Rafael H Llinas, M.D.

• Director, Neurology at Johns Hopkins Bayview
• Professor of Neurology

https://www.hopkinsmedicine.org/profiles/results/directory/profile/0015511/rafael-llinas

Therefore nice guidelines treatment back pain order 100 mg cafergot, in patients with increased bleeding risk or active bleeding pain management for arthritis in dogs purchase cafergot 100 mg mastercard, no-heparin hemodialysis is the preferred method of anticoagulation pain solutions treatment center woodstock order cafergot overnight. The heparinized saline is flushed from the extracorporeal lines before the start of the dialysis treatment so that heparin is not administered to the patient hip pain treatment options generic cafergot 100 mg buy on line. Extracorporeal blood flows are rapidly increased to 250­500 mL/min and maintained throughout the treatment pain treatment arthritis purchase cafergot 100 mg without a prescription, and 25­30 mL saline flushes are administered every 15­30 minutes into the arterial (predialyzer) limb to minimize hemoconcentration and to wash fibrin strands from the dialyzer into the bubble trap. Philadelphia: Hanley and Belfus, 2002) Methods of Hemodialysis Anticoagulation 199 saline administered must be removed during the dialysis to prevent volume overload. One-to-one nursing is required for administration of saline flushes and careful monitoring of the arterial and venous pressure alarms to detect early extracorporeal circuit clotting. No significant loss of clearances has been reported compared to patients on standard anticoagulation. In approximately 5% of the cases, conversion to minimum-dose heparin or treatment discontinuation is required. Disadvantages of this technique include the associated increased ultrafiltration rate required to maintain volume status, which can promote hypotension and increase dialyzer circuit clotting and thrombosis. An additional problem with the no-heparin technique is that blood transfusions cannot usually be given through the dialyzer circuit because of the increased risk of clotting, which may pose difficulty for patients with limited peripheral access. A potential solution, which has been successfully used, is to use a large-bore stopcock to transfuse blood into the venous limb (postdialyzer) of the circuit. An additional disadvantage is the increased technician labor required and the need for close observation, which can potentially elevate dialysis costs. For these reasons, no-heparin strategies are not recommended as a long-term anticoagulation therapy for outpatient hemodialysis. Heparin-Grafted Dialyzers Another alternative to no-heparin hemodialysis is the use of heparin-grafted dialyzers, which have been successfully used alone (without saline flushes) or in combination with a citrate-enriched dialysate. The clotting rate associated with these dialyzers seems to be between 15% and 30%. Preliminary studies suggest that heparin-grafted dialyzers are noninferior to current standard heparin-free dialysis, easy to use, and a reasonable choice for hemodialysis anticoagulation in patients with high bleeding risk. The citrate-enriched dialysate replaces the acetate normally used for acidification, instead utilizing citric acid at a relatively low concentration (2. This results in reduced clotting formation locally in the extracorporeal circuit, which allows a dialysis treatment with either no or only a very low dose of heparin for anticoagulation. Importantly, citrate dialysate lowers serum calcium sufficient to interfere with the clotting cascade, but not enough to cause symptomatic hypocalcemia. Thus, calcium replacement is not necessary, as opposed to regional citrate anticoagulation. This dialysis modality typically 200 Methods of Hemodialysis Anticoagulation involves very slow blood flow rates, which are associated with an increased risk of thrombosis and lower filter life span. No-heparin hemodialysis, though used in very select patients, is usually discouraged when using this modality. Adequate anticoagulation allows for a more continuous therapy, minimizing the interruptions due to clotting, which results in less blood loss and more efficient total dialysis time. Continuous hemodialysis therapy increases the likelihood of complications with prostacyclin or protamine. The alternative for patients with increased risk of bleeding is regional citrate anticoagulation. Similar to intermittent hemodialysis, there are no well-established guidelines regarding dosage. The heparin dose may be drastically reduced in patients with disseminated intravascular coagulation or thrombocytopenia. Unfortunately, there is some systemic anticoagulation with this technique and it may be contraindicated in patients at high risk of bleeding. Despite heparin being the preferred agent in terms of side effect profile and simplicity, evidence from several randomized controlled trials suggest that regional citrate may improve the survival rate of hemofilters and lower bleeding risk compared with heparin in continuous renal replacement therapies. Some protocols use a fixed dose of citrate in relation to blood flow according to an algorithm, whereas others measure postfilter ionized calcium and adjust the citrate dose and/or calcium infusion accordingly. Regional citrate can also cause calcium abnormalities, hypernatremia, and metabolic alkalosis. The possibility of alkalosis may be lessened in part by using an anticoagulant citrate dextrose formula as replacement fluid, which produces less bicarbonate compared with hypertonic trisodium citrate. Methods of Hemodialysis Anticoagulation 201 Management includes discontinuation of citrate infusion, increase in dialysate flow rate, and correction of hypocalcemia with calcium supplementation. Further studies in a larger number of patients are required to more accurately define the relative benefits and/or risks and cost-effectiveness of heparin versus citrate-based anticoagulation. Although citrate is somewhat more complicated for nursing staff, appropriate protocols should simplify procedures, and citrate has slowly become the preferred anticoagulation approach in continuous renal replacement therapy. Combinations of both prostacyclin and low molecular weight heparin have also been described. However, these favorable outcomes are at odds with studies performed during standard hemodialysis and must be interpreted with caution. Larger clinical trials with these agents are needed to establish their role in continuous renal replacement therapies. Heparin-Induced Thrombocytopenia Unfractionated heparin can cause a modest reduction in platelet count (<100,000/ mL), which is usually reversible (heparin-induced thrombocytopenia type I). In approximately 5%­10% of the patients treated with heparin, there is an immunologic reaction characterized by the formation of antibodies against the complex of heparin and platelet factor 4. The main clinical concern in this disorder is a high incidence of arterial and venous thrombosis, rather than bleeding. Given overall safety and reasonable ease of use, no-heparin hemodialysis should be the first option among those with heparin-induced thrombocytopenia. If heparin-free dialysis cannot be performed, then the patient should be anticoagulated with regional citrate or in certain situations even converted to peritoneal dialysis. Melagatran is a novel long-acting direct thrombin inhibitor, which is currently available only in Europe. Patient and machine iCa levels are monitored every 6 hours, and infusion rates are adjusted accordingly. Calcium infusion rates should be accounted for when targeting ultrafiltration rates. Studies with lower concentration citrate solutions (4%­7%) indicate that this strategy is safe and similarly effective for the maintenance of long-term interdialytic patency of hemodialysis catheters. A study using a 30% citrate locking solution found no increase in adverse events and also found a decreased risk of catheter-related