RESUMEN

BACKGROUND: The accuracy of prognostication has important implications for patients, families, and health services since it may be linked to clinical decision-making, patient experience and outcomes and resource allocation. Study aim is to evaluate the accuracy of temporal predictions of survival in patients with cancer, dementia, heart, or respiratory disease. METHODS: Accuracy of clinical prediction was evaluated using retrospective, observational cohort study of 98,187 individuals with a Coordinate My Care record, the Electronic Palliative Care Coordination System serving London, 2010-2020. The survival times of patients were summarised using median and interquartile ranges. Kaplan Meier survival curves were created to describe and compare survival across prognostic categories and disease trajectories. The extent of agreement between estimated and actual prognosis was quantified using linear weighted Kappa statistic. RESULTS: Overall, 3% were predicted to live "days"; 13% "weeks"; 28% "months"; and 56% "year/years". The agreement between estimated and actual prognosis using linear weighted Kappa statistic was highest for patients with dementia/frailty (0.75) and cancer (0.73). Clinicians' estimates were able to discriminate (log-rank p < 0.001) between groups of patients with differing survival prospects. Across all disease groups, the accuracy of survival estimates was high for patients who were likely to live for fewer than 14 days (74% accuracy) or for more than one year (83% accuracy), but less accurate at predicting survival of "weeks" or "months" (32% accuracy). CONCLUSION: Clinicians are good at identifying individuals who will die imminently and those who will live for much longer. The accuracy of prognostication for these time frames differs across major disease categories, but remains acceptable even in non-cancer patients, including patients with dementia. Advance Care Planning and timely access to palliative care based on individual patient needs may be beneficial for those where there is significant prognostic uncertainty; those who are neither imminently dying nor expected to live for "years".

Asunto(s)

Demencia , Neoplasias , Humanos , Estudios Retrospectivos , Datos de Salud Recolectados Rutinariamente , Pronóstico , Cuidados Paliativos , Neoplasias/diagnóstico , Neoplasias/terapia , Muerte , Demencia/diagnóstico

RESUMEN

Patients with cancer are at increased risk of venous thromboembolism (vte). Anticoagulation therapy has been shown to prevent vte; however, unique clinical circumstances in patients with cancer can often complicate the decisions surrounding the administration of prophylactic anticoagulation. No national Canadian guidelines on the prevention of cancer-associated thrombosis have been published. We therefore aimed to develop a consensus-based, evidence-informed guideline on the topic. PubMed was searched for clinical trials and meta-analyses published between 2002 and 2013. Reference lists of key articles were hand-searched for additional publications. Content experts from across Canada were assembled to review the evidence and make recommendations. Low molecular weight heparin can be used prophylactically in cancer patients at high risk of developing vte. Direct oral anticoagulants are not recommended for vte prophylaxis at this time. Specific clinical scenarios, including renal insufficiency, thrombocytopenia, liver disease, and obesity can warrant modifications in the administration of prophylactic anticoagulant therapy. There is no evidence to support the monitoring of anti-factor Xa levels in clinically stable cancer patients receiving prophylactic anticoagulation; however, factor Xa levels could be checked at baseline and periodically in patients with renal insufficiency. The use of anticoagulation therapy to prolong survival in cancer patients without the presence of risk factors for vte is not recommended.

RESUMEN

Patients with cancer are at increased risk of venous thromboembolism (vte). Anticoagulation therapy is used to treat vte; however, patients with cancer have unique clinical circumstances that can often make decisions surrounding the administration of therapeutic anticoagulation complicated. No national Canadian guidelines on the management of established cancer-associated thrombosis have been published. We therefore aimed to develop a consensus-based, evidence-informed guideline on the topic. PubMed was searched for clinical trials and meta-analyses published between 2002 and 2013. Reference lists of key articles were hand-searched for additional publications. Content experts from across Canada were assembled to review the evidence and make recommendations. Low molecular weight heparin is the treatment of choice for cancer patients with established vte. Direct oral anticoagulants are not recommended for the treatment of vte at this time. Specific clinical scenarios, including the presence of an indwelling venous catheter, renal insufficiency, and thrombocytopenia, warrant modifications in the therapeutic administration of anticoagulation therapy. Patients with recurrent vte should receive extended (>3 months) anticoagulant therapy. Incidental vte should generally be treated in the same manner as symptomatic vte. There is no evidence to support the monitoring of anti-factor Xa levels in clinically stable cancer patients receiving prophylactic anticoagulation; however, levels of anti-factor Xa could be checked at baseline and periodically thereafter in patients with renal insufficiency. Follow-up and education about the signs and symptoms of vte are important components of ongoing patient care.

