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Catherine M Clase

Publications and source records attributed to Catherine M Clase.

15 recordsLinked to original sources
PubMed2005

Thromboembolism and anticoagulant management in hemodialysis patients: a practical guide to clinical management.

The need for anticoagulation in dialysis patients is common and the incidence of venous thromboembolism (VTE) and atrial fibrillation in this population is high. While direct data are lacking on the management of anticoagulation in dialysis patients, careful weighing of risks and benefits on the basis of evidence from other populations is crucial. VTE should be managed with adjusted dose warfarin for most patients. Placement of an inferior vena cava filter is a reasonable option for those patients with unacceptable bleeding risks. Studies are ongoing to assess the safety of some low-molecular-weight heparins (LMWH), which may potentially be useful for long-term anticoagulation in hemodialysis patients. In atrial fibrillation the available data on risk of bleeding, risk of stroke, and patient preferences should all be taken into account when considering long-term anticoagulation. We have constructed an evidence model to help quantitate the risks and benefits for an individual patient. The impact of dialysis on risk of bleeding is such that the risk of bleeding will outweigh the benefit in many patients, and anticoagulation will not be used: in some of these patients aspirin therapy may be an alternative. Finally, in the area of prevention of graft and access thrombosis, some randomized controlled trials are available, but none have to date shown benefit from anticoagulation for primary or secondary prevention of thrombosis, and the risk of bleeding in these studies was high.

Anticoagulants↗
PubMed2005

Sensitivity and specificity of color duplex ultrasound measurement in the estimation of internal carotid artery stenosis: a systematic review and meta-analysis.

BACKGROUND: Duplex ultrasound is widely used for the diagnosis of internal carotid artery stenosis. Standard duplex ultrasound criteria for the grading of internal carotid artery stenosis do not exist; thus, we conducted a systematic review and meta-analysis of the relation between the degree of internal carotid artery stenosis by duplex ultrasound criteria and degree of stenosis by angiography. METHODS: Data were gathered from Medline from January 1966 to January 2003, the Cochrane Central Register of Controlled Trials and Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, ACP Journal Club, UpToDate, reference lists, and authors' files. Inclusion criteria were the comparison of color duplex ultrasound results with angiography by the North American Symptomatic Carotid Endarterectomy Trial method; peer-reviewed publications, and >/=10 adults. RESULTS: Variables extracted included internal carotid artery peak systolic velocity, internal carotid artery end diastolic velocity, internal carotid artery/common carotid artery peak systolic velocity ratio, sensitivity and specificity of duplex ultrasound scanning for internal carotid artery stenosis by angiography. The Standards for Reporting of Diagnostic Accuracy (STARD) criteria were used to assess study quality. Sensitivity and specificity for duplex ultrasound criteria were combined as weighted means by using a random effects model. The threshold of peak systolic velocity >/=130 cm/s is associated with sensitivity of 98% (95% confidence intervals [CI], 97% to 100%) and specificity of 88% (95% CI, 76% to 100%) in the identification of angiographic stenosis of >/=50%. For the diagnosis of angiographic stenosis of >/=70%, a peak systolic velocity >/=200 cm/s has a sensitivity of 90% (95% CI, 84% to 94%) and a specificity of 94% (95% CI, 88% to 97%). For each duplex ultrasound threshold, measurement properties vary widely between laboratories, and the magnitude of the variation is clinically important. The heterogeneity observed in the measurement properties of duplex ultrasound may be caused by differences in patients, study design, equipment, techniques or training. CONCLUSIONS: Clinicians need to be aware of the limitations of duplex ultrasound scanning when making management decisions.

Blood Flow Velocity↗
PubMed2005

Coagulation disorders and blood product use in patients undergoing thoracoabdominal aortic aneurysm repair.

Repair of thoracoabdominal aortic aneurysms (TAAA) is associated with major blood loss, often exceeding the patient's intravascular volume, and complex intraoperative and postoperative coagulopathies necessitating large-volume transfusion of blood products. Abnormalities sufficient to cause thrombocytopenia or clinically important prolongation of clotting parameters are rarely present before surgery in elective aneurysms but are more common with ruptured aneurysms. The finding of intraoperative and postoperative deficiencies of clotting factors, along with thrombin generation and activation of the thrombolytic system, is reflective of massive blood losses, visceral ischemia, and massive transfusions. An aggressive strategy of transfusion of blood products is critical to the prevention of clinically significant coagulopathy during surgery. Adjuncts to reduce blood losses and blood product use include low-dose aprotinin or epsilon -aminocaproic acid, intraoperative blood salvaging, and acute normovolemic hemodilution. In TAAA repair, an average blood loss of 5000 to 6000 mL and average transfusion of allogeneic blood products of 50 to 60 U are to be anticipated.