bacteremia as compared to a standard heparin locking solution. Hemodialysis effect on platelet count and function and hemodialysis-associated thrombocytopenia. A comprehensive review of basic principle of coagulation cascade, hemostatic abnormalities in dialysis patients, and principles of anticoagulation and available agents used in routine hemodialysis. Anticoagulant-free Genius hemodialysis using low molecular weight heparin-coated circuits. Results of the HepZero study comparing heparin-grafted membrane and standard care show that heparin-grafted dialyzer is safe and easy to use for heparin-free dialysis. A large, randomized, multicenter, international controlled open-label trial comparing no-heparin hemodialysis strategies vs heparin-grafted dialyzer. The study showed that heparin-grafted membranes are not inferior and are a safe, easy-to-use method for non-heparin dialysis. Safety and efficacy of low molecular weight heparins for hemodialysis in patients with end-stage renal failure: A meta-analysis of randomized trials. Alternate methods of anticoagulation for dialysis-dependent patients with heparin-induced thrombocytopenia. Review of the prevalence, diagnosis, and treatment data regarding heparin-induced thrombocytopenia. Use and safety of unfractionated heparin for anticoagulation during maintenance hemodialysis. Case presentation and comprehensive review of different anticoagulation strategies for hemodialysis, with emphasis on heparin, its pharmacology, dosage, and complications. Randomized, clinical trial comparison of trisodium citrate 30 percent and heparin as catheter-locking solution in hemodialysis patients. This prospective study found that the use of a trisodium citrate catheter locking solution reduced the incidence of catheter-related bacteremia and was not associated with any untoward metabolic consequences compared to standard heparin lock. Regional citrate versus heparin anticoagulation for continuous renal replacement therapy: a meta-analysis of randomized controlled trials. The interest in home hemodialysis has been increasing over the past years because of its flexibility and benefits (which will be further discussed in the following section). Historically, home hemodialysis accounted for about 40% of the dialysis population in the United States in the 1970s and decreased in popularity in the 1980­90s. It is currently experiencing a resurgence in several countries, especially with the interest in more frequent or intensive hemodialysis. In fact, there was a 5-fold increase in patients undergoing home hemodialysis in 2012 (n =7923) versus in 2002 (n = 1563). Basis for Home Hemodialysis Home hemodialysis offers several benefits as compared to conventional facility based hemodialysis. These include improvements in patient outcomes (Blagg et al, 2006), increased freedom of time, cost reduction, as well as an improved quality of life. Improvements in patient outcome with more frequent or intensive home hemodialysis include improved survival (Weinhandl et al, 2012), blood pressure control (Chan et al, 2003), left ventricular geometry (Culleton et al, 2007), phosphate control and mineral metabolism (Walsh et al, 2010), quality of sleep (Hanly et al, 2001), and fertility (Barua et al, 2008). As compared to facility-based hemodialysis, home hemodialysis is cost-effective or cost-saving (Walker et al, 2014) due to lower staff costs and likely medication cost and may have better health outcomes in kidney disease­related quality of life and survival (Van Eps et al, 2010). Requirements There are several prerequisites that need to be addressed before commencing on a home hemodialysis program. A home visit should be conducted prior to further discussion of home dialysis to determine its feasibility and assess the necessary modifications. The availability of a checklist for the home visit may facilitate the process (Table 15. Legal the local legal requirements regarding water supply, as well as land and housing, should be established to ascertain if home hemodialysis is feasible. There should be no legal restriction to the use of the building for the purpose of home hemodialysis. In addition, legal requirements concerning waste disposal, sewage, and electrical supply should also be established before the consideration of home hemodialysis. Consideration should be given toward specific policies regarding potentially biohazardous waste. A unit policy should ideally be in place to decide who is financially responsible for the needed modifications to the home that may be necessary in terms of plumbing and/or electrical renovations. Water Preparation, Standards, and Plumbing Home hemodialysis, as compared to conventional in-center hemodialysis, is potentially a more water-intensive procedure, with larger volumes of water being necessary to reconstitute the dialysate (except for the mobile platform). The total dialysate volume can range between 110 and 150 L for a 6- to 8-hour session of dialysis, as compared to 120 L for a typical conventional session. The water supply can come from various sources, for example, municipal water, feed water. It is important for a full chemical analysis of the water for dialysis to be conducted to determine the degree of water purification necessary. The plumbing system modifications should also take into consideration the level in the home in which the dialysis is done. Should dialysis take place on higher floors, additional components, for example, pump systems and feeder tanks, may be needed to provide the necessary water pressure for the reverse osmosis unit and dialysis machine to function properly. Depending on the local water conditions and regulations, other modifications like backflow preventers and blending devices may also be necessary. Electrical Considerations Including Backup Power Supply A stable power supply is necessary to conduct home hemodialysis. There should also be an overcurrent device installed at the service panel board equipped with a 20-ampere fuse. The dialysis machine should also be connected to a separate branch circuit that does not supply any other outlets. For locations that may experience regular power failures, a backup power supply with its accompanying equipment is recommended. The power supply should be compatible with the dialysis equipment, and it may be necessary for an electrician to review for an outlet for the machine with a dedicated circuit to the circuit breaker. It is important to take into consideration measures to manage hemodialysis in the event of power failure, for example, manual wind-back functions of the machine. Lastly, it is essential to establish the local electricity safety regulations and adhere to them. Dialysis Machine Choice and Other Equipment There are different dialysis machines currently available for home hemodialysis. Some offer the advantage of mobility; however, any machine in general is able to provide effective and good home dialysis. In general, a home dialysis machine should be easy to operate and understand, as this facilitates the learning process for the patient and/or the caregiver. The choice of dialysis machine would also determine the ease of dialysis fluid preparation. Some machines require water filtration systems, while others come with pre-packaged dialysate, or are able to generate on-line dialysis solutions. To prescribe dialysis with this system, one would need to decide on the following parameters: i. Frequency of dialysis per week, as well as the target spKt/V (per session as well as per week) ii. The PureFlow system allows ultrapure product water to be produced from tap water, which is then mixed with the sterile concentrate to produce dialysate solution. It is available in 40­60 L preparations, while the prepackaged solutions come in 5-L bags. This allows for an adjustable headrest that will allow the patient to be comfortable sitting up for the entire duration of the dialysis process and also allows the patient to recline.