RESUMEN

BACKGROUND: Silicosis is one of the oldest occupational lung diseases, but it continues to cause significant morbidity and mortality worldwide. AIMS: To report cases of silicosis presenting to two specialist respiratory clinics. METHODS: A retrospective analysis of prospectively collected data of cases of silicosis in workers referred to specialist respiratory clinics. RESULTS: Over the course of 6 years, six cases were identified. The patients were all male with an age range between 24 and 39 years. The duration of silica exposure ranged between 7 and 20 years (mean 13 years). Four cases were entirely asymptomatic at presentation, and two cases described minimal shortness of breath on exertion. Pulmonary function tests were normal in three cases, and a mild restrictive ventilatory defect was documented in the other cases. All had a low apparent predicted probability of pneumoconiosis based on health questionnaires, spirometry and duration of silica exposure. The initial chest X-ray was abnormal in all six cases with radiological evidence of silicosis (International Labour Office profusion category ≥1/1) on imaging, and all had evidence of silicosis on high-resolution computed tomography (HRCT). Three patients had already progressed to progressive massive fibrosis on HRCT scanning at the time of referral to specialist respiratory services. CONCLUSIONS: The appearances of these six cases of silicosis in young, asymptomatic construction workers emphasizes the importance of enforcing effective exposure control and comprehensive surveillance programmes. Our observations highlight the importance of having a low threshold for early radiological screening to promote early and effective detection of this disease.

Asunto(s)

Exposición Profesional/estadística & datos numéricos , Silicosis/epidemiología , Adulto , Humanos , Pulmón/fisiopatología , Masculino , Enfermedades Profesionales/diagnóstico por imagen , Enfermedades Profesionales/epidemiología , Radiografía , Estudios Retrospectivos , Silicosis/etiología , Reino Unido/epidemiología

RESUMEN

AIM: To investigate the cardiometabolic risk (CMR) assessment and management patterns for individuals with and without type 2 diabetes mellitus (T2DM) in Canadian primary care practices. METHODS: Between April 2011 and March 2012, physicians from 9 primary care teams and 88 traditional non-team practices completed a practice assessment on the management of 2461 patients >40 years old with no clinical evidence of cardiovascular disease and diagnosed with at least one of the following risk factor-T2DM, dyslipidaemia or hypertension. RESULTS: There were 1304 individuals with T2DM and 1157 without. Pharmacotherapy to manage hyperglycaemia, dyslipidaemia and hypertension was widely prescribed. Fifty-eight percent of individuals with T2DM had a glycated haemoglobin (HbA1c) ≤7.0%. Amongst individuals with dyslipidaemia, median low-density lipoprotein cholesterol (LDL-C) was 1.8 mmol/l for those with T2DM and 2.8 mmol/l for those without. Amongst individuals with hypertension, 30% of those with T2DM achieved the <130/80 mmHg target, whereas 60% of those without met the <140/90 mmHg target. The composite glycaemic, LDL-C and blood pressure (BP) target outcome was achieved by 12% of individuals with T2DM. Only 17% of individuals with T2DM and 11% without were advised to increase their physical activity. Dietary modifications were recommended to 32 and 10% of those with and without T2DM, respectively. CONCLUSIONS: Patients at elevated CMR were suboptimally managed in the primary care practices surveyed. There was low attainment of recommended therapeutic glycaemic, lipid and BP targets. Advice on healthy lifestyle changes was infrequently dispensed, representing a missed opportunity to educate patients on the long-term benefits of lifestyle modification.

