Outcomes following a negative computed tomography pulmonary angiography according to pulmonary embolism prevalence: a meta-analysis of the management outcome studies

Pulmonary Embolism and Heart Failure: A Reappraisal

Acute heart failure and acute pulmonary embolism share many features, including epidemiological aspects, clinical presentation, risk factors and pathobiological mechanisms. As such, it is not surprising that diagnosis and management of these common conditions might be challenging for the treating physician, in particular when both are concomitantly present. While helpful guidelines have been elaborated for both acute heart failure and pulmonary embolism, not many studies have been published on the coexistence of these diseases. With a special focus on diagnostic tools and therapeutic options, the authors review the available literature and, when evidence is lacking, present their own approach to the management of dyspnoeic patients with acute heart failure and pulmonary embolism.

Weight-Adjusted Contrast Administration in the Computed Tomography Evaluation of Pulmonary Embolism

INTRODUCTION

Computed tomography pulmonary angiogram (CTPA) is widely considered the gold standard for diagnosis of pulmonary embolism (PE) with previous studies demonstrating high sensitivity and specificity. Despite this, nondiagnostic and indeterminate CTPA rates of 5%-26% remain a concern. As part of a continuing quality assurance program, a new weight-adjusted contrast dose and increased administration rate CTPA protocol was studied with an aim to improve diagnostic accuracy of PE evaluation.

METHODS

A total of 2,398 CTPA examinations were reviewed to assess pulmonary arterial enhancement and PE yield in this retrospective study. Between 1 August 2014 and 1 August 2015, 1,133 patients received a fixed-volume (60 mL) contrast dose technique at 4 mL/s (protocol A). A new protocol was then implemented as part of a continuing quality assurance program. Between 15 September 2015 and 15 September 2016, 1,265 patients received a weight-adjusted contrast dose (1 mL/kg) and increased administration rate (5 mL/s) CTPA technique (protocol B). Studies were classed into categories based on quality of study; diagnostic: HU > 211, nondiagnostic: HU < 211 and PE yield; positive, negative, and indeterminate. These variables were compared with cross-sectional surface area to assess the relationship between patient habitus, CTPA diagnostic quality, and PE yield.

RESULTS

A weight-adjusted contrast dose and increased administration rate CTPA protocol (protocol B) resulted in a significant increase in mean PA enhancement (P < .0001), 55.23% decrease in nondiagnostic studies and 43.04% decrease in indeterminate studies. Protocol B demonstrated increased positive and negative CTPA rates with decreased indeterminate rates from 12.38% to 7.04%. Comparison with cross-sectional area demonstrated significant increase in proportion of diagnostic studies and reduction in nondiagnostic and indeterminate CTPAs using protocol B in obese patients.

CONCLUSIONS

A weight-adjusted contrast dose and increased administration rate CTPA protocol can significantly increase PA enhancement, especially in obese patients, resulting in greater high-quality and fewer nondiagnostic and indeterminate CTPA examinations. A CTPA protocol with a higher rate of conclusive examinations can provide greater confidence in PE evaluation for reporting radiologists and accurate clinical decision-making pathways for referring physicians.

Oncologic Emergencies: Too Much Clotting-Venous Thromboembolism in Malignancy

BACKGROUND

Malignancy predisposes patients to higher risk of venous thromboembolism (VTE), which is the second leading cause of death in patients with cancer.

OBJECTIVE

This narrative review evaluates VTE in malignancy and the emergency medicine investigation and management of this patient population.

DISCUSSION

Patients with malignancy are at higher risk of VTE, including deep venous thrombosis (DVT) and pulmonary embolism (PE). Risk factors include the underlying cancer, other hematologic disorders, cancer therapies, and underlying comorbidities. While patients with malignancy and VTE can present similarly to those without malignancy, incidental VTE is more common in cancer patients. Existing scores such as the Wells and Revised Geneva score can assist in risk stratification in patients with malignancy. A negative D-dimer result in the appropriately risk-stratified patient can be used to exclude VTE, though D-dimer is more commonly elevated at baseline in patients with malignancy. Several scoring systems may be useful to predict recurrent risk of VTE, including the Khorana and Ottawa scores. Treatment includes anticoagulation with direct oral anticoagulants (DOACs) or low molecular weight heparin (LMWH). Outpatient therapy may be appropriate in select patients.

CONCLUSIONS

This narrative review provides key updates in the assessment and management of cancer patients with VTE.