Aortic Aneurysm, Abdominal↗
PubMed2005

Outcomes of acute coronary syndrome in a large Canadian cohort: impact of chronic renal insufficiency, cardiac interventions, and anemia.

BACKGROUND: Chronic renal insufficiency (CRI) has been identified as an important risk factor for cardiac events. Studies in the United States reported decreased survival and decreased use of surgical and medical interventions after myocardial infarction in patients with CRI. METHODS: We studied the impact of renal function on health outcomes in a Canadian cohort of consecutive patients admitted with acute coronary syndrome (ACS) between October 1997 and October 1999. The study design is an observational cohort of 5,549 adult patients who survived to discharge with a discharge diagnosis of ACS. Renal function is classified into 4 levels: (1) normal, glomerular filtration rate (GFR) greater than 80 mL/min/1.73 m2 (>1.33 mL/s); (2) mild CRI, GFR of 60 to 80 mL/min/1.73 m2 (1.00 to 1.33 mL/s); (3) moderate CRI, GFR of 30 to 59 mL/min/1.73 m2 (0.50 to 0.98 mL/s); and (4) severe CRI, GFR less than 30 mL/min/1.73 m2 (<0.50 mL/s). The primary outcome is death. RESULTS: Advanced and moderate CRI independently predicted death (hazard ratio, 1.06; 95% confidence interval [CI], 1.01 to 1.12; and hazard ratio, 1.23; 95% CI, 1.18 to 1.29). Severe anemia (hemoglobin level < 9.0 g/dL [<90 g/L]) also was an independent risk factor for death (hazard ratio, 1.38; 95% CI, 1.18 to 1.61). Use of beta-blockers (hazard ratio, 0.91; 95% CI, 0.86 to 0.97), acetylsalicylic acid (hazard ratio, 0.90; 95% CI, 0.84 to 0.97), lipid-lowering therapy (hazard ratio, 0.84; 95% CI, 0.78 to 0.89), and medical thrombolysis (hazard ratio, 0.89; 95% CI, 0.81 to 0.97) were associated with reduced risk for death. Medical interventions with beta-blockers, acetylsalicylic acid, lipid-lowering therapy, and thrombolysis and surgical intervention were significantly less likely to be used in patients with CRI. CONCLUSION: Despite universal access to health care, Canadian patients with CRI are more likely to die after a cardiac event and less likely to receive important interventions.

Adrenergic beta-Antagonists↗
PubMed2004

Muscle weakness and falls in older adults: a systematic review and meta-analysis.

OBJECTIVES: To evaluate and summarize the evidence of muscle weakness as a risk factor for falls in older adults. DESIGN: Random-effects meta-analysis. SETTING: English-language studies indexed in MEDLINE and CINAHL (1985-2002) under the key words aged and accidental falls and risk factors; bibliographies of retrieved papers. PARTICIPANTS: Fifty percent or more subjects in a study were aged 65 and older. Studies of institutionalized and community-dwelling subjects were included. MEASUREMENTS: Prospective cohort studies that included measurement of muscle strength at inception (in isolation or with other factors) with follow-up for occurrence of falls. METHODS: Sample size, population, setting, measure of muscle strength, and length of follow-up, raw data if no risk estimate, odds ratios (ORs), rate ratios, or incidence density ratios. Each study was assessed using the validity criteria: adjustment for confounders, objective definition of fall outcome, reliable method of measuring muscle strength, and blinded outcome measurement. RESULTS: Thirty studies met the selection criteria; data were available from 13. For lower extremity weakness, the combined OR was 1.76 (95% confidence interval (CI)=1.31-2.37) for any fall and 3.06 (95% CI=1.86-5.04) for recurrent falls. For upper extremity weakness the combined OR was 1.53 (95% CI=1.01-2.32) for any fall and 1.41 (95% CI=1.25-1.59) for recurrent falls. CONCLUSION: Muscle strength (especially lower extremity) should be one of the factors that is assessed and treated in older adults at risk for falls. More clinical trials are needed to isolate whether muscle-strengthening exercises are effective in preventing falls.

Accidental Falls↗
PubMed2003

Renal pathology at autopsy in patients who died after hematopoietic stem cell transplantation.