Asunto(s)

Diabetes Mellitus Tipo 2/complicaciones , Dislipidemias/tratamiento farmacológico , Hiperglucemia/tratamiento farmacológico , Hipertensión/tratamiento farmacológico , Adulto , Anciano , Antihipertensivos/uso terapéutico , Colombia Británica , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Dislipidemias/complicaciones , Terapia por Ejercicio/estadística & datos numéricos , Femenino , Humanos , Hiperglucemia/complicaciones , Hipertensión/complicaciones , Hipoglucemiantes/uso terapéutico , Hipolipemiantes/uso terapéutico , Masculino , Persona de Mediana Edad , Ontario , Atención Primaria de Salud/estadística & datos numéricos , Quebec , Conducta de Reducción del Riesgo

RESUMEN

AIMS: To prospectively evaluate diabetes management in the primary care setting and explore factors related to guideline-recommended triple target achievement [blood pressure (BP) ≤ 130/80 mmHg, A1C ≤ 7% and low-density lipoprotein (LDL)-cholesterol < 2.5 mmol/l]. METHODS: Baseline, 6 and 12 month data on clinical and laboratory parameters were measured in 3002 patients with type 2 diabetes enrolled as part of a prospective quality enhancement research initiative in Canada. A generalised estimating equation model was fitted to assess variables associated with triple target achievement. RESULTS: At baseline, 54%, 53% and 64% of patients, respectively, had BP, A1C and LDL-cholesterol at target; all three goals were met by 19% of patients. The percentage of individuals achieving these targets significantly increased during the study [60%, 57%, 76% and 26%, respectively, at the final visit, p < 0.0001 except for A1C, p = 0.27]. A much smaller proportion of patients had adequate control during the entire study period [30%, 39%, 53% and 7%, respectively]. In multivariable analysis, women, patients younger than 65 years and patients of Afro-Canadian origin were less likely to achieve the triple target. DISCUSSION: As part of a quality enhancement research initiative, we observed important improvements in the attainment of guidelines-recommended targets in patients with type 2 diabetes followed for a 12-month period in the primary care setting; however, many individuals still failed to achieve and especially maintain optimal goals for therapy, particularly the triple target. Results of the multivariable analysis reinforce the need to address barriers to improve diabetes care, particularly in more susceptible groups.

Asunto(s)

Diabetes Mellitus Tipo 2/tratamiento farmacológico , Angiopatías Diabéticas/tratamiento farmacológico , Adulto , Anciano , Antihipertensivos/uso terapéutico , Glucemia/metabolismo , Presión Sanguínea/fisiología , Peso Corporal , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/fisiopatología , Angiopatías Diabéticas/sangre , Angiopatías Diabéticas/fisiopatología , Femenino , Hemoglobina Glucada/metabolismo , Humanos , Hipoglucemiantes/uso terapéutico , Hipolipemiantes/uso terapéutico , Metabolismo de los Lípidos , Masculino , Persona de Mediana Edad , Inhibidores de Agregación Plaquetaria/uso terapéutico , Estudios Prospectivos , Resultado del Tratamiento

RESUMEN

UNLABELLED: Human serum paraoxonase (PON1) activity is reduced in standard hemodialysis (SHD) (4 hours, 3 days/week) patients. Home nocturnal hemodialysis (HNHD) (8 hours, 6 days/week), provides a greater dialysis dose resulting in a greater clearance of metabolites. Whether improvements in the metabolic milieu of HNHD patients results in different PON1 activity levels compared to SHD patients is unclear. We determined serum PON1 mass and arylesterase activities in a group of HNHD patients and compared them to SHD patients and a group of healthy controls (HC). PATIENTS AND METHODS: We measured PON1 arylesterase activity and mass, C-reactive protein (CRP), cystatin C, total and high-density lipoprotein (HDL) cholesterol, triglycerides, apolipoproteins A-I and B in 15 HNHD, 15 SHD and 15 HC participants. RESULTS: PON1 arylesterase activity (p < 0.001) and mass (p < 0.05) were significantly higher in HC participants compared to SHD and HNHD participants, although no significant differences were noted between HD groups. CRP (p < 0.05) was significantly higher in SHD compared to HC participants and there were no significant differences noted between HD groups. Cystatin C (p < 0.001) was significantly different among the 3 groups. There were no significant differences noted in any lipoprotein parameters among the groups. PON1 activity (r = -0.636, p < 0.001) and mass (r = -0.425, p = 0.019) were inversely correlated with CRP in HD patients. CONCLUSION: PON1 is reduced in HNHD patients compared to HC subjects, independent of the concentration of HDL cholesterol. Within subjects on HD, the combination of increased CRP and reduced PON1 may identify subjects at a high risk for cardiovascular complications.

