Design and Implementation of an Anti-Factor Xa Heparin Monitoring Protocol

BACKGROUND

The VA Northeast Ohio Healthcare System introduced a new nurse-driven anti-factor Xa (anti-Xa) protocol for monitoring unfractionated heparin to replace the previous activated partial thromboplastin time protocol.

OBJECTIVE

To design, implement, and evaluate the efficacy of the anti-Xa monitoring protocol.

METHODS

An interdisciplinary team of providers collaborated to develop and implement a nurse-driven, facility-wide anti-factor Xa protocol for monitoring unfractionated heparin therapy. The effectiveness of this protocol was evaluated by retrospective analysis.

RESULTS

We reviewed 100 medical records for compliance with the new anti-Xa monitoring protocol. We then evaluated 178 patients whose anticoagulation was monitored with the anti-Xa assay to determine the time to therapeutic range. We found that 80% of patients receiving the anti-Xa protocol achieved therapeutic anticoagulation within 24 hours, as compared with 54% of patients receiving the activated partial thromboplastin time protocol (P < .001). Protocol conversion also yielded a decrease in blood draws, dose adjustments, and potential calculation errors.

CONCLUSIONS

Monitoring intravenous heparin therapy with the anti-Xa assay rather than activated partial thromboplastin time resulted in a shorter time to therapeutic anticoagulation, longer maintenance of therapeutic levels, and fewer laboratory tests and heparin dosage changes. We believe the current practice of monitoring heparin treatment with activated partial thromboplastin time assays should be reexamined.

What women want: convenient appointment times for cervical screening tests

Little is known about women's preferred appointment times for cervical screening tests. Data from a postal questionnaire survey were used to compare preferred appointment times with those given. Although 33.4%[95% confidence intervals (CI) 31.8%-35.0%] of respondents received appointments between 10h00 and 11h55, only 17.0% (95% CI 15.3%-18.7%) wanted an appointment at that time. Nineteen per cent (95% CI 17.4%-21.0%) of respondents wanted appointments between 18h00 and 20h00, but only 4.4% (95% CI 3.7%-5.1%) received them. Saturday appointments for cervical screening are not given; however, overall approximately 13% of those surveyed would have preferred a Saturday appointment. Preferred times also varied significantly with age and deprivation category. Further research is required to determine whether appointment times for cervical screening can be tailored to meet these expressed needs, and the impact this has on service provision and uptake.

Information given to women invited for cervical screening: results of two postal surveys seven years apart

In South Staffordshire, England, we compared women's views on information provided to them at different stages of the cervical screening program in 1994 with that provided in 2001. An age-stratified random sample of women aged 20-64 years who had a cervical smear taken between January and March 1994 (3856) or between January and March 2001 (4057) were sent postal questionnaires in June 1994 and July 2001, respectively. Response rates in 1994 (3124/3856, 81%) and 2001 (3288/4057, 81%) were similar. Compared to 1994, the proportion of women who thought the invitation letter was clear to read in 2001 increased (70% vs 98%, P < 0.0001); however, letters were thought to be less reassuring in 2001 compared to 1994 (P < 0.0001). In both study periods, 66% of women reported that the procedure was explained to them before the smear was taken. A greater proportion of women received their results by letter in 2001 compared to 1994 (57% vs 41%, P < 0.0001); however, 49% of women waited >4 weeks to receive their results in 2001 compared to 26% in 1994 (P < 0.0001). Bivariate analysis suggests that responses were age related, with older women (> or =45 years) experiencing poorer information provision. The issues highlighted by this study deserve further investigation in other areas.

Information given to women invited for cervical screening: results of two postal surveys seven years apart

In South Staffordshire, England, we compared women's views on information provided to them at different stages of the cervical screening program in 1994 with that provided in 2001. An age-stratified random sample of women aged 20–64 years who had a cervical smear taken between January and March 1994 (3856) or between January and March 2001 (4057) were sent postal questionnaires in June 1994 and July 2001, respectively. Response rates in 1994 (3124/3856, 81%) and 2001 (3288/4057, 81%) were similar. Compared to 1994, the proportion of women who thought the invitation letter was clear to read in 2001 increased (70% vs 98%, P < 0.0001); however, letters were thought to be less reassuring in 2001 compared to 1994 (P < 0.0001). In both study periods, 66% of women reported that the procedure was explained to them before the smear was taken. A greater proportion of women received their results by letter in 2001 compared to 1994 (57% vs 41%, P < 0.0001); however, 49% of women waited >4 weeks to receive their results in 2001 compared to 26% in 1994 (P < 0.0001). Bivariate analysis suggests that responses were age related, with older women (≥45 years) experiencing poorer information provision. The issues highlighted by this study deserve further investigation in other areas.