Acute and chronic renal dysfunction are common after hematopoietic stem cell transplantation (HSCT). Although the pathology of chronic HSCT nephropathy is well described, the histologic changes that accompany acute renal dysfunction after HSCT are less well known because renal biopsies are rarely undertaken in the peritransplantation period. Archival renal tissue from consecutive HSCT recipients who died and underwent autopsy at a single center during an 8-year period was studied. Abnormalities of renal pathology were described, and associations of histologic abnormalities with clinical events were systemically studied. Abnormalities of renal histology were common among the 26 patients in this study. The 3 most common histologic abnormalities were glomerular sclerosis (19/26; 73%), tubular epithelial atypia (19/26; 73%), and tubular calcification (18/26; 69%). Tubulitis (16/24; 67%) and interstitial fibrosis (16/26; 62%) were also frequently observed. Clinical veno-occlusive disease was not associated with histologic evidence of thrombotic microangiopathy in the kidney at autopsy. Also, clinical graft-versus-host disease was not associated with renal tubulitis. Unexpectedly, the proportion of patients with tubular atrophy (54%) or interstitial fibrosis (62%) was high, considering the young age of the patients at transplantation and their normal pretransplantation creatinine clearance. Well-recognized histologic abnormalities are common in the kidneys of patients who die after HSCT. Although we did not demonstrate associations of these histologic changes with clinical variables before death, larger studies with prospectively collected renal tissue are warranted.

Adolescent↗
PubMed2003

Screening for prostate, breast and colorectal cancer in renal transplant recipients.

American Society of Transplantation guidelines recommend screening renal transplant recipients for breast, colorectal and prostate cancer. However there is a lack of evidence to support this practice. Computer simulation modeling was used to estimate the years of life lost as a result of these cancers in 50-year-old renal transplant recipients and subjects in the general population. Renal transplant recipients lost fewer years of life to cancer than people in the general population largely because of reduced life expectancy. In nondiabetic transplant recipients, loss of life as a result of these cancers was comparable with that in the general population only under assumptions of increased cancer incidence and cancer-specific mortality risks. Even with two-fold higher cancer incidence and disease-specific mortality risks, diabetic transplant recipients lost considerably fewer life years to cancer than those in the general population. Recommended cancer screening for the general population may not yield the expected benefits in the average renal transplant recipient but the benefits will be considerably higher than for patients on dialysis. Transplanted patients at above-average cancer risk in good health may achieve the benefits of screening that are seen in the general population.

Colorectal Neoplasms↗
PubMed2002

Thoracoabdominal aortic aneurysm repair: a prospective cohort study of 121 cases.

Between October 1990 and June 2001, 121 patients underwent surgery for thoracoabdominal aortic aneurysm (TAAA)-99 procedures were elective and 22 were for ruptured aneurysms. Between October 1990 and September 1997, the clamp-and-go technique was used for all aneurysms (43 patients), and from October 1997, clamp-and-go was reserved for type IV TAAAs, and atriofemoral bypass (AFB) was used for types I, II, and III (78 patients). Overall hospital mortality was 21.4% (26/121)-12% for the elective group and 64% for the ruptured group. Hospital mortality was associated with age (67 years in survivors vs. 73 years in nonsurvivors, p = 0.03), FEV1<2 L (RR 4.1, p = 0.01), CSF drainage (RR 5.0, p = 0.03), type II aneurysms vs. other aneurysms (RR 3.7, p = 0.02), and relative inexperience (mean rank in the series was 52 in survivors vs. 30 in nonsurvivors, p = 0.01). The overall incidence of neurologic deficits due to spinal cord ischemia was 6.2% (paraplegia in 4.4%). Temporary dialysis was necessary in 13% of patients, and chronic dialysis in 2%. In long-term follow-up of patients undergoing elective repair, 5-year survival was 80% and median survival was 7.9 years. Mortality and neurologic deficits have improved over time as a consequence of either increased surgical experience, the adoption of a protocolized strategy for repair, or secular improvements in ICU care. Long-term survival after elective TAAA repair is excellent.

Acute Kidney Injury↗
PubMed2002

Albuminuria and renal insufficiency prevalence guides population screening: results from the NHANES III.