Asunto(s)

Arildialquilfosfatasa/sangre , Proteína C-Reactiva/metabolismo , Fallo Renal Crónico/enzimología , Diálisis Renal/métodos , Adulto , Biomarcadores/sangre , Enfermedades Cardiovasculares/enzimología , Enfermedades Cardiovasculares/etiología , Femenino , Estudios de Seguimiento , Humanos , Fallo Renal Crónico/complicaciones , Fallo Renal Crónico/terapia , Masculino , Persona de Mediana Edad , Pronóstico , Factores de Riesgo , Factores de Tiempo

RESUMEN

PURPOSE: The creation of a vascular access is necessary in hemodialysis patients, including those with marginal vessels. Upper arm fistulae are attractive due to the ease of creation and of achieving high access flow rates. Cephalic arch stenosis (CAS) can lead to failure of upper arm fistulae and is increasingly identified. We hypothesized that CAS is promoted by high blood flow rates, brachiocephalic fistulae, and an angle of cephalic vein insertion approaching 90 degrees. METHODS: All patients requiring a fistulogram between January 2004 and May 2006 had surveillance fluoroscopy of the central veins. Demographic, clinical and laboratory parameters were collected and the angle of the cephalic vein insertion measured by 3 blinded independent observers. RESULTS: Fifty-eight patients had fistulograms and CAS was detected in 18 subjects. Significant differences between the CAS and non-CAS groups were brachiocephalic fistula site (p = 0.046), access flow (mL/min) (p = 0.012), and absence of diabetes (p = 0.03). Univariate predictors of CAS include access flow (per 100 mL/min) (p = 0.042), platelet count (p = 0.031) and calcium-phosphate product (p = 0.026). The relationship of brachiocephalic site and CAS was confounded by access flow [(per 100 mL/min)*brachiocephalic fistula site (p = 0.016)] and fistula age [brachiocephalic fistula site*fistula age (p = 0.017)]. In multivariate analysis, renovascular disease, calcium-phosphate product, platelet count and access flow (per 100 mL/min)*brachiocephalic fistula predicted CAS (p < 0.001, Negelkerke's R-Square = 0.55). The angle of insertion of the cephalic vein was not predictive for CAS. CONCLUSIONS: CAS may be a long-term consequence of high blood flow rates. The interaction of access flow and brachiocephalic fistula supports the hypothesis that high flow through a brachiocephalic fistula promotes CAS. The multiple factors influencing cephalic arch remodeling require further research.

Asunto(s)

Brazo/irrigación sanguínea , Derivación Arteriovenosa Quirúrgica/efectos adversos , Arteria Braquial/cirugía , Venas Braquiocefálicas/cirugía , Oclusión de Injerto Vascular/etiología , Fallo Renal Crónico/terapia , Diálisis Renal , Adulto , Anciano , Velocidad del Flujo Sanguíneo , Arteria Braquial/fisiopatología , Venas Braquiocefálicas/diagnóstico por imagen , Venas Braquiocefálicas/fisiopatología , Calcio/sangre , Fosfatos de Calcio/sangre , Constricción Patológica , Femenino , Fluoroscopía , Oclusión de Injerto Vascular/epidemiología , Oclusión de Injerto Vascular/fisiopatología , Humanos , Fallo Renal Crónico/diagnóstico por imagen , Fallo Renal Crónico/fisiopatología , Modelos Logísticos , Masculino , Persona de Mediana Edad , Recuento de Plaquetas , Prevalencia , Estudios Prospectivos , Flujo Sanguíneo Regional , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Insuficiencia del Tratamiento

