Computerised tomography for the detection of pulmonary emboli in intensive care patients--a retrospective cohort study

Computed tomography pulmonary angiography (CTPA) for the detection of pulmonary embolism (PE) among trauma patients: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

Computed tomography pulmonary angiography (CTPA) is a standard imaging technique employed for the detection of pulmonary embolism (PE). This systematic review and meta-analysis aims to examine the prevalence of PE among the trauma patients undergoing CTPA.

METHODS

A comprehensive search across PubMed, Scopus, Google Scholar, and Web of Science yielded 13 studies encompassing 5,570 individuals conducted following Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guideline. Studies that used CTPA for the detection of PE among the trauma patients were selected. This resulted in an evaluation of prevalence, trauma types, clinical manifestations, radiological findings, and mortality rates of PE among traumatic patients undergoing CTPA.

RESULTS

The overall prevalence of PE among trauma patients undergoing CTPA was 18% (95% CI = 13-24%). After pooling the existing data, femur fractures were determined to be the most prevalent trauma type (12%). The most prevalent clinical manifestations of PE among trauma patients included shortness of breath, chest pain, and altered vital signs. Radiological findings encompassed various pulmonary abnormalities, such as opacity, ground-glass opacities, and pleural effusions. Mortality rates of PE among the trauma patients ranged from 0% to 29.4% across the included studies.

CONCLUSION

This study provides comprehensive insights into the prevalence, clinical manifestations, radiological findings and mortality of PE among trauma patients undergoing CTPA. According to our findings, lower threshold for CTPA is recommended in patients with lower extremity or spine fractures.

Diagnostic Yield, Radiation Exposure, and the Role of Clinical Decision Rules to Limit Computed Tomographic Pulmonary Angiography-Associated Complications

OBJECTIVES

Computed tomographic pulmonary angiography (CT-PA) is associated with significant cost, contrast, and radiation exposure. Clinical decision rules (CDRs) reduce the need for diagnostic imaging; however, their utility in the medical intensive care unit (MICU) remains unknown. We explored the diagnostic yield and complications associated with CT-PA (radiation exposure and contrast-induced acute kidney injury [AKI]) while investigating the efficacy of CDRs to reduce unnecessary testing.

METHODS

All CT-PAs performed in an academic MICU for 4 years were retrospectively reviewed. The Wells and revised Geneva scores (CDRs) and radiation dose per CT-PA were calculated, and the incidence of post-CT-PA AKI was recorded.

RESULTS

A total of 439 studies were analyzed; the diagnostic yield was 11% (48 PEs). Positive CT-PAs were associated with a higher Wells score (5.8 versus 3.2, P < 0.001), but similar revised Geneva scores (6.4 versus 6.0, P = 0.32). A Wells score of ≥4 had a positive likelihood ratio of 2.1 with a negative predictive value of 98.2. More than half (88.9%) of patients with a Wells score of ≤4 developed an AKI, with 55.6% of those having recovery of renal function.

CONCLUSIONS

There is overutilization of CT-PA in the MICU. The Wells score retains its negative predictive value in critically ill adult patients and may aid to limit radiation exposure and contrast-induced AKI in MICU.

Sub-segmental pulmonary embolism in three academic teaching hospitals: a review of management and outcomes

BACKGROUND

The availability of computed tomography pulmonary angiography (CTPA) has led to an increase in the diagnosis of sub-segmental pulmonary embolism (SSPE). Current clinical practice guidelines do not make any treatment distinctions for SSPE, though the benefits of anticoagulation for SSPE have not been established.

OBJECTIVES

To review the frequency of pulmonary embolism and sub-segmental pulmonary embolism identified through CTPA as well as their management.

METHODS

Cross-sectional review of the charts of 2213 patients who underwent CTPA in three Hamilton teaching hospitals from 2009 to 2011. In-depth review of the charts of patients with SSPE was undertaken to determine the frequency with which patients received anticoagulation therapy for SSPE, as well as bleeding complications and recurrent thrombosis.

RESULTS

A total of 2216 CTPAs were reviewed. The frequency of PE was 24.8% (n = 550). The most frequent filling defect was SSPE in 82 patients (3.9% of total scans and 15.0% of identified PEs). In 55 of these 82 SSPEs, an alternative diagnosis to PE was identified on CT to explain the patients' symptoms. Approximately 52.4% (n = 43) received anticoagulation for SSPE. Major life-threatening bleeding complications occurred in two of the 43 who received anticoagulation for SSPE. There was no documented recurrent thrombosis in any patients with SSPE, with or without anticoagulation.

SUMMARY/CONCLUSIONS

A substantial proportion of patients received anticoagulation for SSPE (52%) and two developed life-threatening bleeding complications. Randomized controlled trial data are needed to further investigate the risks and benefits of anticoagulation in patients with SSPE.

Challenges, controversies, and hot topics in pulmonary embolism imaging

OBJECTIVE

The purpose of this article is to discuss the diagnostic role of pulmonary CT angiography (CTA) in the workup of pulmonary embolism (PE), including specific populations, and issues such as pulmonary CTA combined with indirect CT venography; radiation dose considerations; the management of isolated subsegmental PE; and new technologic developments, such as dual-source/dual-energy pulmonary CTA.

CONCLUSION

The role of pulmonary CTA will continue to grow with the emergence of MDCT and dual-energy CT and their improved capabilities. However, the need for any given CT examination should always be justified on the basis of the individual patient's benefits and risks.