Postoperative Management In the postoperative period joint and pain treatment center lompoc ca buy 100 mg cafergot otc, close monitoring of different electrolytes is required because significant changes may occur (Table 62 treatment pain right hand order 100 mg cafergot free shipping. The hypocalcemic nadir typically occurs during the first 2 to 4 postoperative days southern california pain treatment center generic cafergot 100 mg line. Restoration to normal calcium level may occur within 2 weeks pain treatment lures athletes to germany buy cafergot 100 mg line, but hypocalcemia may remain severe for several months in a subset of patients oriental pain treatment center brentwood buy 100 mg cafergot fast delivery. In patients undergoing autotransplantation, hypocalcemia may persist until the implanted tissue is able to provide adequate function in 2 to 3 weeks up to 1 year after surgery. We speculate that the degree of blood alkalinization with dialysis and resultant decrease in ionized calcium may be contributory. Rapid correction of metabolic acidosis with dialysis should be avoided if possible. Reported risks for hungry bone syndrome include severe preoperative bone disease, osteitis fibrosa cystica, "brown tumors," lower initial serum calcium, and younger patient age. Whereas an initial upsloping postoperative calcium curve based on two calcium measurements within the first 24 hours has been shown to be strongly predictive of a stable postoperative calcium level, a steeply downsloping initial calcium curve may predict eventual hypocalcemia. Strategies to ameliorate postparathyroidectomy hypocalcemia include preoperative administration of an active vitamin D metabolite. As soon as the patient can tolerate oral intake, elemental calcium at 1 to 2 g orally three times a day may be given. Monitoring of calcium levels should be continued every 6 hours for the next 2 to 3 days and tapered off in frequency when calcium levels stabilize. In emergent cases of symptomatic hypocalcemia, 20 to 30 mL of the above solution mixture may be infused over 10 to 15 minutes followed by a continuous infusion at 20 to 30 mL per hour as deemed necessary by subsequent calcium levels and symptoms. Postoperative continuation of vitamin D is recommended to minimize the mean postoperative reduction in serum calcium as well as the amount of calcium required for supplementation. Both vitamin D and calcium doses should be adjusted to maintain normal calcium levels. New-onset hypercalcemia after parathyroidectomy is unusual but may occur as a result of excessive calcium and calcitriol supplements. Alternatively, postoperative persistence of hypercalcemia may signify inadequate parathyroid gland removal, missed ectopic glands, or misdiagnosed cause of hypercalcemia. Radiologic localization of the parathyroid glands is required in persistent hypercalcemic cases for surgical reexploration. Postparathyroidectomy hypophosphatemia is uncommon among patients with renal failure. Nonetheless, hypophosphatemia may occur because of reduced Parathyroidectomy 717 phosphate mobilization from bone and enhanced uptake for bone formation. Patients with significant existing periarticular calcium phosphate deposits may actually benefit from a higher degree of phosphorus mobilization and amelioration of hypophosphatemia. If the patient has concurrent hypocalcemia, phosphate supplementation must be given in between meals to avoid binding with calcium in the gastrointestinal tract and resultant reduction in calcium absorption. As with hypophosphatemia, postparathyroidectomy hypomagnesemia is uncommon among renal patients but may occur in association with the hungry bone syndrome. Correction of hypomagnesemia to normal range is warranted to avoid other metabolic complications, including poor response to calcium supplementation among those with hypocalcemia. The onset and degree of hyperkalemia seem to correlate with the time and degree of hypocalcemia, respectively. Although the responsible mechanisms for postparathyroidectomy hyperkalemia have not been elucidated, we propose that vitamin D deficiency and hypocalcemia may induce insulin deficiency and a resultant reduction in intracellular potassium shift. A low level of 5% dextrose infusion alone has not proved adequate in preventing postparathyroidectomy hyperkalemia. Postoperative elevation of plasma bone-specific alkaline phosphatase has also been described. A significant increase may be observed 4 days after parathyroidectomy with a peak value at 7 to 14 days. A decrease in the alkaline phosphatase level is expected to occur by the third postoperative week with normalization by the sixth postoperative month. The postoperative change in plasma alkaline phosphatase level has been attributed to enhanced osteoblastic activity. Suggested perioperative management guidelines for parathyroidectomy are summarized in Table 62. Other Postparathyroidectomy Complications In addition to the electrolyte and metabolic disturbances observed after parathyroidectomy, other complications may occur. Direct surgical complications include pain, poor wound healing, formation of a hematoma or seroma, and damage to the recurrent laryngeal nerve with vocal cord paralysis. As previously noted, both hypo- and hyperparathyroidism may be observed postoperatively. Hypoparathyroidism may result from inadequate remnant parathyroid mass or poor function of the remnant tissue caused by infarction. In the setting of hypoparathyroidism, existing undiagnosed aluminum-related osteomalacia may worsen. Persistent hyperparathyroidism may occur secondary to missed accessory glands or incomplete parathyroidectomy and may require reexploration. Proliferation of the remnant tissue may contribute to recurrent hyperparathyroidism, particularly among patients with continuing exposure to the uremic milieu. Finally, in some patients with pre­end-stage renal disease, significant postoperative deterioration in renal function has been reported. Levels of different electrolytes may need to be checked more frequently if they are severely abnormal. Although most reports suggest improved long-term survival with parathyroidectomy, current data with calcimimetics have not shown similar benefits. Calcimimetics for secondary hyperparathyroidism in chronic kidney disease patients. Vitamin D response elements in promoters P1 and P2 confer transcriptional responsiveness to 1,25-dihydroxyvitamin D. Chemical ablation of recurrent and persistent secondary hyperparathyroidism after subtotal parathyroidectomy. Japanese Society for Parathyroid Intervention: Guidelines for percutaneous ethanol injection therapy of the parathyroid glands in chronic dialysis patients. Incidence of and risk factors for hungry bone syndrome in 84 patients with secondary hyperparathyroidism. These cysts are associated with potential