Asunto(s)

Protocolos Clínicos/normas , Poliaminas/uso terapéutico , Diálisis Renal/mortalidad , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Sevelamer , Análisis de Supervivencia

RESUMEN

Sleep apnoea is common in patients with end-stage renal disease (ESRD). It was hypothesised that this is related to a narrower upper airway. Upper airway dimensions in patients with and without ESRD and sleep apnoea were compared, in order to determine whether upper airway changes associated with ESRD could contribute to the development of sleep apnoea. An acoustic reflection technique was used to estimate pharyngeal cross-sectional area. Sleep apnoea was assessed by overnight polysomnography. A total of 44 patients with ESRD receiving conventional haemodialysis and 41 subjects with normal renal function were studied. ESRD and control groups were further categorised by the presence or absence of sleep apnoea (apnoea/hypopnoea index > or =10 events.h(-1)). The pharyngeal area was smaller in patients with ESRD compared with subjects with normal renal function: 3.04 +/- 0.84 versus 3.46 +/- 0.80 cm(2) for the functional residual capacity and 1.99 +/- 0.51 versus 2.14 +/- 0.58 cm(2) for the residual volume. The pharynx is narrower in patients with ESRD than in subjects with normal renal function. In conclusion, since a narrower upper airway predisposes to upper airway occlusion during sleep, it is suggested that this factor contributes to the pathogenesis of sleep apnoea in dialysis-dependent patients.

Asunto(s)

Fallo Renal Crónico/complicaciones , Faringe/patología , Apnea Obstructiva del Sueño/etiología , Adulto , Análisis de Varianza , Femenino , Humanos , Fallo Renal Crónico/terapia , Masculino , Persona de Mediana Edad , Polisomnografía , Análisis de Regresión , Diálisis Renal , Factores de Riesgo , Apnea Obstructiva del Sueño/diagnóstico , Apnea Obstructiva del Sueño/patología

RESUMEN

The need to improve the dialysis outcomes, the negative results from the HEMO and ADEMEX studies as well reports of clinical benefits have rekindled the interest in daily hemodialysis. Although no randomized controlled studies have been published, a large number of manuscripts have described significant benefits from both the short or nocturnal forms of daily (quotidian) dialysis or hemo(dia)filtration. They include improved quality of life, hemodynamic stability, blood pressure control with minimal number of medications, anemia control, regression of cardiac hypertrophy and improved nutrition. Furthermore, quotidian nocturnal hemodialysis provides higher dialysis dose, and has been described to improve endothelial as well as endothelial progenitor cell function, heart rate variability, sleep and phosphate control while it offers unrestricted diet. Several studies have pointed to a lower overall cost and improved cost utility when treating patients using quotidian hemodialysis at home. The obstacles to widespread use are the reimbursement structure in most countries, the willingness and ability of the patients to do home hemodialysis and the availability of user-friendly machines. A prospective randomized controlled study sponsored by the National Institutes of Health (NIH) and US Centers for Medicare and Medicaid services (CMS) currently underway will be pivotal in confirming these benefits and convincing the stakeholders to promote the use of daily hemodialysis.

Asunto(s)

Fallo Renal Crónico/terapia , Diálisis Renal/estadística & datos numéricos , Costos y Análisis de Costo , Humanos , Calidad de Vida , Diálisis Renal/efectos adversos , Diálisis Renal/economía

RESUMEN

In this issue, Tonelli et al. describe the cost-effectiveness of arteriovenous fistulae (AVF) screening, and conclude that such a program represents "good value for money." Here, I examine the robustness of this conclusion by considering traditional definitions of acceptable cost-effectiveness and more pragmatic definitions, which include consideration of the maximum amount that society would be willing to pay for hemodialysis.

