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Biomedical subjects

M W Sproule

Publications and source records attributed to M W Sproule.

8 recordsLinked to original sources

High resolution computed tomographic assessment of airway wall thickness in chronic asthma: reproducibility and relationship with lung function and severity.

BACKGROUND: In some patients chronic asthma results in irreversible airflow obstruction. High resolution computed tomography (HRCT) has been advocated for assessing the structural changes in the asthmatic lung and permits investigation of the relationships between airway wall thickening and clinical parameters in this condition. METHODS: High resolution CT scanning was performed in 49 optimally controlled asthmatic patients and measurements of total airway and lumen diameter were made by two independent radiologists using electronic callipers. Wall area as % total airway cross sectional area (WA%) and wall thickness to airway diameter ratio (T/D) were calculated for all airways clearly visualised with a transverse diameter of more than 1.5 mm, with a mean value derived for each patient. Intra- and inter-observer variability was assessed for scope of agreement in a subgroup of patients. Measurements were related to optimum forced expiratory volume in 1 second (FEV1), forced mid expiratory flow, carbon monoxide gas transfer, two scores of asthma severity, airway inflammation as assessed with induced sputum, and exhaled nitric oxide. RESULTS: Neither observer produced a statistically significant difference between measurements performed on two occasions but there was a significant difference between observers (limits of agreement -2.6 to 6.8 for WA%, p<0.0001). However, mean WA% measured on two occasions differed by no more than 5.4% (limits of agreement -4.0 to 5.4; mean (SD) 0.7 (2.4)). Statistically significant positive associations were observed between both WA% and T/D ratio and asthma severity (r(S)=0.29 and 0.30, respectively, for ATS score), and an inverse association with gas transfer coefficient was observed (r(S)=-0.43 for WA% and r(S)=-0.41 for T/D). No association was identified with FEV1 or airway inflammation. CONCLUSIONS: The airway wall is thickened in more severe asthma and is associated with gas transfer coefficient. This thickening does not relate directly to irreversible airflow obstruction as measured with FEV1.

Airway Obstruction↗

Abnormal coagulation and deep venous thrombosis in patients with advanced cancer.

Many studies have demonstrated increased coagulation activation in cancer patients and have shown evidence of chronic, low-grade disseminated intravascular coagulation, although most patients remained asymptomatic. In general, patients have not been screened for deep venous thrombosis (DVT). We screened 98 patients with advanced malignancy for DVT using light reflection rheography. Coagulation profiles of DVT and non-DVT groups were studied. We found a high prevalence of DVT (50%) on screening. Overall, the patients had raised levels of fibrinogen (66% patients), factor VIII:C (43%), fragment 1 + 2 (71%) and TAT levels (89%). Patients with DVT had a significantly lower level of fibrinogen than those without (4.0 g/dl, SD 1.4, compared with 4.7 g/dl SD 1.6, P = 0.04). There was no significant difference in other coagulation or liver function tests between the DVT and non-DVT groups. The wide variation of results makes their interpretation difficult and unlikely to be of predictive value in estimating individual thrombotic risk.

Adult↗

The prevalence and associated variables of deep venous thrombosis in patients with advanced cancer.

The prevalence of venous thromboembolism (VTE) in cancer patients has been estimated as up to 15% antemortem, and higher (over 50% in pancreatic tumours) postmortem owing to the asymptomatic nature of many episodes of VTE. We investigated the prevalence of deep venous thrombosis (DVT) in a population of 298 hospice inpatients with advanced cancer. They were screened for the presence of DVT using light reflection rheography; 258 (86.6%) patients were evaluable for DVT, which was found in 135 (52%; 95% confidence interval 46-58). Factors associated (multivariate analysis) with the presence of DVT were: poor mobility, reduced serum albumin level and higher serum urea. A DVT risk assessment index was calculated using these variables. The three highest categories all had significant rates of DVT and, although the lowest category had a low rate of DVT, it accounted for less than 10% of all patients tested. DVT is common in patients with advanced cancer. It was found to be significantly associated with the above variables, but a combined index was of limited clinical application. In view of the number of patients identified with DVT, repeated small pulmonary emboli may be responsible for more symptoms than previously recognized in cancer patients.

Adult↗

The value of light reflection rheography as a screening tool for deep venous thrombosis.

Deep venous thrombosis (DVT) is a common condition in which the clinical diagnosis is notoriously inaccurate. The diagnosis is usually made in the Radiology Department by either Doppler ultrasound or conventional venography. The high clinical suspicion for DVT and the availability of these imaging modalities places an ever increasing burden on radiology departments. Light reflection rheography (LRR) is a non-invasive technique for assessing venous disorders. It is easy and quick and can be performed at the bedside or in the Radiology Department. LRR was prospectively compared with conventional venography in 50 consecutive patients undergoing investigation for possible DVT. LRR was entirely normal in 24 patients and this was confirmed on venography in each case. In practice it was not always possible to differentiate between DVT and venous insufficiency in the 26 abnormal tracings but all 15 cases of venography-proven DVT were within this group. There were no false negative diagnoses of DVT. LRR is a simple and quick method of screening for DVT with significant cost saving implications. A normal tracing reliably excludes the diagnosis, whilst all abnormal tracings should undergo Doppler ultrasound or venography.

False Negative Reactions↗

CT manifestations of respiratory syncytial virus infection in lung transplant recipients.

PURPOSE: The purpose of our study was to evaluate CT findings during respiratory syncytial virus (RSV) infection in lung transplant recipients and to identify sequelae. METHOD: Thirty-nine CT scans prior to, during, and following acute infection in 10 lung transplant recipients were reviewed. Abnormalities that were new from baseline observations and occurred within 4 weeks of diagnosis were defined as acute. Chronic findings were defined as those present >4 weeks after diagnosis. RESULTS: Findings in nine patients were ground-glass (seven), air-space (five), and tree-in-bud (four) opacities and acute bronchial dilatation (four) and wall thickening (four). Patients lacked pleural effusions or lymph node enlargement. Five of seven patients with follow-up exams had new air trapping (three), persistent bronchial dilatation (three), and thickening (two). Three and 2 of the 10 patients developed bronchiolitis obliterans syndrome and obliterative bronchiolitis, respectively. CONCLUSION: During acute infection, patients commonly had ground-glass opacities but lacked pleural effusions and lymph node enlargement. There can be chronic sequelae after infection.

Acute Disease↗