Usefulness of clinical prediction rules, D-dimer, and arterial blood gas analysis to predict pulmonary embolism in cancer patients

Objectives: Pulmonary embolism [PE] is seven times more common in cancer patients than non-cancer patients. Since the existing clinical prediction rules [CPRs] were validated predominantly in a non-cancer population, we decided to look at the utility of arterial blood gas [ABG] analysis and D-dimer in predicting PE in cancer patients

Methods: Electronic medical records were reviewed between December 2005 and November 2010. A total of 177 computed tomography pulmonary angiograms [CTPAs] were performed. We selected 104 individuals based on completeness of laboratory and clinical data. Patients were divided into two groups, CTPA positive [patients with PE] and CTPA negative [PE excluded]. Wells score, Geneva score, and modified Geneva score were calculated for each patient. Primary outcomes of interest were the sensitivities, specificities, positive, and negative predictive values for all three CPRs

Results: Of the total of 104 individuals who had CTPAs, 33 [31.7%] were positive for PE and 71 [68.3%] were negative. There was no difference in basic demographics between the two groups. Laboratory parameters were compared and partial pressure of oxygen was significantly lower in patients with PE [68.1 mmHg vs. 71 mmHg, p = 0.030]. Clinical prediction rules showed good sensitivities [88?100%] and negative predictive values [93?100%]. An alveolar-arterial [A-a] gradient > 20 had 100% sensitivity and negative predictive values

Conclusions: CPRs and a low A-a gradient were useful in excluding PE in cancer patients. There is a need for prospective trials to validate these results

Saudi clinical practice guideline for the diagnosis of the first deep venous thrombosis of the lower extremity

The diagnosis of deep venous thrombosis [DVT] may be challenging due to the inaccuracy of clinical assessment and diversity of diagnostic tests. On one hand, missed diagnosis may result in life-threatening conditions. On the other hand, unnecessary treatment may lead to serious complications. As a result of an initiative of the Ministry of Health of the Kingdom of Saudi Arabia [KSA], an expert panel led by the Saudi Association for Venous Thrombo-Embolism [SAVTE; a subsidiary of the Saudi Thoracic Society] with the methodological support of the McMaster University Working Group, produced this clinical practice guideline to assist healthcare providers in evidence-based clinical decision-making for the diagnosis of a suspected first DVT of the lower extremity. Twenty-four questions were identified and corresponding recommendations were made following the Grading of Recommendations, Assessment, Development and Evaluation [GRADE] approach. These recommendations included assessing the clinical probability of DVT using Wells criteria before requesting any test and undergoing a sequential diagnostic evaluation, mainly using highly sensitive D-dimer by enzyme-linked immunosorbent assay [ELISA] and compression ultrasound. Although venography is the reference standard test for the diagnosis of DVT, its use was not recommended

Knowledge of thromboprophylaxis guidelines pre- and post-didactic lectures during a venous thromboembolism awareness day at a tertiary-care hospital

Didactic lectures are frequently used to improve compliance with practice guidelines. This study assessed the knowledge of health-care providers [HCPs] at a tertiary-care hospital of its evidence-based thromboprophylaxis guidelines and the impact of didactic lectures on their knowledge. The hospital launched a multifaceted approach to improve thromboprophylaxis practices, which included posters, a pocket-size guidelines summary and didactic lectures during the annual thromboprophylaxis awareness days. A self-administered questionnaire was distributed to HCPs before and after lectures on thromboprophylaxis guidelines [June 2010]. The questionnaire, formulated and validated by two physicians, two nurses and a clinical pharmacist, covered various subjects such as risk stratification, anticoagulant dosing and the choice of anticoagulants in specific clinical situations. Seventy-two and 63 HCPs submitted the pre- and post-test, respectively [62% physicians, 28% nurses, from different clinical disciplines]. The mean scores were 7.8 +/- 2.1 [median = 8.0, range = 2-12, maximum possible score = 15] for the pre-test and 8.4 +/- 1.8 for the post-test, P = 0.053. There was no significant difference in the pre-test scores of nurses and physicians [7.9 +/- 1.7 and 8.2 +/- 2.4, respectively, P = 0.67]. For the 35 HCPs who completed the pre- and post-tests, their scores were 7.7 +/- 1.7 and 8.8 +/- 1.6, respectively, P = 0.003. Knowledge of appropriate anticoagulant administration in specific clinical situations was frequently inadequate, with approximately two-thirds of participants failing to adjust low-molecular-weight heparin doses in patients with renal failure. Education via didactic lectures resulted in a modest improvement of HCPs' knowledge of thromboprophylaxis guidelines. This supports the need for a multifaceted approach to improve the awareness and implementation of thromboprophylaxis guidelines