 1999 for peritoneal dialysis patients, among hemodialysis patients, admissions for bacteremia/septicemia continue to rise sharply, reaching 112 per 1,000 patient years similar to the rate of 109 for vascular access infections, and possibly reflecting an increased use of cuffed catheters. In 2010 USRDS Annual Data Report hospitalization in 2008, increased again, to a point 45.8 percent above their 1993 level. In 2007-2008, women treated with hemodialysis were 16 percent more likely to be hospitalized, overall, than male. They also had a greater risk than men of cardiovascular, infectious, and vascular access hospitalizations 11, 14, and 29 percent greater, respectively. Recently unpublished our data are more different than those we published in 1998. We found in 189 patients that female had more possibility to start HD with double lumen catheter than male and also patients with heart failure ind ependent of sex. Female patients had PTEF grafts as first vascular access (p=0,023) and the elderly patients had more complications and more vascular access procedures (p=0.026). Non-tunnelled double lumen catheters complications The non-tunnelled double lumen catheters complications concern the insertion, the infection and thrombosis of the vessel. The severity and likelihood of insertion complications varies with the site of insertion. The complication rate and the severity are lowest in the femoral position. The primary problem is perforation of the femoral artery. Bleeding usually resolves within minutes of direct compression. Large femoral or retroperitoneal hematomas occur occasionally . Subclavian insertion complications are potentially more serious. Over-insertion of guide-wire can occasionally lead to atrial or ventricular arrhythmias. The vast majority of these are transient and hemodynamically insignificant . Penetration or cannulation of the subclavian artery can lead to hemothorax, which in some cases requires a thoracotomy tube. Cases of pericardial rupture and tamponade also have been described . Subclavian insertion from the left has an increased risk of atrial perforation which can present with acute hemopericardium upon initiation of dialysis. The incidence of pneumothorax varies from less than 1 percent to mor e than 10 percent of insertions, depending on the skill and experience of the physician. The risk of pneumothorax is greater from the left than right side, since the pleura and dome of the lung are higher on the left . Due to high rate of catheter-induced subclavian stenosis and subsequent loss of the ipsilateral arm for future hemodialysis access internal jugular vein insertion, particularly the right internal jugular vein is the preferred site of insertion. At internal jugular insertions carry a higher likelihood of carotid artery penetration, but a lower risk of pneumothorax (0.1 percent). Ultrasound guided cannulation of the vessel is recommended to minimize these complications. The location of the catheter tip in subclavian and internal jugular insertion should always be confirmed by fluoroscopy or x-ray prior to the initiation of hemodialysis or the administration of anticoagulants. Ultrasound-guided catheter insertion is lesser likelihood of arterial puncture or pneumothorax . Prevention and treatment of catheter thrombosis are important clinical issues. To prevent formation of thrombus, both lumens of the double lumen catheter are instilled with heparin following hemodialysis. The amount injected should only fill the catheter lumen to minimize systemic heparinization. Anecdotal evidence suggest that chronic anticoagulation with warfarin or low molecular weight heparin may also prevent catheter thrombus, due to either intraluminal clot or fibrin sheath formation . Lytic agents such as urokinase and alteplase are effective in treatment of catheter thrombosis. Alteplase has effectiveness rates in thrombosis treatment comparable to that observed with urokinase . However if non-cuffed catheters cannot have adequate blood flow then they should be exchanged. Ventral vein catheters are associated with the development of central vein stenosis . This complication appear s to occur more often with subclavian (40 to 50 percent of cases in some studies) than with internal jugular insertions (up to 10 percent) . It has been proposed that central venous cannulation creates a nidus of vascular injury and fibrosis. The rapid blood flows associated with the hemodialysis catheter then create turbulence that can accelerate endothelial proliferation, eventually leading to venous stenosis . The K/DOQI guidelines therefore recommend avoiding placement in the subclavian vein, unless no other options are available. If central venous thrombosis is detected early, it responds well to directly applied thrombolytic therapy or to percutaneous transluminal angioplasty when the fibrotic stenosis can be crossed with a guidewire . The infection risks associated with temporary double lumen catheters include local exit site infection and systemic bacteremia, both of which require prompt removal of the catheter and appropriate intravenous antibiotic therapy . Bacteremia gene rally results from either contamination of the catheter lumen or migration of bacteria from the skin through the entry site, down the hemodialysis catheter into the blood stream . Skin flora, Staphylococcus and Streptococcus species, are responsible for the majority of infections. There is conflicting evidence concerning the risk of infection based upon the site of insertion. In the largest prospective randomized study, the risk of infection was not reduced with jugular versus femoral venous catheterization . A prospective nonrandomized studies suggest that the infection risk appears to sequentially increase for hemodialysis catheters inserted into the subclavian, internal jugular, and femoral veins, respectively . Overall, compared with the subclavian vein, the internal jugular vein remains the preferred access site in ambulatory patients because of the high rate of central vein stenosis associated with subclavian vein catheterization (see above). In the Intensive Care Unit, either femoral or internal jugular vein placement is satisfactory, with the use of ultrasound making internal jugular vein placement safer. The best solution is to prevent the infection by proper placement technique, optimal exit site care and management of the catheter within the HD facility . Arteriovenous fistulas complications Complications of AVFs can be divided into early and late causes. Early causes include inflow problems such as small or atherosclerotic arteries, or juxta-anastomotic stenosis so a pre-operative evaluations for suitable access sites has to been performed . The aetiology of this acquired lesion is not entirely clear, but may be related to manipulating the free end of the vein, torsion, poor angulation, or loss of the vasa vasorum during anatomic dissection. This lesion often can be adequately treated with angioplasty or by surgical revision . Outflow problems may include accessory veins that divert blood flow from the intended superficial vessel to deeper conduits, or central venous stenosis in patients with prior central venous catheters. Vessels smaller than one-fourth of the fistula diameter are usually not hemodynamically relevant. Juxta-anastomotic stenosis and accessory veins are the most common causes for early failure AVFs when pre-operative evaluations for suitable access sites have been performed . Late causes for failure of AVFs include venous stenosis, thrombosis, and acquired arterial lesions such as aneurysms or stenosis. Venous stenosis may become apparent as flow decreases over time, worsening weekly Kt/V ([dialyzer clearance _ time]/body volume) or increasing recirculation. Native fistulas typically will not thrombose until flow is severely diminished. Static pressure measurements, which are helpful in graft monitoring, do not appear as helpful in AVFs, since collaterals surrounding the stenosis area often develop, effectively masking the rise in fistula outflow resistance. Stenotic lesions can be treated by angioplasty. Thrombectomy of fistulas, although technically more challenging than in AVGs, is often successful and if flow is re-established, primary patency is longer than in grafts . Aneurysms may form over the course of years as the fistula increases with increased flow and, unless associated with stenotic lesions, are more a cosmetic than functional concern. If the skin overlying the aneurysm is blanching or atrophic, or if there are signs of ulceration