complications, including significant bleeding and malignant neoplasms. Epidemiology Acquired cystic kidney disease is more commonly observed in men and those of African descent. Acquired renal cysts are found in fewer than 10% of predialysis patients with long-standing azotemia (serum creatinine >2. However, the incidence increases to 10% to 20% after 1 to 3 years of dialysis and to 90% or greater in those dialyzed for more than 8 to 10 years. These cysts have been reported in patients on either peritoneal dialysis or hemodialysis. Pathophysiology the pathophysiology of acquired renal cysts is uncertain, but numerous etiologic factors have been proposed, including ischemia, intratubular obstruction from casts or calcium oxalate crystals, and interstitial fibrosis leading to extratubular constriction and obstruction. These cysts form from tubules and often remain in communication with one or more tubular segments. The cysts are usually lined by a single layer of epithelial cells, which reveal an increased proliferative capacity, and some may demonstrate epithelial hyperplasia with tufting of the cells. The immunophenotype of most cystlining cells is often consistent with proximal tubular epithelial cells but can also consist of distal nephron epithelial cells. Cysts tend to be larger and more numerous and to exhibit increased growth in males compared with females. The proto-oncogene c-jun has been noted to be increased in early cyst formation associated with hyperplastic epithelium. Other potential 721 722 Acquired Cystic Kidney Disease "renotropic factors" remain to be identified. Of interest, apolipoprotein L1 (ApoL1) is expressed in proximal tubular epithelial cells, and microcystic tubular dilation and thyroidization-type tubular atrophy were recently found to be fairly specific features in the kidneys of patients with two ApoL1 risk alleles (G1 or G2 variants). In the earliest reports, one third of patients with cysts were found to have neoplasms. Most neoplasms were small, which were classified as renal adenomas based on their size (<5 mm) and may be multifocal and bilateral. Some of these tumors may develop in the native kidneys of patients after kidney transplantation. Tumors have even occurred in pediatric patients who have been on dialysis for a prolonged period. Diagnosis and Screening Two imaging techniques have been the mainstays for detection of renal cysts. However, end-stage kidneys are often shrunken and exhibit marked increased echogenicity, making cysts difficult to detect with ultrasonography. In addition, the low resolution of this technique may preclude the detection of small cysts and tumors (<0. Magnetic resonance imaging with gadolinium for further evaluation of complicated cystic renal lesions may be the best technique. Schwarz and colleagues have recently suggested screening guidelines for kidney transplant patients. The frequency of ultrasound screening would increase with the complexity of renal cysts as detected by imaging. However, screening may be more beneficial in younger patients and those with fewer comorbidities and longer life expectancies. Other factors to be considered include the duration of azotemia (serum creatinine >2. This screening will identify those patients with tumors before instituting active immunosuppression therapy. A similar conservative approach is used for the treatment of retroperitoneal hematomas, although nephrectomy may be needed for uncontrollable hemorrhage or intractable pain. However, nephron-sparing surgeries (radiofrequency ablation or cryoablation) and even active surveillance are gaining acceptance, especially in patients who may be poor surgical candidates. Nephrectomy should also be performed in all patients with tumors of any size who are candidates for renal transplantation. Development of acquired cystic disease and adenocarcinoma of the kidney in glomerulonephritic chronic hemodialysis patients. Increased proto-oncogene activation in early tumors associated with acquired cystic kidney disease. Comparison of acquired cystic kidney disease between hemodialysis and continuous ambulatory peritoneal dialysis. Renal cell carcinoma in transplant recipients with acquired cystic kidney disease. Recommended screening guidelines for renal neoplasia after kidney transplantation. Furthermore, kidney disease accounts for most of the excessive cardiovascular and all-cause mortality risk associated with diabetes. Recent guidelines continue to support early initiation for patients with diabetes. Relative to other outcomes data, information concerning mortality rates and factors that influence mortality soon after initiation of dialysis in incident dialysis patients is limited. Mortality risk among hemodialysis patients is highest in the first 3­4 months after dialysis initiation. Dysglycemia the maintenance of glucose homeostasis is affected both by diabetes and by kidney failure. The core pathologic defects in diabetes are decreased insulin secretion (type 1) and insulin resistance, impaired insulin secretion, increased hepatic glucose production, decreased glucose uptake by muscle, and increased renal glucose reabsorption (type 2). When kidney impairment progresses, additional alterations occur which may further cause dysglycemia: insulin secretion by the pancreas is reduced, and insulin clearance is diminished. With a molecular weight of 6000, insulin has a high renal clearance through filtration and secretion. Abnormal glucose homeostasis is further affected in uremic individuals by peripheral insulin resistance, involving defective glucose uptake and reduced muscle protein anabolism (but not cellular potassium uptake). Glucose uptake mediated by specific transporter proteins is a major action of insulin. Improvement with dialysis treatment is due at least in part to removal of uremic toxins. A significant reduction in insulin requirements following a hemodialysis treatment may be anticipated. In the general population, prediabetes is identified by a hemoglobin A1c (HbA1c) value of 5. The risk of diabetes is not linear, but increases with higher HbA1c levels below the diabetic range. Prediabetes is associated with increased risk of all-cause and cardiovascular mortality in the general population. In the general diabetes population, HbA1c is the primary predictor of diabetic complications. HbA1c reflects average blood glucose concentrations over approximately the 3 preceding months, correlates fairly well with blood glucose levels, and has provided evidence in interventional trials of the benefit of tight glycemic control. Compared with the general diabetic population, correlation with average glucose levels is weaker. The most likely sources of discordance from other glycemic tests in kidney patients are anemia, the use of erythrocyte-stimulating agents, and the administration of intravenous iron.