Asunto(s)

Derivación Arteriovenosa Quirúrgica/efectos adversos , Derivación Arteriovenosa Quirúrgica/economía , Diálisis Renal/economía , Constricción Patológica/diagnóstico , Análisis Costo-Beneficio , Costos de la Atención en Salud , Humanos , Tamizaje Masivo , Resultado del Tratamiento

RESUMEN

Although sleep apnoea is very common in patients with end-stage renal disease, the physiological mechanisms for this association have not yet been determined. The current authors hypothesised that altered respiratory chemo-responsiveness may play an important role. In total, 58 patients receiving treatment with chronic dialysis were recruited for overnight polysomnography. A modified Read rebreathing technique, which is used to assess basal ventilation, ventilatory sensitivity and threshold, was completed before and after overnight polysomnography. Patients were divided into apnoeic (n = 38; apnoea/hypopnoea index (AHI) 35+/-22 events.h(-1)) and nonapnoeic (n = 20; AHI 3+/-3 events.h(-1)) groups, with the presence of sleep apnoea defined as an AHI >10 events.h(-1). While basal ventilation and the ventilatory recruitment threshold were similar between groups, ventilatory sensitivity during isoxic hypoxia (partial pressure of oxygen (PO2) 6.65 kPa) and hyperoxia (PO2) 19.95 kPa) was significantly greater in apnoeic patients. Overnight changes in chemoreflex responsiveness were similar between groups. In conclusion, these data indicate that the responsiveness of both the central and peripheral chemoreflexes is augmented in patients with sleep apnoea and end-stage renal disease. Since increased ventilatory sensitivity to hypercapnia destabilises respiratory control, the current authors suggest this contributes to the pathogenesis of sleep apnoea in this patient population.

Asunto(s)

Fallo Renal Crónico/tratamiento farmacológico , Insuficiencia Renal/tratamiento farmacológico , Síndromes de la Apnea del Sueño/tratamiento farmacológico , Apnea Obstructiva del Sueño/tratamiento farmacológico , Adulto , Anciano , Obstrucción de las Vías Aéreas , Femenino , Humanos , Hipoxia , Fallo Renal Crónico/complicaciones , Masculino , Persona de Mediana Edad , Monitoreo Fisiológico , Polisomnografía , Insuficiencia Renal/complicaciones , Respiración , Síndromes de la Apnea del Sueño/complicaciones , Apnea Obstructiva del Sueño/complicaciones

RESUMEN

Home nocturnal hemodialysis (HNHD) is cost-effective relative to in-center hemodialysis (IHD) in short-run analyses. The effect in long-run analyses, when technique failures, declining benefits, delayed training, transplantation and death are considered, is unknown. We used decision analysis techniques to examine the relative cost-effectiveness of HNHD and IHD, projecting future costs and health effects over a lifetime with end-stage renal disease. We developed a Markov state-transition model comparing two strategies: only IHD or starting on IHD and subsequently transferring to HNHD. The model incorporates transplantation. In the base case, half the population was eligible for transplantation, with (1/3) of grafts from live donors. The time to transplant was 0.75 years for live and 5 years for deceased donor transplants. The delay before initiation of HNHD was 5 years. Costs and outcomes were discounted at 3% per annum. Model parameters were derived from a literature review. We also conducted one-way sensitivity analyses and Monte Carlo simulations. The HNHD strategy was associated with a quality-adjusted survival estimate of 5.79 quality-adjusted life years (QALYs), with lifetime costs of $538 094. The values for IHD were 5.31 QALYs and $543 602, respectively. Thus, HNHD is cost saving while improving quality of life. The incremental cost-utility ratio was consistently less than $50 000 per QALY in sensitivity and Monte Carlo analyses. Important determinants of cost-effectiveness were transplantation time and whether benefits declined over time. Our model suggests that HNHD improves quality-adjusted survival over IHD at an economically attractive cost-effectiveness ratio.

