Étude BPCO-EP : prévalence et prédiction de l’embolie pulmonaire dans l’exacerbation de la broncho-pneumopathie obstructive chronique

[Incidence of venous thromboembolism in men admitted to a pneumology unit for acute respiratory disease]

BACKGROUND

Venous thromboembolism (VTE) is a major source of morbidity and mortality all over the world. It is one of the complications arising in a hospital environment. The main aim of this study is to estimate the incidence of VTE in respiratory inpatients.

METHOD

The authors carried out a prospective study on acute respiratory disease inpatients. A medical analytical index card was used. An echo-venous Doppler of lower limbs was practiced on D1 and D10 of hospitalization. The Wells scored was used to estimate the clinical probability of the occurrence of VTE.

RESULTS

Seven of 100 patients studied developed VTE (95% CI : 2-12%), four of which presented a pulmonary embolism. The patients with VTE are 60-years-old±11.67. The incidence of VTE includes 20% (95% CI : 12.2-27.8%) of the patients hospitalized for bronchial cancer, 7.14% (95% CI : 2.1-12.18) of the patients presenting pulmonary tuberculosis and 4.54% (95% CI : 0.46-8.62%) of the patients hospitalized for exacerbation of chronic obstructive pulmonary disease (COPD). The duration of hospitalization was prolonged for the treatment of VTE (21±4.41 days for these patients compared with 12±5 days in the absence of VTE (P<0.001)). The analysis of the various risk factors shows that a Performance Status>2 (P=0.005) and lung cancer (P=0.028) are the factors most incriminated in the occurrence of VTE. It is associated with a mortality of 2%.

CONCLUSION

VTE is a reality which is necessary to prevent in respiratory inpatients in situations at risk, especially in patients with lung cancer and with a PS>2.

Bayes pulmonary embolism assisted diagnosis: a new expert system for clinical use

BACKGROUND

The diagnosis of pulmonary embolism demands flexible decision models, both for the presence of clinical confounders and for the variability of local diagnostic resources. As Bayesian networks fully meet this requirement, Bayes Pulmonary embolism Assisted Diagnosis (BayPAD), a probabilistic expert systems focused on pulmonary embolism, was developed.

METHODS

To quantitatively validate and improve BayPAD, the system was applied to 750 patients from a prospective study done in an Italian tertiary hospital where the true pulmonary embolism status was confirmed using pulmonary angiography or ruled out with a lung scan. The proportion of correct diagnoses made by BayPAD (accuracy) and the correctness of the pulmonary embolism probabilities predicted by the model (calibration) were calculated. The calibration was evaluated according to the Cox regression-calibration model.

RESULTS

Before refining the model, accuracy was 88.6%. Once refined, accuracy was 97.2% and 98%, respectively, in the training and validation samples. According to Cox analysis, calibration was satisfactory, despite a tendency to exaggerate the effect of the findings on the probability of pulmonary embolism. The lack of some investigations (like Spiral computed tomographic scan and Lower limbs doppler ultrasounds) in the pool of available data often prevents BayPAD from reaching the diagnosis without invasive procedures.

CONCLUSIONS

BayPAD offers clinicians a flexible and accurate strategy to diagnose pulmonary embolism. Simple to use, the system performs case-based reasoning to optimise the use of resources available within a particular hospital. Bayesian networks are expected to have a prominent role in the clinical management of complex diagnostic problems in the near future.

Pulmonary embolism and deep venous thrombosis in hospitalized adults with chronic obstructive pulmonary disease

BACKGROUND

Hospitalized patients with exacerbations of chronic obstructive pulmonary disease (COPD), when routinely evaluated for pulmonary embolism (PE), show PE in 25-29% of cases. We assessed the rate of diagnosis of PE and deep venous thrombosis (DVT) in hospitalized patients with COPD and the influence of age on relative risk compared with hospitalized patients who do not have COPD.

METHODS

A retrospective evaluation of data in hospitalized adults with and without COPD from the National Hospital Discharge Survey.