In general natural treatment for post shingles pain buy cafergot overnight delivery, pets should not be allowed during the dialysis process pain management in dogs and cats generic cafergot 100 mg with amex, as they may pose both a hygiene and safety problem pain treatment center bethesda md order cafergot in united states online. Even if the pet is supervised laser pain treatment for dogs purchase cafergot 100 mg overnight delivery, the pet should be kept out of the room during treatment initiation spine diagnostic pain treatment center baton rouge cheap cafergot 100 mg buy on-line. These hygiene requirements should extend to both the patient as well as any family member who may be assisting with the dialysis process. The participation of the family should also be assessed as part of the home visit prior to the consideration of home hemodialysis. Safety All dialysis machines should be equipped with monitors to detect exact arterial and venous pressures, with settings to narrow alarm ranges. The alarm type is usually sound based but may need to be light based in special circumstances. Leak detectors should be placed around the vascular access site, under the dialysis machine, as well as the water treatment system, to detect either blood, dialysate, or water leaks. Flashlights should be kept within easy reach so that the patient has an alternative light source in the event of a power failure to allow termination of treatment. Twenty-four-hour access to the supporting dialysis care facility or technical support should be available in the event of emergencies. The relevant contact numbers for the dialysis unit and technical support should also be within easy access in the dialysis room. Medical Staff and Technical Support Machine breakdowns may occur, for example, due to electrical or water problems. The dialysis unit supporting the patient should also be informed if a machine breakdown occurs so that the appropriate advice can be given and the technical staff directed to the home to service the machine. Disposal of Waste For most patients, disposal of the effluent via the sewage system provides the best option. Appropriate drainage systems should be taken into consideration during the planning process. All sharps should be collected in a dedicated sharps container for proper disposal. The other waste can be disposed of with the general waste, but should be double-bagged. Recycling of plastic waste can also be considered, given that the dialysis process has a high amount of plastic waste production. The patient Home Preparation and Installation for Home Hemodialysis 213 should check with the dialysis unit providing the dialysis support regarding any extra waste disposal requirements. Conclusion Medical and technical support is essential for the development of a home hemodialysis program and training. With proper preparation, the establishment of home hemodialysis can be facilitated safely and efficiently and allow the patient to benefit from this treatment modality. This article describes how home hemodialysis may allow for improved fertility, which may be an important consideration for female patients in the childbearing age group. Comparison of survival between short-daily hemodialysis and conventional hemodialysis using the standardized mortality ratio. This article describes improved survival for patients on short daily dialysis compared with conventional hemodialysis. Short-term blood pressure, noradrenergic, and vascular effects of nocturnal home hemodialysis. Effect of frequent nocturnal hemodialysis vs conventional hemodialysis on left ventricular mass and quality of life: a randomized controlled trial. This article provides an insight into how nocturnal hemodialysis improves left ventricular mass, an important predictor of cardiovascular disease and mortality. This review article provides an overview of the benefits, risks, as well as the possible target population for intensified home hemodialysis. This article describes how nocturnal dialysis is associated with improvements in general as well as kidney disease­ related quality of life and physical functioning. The cost-effectiveness of contemporary home haemodialysis modalities compared with facility haemodialysis: a systematic review of full economic evaluations. This article compares home hemodialysis and facility-based hemodialysis and reviews the economic benefits of home hemodialysis. The effects of nocturnal compared with conventional hemodialysis on mineral metabolism: a randomized-controlled trial. This article describes how nocturnal dialysis is associated with improvements in phosphate control, as well as reducing the need for phosphate binders. Survival in daily home hemodialysis and matched thrice-weekly in-center hemodialysis patients. This article describes the improved survival for patients on daily home hemodialysis as compared to patients on thrice-weekly in-centre hemodialysis. Although the emphasis during the early years was mainly on optimizing hydraulics and mechanical aspects, the current development goes far beyond filling the abdomen and draining the dialysate. Modern cyclers are highly integrated devices that are designed to communicate and exchange data with other devices. Mechanical Aspects and Hydraulics Peritoneal dialysis cyclers are designed to automatically deliver multiple exchanges of dialysate solution. The dialysate flow is regulated by a central control unit that may include pumps, weigh scales, occluders, manifolds, electronics, and other mechanical components. A display screen and control board is needed to enter patient treatment parameters and monitor treatment success. The filling of the abdomen and draining of the dialysate can be performed by gravity- or pump-based systems. Mechanically, cyclers can be categorized as devices that exclusively use gravity, combine gravity and pumps, or use pumps only. In either case, the cycler ensures that the fluid is heated to body temperature and the exact prescribed volume of dialysate is delivered to the patient. After the prescribed dwell period, the spent dialysate flows by gravity through the patient line into a weigh bag where the volume is measured to ensure complete drain and determine ultrafiltration. The dialysate is then either collected in an additionally attached drainage bag or disposed directly into the sewage. The transfer of dialysate into the sewage line can be accomplished by gravity or via a pump. The control panel controls temperature and dwell time and monitors drain time and drainage volume. Most cyclers simply ensure that a predetermined percentage of inflow volume is drained before a new cycle takes place. Inflow volume is determined and measured by a volume control unit or heating cabinet. Combined Gravity- and Pump-Based Cyclers There are various systems that combine one or multiple active pumps and gravitybased transport of the dialysate. In the simplest setup, one pump is added to a gravity-based system to help drain the dialysate effectively from the weigh bag to the drainage bag or sewer. With any option of combined gravity- and pump-based cyclers, the fill and drain of the patient is performed by gravity only. After completion of the dwell, the