[Right-ventricular dysfunction and the pulmonary vascular obstruction index: predictable variables of the clinical course over 3 months in patients with acute lung emboli]. / Rechterventrikeldisfunctie en index voor pulmonale vasculaire obstructie: voorspellende variabelen voor het klinische beloop gedurende 3 maanden bij patiënten met acute longembolie.

OBJECTIVE: To quantify right-ventricular dysfunction and the pulmonary artery obstruction index, in patients with acute pulmonary embolism, using helical CT, and to assess the prognostic value of these parameters. DESIGN: Prospective. METHOD: In 120 consecutive patients with proven acute pulmonary embolism, the extent of right-ventricular dysfunction was assessed by quantifying the ratios of the right to left-ventricular short-axis diameters (RV/LV ratio) and the extent ofobstruction ofthe pulmonary-artery circulation by using helical CT images. Regression analysis was used to correlate these parameters with patient outcome. RESULTS: Right-ventricular dysfunction (RV/LV ratio > 1.0) was seen in 69 patients (57.5%). Seven patients died as a direct result of pulmonary embolism. Both the RV/LV ratio and the obstruction index were significant risk factors for mortality within three months (p = 0.04 and 0.01 respectively). The positive predictive value for pulmonary embolism-related mortality of an RV/LV ratio > 1.0 was 10.1% (95% CI: 2.9-17.4). The negative predictive value for an uneventful outcome of an RV/LV ratio < or = 1.0 was 100% (95% CI: 94.3-100). There was a 11.2-fold risk of dying of pulmonary embolism in patients with an obstruction index > or = 40% (95% CI: 1.3-93.6). CONCLUSION: Markers of right-ventricular dysfunction and pulmonary vascular obstruction, assessed by helical CT-examination at baseline, help to predict mortality during follow-up of patients with acute pulmonary embolism.

Technegas versus (81m)Kr ventilation-perfusion scintigraphy: a comparative study in patients with suspected acute pulmonary embolism.

UNLABELLED: 81mKr is widely used as a ventilation agent to diagnose pulmonary embolism (PE). However, (81m)Kr is expensive, which limits its continuous availability. Technegas can be an alternative ventilation agent with the advantage of being less expensive and available daily. The aim of this study was to compare the value of technegas with that of (81m)Kr in the detection of PE. METHODS: Ninety-two consecutive patients (29 men; mean +/- SD, 53 +/- 17 y old) with at least one segmental perfusion defect (Hull criteria) were studied prospectively. Perfusion and ventilation (V/Q) lung scintigraphy with both technegas and (81m)Kr were performed within 24 h on all patients. V/Q lung scan results were classified as high probability for PE (normal ventilation study) or nondiagnostic (abnormal ventilation study). All V/Q lung scans were read by two experienced nuclear physicians in consensus. For the intra- and interobserver variabilities, two experienced observers independently read the V/Q lung scans. RESULTS: (81m)Kr and technegas showed a good agreement (kappa, 0.68; 95% confidence interval [CI], 0.53-0.82). However, technegas significantly increased the number of nondiagnostic V/Q lung scans (P: = 0.035). In 15 patients, a discrepancy was found between (81m)Kr and technegas. False-positive V/Q lung scan results occurred in 4 of 12 patients (33%) with (81m)Kr and in 2 of 3 patients (66%) with technegas. The intra- and interobserver variabilities were 0.71-0.88 (95% CI, 0.56-1.0) for perfusion/(81m)Kr and 0.74-0.96 (95% CI, 0.58-1.0) for perfusion/technegas. CONCLUSION: In comparison with (81m)Kr, technegas does not result in more false-positive V/Q lung scan results. The use of technegas, however, increases the number of nondiagnostic V/Q lung scan results, which would increase the demand for further additional testing to confirm or refute PE.

Acute pulmonary embolism: impact of selection bias in prospective diagnostic studies. ANTELOPE Study Group. Advances in New Technologies Evaluating the Localization of Pulmonary Embolism.