BACKGROUND: A number of screening criteria, applied either at a single point in time or serially, can be used for the purpose of identifying individuals at risk of end-stage renal disease (ESRD). This study focused on two such criteria measured on a single occasion, proteinuria and renal insufficiency, and examined their prevalence in a sample representative of the adult U.S. non-institutionalized population. Such knowledge guides the utility of population screening to prevent ESRD. METHODS: The prevalence of albuminuria (microalbuminuria and macroalbuminuria from a random urine albumin-to-creatinine ratio) and renal insufficiency [glomerular filtration rate (GFR) estimated from serum creatinine] was determined in different age categories in various adult screening groups in the cross-sectional Third National Health and Nutrition Examination Survey (NHANES III). RESULTS: A total of 14,622 adult participants were included in the analysis. In the general population, 8.3% and 1.0% of participants demonstrated microalbuminuria and macroalbuminuria, respectively. To identify one case of albuminuria, one would need to screen three persons with diabetes mellitus, seven non-diabetic hypertensive persons, or six persons over the age of 60. When albuminuria and renal insufficiency were considered together, it was clear that these tests were identifying different segments of the population; 37% of participants with a GFR less than 30 mL/min/1.73 m2 demonstrated no albuminuria. Non-albuminuric renal insufficiency was most evident in the ages of 60 to 79; 34% of diabetics, and 63% of non-diabetic hypertensives with a GFR less than 30 mL/min/1.73 m2 demonstrated no albuminuria. CONCLUSIONS: Albuminuria is prevalent, and when considered together, screening tests of albuminuria and renal insufficiency measured on a single occasion identify different segments of the population. The prevalence of albuminuria and renal insufficiency in populations of interest should be considered, as this knowledge has implications for the effectiveness of screening.

Adult↗
PubMed2002

The effectiveness of aerobic and muscle strength training in patients receiving hemodialysis and EPO: a randomized controlled trial.

BACKGROUND: Individuals with end-stage renal disease on hemodialysis therapy have reduced aerobic exercise capacity and reduced muscle strength. METHODS: This was a single-blind, randomized, placebo-controlled trial of an exercise intervention in hemodialysis patients administered erythropoietin. The intervention consisted of progressive resisted isotonic quadriceps and hamstrings exercise and training on a cycle ergometer three times weekly for 12 weeks. Individuals in the control group underwent a nonprogressive program of range-of-motion exercises. Both groups were observed for an additional 5 months without intervention. Outcomes were assessed without knowledge of treatment assignment at baseline, 12 weeks, and 5 months. A healthy age- and sex-matched sample provided comparative data. RESULTS: Our sample was relatively high functioning, with a mean score on the Physical Function subscale of the Short Form 36 (SF-36) of 76 of 100. At 12 weeks, there were large and statistically significant differences in favor of the experimental group on the submaximal exercise test (14 W; 95% confidence interval, 2 to 26) and muscle strength (45 lb; 95% confidence interval, 9 to 81), but not in the 6-minute walk, symptoms questionnaire, or SF-36. Differences between the intervention and control groups at 12 weeks were not evident on retesting 5 months after the end of the intervention. Compared with the healthy sample, patients were significantly lower functioning on the submaximal exercise test, muscle strength, and 6-minute walk test at baseline. CONCLUSION: In this high-functioning sample, the exercise program improved physical impairment measures, but had no effect on symptoms or health-related quality of life. The impact on patients with a greater degree of physical dysfunction needs to be rigorously studied.

Anemia↗
PubMed2002

Subclavian carotid transposition and bypass grafting: consecutive cohort study and systematic review.

PURPOSE: We describe outcomes in a cohort of patients undergoing subclavian carotid transposition (SCT) for occlusive disease of the first segment of the subclavian artery and perform a systematic review of the literature on SCT and carotid subclavian bypass grafting (CSB). METHODS: Relevance, validity and extraction of review results were done in duplicate. Data were collected prospectively in our consecutive cohort of patients. RESULTS: From September 1990 to February 2001, we performed 27 SCTs, four for aneurysmal disease and 23 for occlusive disease. SCTs done for aneurysms were excluded from the current analysis. In patients with occlusive disease, the primary indications for surgery were vertebrobasilar and carotid symptoms (10, 44%), vertebrobasilar insufficiency (7, 30%), vertebrobasilar and arm symptoms (4, 17%), carotid symptoms (1, 4%), and vertebrobasilar, carotid, and arm symptoms (1, 4%). An SCT was performed in conjunction with an endarterectomy of the carotid artery in 12 patients (52%), with an endarterectomy of the subclavian artery in seven patients (30%), and with an endarterectomy of the vertebral artery in six patients (26%). A lymph leak complicated two surgeries (9%). In our series, patients improved clinically after surgery, and reconstructions were all found to be patent by means of Doppler ultrasound scanning at a mean follow-up of 25 +/- 21 months. Three patients (13%) died during follow-up of complications of coronary artery disease. From 1966 to 2000, 516 patients who underwent CSB and 511 patients who underwent a SCT were reported in the literature. Patency rates were 84% and 98%, respectively (P <.0001; absolute risk reduction, 15%; number-needed-to-treat-differently, 7), and the rates of freedom from symptoms were 88% and 99%, respectively, at a mean follow-up of 59 +/- 17 months (range, 1-228 months). CONCLUSION: Our cohort study showed that SCT is safe and effective for reconstruction of the first segment of the subclavian artery. The systematic review suggested that rates of patency and freedom from clinical symptoms are higher with SCT than with CSB.