inflow lines are occluded and the fluid is passively drained into a weigh bag mounted on a second weight transducer. Once drainage is accomplished, the pump voids the spent dialysate into a drain bag or sewer. All these functions are integrated by a control cabinet using microprocessors that allow precise control of inflow volume, ultrafiltration monitoring, dwell time, drain time, and number of cycles. The incorporation of active transfer of dialysate to a measuring unit located above the patient level allows for the design of simpler tubing sets and the practical use of larger volumes with a potential reduction in cost of therapy. Pump-Based Cyclers Various systems have been designed to actively infuse and drain dialysate. The first actively infuses warmed dialysate into the patient, and the second generates negative pressure to drain the spent dialysate. A more ingenious alternative is the use of an integrated cassette design for easy setup of the cycler. The exact measurement of fluid volume flowing through the cassette can be used for volumetric control and eliminates the need for weigh scales. Examples of contemporary cyclers shown for educational purposes only and are not available or approved in all countries. Various connectors have been used, including spikes, Luer locks, and threaded male­female connectors with recessed pathways. Dialysate bags with integrated patient and drain lines add more convenience for the patient due to fewer connections. Automated connections use a stationary manifold and a moving tray (connection rail) to attach the bag lines to the cassette. This technology simplifies the procedure and reduces the risk of touch contamination by the patient. Information Technology and Connectivity Modern cyclers have incorporated new functions as a result of continuously advancing electronics, computer systems, and connectology. Color touchscreens, direct interface with central computers in medical centers or dialysis facilities, and accessory programs allow comprehensive record keeping and easy access to patient and prescription data. With this information readily available, the renal team can monitor adequacy of the dialysis treatment, provide feedback to the patient based on his or her clinical parameters and documented treatment compliance and incorporate changes in the prescription. In some cases, the dialysis prescription may be downloaded in the clinic to an external memory device that is reinserted into the cycler by the patient at home and the cycler is automatically reprogrammed with the new prescription. Data encryption with various levels of user rights ensures that only authorized individuals can access and/or modify part or all available information. Data provided by the cycler can also be used by technical support teams to troubleshoot and diagnose potential malfunctions of the device. User Interface and Ease of Use Much effort has been put into enhancing usability and user experience of modern cyclers. Technology advances include user interfaces with large graphical touchscreen displays, large soft buttons in selectable colors, and soft keypads for entering numerical values. The user-friendly screens allow for easy selection of regimen, times, and volumes. Patients may be guided at all times through on-screen video and audio instructions in the language of his or her choice. Dialysate fluid bag connections and patient line connections are illustrated in a stepwise manner and explained on the display for easy operation. The incorporation of bar codes has been used to automatically identify the type of solution employed. This feature ensures selection of the correct dialysis solution based on the latest prescription. Other approaches to enhance ease of use are integrated voice commands, visual and audio feedback, and alarms. Cost Considerations the many models of cyclers on the global market reflect the requirements of different regimens, prescriptions, and availability of funds devoted to renal replacement therapy in different countries. The convenience and safety offered by the state-ofthe-art cycler technology is impressive but not essential to the delivery of adequate care. Compared with manual peritoneal dialysis, the use of a cycler necessarily increases the cost of therapy. Using fewer but larger-volume dialysate bags manufactured with less expensive material and simplified packaging; 2. Reducing the number of necessary connections and other steps that require additional, often expensive materials to maintain an aseptic environment; and 4. Reduction of disposables through reutilization of solution bags as drainage bags and the elimination of drain bags by direct disposal of spent dialysate into the sewage lines. The disposable cassette may load automatically with silicone membrane valves that can be independently opened and closed using a pin and a small motor to fill or drain the dialysate. Some cyclers already offer more flexible prescription options to individualize each single dialysate exchange. New possibilities emerge through increasing wireless connectivity of medical devices using Wi-Fi or Bluetooth. Since home care means that assistance may be needed at any time, enhanced connectivity and integrated cameras may allow video-conferencing capability with direct and timely access to the dialysis nurse or the nephrologist at the touch of a button. Recent advances allow much improved usability and integration of information from multiple sources to facilitate comprehensive management of the peritoneal dialysis patient. Modern cyclers have come a long way to become interactive, user-centered medical devices that partner with the patient and physician in delivering a highly individualized dialysis treatment and user experience. Technological advances in membrane design, chemical composition, and sterilization methods have led to enhanced performance and versatility to the extent that dialyzer choice may reduce morbidity and prolong survival. The membrane is the core of the dialyzer, and the dialyzer is the core of the extracorporeal treatment. According to this concept, it is clear the importance of the dialyzer to obtain the best blood purification for each individual clinical need. There is currently a wide selection of dialyzers in terms of type of membrane, surface, characteristics of surface, and method of sterilization. The membrane is the "device" that allows one to obtain the processes of diffusion, convection, and adsorption required to purify the blood in the extracorporeal circulation. The membrane allows one to broaden the spectrum of uremic toxins that can be removed depending on its chemical and physical characteristics. Thus, bioengineering advances over the last decade have resulted in the introduction of a wide spectrum of hemodialyzers and filters together with a multitude of different membranes that are currently available commercially. The first major distinction, between the types of membranes, can be made by dividing the membranes into cellulosic and synthetic as shown in Table 17. The polymer used in the dialysis membrane essentially determines the chemical and physical behavior of the membrane and its possible uses in the extracorporeal purification.