We evaluated selection bias in a prospective study of 1,162 consecutive patients with suspected pulmonary embolism. Of these, 983 were eligible, and 627 could actually be included. During two months extensive data were collected on all non-included patients. Finally, our patient characteristics were compared with those of the PIOPED study (1990) and the study of Hull et al. (1994). Compared with included patients, the non-included patients had more often non-diagnostic V/Q scans (50% vs. 36%, p <0.01) and were more often already hospitalized (31% vs. 22%, P = 0.04). The subgroup of patients not included due to refusal or inability to give informed consent (IC) was older (mean age 61 vs. 53 years, P <0.01), more often suffered from malignancies (26% vs. 11%, P <0.01) and frequently had non-diagnostic V/Q scans (57%) as compared to included patients. In our study, 54% of all patients screened was eventually included versus 27% in the PIOPED study. In the PIOPED study patients who had contra-indications for pulmonary angiography were excluded, while in the study of Hull et al. those with inadequate cardiorespiratory reserve were excluded. In studies on new diagnostic technologies, patient selection bias does occur. The potential for such a selection bias should be taken into account when diagnostic strategies are devised to improve their generalizability and acceptability.

Diagnosing acute pulmonary embolism: effect of chronic obstructive pulmonary disease on the performance of D-dimer testing, ventilation/perfusion scintigraphy, spiral computed tomographic angiography, and conventional angiography. ANTELOPE Study Group. Advances in New Technologies Evaluating the Localization of Pulmonary Embolism.

In patients with chronic obstructive pulmonary disease (COPD), differentiating a pulmonary embolism (PE) from an exacerbation of COPD can be difficult, since clinical signs and symptoms of the two conditions overlap. Development of reliable noninvasive or minimally invasive techniques for the diagnosis of PE is, especially in these patients, necessary. In this study we assessed the effect of COPD on the accuracy of the clinical probability estimate (CPE), spiral computed tomographic angiography (SCTA), D-dimer analysis, ventilation perfusion (V/Q) scintigraphy, and pulmonary angiography for the diagnosis of PE. From May 1997 through March 1998, 627 consecutive patients with suspected PE were investigated in six teaching hospitals. In these patients, D-dimer testing, CPE, V/Q scintigraphy, and SCTA and/or pulmonary angiography were performed according to a strict diagnostic protocol. The patients were also independently categorized as having COPD or not. A diagnosis of COPD was established in 91 patients (15%). The prevalence of PE was similar in patients with and without COPD (29% and 31%, respectively), notwithstanding the larger proportion of nondiagnostic V/Q scan results in patients with COPD (46% versus 21%, p < 0.001). The distribution of CPEs, diagnostic value of the D-dimer assay and SCTA, and reproducibility of pulmonary angiography were comparable among patients with and without COPD. The presence of COPD does not affect the diagnostic performance of CPE, D-dimer testing, SCTA, or pulmonary angiography. Furthermore, although more nondiagnostic V/Q scan results can be expected in the presence of COPD, V/Q scintigraphy remains a valuable screening test in patients with COPD.

Normal perfusion scintigraphy in pulmonary embolism. Causes and diagnostic alternatives.

Diagnosing pulmonary embolism (PE) is a challenge for many physicians as it is a frequently occurring disease with nonspecific symptoms and signs. Ventilation-perfusion (V/Q) scintigraphy is widely used as the first step in diagnosing PE since it is non-invasive and highly sensitive. With a normal perfusion scan, clinically relevant pulmonary thrombo-emboli are considered to be absent. In an ongoing study assessing the value of spiral CT in the diagnosis of PE, we encountered a patient who had a normal perfusion scan while a large partially occluding thrombus in the right lower lobe artery and its branches was depicted by spiral CT and pulmonary angiography. In this article, we discuss the significance of normal findings in perfusion scintigraphy, the causes of false-negative perfusion scans and the role of alternative techniques such as spiral CT and pulmonary angiography.

The prognostic significance of subclinical hepatic encephalopathy.