Aged↗
PubMed2002

Prevalence of low glomerular filtration rate in nondiabetic Americans: Third National Health and Nutrition Examination Survey (NHANES III).

End-stage renal disease is an important and costly health problem. Strategies for its prevention are urgently needed. Knowledge of the population-based prevalence of renal insufficiency in nondiabetic adults would inform such strategies. Black and white nondiabetic adult participants in the Third National Health and Nutrition Examination Survey were analyzed. The analysis was stratified by age, gender, and race, and four clinically applicable methods were used to assess renal function. There were 13,251 complete records for analysis. By the Modification of Diet in Renal Diseases (MDRD) GFR (GFR) prediction Equation 7, 58% (95% confidence interval [CI], 56 to 60%) of the total adult nondiabetic black and white US population had MDRD GFR below 80 ml/min per 1.73m(2), 13% (95% CI, 11 to 14%) below 60 ml/min per 1.73m(2), and 0.26% (95% CI, 0.19 to 0.33%) below 30 ml/min per 1.73m(2). By the Cockcroft-Gault formula, the equivalent figures were 39% (95% CI, 37 to 41%), 14% (95% CI, 12% - 16%), and 0.81% (95% CI, 0.46 to 1.2%), respectively. The findings of an unexpectedly high prevalence of low clearance and the increased prevalence of low clearance with age were consistent across the four clearance estimation methods used and for each race-sex stratum. The absolute magnitude of the prevalence of low clearance was, however, dependent on the clearance method used. Assessed by estimation from serum creatinine, low clearance may be very common, particularly with advancing age. The prognosis (in terms of risk for progression and end-stage renal disease) of low clearance in unreferred populations may differ from that in referred populations and requires further study.

Adult↗
PubMed2002

Cumulative risk for developing end-stage renal disease in the US population.

The individual risk of developing end-stage renal disease (ESRD) and its overall impact on life expectancy is not known. This study's objectives were to determine the effect of ESRD on life expectancy for a cohort of 20-yr-olds and to compare this impact to that of several cancers for which population-based screening programs exist. A computer simulation, stratified by race (white, black) and by gender was used to calculate cumulative lifetime risk of ESRD, life-years lost to ESRD, and cumulative Medicare payments for ESRD. Similar calculations were made for breast, prostate, and colorectal cancer. The cumulative lifetime risk of ESRD for a 20-yr-old black woman is 7.8%. Equivalent risks for black men are 7.3%, white men 2.5%, and white women 1.8%. Lost years of life attributable to ESRD are 1.09, 1.10, 0.40, and 0.32 yr for black women, black men, white men, and white women, respectively. In blacks, ESRD is responsible for nearly as much loss of life-years as breast cancer in women and more loss of life-years than colorectal or prostate cancer in men. In addition, treatment costs for ESRD in this population are many-fold more expensive than cumulative treatment costs of these cancers. Exploring new screening and treatment strategies may be warranted to prevent ESRD, particularly in the US black population.

Adult↗
PubMed2002

Low-intensity warfarin is ineffective for the prevention of PTFE graft failure in patients on hemodialysis: a randomized controlled trial.

Polytetrafluoroethylene (PTFE) dialysis grafts in patients with end-stage renal disease (ESRD) are prone to thrombotic failure. The objective of this multicenter, randomized, double-blind, placebo-controlled clinical trial was to determine if warfarin reduces the risk of failure of PTFE dialysis grafts. Patients with ESRD and newly placed PTFE grafts were studied at community and academic dialysis centers in Southwestern Ontario. Patients were allocated to receive warfarin or matching placebo, with the warfarin administered to achieve a target INR of 1.4 to 1.9. Time to graft failure was the main outcome measure. A total of 107 patients (56 allocated to warfarin) were randomized. The time-to-event analysis revealed no significant difference in the likelihood of graft survival between the two groups (odds ratio, 1.76 in favor of placebo; 95% confidence interval, 0.72 to 4.34). Six major bleeds occurred in five patients allocated to warfarin compared with none in the patients who received placebo (P = 0.03). In conclusion, low-dose warfarin was associated with an excess of clinically important major bleeding in patients with ESRD enrolled in this study. Furthermore, low-intensity, monitored-dose warfarin does not appear to prolong PTFE graft survival.

Adult↗