Risk of deep vein thrombosis in patients with cellulitis and erysipelas : A systematic review and meta-analysis

Introduction

The occurrence of deep vein thrombosis (DVT) is often considered in patients with cellulitis and erysipelas because of the common presentation of unilateral limb swelling, erythema and pain. Different authors however have reached different conclusions about the prevalence of DVT in these patients and for the need for compression ultrasound (CUS). The purpose of this study is to determine the prevalence of DVT in patients with cellulitis and erysipelas, and inform the utility of CUS.

Methods

A systematic literature search was conducted of Medline and Cochrane for studies that reported groups of patients with cellulitis or erysipelas who had CUS to evaluate for DVT. Study quality assessment was based on the Newcastle-Ottawa Quality Assessment Scale for Cohort Studies. The incidence rates from the included studies were pooled using a random-effects model to calculate an overall DVT rate. Individual and pooled DVT rates with corresponding upper and lower limits were graphed as a forest plot. Between-study heterogeneity was estimated using the I² statistic.

Results

Nine studies were included totaling 1054 patients with cellulitis or erysipelas with 18 DVTs. The overall pooled incidence rate was 2.1% (95% confidence interval, 0.5%-9.1%) for proximal DVT and 3.1% (95% confidence interval, 1.9%-4.9%) for any DVT. When analyzed separately, the pooled incidence rate for the three retrospective studies was 1.1% (95% CI, 0.6%-2.2%), while the rate for the six prospective studies was 7.8% (95% CI, 4.2%-14.2%).

Conclusion

The risk of DVT in cellulitis and erysipelas is low compared to the average risk of patients referred for CUS and comparable to low risk patients as determined by the commonly employed Wells criteria.     

Image quality and artefact generation post-cerebral aneurysm clipping using a 64-row multislice computer tomography angiography (MSCTA) technology: A retrospective study and review of the literature

Purpose

Computed tomography angiography (CTA) is a time and cost saving investigation for postoperative evaluation of clipped cerebral aneurysm patients. A retrospective study was conducted to analyse image quality and artefact generation due to implanted aneurysm clips using a new technology.

Methods

MSCTA was performed pre- and postoperatively using a Philips Brilliance 64-detector-row CT scanner. Altogether, 32 clipping sites were analysed in 27 patients (11 female and 16 male, mean ages 52a, from 24 to 72 years). Clip number per aneurysm was 2.3 mean (from 1 to 4), 54 clips were made of titanium alloy and 5 of cobalt alloy.

Results

Altogether, image quality was rated 1.8 mean, using a scale from 1 (very good) to 5 (unserviceable) and clip artefacts were rated 2.4 mean, using a 5 point rating scale (1 no artefacts, 5 unserviceable due to artefacts). A significant loss of image quality and rise of artefacts was found when using cobalt alloy clips (1.4 versus 4.2 and 2.1 versus 4.0). In 72% of all investigations, an excellent image quality was found. Excluding the cobalt clip group, 85% of scans showed excellent image quality. Artefacts were absent or minimal (grade 1 or 2) in 69% of all investigations and in 81% in the pure titanium clip group. In 64-row MSCTA of good image quality with low artefacts, it was possible to detect small aneurysm remnants of 2 mm size in individual patients.

Conclusion

By using titanium alloy clips, in our study up to 85% of postoperative CTA images were of excellent quality with absent or minimal artefacts in 81% and seem adequate to detect small aneurysm remnants.     

Comparison of high specificity with standard versions of a quantitative latex D-dimer test in the assessment of community pulmonary embolism: HaemosIL D-dimer HS and Pulmonary Embolism

Background

D-dimer assays are sensitive but have poor specificity. False positive results lead to extra imaging and hospital admissions.

Objectives

To make a pilot comparison of the diagnostic accuracy of the standard quantitative latex HemosIL D-dimer assay with a newer HemosIL D-dimer HS version designed to have improved specificity.

Patients / Methods

Consecutive patients presenting from the community to an Emergency Department that were investigated for suspected pulmonary embolism using a D-dimer test were included in the study. Standard and D-dimer HS tests were performed. Pulmonary Embolism was diagnosed on the basis of imaging studies or post-mortem at any time from presentation to 90 days thereafter.

Results

The prevalence of Pulmonary Embolism was 4.5% (18/402). The sensitivity, specificity, negative predictive value, and positive predictive value for the standard quantitative D-dimer test was 100% (81.5 - 100.0), 49.2% (44.1 - 54.3),100% (98.1 - 100.0), and 8.5% (5.1 - 13.0), respectively, and 100% (81.5 - 100.0), 58.3% (53.2 - 63.3),100% (98.4 - 100.0), and 10.1% (6.1 - 15.5), for the D-dimer HS test. There were 35 (16%) fewer ‘false positives’ using the D-dimer HS assay compared with the standard assay.

Conclusions

D-dimer HS has superior specificity to the standard quantitative D-dimer test without any loss of sensitivity. The generation of fewer false positive results should lead to less unnecessary diagnostic imaging; the use of which is associated with increased hospital admissions and length of stay. The HS assay may therefore have significant health economic benefits.