Data enhancement for co-morbidity measurement among patients referred for sleep diagnostic testing: an observational study

<p>Abstract</p> <p>Background</p> <p>Observational outcome studies of patients with obstructive sleep apnea (OSA) require adjustment for co-morbidity to produce valid results. The aim of this study was to evaluate whether the combination of administrative data and self-reported data provided a more complete estimate of co-morbidity among patients referred for sleep diagnostic testing.</p> <p>Methods</p> <p>A retrospective observational study of 2149 patients referred for sleep diagnostic testing in Calgary, Canada. Self-reported co-morbidity was obtained with a questionnaire; administrative data and validated algorithms (when available) were also used to define the presence of these co-morbid conditions within a two-year period prior to sleep testing.</p> <p>Results</p> <p>Patient self-report of co-morbid conditions had varying levels of agreement with those derived from administrative data, ranging from substantial agreement for diabetes (κ = 0.79) to poor agreement for cardiac arrhythmia (κ = 0.14). The enhanced measure of co-morbidity using either self-report or administrative data had face validity, and provided clinically meaningful trends in the prevalence of co-morbidity among this population.</p> <p>Conclusion</p> <p>An enhanced measure of co-morbidity using self-report and administrative data can provide a more complete measure of the co-morbidity among patients with OSA when agreement between the two sources is poor. This methodology will aid in the adjustment of these coexisting conditions in observational studies in this area.</p

Predictors of outcome with medical therapy in patients with pleural infection treated with intra-pleural fibrinolytics

In patients with pleural infection, the failure of medical treatment (drainage and antibiotics) results in the need for surgery and/or death. It would be clinically helpful to be able to predict this failure at the time of presentation. We examined clinical predictors of outcome with medical therapy in 85 consecutive, prospectively identified patients (55 male; 30 female) receiving 14F chest drainage, antibiotics and intra-pleural fibrinolytics for pleural infection. Indices recorded included age, the length of history prior to admission, delay in initiating antibiotic treatment, antibiotic choice, time to drainage of the effusion, blood and pleural fluid bacteriology, pleural fluid pH, lactate dehydrogenase (LDH), glucose and pleural fluid appearance (purulent/non-purulent) and, in a sub-set, maximum pleural thickness on CT scan (46 patients). Decisions about surgical referral were made before data analysis. The clinical features were compared in those where medical therapy failed (surgery and/or death) with those where it succeeded. There were 13 (15%) failures of medical therapy with 11 (13%) of patients requiring surgery. There were 4 deaths (2 following surgery). Frank pleural fluid purulence was more frequent in patients failing medical therapy (10/13 failures v 29/72 successes, p&lt;0.02 chi-square) and the absence of purulence was a useful predictor of medical success, (predictive value 93%). The presence of frank purulence was not clinically useful in predicting medical treatment failure, (predictive value 26%). There was a trend towards positive blood culture predicting medical failure which was mostly due to an association with mortality (5/13 failures v 11/72 successes, p=0.05 chi-square) There were no clinically or statistically significant differences in any other end point. In particular there were no differences in symptom duration prior to admission, pleural fluid biochemistry or positive culture, age, delayed chest drainage, delay to antibiotic administration or CT assessed pleural thickness. Of the end points considered in this study, frank pleural fluid purulence was the only clinically useful predictor of outcome with medical therapy in pleural infection

Intrapleural streptokinase in the drainage of malignant multiloculated pleural effusions

Background - Malignant pleural effusions are a frequent complication of advanced malignancy, and cause considerable morbidity from dyspnoea. The drainage and subsequent control of malignant effusions relieves symptoms and maintains quality of life, and is difficult in patients with multiloculated or septated effusions. We report the use of intrapleural streptokinase (IPSK) to aid pleural drainage in 10 consecutive patients with malignant multiloculated pleural effusions resistant to standard chest tube darinage. Methods - Ten patients with malignant multi-loculated pleural effusions were given twice daily doses of intrapleural streptokinase 250,000 i.u. when inadequate drainage was achieved by tube thoracostomy alone. Outcome was assessed by chest radiograph and dyspnoea control. Results - Radiographic improvement and control of dyspnoea was seen in all 10 patients. There was a reduction in the largest linear dimension of the collection in 9/10 patients (mean[SD] 6.5 [3.34]cm; C.I. 4.36-9.14, p&lt;0.0001, paired t-test). Eight patients showed a &gt;75% reduction in volume of pleural effusion with IPSK and 9/10 patients had ≤ 10% area of hemithorax occupied by residual pleural effusion after treatment. Conclusions - Intrapleural streptokinase controls dyspnoea by improving the drainage of malignant multiloculated pleural effusions in patients who fail to drain adequately with a standard chest tube. This technique improves dyspnoea and so maintains quality of life in patients with this otherwise difficult clinical problem

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. © 2000 The Royal College of Radiologists

Anti-streptokinase antibody inhibition of streptokinase induced fibrinolysis following intra-pleural streptokinase

Background. Anti-streptokinase immunoglobulin (IgG) induced by intravenous (IV) streptokinase (SK) can reduce the effectiveness of repeated SK use, or lead to an increased incidence of immune mediated adverse reactions. It is therefore advised that IV SK exposed patients receive an alternative fibrinolytic for later exposures. It is not known whether intra-pleural streptokinase (IPSK) induces a similar response. Methods. We studied 18 patients (age 35-81) receiving IPSK for drainage of multiloculated pleural effusion (13 infected; 5 malignant). All patients received 250,000i.u. IPSK twice daily to a maximum of 1,500,000i.u. The development of functionally important circulating antibodies against SK was assessed by comparing the inhibition of SK-induced fibrinolytic activity (Streptokinase-Resistance test) before SK administration with that 10-14 days later. Serial dilution's of SK (20μL) were added to citrated plasma (160μL) containing thrombin (20μL). The lowest concentration of SK achieving complete lysis was noted and expressed as the SK resistance titre. Results. SK resistance titres rose in 7/18 patients (39%) and in 4/18 (22%) there was at least a four-fold rise in titres. No patients had allergic reactions following IPSK administration. Conclusions. A minority of patients receiving IPSK experience a rise in functionally significant anti-streptokinase antibodies. The frequency of this rise is less than that seen following IV SK, but is sufficient to warrant the use of an alternative fibrinolytic if this is subsequently indicated

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 &lt; 0.05) and percentage predicted maximal mid-expiratory flow rate between 25 and 75% of the vital capacity (r = -0.54; P &lt; 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. (C) 2000 The Royal College of Radiologists