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Biomedical subjects

C W Davies

Publications and source records attributed to C W Davies.

At least 19 recordsLinked to original sources
PubMed2001

Case control study of cerebrovascular damage defined by magnetic resonance imaging in patients with OSA and normal matched control subjects.

STUDY OBJECTIVES: To assess whether MRI detectable evidence of silent cerebrovascular disease is more prevalent in patients with obstructive sleep apnea (OSA) when compared to carefully matched control subjects. DESIGN AND SETTING: Case-control study of patients with OSA attending a specialist sleep clinic and matched control subjects drawn from the normal community. PARTICIPANTS: Forty-five sleep clinic patients with moderate to severe OSA and excessive daytime sleepiness, matched to 45 control subjects without excessive sleepiness or evidence of OSA on a sleep study. Matched variables included age, body mass index (BMI), alcohol and cigarette consumption, treated hypertension, and ischaemic heart disease. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: All subjects underwent 24-hour ambulatory blood pressure recordings (before treatment in OSA patients) and sagittal T1, axial T2, and coronal dual echo cerebral MRI imaging to detect clinically silent abnormalities related to hypertensive cerebrovascular disease; areas of high signal foci in deep white matter (DWM), lacunae, and periventricular hyperintensity. Lacunae/high signal foci in DWM and/or periventricular hyperintensity were present in 15 (33%) OSA subjects and 16 (35%) controls, despite significant increases in mean daytime diastolic blood pressure (4.6mmHg, p<0.05), and both nighttime diastolic (7.2mmHg, p<0.001) and systolic blood pressures (9.2mmHg, p<0.05) in OSA subjects. These data exclude more than a 17% excess prevalence of MRI detected minor cerebrovascular disease in the OSA patients, with 95% confidence. CONCLUSIONS: Sub-clinical cerebrovascular disease is prevalent in both clinic patients with OSA and their matched control subjects. Despite the increased arterial blood pressures, there is, however, no apparent excess of MRI-evident subclinical cerebrovascular disease in patients with OSA compared to appropriately matched control subjects.

Adult↗
PubMed2000

Air trapping in sarcoidosis on computed tomography: correlation with lung function.

AIMS: To document the presence and extent of air trapping on high resolution computed tomography (HRCT) in patients with pulmonary sarcoidosis and correlate HRCT features with pulmonary function tests. METHODS: Twenty-one patients with pulmonary sarcoidosis underwent HRCT and pulmonary function assessment at presentation. Inspiratory and expiratory HRCT were assessed for the presence and extent of air trapping, ground-glass opacification, nodularity, septal thickening, bronchiectasis and parenchymal distortion. HRCT features were correlated with pulmonary function tests. RESULTS: Air trapping on expiratory HRCT was present in 20/21 (95%) patients. The extent of air trapping correlated with percentage predicted residual volume (RV)/total lung capacity (TLC) (r = 0.499;P < 0.05) and percentage predicted maximal mid-expiratory flow rate between 25 and 75% of the vital capacity (r = -0.54;P < 0.05). Ground-glass opacification was present in four of 21 (19%), nodularity in 18/21 (86%), septal thickening in 18/21 (86%), traction bronchiectasis in 14/21 (67%) and distortion in 12/21 (57%) of patients; there were no significant relationships between these CT features and pulmonary function results. CONCLUSION: Air trapping is a common feature in sarcoidosis and correlates with evidence of small airways disease on pulmonary function testing.

Adult↗
PubMed2000

Computed tomography and ultrasound in parapneumonic effusions and empyema.

