Subselecting Patients at Risk for Pulmonary Embolism

100 post-operative subjects were observed following total hip replacement using 125I-fibrinogen (125I-Fg) and impedance plethysmography (IPG) with thigh cuff. Phlebo-grams were obtained if these tests indicated venous thrombosis. Also, lung scan was obtained if clinical evidence of pulmonary embolism developed. Sustained significant isotope localization occurred in 40. 32 of these had abnormal IPG. Four patients had minor pulmonary embolism, which was associated with abnormality of either 125I-Fg or IPG. All major obstructive venous thrombosis and all moderately extensive thrombosis was associated with abnormal IPG. Only minute thrombi were not correctly classified by IPG. The following conclusions are supported by this experience. 1) If prospectively applied in patients at risk, the combination of both techniques (125I-Fg, IPG) is capable of detecting all silent venous thrombosis even minute thrombi of negligible significance. 2) IPG is capable of detecting all major obstructive and all moderately extensive thrombi, that is, all thrombosis of clinical significance arising in the leg. 3) Minute thrombi will not be detected by IPG alone and small emboli resulting from detachment of such minute thrombi would be unheralded unless monitoring includes 125I-Fg.

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Lethal Trauma Pulmonary Embolism is a Black Swan Event in Patients at Risk for Deep Vein Thrombosis: An Evidence-Based Review

The American Surgeon ◽

10.1177/000313481708300431 ◽

2017 ◽

Vol 83 (4) ◽

pp. 403-413 ◽

Cited By ~ 2

Author(s):

C. Michael Dunham ◽

Gregory S. Huang

Keyword(s):

At Risk ◽

Pulmonary Embolism ◽

Deep Vein Thrombosis ◽

Confidence Interval ◽

Hospital Stay ◽

Trauma Patients ◽

Black Swan ◽

Vein Thrombosis ◽

Patients At Risk ◽

Deep Vein

We delineated the incidence of trauma patient pulmonary embolism (PE) and risk conditions by performing a systematic literature review of those at risk for deep vein thrombosis (DVT). The PE proportion was 1.4 per cent (95% confidence interval = 1.2–1.6) in at-risk patients. Of 10 conditions, PE was only associated with increased age (P < 0.01) or leg injury (P < 0.01; risk ratio = 1.6). As lower extremity DVT (LEDVT) proportions increased, mortality proportions (P = 0.02) and hospital stay (P = 0.0002) increased, but PE proportions did not (P = 0.13). LEDVT was lower with chemoprophylaxis (CP) (4.9%) than without CP (19.1%; P < 0.01). PEwas lower withCP (1.0%) than without CP (2.2%; P = 0.0004). Mortality was lower with CP (6.6%) than without CP (11.6%; P = 0.002). PE was similar with (1.2%) and without (1.9%; P = 0.19) mechanical prophylaxis (MP). LEDVT was lower with MP (8.5%) than without MP (12.2%; P = 0.0005). PE proportions were similar with (1.3%) and without (1.5%; P = 0.24) LEDVTsurveillance. Mortality was higher with LEDVTsurveillance (7.9%) than without (4.8%; P < 0.01). A PE mortality of 19.7 per cent (95% confidence interval = 18–22) 3 a 1.4 per cent PE proportion yielded a 0.28 per cent lethal PE proportion. As PE proportions increased, mortality (P = 0.52) and hospital stay (P = 0.13) did not. Of 176 patients with PE, 76 per cent had no LEDVT. In trauma patients at risk for DVT, PE is infrequent, has a minimal impact on outcomes, and death is a black swan event. LEDVTsurveillance did not improve outcomes. Because PE was not associated with LEDVT and most patients with PE had no LEDVT, preventing, diagnosing, and treating LEDVT may be ineffective PE prophylaxis.

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