OBJECTIVE: Subclinical hepatic encephalopathy may have prognostic significance with regard to the development of clinical hepatic encephalopathy and survival. METHODS: We studied 116 consecutive patients with histologically proven cirrhosis of the liver for subclinical hepatic encephalopathy, using Number Connection Test A, Digit Symbol Test, and spectral analysis of the electroencephalogram. RESULTS: Twenty-five patients (22%) were diagnosed as having subclinical hepatic encephalopathy. Patients with subclinical hepatic encephalopathy were older, had a higher Child-Pugh score, and more often had esophageal or gastric varices and episode(s) of clinical hepatic encephalopathy in their history. During a median follow-up of 29 months (range, 1-49 months), patients with subclinical hepatic encephalopathy significantly more often had episodes of clinical hepatic encephalopathy; survival, however, was similar to that of patients without subclinical hepatic encephalopathy, and was determined mainly by the Child-Pugh score. The Child-Pugh score was also superior to subclinical hepatic encephalopathy in predicting episodes of clinical hepatic encephalopathy. CONCLUSIONS: The prognostic significance of subclinical hepatic encephalopathy appears limited.

Subclinical hepatic encephalopathy impairs daily functioning.

Subclinical hepatic encephalopathy (SHE) is assumed to have a negative effect on patients' daily functioning; therefore, treatment is recommended. However, no studies have been performed that document the clinical relevance of SHE. We performed a study in which the prevalence of SHE was determined in 179 outpatients with cirrhosis using two psychometric tests (Number Connection Test Part A [NCT-A] and the Digit Symbol Test [DGT]) and automated analysis of the electroencephalogram (EEG). SHE was defined by the presence of at least one abnormal psychometric test and/or abnormal slowing of the EEG. The influence of cirrhosis and SHE on patients' daily functioning was assessed using the Sickness Impact Profile (SIP) questionnaire. The distribution of SIP scores of the patients with cirrhosis differed from the reference scores of the general population. Patients with cirrhosis and SHE (n = 48) reported significantly more impairment in all 12 scales of the SIP, in the psychosocial subscore, the physical subscore, as well as in the total SIP score, compared with cirrhotic patients without SHE (n = 131). Multivariate analysis taking into account severity of liver disease (Child-Pugh score), presence of varices, and alcoholic etiology, showed that SHE independently was related to a diminished total SIP score. The reproducibility of the SIP was high when the test was repeated after a 3-month period. We conclude that SHE implies impaired daily functioning and warrants attempts at treatment.

The diagnosis of subclinical hepatic encephalopathy in patients with cirrhosis using neuropsychological tests and automated electroencephalogram analysis.

Neuropsychological tests used for the assessment of subclinical hepatic encephalopathy (SHE) may overdiagnose SHE because scores are usually not corrected for age. The aim of this study was to estimate the prevalence of SHE using two easy administrable psychometric tests (Number Connection Test part A [NCT-A], Symbol Digit Test [SDT]) with age-related normal values. In addition, spectral electroencephalogram (EEG) was used, which is the in-house electrophysiological method for quantifying encephalopathy. One hundred and thirty-seven consecutive patients (mean age 49 years, range 17-77) with cirrhosis without any clinical signs of encephalopathy, were screened for SHE. In addition, the Child-Pugh score and the arterial blood ammonia were determined. Patients with concurrent use of alcohol, benzodiazepines or anti-epileptics were excluded. Fifty percent of the patients had an abnormal NCT according to the standard recommended procedure, in contrast only 7% of the patients had an abnormal NCT when scores corrected for age were used. Combining the results of the spectral EEG and the psychometric tests corrected for age yielded a higher prevalence of SHE (23%) than when each test method was used alone (17% vs. 10% abnormal, respectively). Severity of liver disease correlated with the presence of SHE, because the prevalence of abnormal tests increased from 14% in Child-Pugh grade A to 45% in Child-Pugh grade B or C. Age above 40 years and an elevated blood ammonia level were significant determinants related to an abnormal EEG. We conclude that the NCT uncorrected for age markedly overdiagnoses SHE and, therefore, should not be used as a test for the screening of SHE. Using a combination of spectral EEG and two psychometric tests with age-corrected normal values a low prevalence of SHE in patients with Child A liver cirrhosis is found. Older patients with an elevated arterial ammonia are more prone to develop SHE than younger patients with an equal arterial ammonia concentration.