AIM: Imaging of pleural empyema by ultrasound (US) or computed tomography (CT) is used to confirm the diagnosis and facilitate drainage. However, the information gained from US and CT may also have prognostic significance. The aim of the present study was to determine if CT and US appearances correlated with the severity of infection as determined by established microbiological and biochemical indicators, and to establish whether either technique could predict those patients who will fail drainage and require surgery. MATERIALS AND METHODS: Fifty patients with parapneumonic effusions were assessed. All had thoracic CT and the results of thoracic US were available in 36 patients. Imaging features were compared to the stage of the effusion and clinical outcome. RESULTS: At US, 7/36 (19%) pleural collections were anechoic, 5/36 (14%) were hyperechoic without septae and 24/36 (67%) were hyperechoic with septae. There was no relationship between US appearances and the presence of pus, the effusion stage or the need for surgical treatment. On CT pleural enhancement was seen in all patients. There was evidence of pleural thickening in 46/50 (92%) and thickening of extrapleural fat in 38/50 (76%). There was a trend for mean pleural thickness to increase with an increasing stage of pleural infection. However, a wide range of appearances were seen and overall the thickness of pleural/extrapleural tissues was not significantly related to the stage of effusion or to the requirement for surgery. CONCLUSIONS: Although US and CT have established roles in the investigation of parapneumonic effusions, neither technique reliably identifies the stage of pleural infection or predicts those patients who subsequently require surgical intervention after failed management by chest tube drainage and intrapleural fibrinolytics. Kearney, S. E. (2000). Clinical Radiology 55, 542-547.

Adult↗
PubMed2000

An evaluation of computed tomography as an aid to diagnosis in patients undergoing bronchoscopy for suspected bronchial carcinoma.

AIM: To determine whether computed tomography (CT) can predict the likelihood of obtaining a positive tissue diagnosis at fibreoptic bronchoscopy (FOB), or demonstrate an alternative means of achieving a tissue diagnosis, in patients presenting with a high clinical suspicion of primary bronchogenic carcinoma and an abnormal chest radiograph (CXR). MATERIALS AND METHODS: Sixty-two patients presenting with a high clinical suspicion of carcinoma and an abnormal CXR had chest and liver CT and FOB performed. All patients subsequently had histocytological confirmation of malignancy. Features recorded from the CTs included: the site and characteristics of a mass if present, and its relationship to adjacent airways; the presence of presumed metastatic disease; and a CT prediction of the likelihood of positive FOB was made. RESULTS: Of the patients, 41/62 (66%) had inoperable stage IIIb/IV disease. Fibreoptic biopsy yielded positive tissue diagnoses in 38/62 (61%). Computed tomography features predicting a positive FOB in this group included: ill-definition of the mass (12/15, 80%); a mass <4 cm from the origin of the nearest lobar bronchus (36/53, 68%); an endobronchial component of mass (22/24, 92%); a segmental or larger airway leading to the mass (30/35, 86%). Overall, CT had positive and negative predictive values for positive FOB of 85% and 78% respectively. The accuracy of the overall CT prediction of positive FOB was better than the accuracy of any of the individual factors. Seventeen of 62 (27%) patients had presumed metastatic disease suitable for percutaneous biopsy. CONCLUSION: Computed tomography is useful in predicting the likelihood of achieving positive histocytology at FOB. The overall CT prediction is superior to any of the individual CT features taken alone.Bungay, H. K. (2000). Clinical Radiology 55, 554-560.

Aged↗
PubMed2000

Lymphoid interstitial pneumonitis associated with common variable hypogammaglobulinaemia treated with cyclosporin A.

Lymphoid interstitial pneumonitis (LIP) is a rare clinicopathological entity that may be associated with common variable immune deficiency (CVID) and may lead to respiratory failure and death. Some patients may respond to prolonged corticosteroid treatment. We hypothesised that, in view of the predominant T cell nature of LIP, cyclosporin A would be a more appropriate choice of immunosuppressive agent and report the first case of its successful use in a woman with LIP associated with CVID.

Adult↗
PubMed2000

Xanthoma disseminatum with respiratory tract involvement and fatal outcome.

Xanthoma disseminatum (XD) is a rare mucocutaneous xanthomatosis classified as a benign form of non-Langerhans' cell histiocytosis. The case history is presented of a 61 year old woman with XD who developed dyspnoea and spirometric features of airflow obstruction. Bronchoscopy and computed tomography confirmed involvement of the large and medium sized bronchi and she subsequently died from acute respiratory failure. The post-mortem findings and the importance of respiratory tract disease in this unusual condition are discussed.

Airway Obstruction↗
PubMed2000

Case-control study of 24 hour ambulatory blood pressure in patients with obstructive sleep apnoea and normal matched control subjects.