Response patterns to a postal survey using a cervical screening register as the sampling frame

This study compared different types of respondent to a postal survey. A random sample of women aged 20-64 years (n = 4057) was selected from a population-based cervical screening register to examine their information experience during the screening programme. The initial response rate was 57%, and this increased to 81% after one reminder. Respondents were older (P < 0.0001) than non-respondents, but both groups were comparable with regard to attendance history for cervical screening (respondents 89.3%; non-respondents 89.1%) and normal smear test results (respondents 84.0%; non-respondents 81.4%). Early and late respondents were similar in age. Compared with late respondents, early respondents were more likely to live in highly affluent (P < 0.0001) and rural areas (P = 0.026). They were also more likely to be non-attenders (P < 0.0001), but they were less likely to have had inadequate smear results (P = 0.030) than late respondents. These results suggest that consideration should be given to factors other than sociodemographic differences when examining response patterns to postal surveys.

The kinetics of the tanning response to tanning bed exposures

No clinical studies have been published documenting the development of pigmentation following the use of the Food and Drug Administration (FDA) recommended exposures from a tanning bed. Panelists were exposed three times weekly for eight weeks (24 exposures) using the FDA recommended exposure schedule. The initial tan was noted after only six exposures and quantitatively increased through the remainder of the study.

Effect of patient age on tests of the acute-phase response

Tests of the acute-phase response are used to screen for occult disease in the elderly, but there is little consensus as to their diagnostic value because of uncertainty as to the effect of age on reference ranges. We have therefore measured, as a function of age, the blood concentration of acute-phase proteins (C-reactive protein, alpha 1-acid glycoprotein, fibrinogen, albumin, and globulin) in parallel with three screening tests of the acute-phase response (erythrocyte sedimentation rate, plasma viscosity, and zeta sedimentation ratio). The study included 164 healthy individuals (age range, 25 to 84 years) plus 91 elderly ill but ambulant patients (age range, 65 to 84 years) from a family practitioner screening clinic. Reference ranges for the erythrocyte sedimentation rate, plasma viscosity, and zeta sedimentation ratio rose with age, with the erythrocyte sedimentation rate showing a particularly wide reference range. Healthy individuals aged 75 to 84 years, compared with those aged 65 to 74 years, showed a trend to a lower reference range for all three screening tests that may have reflected survival of the fittest individuals to the higher decade. Precise reference ranges are therefore required in the elderly; when these were used, the three screening tests showed a significant difference between elderly well and ill individuals.

Assessment of Diesse Ves-matic automated system for measuring erythrocyte sedimentation rate

Measurement of the erythrocyte sedimentation rate (ESR) using a closed tube system reduces the biohazard risk to laboratory staff. The Diesse Ves-matic system offers manual or vacuum collection of blood into plastic tubes, automated mixing of the sample, and automated reading of the end point after 20 minutes of sedimentation. This system was compared with the 1977 Westergren ESR method of the International Council for Standardization in Haematology (ICSH) and with the 1988 ICSH undiluted ESR method. Manually collected Ves-matic samples showed good agreement with ICSH values, although there was a tendency to false low results at low ESR values which may represent dilution of plasma protein with excess citrate. Vacuum collected Ves-matic samples also showed good agreement with ICSH values, although there was a tendency to false high results which may reflect a change in the blood: citrate ratio caused by loss of anticoagulant diluent or vacuum from plastic tubes during storage. The Diesse Ves-matic system incorporates several improvements over previous technology and offers a safer, quicker, and more standardised ESR.

Evaluation of a 200 mm long vacuum aspiration tube for measurement of erythrocyte sedimentation rate

The ESrT-system 200 comprises a 215 mm long vacuum aspiration venepuncture tube which contains anticoagulant diluent for the measurement of the erythrocyte sedimentation rate (ESR) without direct handling of the blood sample. This combines the advantage of a tube of "Westergren" length with a reduction in biohazard risk. Blood from 160 patients (ESR range 2-135 mm/first hour) was tested in parallel with the selected Westergren ESR method of the International Committee for Standardization in Haematology (ICSH) and a close correlation (r = 0.967) between the two methods was obtained. A second Westergren ESR, using anticoagulated but undiluted blood, was measured on 58 specimens to give an ICSH "expected" ESR. The ESrT-system 200 result was within 12 mm/first hour of the "expected" result for 91% of the specimens. This new ESR system is simple to use, does not require mathematical correction of the ESR reading for tube length, and gives results that are comparable with those obtained with the ICSH Westergren method.