Mortality in Patients Treated for Pulmonary Embolism

Alpert, Joseph S.; Smith, Roger E.; Carlson, C. J.; Ockene, Ira S.; Dexter, Lewis; Dalen, James E.

doi:10.1001/jama.1976.03270140029017

Cited by 305 publications

(87 citation statements)

References 5 publications

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“…On the scale of the whole lung one can assume that the orientation of the capillaries is random. Equation [2] is symmetric about zero and would integrate to zero over all values of . However, HP gas MRI can image structures with resolution of ϳ200 m or less (6), and since this approximates the size of single alveolus in which the distribution of blood capillaries has certain local order (see Fig.…”

Section: Methodsmentioning

confidence: 99%

“…3 for a rendition of the honeycomb-like structure (7)), Eq. [2] would integrate to a nonzero value in voxels the size of a single alveolus or for a limited number of alveoli. In fact, given that the average diameter of alveoli is ϳ300 m, there will be, on average, about three alveoli in an imaging pixel of 1-mm resolution, and Eq.…”

Section: Methodsmentioning

confidence: 99%

“…PE is notoriously difficult to diagnose, since it is fairly asymptomatic, with symptoms often limited to mild chest pain and shortness of breath. Yet diagnosis of the disease is important because if untreated, PE has an estimated mortality of 30%, which is 10 times the mortality at one year of treated PE (2). Naturally, accurate emboli diagnosis can be realized through high-resolution visualization of regional lung perfusion.…”

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confidence: 99%

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Indirect detection of lung perfusion using susceptibility‐based hyperpolarized gas imaging

Dimitrov

Insko

Rizi

et al. 2005

Magnetic Resonance Imaging

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Purpose:To address the problem of inadequate signal-tonoise ratio (SNR) encountered in lung perfusion magnetic resonance imaging (MRI) by developing an indirect detection based on the strong hyperpolarized (HP) gas signal. Materials and Methods:Our model is based on detecting the effects of gadolinium (Gd) flowing through lung capillaries by recording the phase of the nearby alveolar HP gas. In a HP gas 3 He phantom we imaged gas phases before and after removing tubes containing paramagnetic solution away from the phantom. We also imaged HP gas phases in pig lungs before and after injection of Gd. Finally, parenchymal spin phase in excised lungs was measured as a function of Gd concentration. Results:In the phantom, the differential phase map displayed a pattern characteristic of a susceptibility-induced dipole field, showing the possibility of an indirect detection. In vivo, the differential phase map showed homogeneous appearance, as expected for uniform perfusion in healthy lungs. Ex vivo, the parenchymal spin phases were shown to depend linearly on Gd concentration. Conclusion:Our method should allow indirect perfusion (Q) and direct ventilation (V) to be assessed simultaneously, thus allowing for diagnosis of V/Q mismatches. The linear dependency of parenchymal spin phase vs. Gd concentration may allow for quantification of lung perfusion.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

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Indirect detection of lung perfusion using susceptibility‐based hyperpolarized gas imaging

Dimitrov

Insko

Rizi

et al. 2005

Magnetic Resonance Imaging

View full text Add to dashboard Cite

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“…This falls to less than 8% if pulmonary embolism is diagnosed and appropriately treated. [6][7][8][9] Diagnosing pulmonary embolism can be challenging because it is in the differential diagnosis of many common clinical presentations, including chest pain, shortness of breath, and hemoptysis. Studies suggest that only 8% − 30% of patients suspected of having a pulmonary embolism actually have the condition.…”

Section: Introductionmentioning

confidence: 99%

Ambulatory vital signs in the workup of pulmonary embolism using a standardized 3-minute walk test

Amin

Perry

Stiell

et al. 2015

CJEM

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Objective: Diagnosing pulmonary embolism can be difficult given its highly variable clinical presentation. Our objective was to determine whether a decrease in oxygen saturation or an increase in heart rate while ambulating could be used as an objective tool in the diagnosis of pulmonary embolism. Methods: This was a two-site tertiary-care-centre prospective cohort study that enrolled adult emergency department or thrombosis clinic patients with suspected or newly confirmed pulmonary embolism. Patients were asked to participate in a standardized 3-minute walk test, which assessed ambulatory heart rate and ambulatory oxygen saturation. The primary outcome was pulmonary embolism. Results: We enrolled 114 patients, including 30 with pulmonary embolism (26.3%). A ≥2% absolute decrease in ambulatory oxygen saturation and an ambulatory change in heart rate >10 beats per minute (BPM) were significantly associated with pulmonary embolism. An ambulatory heart rate change of >10 BPM had a sensitivity of 96.6% (95% confidence interval [CI] 83.3 to 99.4) and a specificity of 31.0% (95% CI 22.1 to 45.0) for pulmonary embolism. A ≥2% absolute decrease ambulatory oxygen saturation had a sensitivity of 80.2% (95% CI 62.7 to 90.5) and a specificity of 39.3% (95% CI 29.5 to 50.0) for pulmonary embolism. The combination of both variables yielded a sensitivity of 100.0% (95% CI 87.0 to 100.0) and a specificity of 11.0% (95% CI 6.6 to 21.0). Conclusion: In summary, our study found that an ambulatory heart rate change of >10 BPM or a ≥2% absolute decrease in ambulatory oxygen saturation from baseline during a standardized 3-minute walk test are highly correlated with pulmonary embolism. Although the findings appear promising, neither of these variables can currently be recommended as a screening tool for pulmonary embolism until larger prospective studies examine their performance either alone or with pre-existing rules. RÉSUMÉObjectif: L'embolie pulmonaire peut être difficile à diagnostiquer étant donné son tableau clinique très variable. L'étude visait à déterminer si une diminution du degré de saturation du sang en oxygène ou une augmentation de la fréquence cardiaque en cours de déambulation pouvait servir d'outil objectif de diagnostic de l'embolie pulmonaire. Méthode: Il s'agit d'une étude prospective de cohortes, menée dans deux centres hospitaliers de soins tertiaires, à laquelle ont participé des patients provenant d'un service d'urgence pour adultes et d'un centre de thrombose, chez qui était soupçonnée ou avait été confirmée depuis peu une embolie pulmonaire. L'on a demandé aux patients de participer à une épreuve de marche normalisée de 3 minutes au cours de laquelle étaient évalués la fréquence cardiaque et le degré de saturation du sang en oxygène, en mode ambulatoire. Le principal critère d'évaluation était l'embolie pulmonaire. Résultats: Ont participé à l'étude 114 patients, dont 30 souffraient d'une embolie pulmonaire (26,3 %). Une diminution absolue ≥2 % du degré de saturation du sang en oxygène en cours d...

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“…PE is truly an unsuspected killer with profound clinical implications. Although patients in whom PE is diagnosed and treated have a mortality rate of only 3% to 8% [3,14,15], those in whom the diagnosis is missed have a fourfold to sixfold greater mortality [3,6,15].…”

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confidence: 99%