BACKGROUND: There is considerable debate regarding the relationship between obstructive sleep apnoea (OSA) and hypertension. It is unclear whether OSA is an independent vascular risk factor as studies attempting to assess this association have produced conflicting results because of confounding variables such as upper body obesity, alcohol, and smoking. A case-control study of 24 hour ambulatory blood pressure was undertaken in patients with OSA and matched controls to assess whether OSA is an independent correlate of diurnal hypertension. METHODS: Forty five patients with moderate to severe OSA and excessive daytime sleepiness were matched with 45 controls without OSA in a sleep study. Matched variables included age, body mass index (BMI), alcohol, cigarette usage, treated hypertension, and ischaemic heart disease. Upper body obesity was compared by waist:hip and waist:height ratios; 24 hour ambulatory blood pressure recordings were performed (before treatment for OSA) in all subjects. RESULTS: Patients with OSA had significantly increased mean (SD) diastolic blood pressure (mm Hg) during both daytime (87.4 (10.2) versus 82.8 (9.1); p=0.03, mean difference 4.6 (95% CI 0.7 to 8.6) and night time (78.6 (9.3) versus 71.4 (8.0); p<0.001, mean difference 7.2 (95% CI 3.7 to 10.6)), and higher systolic blood pressure at night (119.4 (20.7) versus 110.2 (13.9); p=0.01, mean difference 9.2 (95% CI 2.3 to 16.1)). The nocturnal reduction in blood pressure ("dipping") was smaller in patients with OSA than in control subjects. CONCLUSIONS: Compared with closely matched control subjects, patients with OSA have increased ambulatory diastolic blood pressure during both day and night, and increased systolic blood pressure at night. The magnitude of these differences is sufficient to carry an increased risk of cardiovascular morbidity. The slight excess of upper body fat deposition in the controls may make these results conservative.

Adult↗
PubMed2000

The characteristics and significance of thoracic lymphadenopathy in parapneumonic effusion and empyema.

The occurrence of significant mediastinal lymphadenopathy together with pleural effusion or empyema inevitably raises concern about the presence of intrathoracic malignancy or granulomatous disease. Lymph node enlargement may also occur when pneumonia is accompanied by a parapneumonic effusion or empyema. Features that allow "benign" lymph node enlargement to be distinguished from malignant causes have not previously been determined. The present study aims to establish the CT characteristics of enlarged nodes in parapneumonic effusion. The appearances of mediastinal lymph nodes were recorded in 50 consecutive patients with parapneumonic effusion/empyema. 18 (36%) had mediastinal lymphadenopathy (node size greater than 1 cm). The mean number of enlarged nodes was 1.9 (range 1-3) and the mean size was 1.4 cm (2 cm maximum). Seven patients had a single involved site, nine patients two sites and two patients three sites. The right paratracheal area was most commonly involved and the subcarinal area contained the largest nodes. The presence of enlarged nodes did not correlate with biochemical and microbiological stage of pleural infection, length of history, or extent of consolidation. This study shows that mediastinal lymphadenopathy is commonly associated with parapneumonic effusion and that multiple sites may be involved. The degree of enlargement is moderate although lymphadenopathy of greater than 2 cm size should raise the possibility of other pathology.

Adult↗
PubMed1999

Predictors of outcome and long-term survival in patients with pleural infection.

In pleural infection, medical treatment failure (chest-tube drainage and antibiotics) requires surgery and increases mortality. It would be helpful to predict which patients will fail this approach. We examined clinical predictors in 85 consecutive patients with pleural infection receiving chest drainage and intrapleural fibrinolytics, and recorded age, length of history, antibiotic delay and choice, time to drainage, blood/pleural fluid (PF) bacteriology, PF pH, lactate dehydrogenase (LDH), glucose and appearance, effusion size, pleural thickness on computed tomographic (CT) scan, and survival from time of drainage. Failures (surgery/death) were compared with successes. There were 13 (15%) medical failures. PF purulence was more frequent in medical failures (10 of 13 versus 29 of 72 successes, p < 0.02 chi-square). Absence of purulence was a useful predictor of success (positive predictive value [PPV] 93%). Purulence was not useful in predicting medical failure (PPV 26%). There was a trend for positive blood culture to predict failure (5 of 13 failures versus 11 of 72 successes, p = 0.05 chi-square), but no significant differences in other endpoints. Twelve (14%) patients died in follow-up, all with comorbidity within 400 d after drainage. Probability of survival at 4 yr was 86%. Of endpoints considered in this study, PF purulence was the only useful predictor of outcome with medical therapy in pleural infection. There is good long-term survival from pleural infection.

