Diagnostic Performance In Patients Research Articles

Dual time point FDG PET for evaluation of malignant pleural mesothelioma

To evaluate whether 2-deoxy-2-18F-fluoro-D-glucose (FDG) positron emission tomography (PET) is more useful in differentiating malignant from benign pleural lesions, and whether delayed FDG PET imaging can improve the diagnostic performance in patients with suspicion of malignant pleural mesothelioma (MPM). Thirty-three patients who were suspected of having MPM were examined with FDG PET. PET imaging (whole body) was performed at 60 min (early) post-FDG injection and repeated at 120 min (delayed) after injection only in the thoracic region. We evaluated the FDG uptake visually and semiquantitatively. The semiquantitative analysis using the standardized uptake value (SUV) was determined for both early and delayed images (SUVearly and SUVdelayed, respectively). The final diagnosis was MPM in 17 patients and benign pleural disease in 16 patients. The sensitivity, specificity, and accuracy to detect MPM on both early and delayed PET were all 88%. The mean value of SUVdelayed in MPM was significantly higher than that of SUVearly (P < 0.001). The mean values of SUVearly and SUVdelayed in MPM were significantly higher than the corresponding values in benign pleural disease (P < 0.01, respectively). FDG PET seems to be a useful imaging modality for differential diagnosis of MPM. In addition, the diagnostic performance on delayed PET was the same as that on early PET, although SUVdelayed was significantly higher than SUVearly in patients with MPM.

Função renal de pacientes de unidade de terapia intensiva: creatinina plasmática e proteína carreadora do retinol urinário

The early assessment of renal dysfunction using common markers does not provide either a sensitive or specific indication of renal dysfunction in critically ill patients. More specific and sensitive markers are desirable for the early detection of an initial renal pathophysiological process. Urinary retinol-binding protein could be an alternative method to early evaluation of renal function in these patients. This study followed-up 100 critical care patients and assessed their clinical and laboratory variables, including plasma creatinine and urinary retinol-binding ratio, and demographic variables. The sample was characterized by geriatric (63.4±15.6 years), male (68%), being 53% surgical patients. Statistical analysis showed association between plasma creatinine and the following variables: gender (p-0.026), age (p-0.038), use of vasoactive drugs (p-0.003), proteinuria (p-0.025), Acute Physiological Chronic Health Evaluation (APACHE) II score (p-0.000), urea (p-0.000), potassium (p-0.003) and estimated creatinine clearance (p-0.000). Urinary retinol-binding protein was correlated with more variables: weight, use of invasive ventilation (p-0.000), use of nonsteroidal antiinflammatory drugs (p-0.018), use of vasoactive drugs (p-0.021), high temperature (>37.5ºC) (p-0.005), proteinuria (p-0.000), bilirubinuria (p-0.004), urinary flow (p-0.019), minimal diastolic pressure (p-0.032), minimal systolic pressure (p-0.029), APACHE II (p-0.000), creatinine (p-0.001), urea (p-0.001), estimated creatinine clearance (p-0.000). Urinary retinol-binding protein also tended to associate with previous renal disease, vasculopathy and neoplasm. Sodium excretion fraction correlated with plasma creatinine and urinary retinol-binding protein in univariate analysis. Urinary retinol-binding protein might be considered in clinical practice as a better marker regarding diagnostic performance in patients at risk of developing acute kidney injury, when compared with other markers routinely used. Moreover, urinary retinol-binding protein has other features of a good diagnostic test - it is a practical and non-invasive method.

Quantitative Analysis of Acid-Base Disorders in Patients with Acute on Chronic Respiratory Failure and Acute Respiratory Distress Syndrome. A Prospective, One Center Study