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The two sides of a chemical reaction (and therefore a chemical equation) ­ the reactants and the products ­ must balance midsouth pain treatment center reviews order cafergot 100 mg online. In other words pain treatment and wellness center cafergot 100 mg on line, no atoms/molecules are lost in a chemical reaction pain treatment center of baton rouge generic cafergot 100 mg overnight delivery, they are just organised differently pain treatment journal cafergot 100 mg with mastercard. Another thing to be aware of with chemical reactions is that although the numbers of atoms are the same before and after the reaction acute pain treatment guidelines buy cheap cafergot, during a chemical reaction, something extra is usually produced every time ­ namely, heat. This is known as an exothermic reaction, which is a process/reaction that gives out energy in the form of heat. In a chemical equation, the reactants and the product may be separated by a single arrow as in the earlier example of H2O. This indicates that the reaction occurs only in one direction, namely in the direction that the arrow is pointing. Sometimes the reactants and product may be separated by two arrows ­ one above the other and pointing in different directions. 0 Another important principle to be aware of, as regards chemical reactions and equations, is that a chemical equation has to be consistent. If electrical charges are involved (as occurs with the involvement of ions), the net charge on both sides of the equation must be equal ­ that is, they must balance. However, balancing a chemical equation (and thus a reaction) may require the altering of the quantity of molecules. However, if an atom or molecule is preceded by a large number, then that applies to everything immediately afterwards until another mathematical symbol. In this chemical reaction/equation, two molecules of hydrogen chloride (in the form of two ions of chloride, Cl-, and two ions of hydrogen, H+) along with one atom of zinc have been changed to one molecule of zinc chloride (ZnCl2) and one molecule of hydrogen (H2). So, even though the original atoms have now been combined differently following the chemical reaction, Basic scientific principles of physiology Chapter 1 the balance between the two sides of the equation in terms of numbers and types of atoms and electrical charge has not been altered. The presence of the doubleheaded arrow means that the equation is capable of being reversed, so that the products become the reactants, and the reactants the products. Counting the numbers and types of each atom on both sides demonstrates again that nothing is added and nothing deleted when the reaction takes place ­ everything is just rearranged in such a way that elements that can be used by the body are produced (along with any waste elements, which are then excreted). This is the end of the section on chemical equations, and as can be seen, if someone can do simple arithmetic, then they can understand and work with chemical equations (remembering that the equations are a depiction of chemical reactions that are taking place within the body all the time). In contrast, the attainment and maintenance of a single reliable, long-lasting dialysis access with minimal complications continue to be challenging. Achievement of such an access is associated with optimal patient clinical outcomes, superior quality of life, and minimal costs. This approach contrasts to a prior, more static approach where the goal was to attain an "ideal vascular access" for all patients for all time. Theoretically, such an ideal access would improve outcomes and limit costs, yet a onesize-fits-all approach may inadvertently have unintended negative consequences to both patients and health care systems. Similarly, the importance of hemodialysis vascular access planning, creation, and maintenance in a patient transitioning from transplantation will be briefly discussed. Multidisciplinary Approach to Vascular Access Strategy and Roles Key members of the multidisciplinary vascular access team include the nephrologist, surgeon, endovascular interventionalists, vascular access coordinator, cannulator (typically nurse or technician), the patient, and his or her support system. The planning, creation, and maintenance phases of the vascular access have different emphases, and, as such, a different team member may "lead" where needed and appropriate. This requires a mutual respect and trust among team members where clear, timely, and effective communication between health team members, and between health team members and the patient and their support team, is critical for successful access care. The vascular access coordinator facilitates communication and activities across all phases. The patient and his or her support system should be engaged to participate in informed decision making during all phases. When patients and their family members are active participants in the decision-making process, adherence greatly improves. For example, in a nationwide study of >3000 patients, patients who received education about vascular access had an odds ratio of 2. A key element to emphasize in the education of patients about hemodialysis vascular access is to preserve veins by protecting them against venopunctures, intravenous lines, central venous catheterizations, and pacemaker insertions on the side of the planned future hemodialysis vascular access. For example, when venous access is required, only the dorsal aspect of the hand should be used. Patients already undergoing hemodialysis can have blood drawn during their hemodialysis session to preserve veins. This emphasis on vein preservation, as well as other important vascular access education, must be supported by health care workers and administration alike within the hospital or dialysis facility, in order for it to be effective. Optimal patient outcomes and lowered costs will reinforce the effectiveness of comprehensive modality and access education. Patient and Vascular Access History A "hemodialysis access­focused" history is unique and required in planning dialysis access. Physical Examination the focused physical examination includes a detailed inspection of the neck, chest, abdomen, and extremities. The hemodialysis vascular access examination requires a relaxed patient in a comfortable environment. A cold room will cause vessel vasoconstriction and potentially underestimate the size of available vessels. The arterial assessment includes evaluation of pulse quality, segmental blood pressure, and the Allen test. The venous system comprises a detailed inspection and palpation for vessel integrity, caliber, and size. Consider grafts if hemodialysis needed, or catheter if strong patient preference Consider graft or catheter if strong patient preference Good fistula candidate Poor Good Assess for fistula. Consider risk of fistula failure (age, comorbidities, vessel quality /suitability), vascular sites available, prior access failure, future access sites and possibilities Poor fistula candidate No Proceed with fistula creation Is prolonged catheter dependency anticipated Imaging must document full compressibility and patency of all vessels examined with absence of any luminal defects and/ or thrombosis. A photoplethysmography probe is used to obtain the baseline thumb arterial flow Doppler signal without any compression maneuvers. The signals are then obtained repeatedly while manually compressing the radial artery first, the ulnar artery next, and then both arteries together. The value of preoperative vessel mapping has ranged from harmful (leading to delays in access creation and greater failures), equivocal (similar outcomes to physical exam), and superior with improved fistula outcomes. Snuffbox radiocephalic fistula: an anastomosis between the distal radial artery and cephalic vein (between the tendons of the extensor pollicis brevis and extensor pollicis