Adolescent↗
PubMed1999

Spontaneous regression of pulmonary metastases demonstrated by CT.

Two cases of disappearing or spontaneous regression of pulmonary metastases on CT are presented. In both cases, cytological proof was obtained by radiologically guided fine needle aspiration. The lesions subsequently regressed on follow-up CT studies without recognized systemic treatment.

Aged↗
PubMed1999

Intrapleural streptokinase in the management of malignant multiloculated pleural effusions.

OBJECTIVE: Pleural effusions are a frequent complication of malignancy and cause considerable morbidity from dyspnea. The drainage and control of malignant effusions relieve symptoms and maintain quality of life but these are difficult in patients with multiloculated effusions in whom drainage usually fails. This observational series reports the use of intrapleural streptokinase (IPSK) in the management of malignant multiloculated pleural effusions resistant to standard chest tube drainage. METHODS: Ten consecutive patients with malignant multiloculated pleural effusions, aged 39 to 89 years, were given 250,000-IU doses of IPSK twice daily after failure to drain the effusions with a standard chest tube because of multiloculation and multiseptation, as demonstrated by CT or ultrasound scanning. Outcome was assessed by radiographic improvement and symptom control. RESULTS: All 10 patients responded to between 500,000 and 1,500,000 IU of streptokinase. There was an increase in pleural fluid drained (mean volume+/-SD; pre-IPSK, 843+/-690 mL; post-IPSK, 2,368+/-1,051 mL; p < 0.001, paired t test), and radiographic improvement was seen in all 10 patients. All subjects tolerated the instillation of streptokinase well. One subject required opiate analgesia for transient chest pain, and there were no hemorrhagic or allergic complications. One patient died of unrelated septicemia. CONCLUSIONS: This series suggests that IPSK may be useful in the drainage of malignant multiloculated pleural effusions in patients who fail to drain adequately with a standard chest tube. Malignant pleural effusions should not be considered a contraindication to IPSK.

Adult↗
PubMed1998

The systemic fibrinolytic activity of intrapleural streptokinase.

Intrapleural fibrinolytics probably improve the drainage of loculated pleural effusions and empyemas. Studies of crude indices of systemic coagulation suggest this effect is accompanied by little systemic fibrinolysis, but few studies have assessed this in detail. This study examines the systemic fibrinolytic activity of two intrapleural streptokinase (IPSK) regimes in detail. Eight patients received a single dose of 250,000 IU IPSK, and a further eight received serial doses of 250,000 IU IPSK every 12 h for 3 d (total dose: 1.5 million IU). Each dose was retained in the pleural cavity for 2 h. Venous blood for prothrombin time, activated partial thromboplastin time, thrombin time, fibrinogen, and D-dimers due to fibrin degradation were measured before any IPSK. These end points were then remeasured 24 h after IPSK in the single-dose group and after 24, 48, and 72 h in the group receiving serial doses. There were no physiologic or statistical differences in any of the indices after administration of IPSK. IPSK administered up to a dose of 1.5 million IU does not cause significant activation systemic fibrinolysis in humans.

Adult↗
PubMed1997

Recurrent post-partum pulmonary eosinophilia.

In 1980 a 23 year old woman developed idiopathic eosinophilic pneumonia which was successfully treated with corticosteroids. She subsequently developed two identical relapses in the post-partum period.

Adult↗
PubMed1996

Treatment of a symptomatic hepatic cyst by tetracycline hydrochloride instillation sclerosis.

We report the case of an 84-year-old woman with abdominal pain, distension and inferior veno-caval compression due to a large non-parasitic hepatic cyst. She was treated by instillation of tetracycline hydrochloride into the hepatic cyst. Six months after treatment, the patient is asymptomatic, with no reaccumulation of the hepatic cyst. We conclude that symptomatic hepatic cysts may be successfully treated by tetracycline hydrochloride instillation sclerosis.

Aged↗