Asunto(s)

Hemodiálisis en el Domicilio , Fallo Renal Crónico/terapia , Análisis Costo-Beneficio , Técnicas de Apoyo para la Decisión , Hemodiálisis en el Domicilio/economía , Hemodiálisis en el Domicilio/mortalidad , Humanos , Fallo Renal Crónico/economía , Fallo Renal Crónico/mortalidad , Cadenas de Markov , Años de Vida Ajustados por Calidad de Vida , Sensibilidad y Especificidad , Factores de Tiempo

Asunto(s)

Diálisis Renal , Intento de Suicidio , Ácido Valproico/envenenamiento , Trastorno Bipolar/tratamiento farmacológico , Femenino , Escala de Coma de Glasgow , Humanos , Persona de Mediana Edad , Naloxona/uso terapéutico , Intoxicación/terapia , Ácido Valproico/sangre

RESUMEN

Epidemic growth rates and the enormous cost of dialysis pressure end-stage renal disease (ESRD) delivery systems around the world. Payers of dialysis services can constrain costs through (1) limiting access to dialysis, (2) reducing the quality of dialysis, and (3) placing constraints on modality distribution. In order to secure the necessary resources for ESRD care, we propose that the nephrology community consider the following suggestions: First, future leaders in dialysis should acquire additional advanced training in innovative pathways such as health care economics, business and health care administration, and health care policy. Second, the international nephrology community must strongly engage in ongoing advocacy for accessible, high quality, cost-effective care.Third, efforts should be made to better define and then implement optimal dialysis modality distributions that maximize patient outcomes but limit unnecessary costs. Fourth, industry should be encouraged to lower the unit cost of dialysis, allowing for improved access to dialysis, especially in developing countries. Fifth, research should be encouraged that seeks to identify measures that will reduce dialysis costs but will not impair quality of care. Finally, early referral of patients with progressive renal disease to nephrology clinics, empowerment of informed patient choice of dialysis modality, and proper and timely access creation should be encouraged and can be expected to help limit overall expenditures. Ongoing efforts in these areas by the nephrology community will be essential if we are to overcome the challenges of ESRD growth in this new decade.

Asunto(s)

Diálisis Renal/economía , Costos y Análisis de Costo , Humanos , Diálisis Renal/normas

RESUMEN

The prevalence of electrocardiographic poor R-wave progression was estimated by reviewing all electrocardiograms recorded in Glasgow Royal Infirmary over a 2-week period. It was found to be higher in women (19% vs. 11%) than in men. To investigate one possible reason, the effect of chest electrode positioning in women was thereafter examined. Eighty four women were recruited to a study in which chest electrodes were placed strictly in adherence with recommendations of using the 4th and 5th intercostal spaces as references and also using the more widely adopted technique of placing electrodes V3 to V6 under the left breast. R wave amplitudes were compared in V3 to V6 from both sets of recordings. It was found that measurements recorded on the breast by electrode V3 have a significantly smaller R wave magnitude compared to corresponding measurements below the breast, the mean difference being 34 (95% confidence interval [CI] of 7 to 60) microvolts. For V5 and V6, the reverse is true with measurements taken on the breast being larger, on average, than those taken below the breast by 119 (95% CI of 87 to 152) and 134 (95% CI of 108 to 160) microvolts respectively. For V4, there was no significant difference. Seventeen women with poor R wave progression suggestive of old anterior myocardial infarction had clinical data examined from which it was determined that 11 had a history suggestive of myocardial infarction, ie, the positive predictive value was 65% (95% CI of 42% to 87%). It was concluded that positioning of electrodes beneath rather than on top of the breast was not responsible for the increased prevalence of poor R wave progression in women and that the criterion of isolated poor R wave progression was too nonspecific to be of clinical value.