Sunday, October 13, 2019

machiavelli :: essays research papers fc

Niccolo Machiavelli Statesman and Political Philosopher 1469 - 1527 No enterprise is more likely to succeed than one concealed from the enemy until it is ripe for execution. —Machiavelli from The Art of War I was born on May 3, 1469 in Florence, Italy. I was a political philosopher and diplomat during the Renaissance, and I’m most famous for my political treatise, The Prince (1513), that has become a cornerstone of modern political philosophy. My life was very interesting. I lived a nondescript childhood in Florence, and mine main political experience in my youth was watching Savanarola from afar. Soon after Savanarola was executed, I entered the Florentine government as a secretary. My position quickly rose, however, and was soon engaging in diplomatic missions. I met many of the important politicians of the day, such as the Pope and the King of France, but none had more impact on me than a prince of the Papal States, Cesare Borgia. Borgia was a cunning, cruel man, very much like the one portrayed in The Prince. I did not truly like Borgia's policies, but I thought that with a ruler like Borgia the Florentines could unite Italy, which was my goal throughout life. Unfortunately for myself, I was dismissed from office when the Medici came to rule Florence and the Republic was overthrown. The lack of a job forced me to switch to writing about politics instead of being active. My diplomatic missions were my last official gove rnment positions. When I lost my office, desperately I wanted to return to politics. I tried to gain the favor of the Medici by writing a book of what I thought were the Medici's goals and dedicating it to them. And so The Prince was written for that purpose. Unfortunately, the Medici didn't agree with what the book said, so I was out of a job. But when the public saw the book, they were outraged. The people wondered how cruel a man could be to think evil thoughts like the ones in The Prince, and this would come back to haunt me when I was alive and dead. However, if the people wanted to know what my self really stood for, they should have read my "Discourses on Livy", which explains my full political philosophy. But not enough people had and have, and so the legacy of The Prince continues to define my person to the general public.