Comparison of BD Vacutainer SST Plus Tubes with BD SST II Plus Tubes for common analytes.

Serum separator tubes were introduced 25 years ago and are widely used in the clinical laboratory today for routine collection of blood. These tubes have gained widespread acceptance due to the advantage of the barrier gel that facilitates rapid separation of serum from cellular constituents of blood and thus reduces hemolysis. However, there are some limitations associated with gel tubes (i.e., gel stability and analyte incompatibilities). The serum separator BD SST tubes manufactured by BD are widely used in clinical laboratories. Recently, BD has developed a new barrier gel, which is superior to the existing gel. We studied the stability of common analytes when serum specimens were stored in the new BD SST II tubes by comparing the performance with the existing BD SST tubes. We did not observe any significant reduction in concentrations of 42 commonly ordered analytes using the new BD SST II tubes. Significant differences were noted at low serum volumes for estradiol in both tube types over time. We conclude that the new BD SST II tubes are suitable for collection of blood and storage of serum for commonly ordered laboratory tests.

Vascular risk factors correlate to the extent as well as the severity of coronary atherosclerosis.

BACKGROUND: Because most acute coronary events result from thrombosis at sites of minor plaque, the extent of non-obstructive coronary artery disease (CAD), rather than simply the number of severe stenoses, might be clinically relevant. OBJECTIVE: To examine the relationship between vascular risk factors and a novel extent score for CAD that measures the percentage of the coronary tree involved with atheromatous plaque, as judged by coronary angiography. METHODS: We assessed the extent and severity of CAD and the presence of vascular risk factors of 429 consecutive eligible patients (296 men, aged 61 +/- 11 years) who presented for elective coronary angiography. Detailed analyses of lipid levels were performed for 126 subjects. RESULTS: The mean extent score was 54 (range 0-100). The presence of diabetes (P < 0.001), current or former smoking (P < 0.005) and a history of hypertension (P < 0.001) were all strongly associated with the CAD extent score, as was severity of disease. For the 283 patients with one or no severe stenosis, diabetes was associated with a greater extent score (57 versus 41%, P < 0.005), as was smoking (49 versus 34%, P < 0.005). For the 126 patients with detailed data on lipid levels, extent of coronary artery disease was independently correlated to age (P < 0.005), male sex (P < 0.05), presence of diabetes (P < 0.05), hypertension (P < 0.05), level of lipoprotein (a) (P < 0.005) and low-density:high-density lipoprotein ratio (P < 0.01) in multivariable analysis. CONCLUSIONS: Extent of CAD, as well as its severity, is significantly associated with traditional vascular risk factors. Because most acute coronary events occur at sites of minor plaque, this might explain the mechanism whereby risk factors confer adverse prognostic significance.

Evidence for association of anaemia with vascular dementia.

The present investigation aimed to examine associations of anaemia with dementia. Analysis of community-dwelling, elderly subjects characterized for different dementias failed to confirm a previously reported association of anaemia with Alzheimer's disease (AD) but revealed instead a significant association with vascular dementia (VAD). Nearly 45% of VAD subjects were anaemic, compared with 17% of controls. Close to one-third of all subjects with haemoglobin levels > 0.5 g/dl below reference anaemia levels had VAD. Co-existing VAD may explain previous links between AD and anaemia. The association was independent of age, dementia severity and a range of other factors including vitamin B 12 and folate levels. Anaemia can exacerbate focal cerebral ischaemia and could precipitate or amplify VAD symptoms in elderly subjects with vasculopathy.

Autologous blood transfusion for elective surgery.

Between September 1983 and June 1985, 336 patients were assessed by the Autologous Blood Transfusion Service; 267 men, mean age, 65 (range, 16-75) years, and 40 women, mean age, 63 (range, 40-70) years, participated in the programme (29 patients were excluded as unsuitable). Orthopaedic and vascular surgery accounted for 80% of the cases. Complications were minor even in this elderly group. Surgical and transfusion details for a one-month period were studied retrospectively. Of the surgical cases that required crossmatched blood, 50% were for "emergency" and "burn" surgery, and 50% for elective surgery. Forty-five per cent of this latter group were unsuitable as autologous donors, 21% had participated in the autologous blood transfusion programme, and an additional 34% were deemed to be suitable donors. The realistic upper limits of our autologous blood transfusion programme were determined as being 55% of elective cases that require crossmatched blood. To be efficient an autologous blood transfusion service must be incorporated into an existing homologous blood transfusion service and must complement, rather than replace, homologous blood transfusion.