Background: With Stewart approach, pH depends on strong ion difference (SIDe), PaCO2 and non volatile weak acids (Atot). This approach might detect complex acid-base disorders undetected by conventional approach. We de- signed this study to describe acid-base disorders with both Stewart and conventional approaches and to compare the diagnostic performance in patients with chronic respiratory failure (CRF) in acute respiratory failure (ARF) or with acute respiratory distress syndrome (ARDS) because they are expected to have complex acid-base disorders. Conventional ap- proach was based on standardized base excess (SBE), bicarbonate (HCO3 - ) and anion gap (AG). Working hypotheses were that in CRF, metabolic alkalosis was associated with respiratory acidosis and in ARDS, Stewart approach was able to identify metabolic acidosis not detected with the conventional approach. Methods: Observational study in a medical ICU of a University hospital on 36 patients with obstructive CRF (CRFo), 36 with non obstructive CRF (CRFno) and 28 with ARDS prospectively included over 8 months. Measurements were per- formed on ICU admission, day 1 and day 2 after admission. Results: Metabolic alkalosis occurred in less than 5% of samples in CRF patients and in 0 ARDS patient. As compared to CRF patients, ARDS patients exhibited lower SBE, higher AG, lower SIDe and lower Atot. In ARDS, low SIDe was pri- marily due to elevated unidentified anions. Hypoalbuminemia was present in more than 75% of patients without dif- ference between groups. Normal values of SBE, HCO3 - and AG were very common. Stewart approach detected low SIDe in 13% of samples with normal SBE, in 13.8% of samples with normal HCO3 - , and in 11% of samples with normal AG corrected for abnormal albumin concentration, without difference between CRF and ARDS. Conclusions: In these selected critically ill patients, Stewart approach exceeded the diagnostic performance of the conven- tional approach even when AG corrected was taken into account. Further studies in CRF patients with chronic hypercap- nia and elevated bicarbonatemia are required to assess the incidence of associated metabolic alkalosis.

Effect of patient location on the performance of clinical models to predict pulmonary embolism

Introduction Current clinical likelihood models for predicting pulmonary embolism (PE) are used to categorize outpatients into low, intermediate and high clinical pre-test likelihood of PE. Since these clinical prediction rules were developed using outpatients it is not known if they can be applied universally to both inpatients and outpatients with suspected PE. Thus, the purpose of this study was to determine the effect of patient location on the performance of clinical models to predict PE. Materials and methods Two clinical models (Wells and Wicki) were applied to data from the multi-centered PIOPED study. The Wells score was applied to 1359 patients and the Wicki score was applied to 998 patients. 361 patients (27%) from the PIOPED study did not have arterial gas measurement and were excluded from the Wicki score patient group. Patients were stratified by their location at the time of entry into the PIOPED study as follows: outpatient/emergency, surgical ward, medicine/coronary care unit or intensive care unit. The diagnostic performance of the two clinical models was applied to the various patient locations and the performance was evaluated using the area under a fitted receiver operating characteristic curve (AUC). Results The prevalence of PE in the three clinical probability categories were similar for the two scoring methods. Both clinical models yielded the lowest diagnostic performance in patients referred from surgical wards. The AUC for both clinical prediction rules decreased significantly when applied to inpatients in comparison to outpatients. Conclusions Current clinical prediction rules for determining the pre-test likelihood of PE yielded different diagnostic performances depending upon patient location. The performance of the clinical prediction rules decreased significantly when applied to inpatients. In particular, the rules performed least well when applied to patients referred from surgical wards suggesting these rules should not be used in this patient group. As expected the clinical prediction rules performed best in outpatients with the optimum diagnostic performance in patients referred from emergency and outpatient wards.

Soluble oncoprotein 185 HER-2 in pleural fluid has limited usefulness for the diagnostic evaluation of malignant effusions

Objectives: To investigate whether pleural levels of the soluble oncoprotein 185 HER-2 (sp185 HER-2), individually or in combination with CEA and CA 15-3, were useful for the diagnosis of malignant effusions. Design and methods: Levels of CEA, CA 15-3, and sp185 HER-2 were measured in the pleural fluid from 135 malignant and 103 benign effusions. Thresholds of these tumor markers were chosen for a diagnostic specificity of ≥99%. Results: Pleural sp185 HER-2 levels greater than 25 ng/mL were observed in 20% of breast and 10% of lung adenocarcinomas, and predicted a malignant effusion with a sensitivity of 7% and a likelihood ratio of 7.6. Combination of CEA and CA 15-3 resulted in 50% sensitivity, while adding sp185 HER-2 to this panel nonsignificantly increased sensitivity by 5% ( P = 0.45). Only 1 patient with breast adenocarcinoma among 45 cytology-negative malignant effusions had sp185 HER-2 above the diagnostic cutoff point. Conclusion: Measurement of pleural fluid sp185 HER-2 has poor diagnostic performance in patients with malignant effusions.