RESULTS

From 1979 to 2003, 58,392,000 adults 20 years of age and older, were hospitalized with COPD in the United States. Among these patients, PE was diagnosed in 381,000 (0.65%) and DVT in 632,000 (1.08%). The relative risk of PE in adults hospitalized with COPD was 1.92 and for DVT it was 1.30. Relative risks were age dependent. Among those aged 20-39 years with COPD, the relative risk of PE was 5.34. Among patients aged 40-59 years, the relative risk of PE decreased to 2.02, and among patients aged 60-79 years the relative risk of PE was 1.23.

CONCLUSION

These data, when compared with the rate of diagnosis of PE in hospitalized patients with exacerbations of COPD, all of whom were evaluated for PE, indicate that PE in patients with COPD is generally underdiagnosed. In young adults, other risk factors in combination with COPD are uncommon, so the contribution of COPD to the risk of PE becomes more apparent than in older patients.

Should pulmonary embolism be suspected in exacerbation of chronic obstructive pulmonary disease?

BACKGROUND

The cause of acute exacerbation of chronic obstructive pulmonary disease (COPD) is often difficult to determine. Pulmonary embolism may be a trigger of acute dyspnoea in patients with COPD.

AIM

To determine the prevalence of pulmonary embolism in patients with acute exacerbation of COPD.

METHODS

123 consecutive patients admitted to the emergency departments of two academic teaching hospitals for acute exacerbation of moderate to very severe COPD were included. Pulmonary embolism was investigated in all patients (whether or not clinically suspected) following a standardised algorithm based on d-dimer testing, lower-limb venous ultrasonography and multidetector helical computed tomography scan.

RESULTS

Pulmonary embolism was ruled out by a d-dimer value <500 microg/l in 28 (23%) patients and a by negative chest computed tomography scan in 91 (74%). Computed tomography scan showed pulmonary embolism in four patients (3.3%, 95% confidence interval (CI), 1.2% to 8%), including three lobar and one sub-segmental embolisms. The prevalence of pulmonary embolism was 6.2% (n = 3; 95% CI, 2.3% to 16.9%) in the 48 patients who had a clinical suspicion of pulmonary embolism and 1.3% (n = 1; 95% CI, 0.3% to 7.1%) in those not suspected. In two cases with positive computed tomography scan, the venous ultrasonography also showed a proximal deep-vein thrombosis. No other patient was diagnosed with venous thrombosis.

CONCLUSIONS

The prevalence of unsuspected pulmonary embolism is very low in patients admitted in the emergency department for an acute exacerbation of their COPD. These results argue against a systematic examination for pulmonary embolism in this population.

Pulmonary embolism in patients with chronic obstructive pulmonary disease or congestive heart failure

BACKGROUND

The diagnosis of pulmonary embolism (PE) is often unreliable in patients with chronic obstructive pulmonary disease (COPD) or congestive heart failure (CHF).

SUBJECTS AND METHODS

Registro Informatizado de la Enfermedad TromboEmbólica (RIETE) is an ongoing registry of consecutive patients with acute venous thromboembolism. In this study, the clinical characteristics, laboratory findings, and clinical outcomes of all enrolled patients with acute PE, with or without underlying cardiopulmonary diseases, were compared and contrasted. In addition, the performance of 2 clinical models for the diagnosis of PE was retrospectively evaluated.

RESULTS

As of January 2005, 4444 patients with symptomatic PE have been enrolled in RIETE. Of those, 632 patients (14%) had COPD and 422 (9.5%) had CHF. Significant differences were found in clinical presentation and 3-month outcomes among the 3 groups. With the Geneva model, there was a lower percentage of PE patients with COPD (relative risk [RR] 0.82; 95% confidence interval [CI], 0.66-1.02) or CHF (RR 0.73; 95% CI, 0.56-0.95) who fell into the low pretest probability category, compared with patients with neither. Besides, the percentage of patients with high probability of PE was similar among the 3 patient groups. The frequency of COPD (61%) and CHF (72%) patients with a high pretest probability for PE increased when using the Pisa score, but the percentage of COPD patients into the high probability group was lower (RR 0.60; 95% CI, 0.51-0.71).

CONCLUSIONS

Significant differences exist in PE patients with and without underlying cardiopulmonary diseases. The performance of the 2 clinical prediction models varied according to the presence or absence of underlying COPD or CHF.