Asunto(s)

Electrocardiografía/métodos , Infarto del Miocardio/diagnóstico , Adulto , Anciano , Anciano de 80 o más Años , Mama/anatomía & histología , Electrodos , Reacciones Falso Positivas , Femenino , Humanos , Persona de Mediana Edad , Infarto del Miocardio/epidemiología , Prevalencia

RESUMEN

Effects of human glucagon-like peptide I (GLP-I)(7-36)amide were examined in volunteers having insulin-dependent diabetes mellitus (IDDM) with residual C-peptide (CP) secretion (n = 8, 7 men and 1 woman; age, 31 +/- 1.4 years; body mass index, 24.7 +/- 0.7 kg/m2; duration of diabetes, 3.2 +/- 0.8 years; insulin dose, 0.41 +/- 0.05 U.kg-1.day-1; meal-stimulated CP, 1.0 +/- 0.2 nmol/l [means +/- SE]). After a mixed meal (Sustacal, 30 kJ/kg body wt), intravenous injection of GLP-I, 1.2 pmol.kg-1.min-1 through 120 min, virtually abolished increments of plasma glucose, CP, pancreatic polypeptide (PP), and glucagon concentrations, with no significant effect on plasma gastrin levels during the infusions. At reduced dosage (0.75 pmol.kg-1.min-1), GLP-I had lesser effects on plasma glucose and CP levels. On cessation of intravenous GLP-I infusions after the meals, plasma glucose, CP, PP, and glucagon concentrations rebounded toward control levels by 180 min, and the response of plasma gastrin was prolonged. These rebound responses are consistent with intestinal delivery of food retained in the stomach on escape from inhibition of gastric emptying by GLP-I. Infusion of 1.2 pmol.kg-1.min-1 GLP-I with 20 g glucose (10% dextrose in water) injected intravenously over 60 min enhanced plasma responses of immunoreactive CP; the mean incremental areas under concentration curves (0-60 min) increased sixfold, but the glycemic excursion was not affected. Thus, in CP-positive IDDM, pharmacological doses of GLP-I reduce glycemic excursions after meals by a mechanism(s) not dependent on stimulation of insulin secretion, presumably involving delayed gastric emptying.(ABSTRACT TRUNCATED AT 250 WORDS)

Asunto(s)

Glucemia/efectos de los fármacos , Diabetes Mellitus Tipo 1/fisiopatología , Glucagón/farmacología , Fragmentos de Péptidos/farmacología , Precursores de Proteínas/farmacología , Adulto , Glucemia/análisis , Péptido C/sangre , Diabetes Mellitus Tipo 1/sangre , Ingestión de Alimentos/fisiología , Femenino , Péptido 1 Similar al Glucagón , Humanos , Infusiones Intravenosas , Insulina/sangre , Masculino

RESUMEN

Nitrate concentrations in groundwater have been shown to be reduced during passage through riparian soils and a possible mechanism for this reduction is bacterial denitrifieation. For denitrification to occur there must be sufficient available C as an energy source. We examined the competition for organic substrate between microbial processes during the anaerobic decomposition of plant matter in a laboratory study. Fresh and senescent pine needles (Pinus radiata D. Don) and watercress leaves (Rorippa nasturtium-aquaticum L.Hayek) were added to an organic riparian soil, incubated anaerobically for 90 d and production of CO2 and CH4 measured. At 9-d intervals NO3 and acetylene were added to a replicate and production of CO2 , CH4 , and N2 O was followed. In the absence of NO3 , watercress produced the most CO2 and CH4 (21% of added C), followed by fresh pine needes (10%), and senescent pine needles (6%). First-order rate constants calculated for gaseous C production were 0.033 d-1 , 0.0088 d-1 , and 0.0071 d-1 for watercress, fresh, and senescent pine needles, respectively. As plant tissue became increasingly decomposed via fermentation, less N2 O and CO2 was produced following NO3 addition, presumably because the remaining plant matter was more resistant to further degradation. Denitrification and CO2 production in the watercress and fresh pine needle treatments were up to 5 times higher than that measured in the senescent pine needle treatment. As the same amount of C was added to all treatments, these results suggested that the lability of added C was of greater importance than the quantity of C added in regulating microbial response. The response of denitrifying bacteria to the addition of NO3 was rapid, even after 99 d of incubation in the absence of either NO3 or oxygen as an electron acceptor. This suggested that denitrifying bacteria could survive and compete for C in riparian soils where NO3 concentrations fluctuate.