longus in the anatomic snuffbox). The optimal progression of access is from the nondominant upper extremity distally to proximally, using autogenous veins (A). Once all autogenous veins have been exhausted, prosthetic graft should be used in the same progression. When upper extremity access sites have been depleted, the lower extremities can be used (C = autogenous fistula; D = prosthetic graft). The progression suggested is based on the durability of the conduit and likelihood of complications such as access thrombosis, steal syndrome, and infection. Radiocephalic fistula: the Brescia-Cimino fistula connects the radial artery to the cephalic vein. Radiobasilic transposition: the basilic vein in the forearm is also an excellent conduit for hemodialysis, although it needs to be transposed to the radial region for good function. Mobilization of the basilic vein, with retunneling, is a good alternative when the cephalic vein is not available in the forearm. Brachiocephalic (a variant is the Gracz fistula): a brachial artery to cephalic vein anastomosis; or brachiobasilic: brachial artery and transposed basilic vein anastomosis. Special circumstances · Veins with adequate diameter but inadequate length: the addition of harvested veins, such as saphenous veins, can be used to provide extra length that may be required (as in transposed fistulas) and is an option. Tunneling and transposition of veins may allow the approximation required to create an arteriovenous anastomosis. If successful, the second stage is to transpose the matured vein to a subdermal location to allow for cannulation. Straight forearm: a straight graft from the radial artery to the median cubital vein. Loop forearm: a loop graft connecting the distal brachial artery or proximal radial artery to the median cubital vein. Straight or curved upper arm: grafts of various configurations can connect the brachial artery with the basilic, brachial, or axillary vein. However, they may also be cuffed and tunneled within the subcutaneous tissue to reach the target vein. The right internal jugular vein is preferred to the left internal jugular vein because of a more direct route to the right atrium. Subclavian vein catheters should be avoided because of their high risk of central vein stenosis. After insertion, the position should be checked by a chest radiograph in the upright position. Regardless of location, all insertions should be guided by ultrasound, using the Seldinger technique. It is important to use a dilator over the guidewire before inserting the catheter to minimize vessel trauma. Lower Extremity Femoral Region When all upper extremity sites have been exhausted, lower extremity access (primarily femoral) may be the only option. As with upper extremity access, lower extremity 34 Vascular Access for Hemodialysis in Adults Table 2. Stenosis of internal jugular veins is more common than previously indicated (up to 30% or more) and may rival the rate of central stenosis found with subclavian veins. However, the risk factors, timing, and onset of central stenosis is currently not well understood. This approach to preserve neck veins is particularly important to consider in patients with good prognosis and/or an expected long-term survival (particularly if they are not transplant candidates). Because of the higher flow rates through femoral vessels, there may be a greater risk of steal syndrome. There is also the potential risk of greater bacterial colonization and infection; careful access care using aseptic technique is required regardless of the location but special care is required in situations that put patients at high risk of access infection in the femoral region, such as diarrheal illness. A randomized controlled trial and several meta-analyses have demonstrated equivalent thrombosis and infection rates using tunneled femoral catheters compared with internal jugular catheters. However, except when there are no other available access options, femoral catheters should only be used for limited time frames and only when necessary. Unusual Locations Axillary-axillary/femoral-popliteal: When all conventional access sites have been exhausted, the access surgeon must be creative to obtain a permanent access. Connecting an available and adequate large artery to any acceptable outflow vein can, in necessary situations, result in a functional chronic dialysis access. It is critical, before a dialysis access is created, to consider the "exit strategy," that is, what corrective options are available for the patient in case of complications and/or what type and where the next access will be created. The presence of a palpable thrill, pulse quality, and appearance of the overlying skin. However, the patient who requires emergent or urgent hemodialysis deserves separate discussion. Emergent patient: the emergent patient requires immediate hemodialysis to limit or prevent life-threatening complications such as hyperkalemia, pulmonary edema refractory to medical management, uremic seizures, uremic pericarditis, and uremic bleeding, especially prior to required surgeries. In most cases, a temporary uncuffed femoral catheter is the most appropriate access. After dialysis has been completed, more permanent access can be discussed, if required. Again the focus is on saving central veins if the patient is anticipated to require permanent dialysis in the future. Other situations exist; however, the common factor is that the patient does not fit the criteria of "emergent" dialysis and has limited time (1­3 weeks) before dialysis becomes critically necessary. If hemodialysis is appropriate, an early cannulation graft can be placed and used within 72 hours. Once the graft becomes problematic, a fistula can be created by the cephalic vein developed by the graft. Buttonhole cannulation is associated with increased risk of infection and associated serious complications (septic emboli and metastatic seeding. Buttonhole cannulation should only be used in special circumstances such as those with short or limited cannulation length and convoluted and/or large aneurysmal fistulas. The newer "early cannulation grafts" can be used within 24 hours of creation while the standard grafts can be used 2­4 weeks after creation (depending on extremity swelling). A variety of synthetic and biologic materials can be used and/or are in development. Examples of biologic material­based grafts include bovine heterografts, bovine mesenteric vein, cryopreserved saphenous vein, human umbilical vein, and engineered human extracellular matrix compositions. There are a number of graft types (straight, tapered, spiral) and configurations that can be placed within the body (straight, loop, curve). Grafts can connect two vessels that may not otherwise be possible because of their distance. Thus, a graft can be used for almost any patient if he or she has acceptable receiving vessels. Multiple agents have been used to reduce stenosis and thrombosis such as warfarin, dipyridamole, sulfinpyrazone, ticlodipine, aspirin, dipyridamole and aspirin (Aggrenox), and fish oil. Only Aggrenox and fish oil have been found to be effective in reducing thrombosis and improving graft patency in randomized controlled trials. When hemodynamically significant stenosis (typically evidenced by clinical signs or symptom; see "On Dialysis Rounds" section) or thrombosis occurs, corrective endovascular or surgical intervention is needed to maintain or salvage graft patency. Previously, grafts have been shown to have a significantly greater infection risk than fistulas (up to 10-fold higher), but in recent data, they have shown equivalent infection risk. This may be due to more consistent perioperative antibiotic coverage, better attention to hygiene by patients, and use of aseptic cannulation technique by cannulators. Indeed, graft infection is a modifiable complication (see chapter on vascular access infections).

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