الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Venous thromboembolism (VTE), clinically manifested by PE or DVT, is the third most common acute cardiovascular syndrome after myocardial infarction and stroke worldwide. A major number of patients die of acute PE before being diagnosed or suddenly within a few hours from the acute event before receiving treatment. As the awareness of the disease is increasing as long as the non-invasive diagnostic modalities, the tendency to suspect the disease and to diagnose it, is also increasing.
CTPA is currently the gold standard non-invasive tool for diagnosing PE, though very useful and available in most circumstances, but it confers radiation danger and unsuitability under some occasions including pregnancy, renal insufficiency and IV contrast allergy.
In the era of ultrasound, it has earlier been introduced as a non-invasive, bedside, safe, and rapid diagnostic modality of PE.
The aim of the current study was investigating LUS for diagnosing PE and assessing sensitivity, specificity, NPV, and PPV of LUS.
This prospective observational study carried out on 30 patients with suspected PE that had intermediate or high clinical pretest probability for PE on Wells score admitted to pulmonology department of Alexandria main university hospital.
All patients were subjected to complete medical and surgical history taking including risk factors for VTE, and routine laboratory investigations including urea, creatinine, d-dimer, and ABG (Ph, PCo2, Po2, Hco3). LUS was performed to all suspected cases by a pulmonologist along with CTPA, the gold standard for diagnosis, echocardiography, and CUS were also performed to all patients. We excluded patients with contraindications for CTPA and those who are hemodynamically unstable.
In this study, PE was confirmed by LUS if at least a single hypoechoic, hypoperfused (by color doppler imaging), round or wedge-shaped pleural based consolidation was detected with or without pleural effusion.
Out of the 30 suspected cases, 18 patients (60%) had a final diagnosis of PE by CTPA. Twelve patients out of the 30 suspected cases (40%) were considered PE positive by LUS. Out of the 11 cases truly diagnosed as PE by LUS (excluding the single false positive case), 6 (54.5%) had isolated peripheral thromboembolus, whereas 5 (45.5%) had central combined with peripheral thromboembolus. While out of the 7 PE missed cases by LUS, 3 (42.9%) had isolated peripheral thromboembolus, 3 (42.9%) had central combined with peripheral thromboembolus, and one (14.3%) isolated central thromboembolus.
According to LUS, 17 consolidations with hypoperfusion (infarctions) were detected in 12 patients with a mean of 1.4 infarction per patient. The mean ± SD. size of infarctions was 2.68 ± 0.62 cm respecting the maximum dimension of each infarction with a minimum of 2 cm and a maximum of 3.9 cm.
Thirteen (76.4%) infarctions out of the 17 were wedge in shape, while 4 (23.5%) were round. 13 (76.4%) infarctions were on the left side, whereas 4 (23.5%) were on the right side. Concerning the site, 15 (88.2%) located in the lower lobe, and 2 (11.7%) located in the upper lobe.
LUS in comparison to the gold standard CTPA showed to be true positive in 11 patients (36.6%), false positive in one patient (3.3%), true negative in 11 patients (36.6%), and false negative in 7 patients (23.3%).
An overall sensitivity of 61.1%, specificity of 91.6%, PPV of 91.6%, NPV of 61.1%, and accuracy of 73.3% were detected by LUS. With statistically significant p value (0.004) (p significant at ≤ 0.05).
CUS in comparison to the gold standard CTPA showed to be true positive in 9 patients (30%), false positive in 2 patients (6.6%), true negative in 10 patients (33.3%), and false negative in 9 patients (30%) with an overall sensitivity of 50%, specificity of 83.3%, PPV of 81.8%, NPV of 52.6%, and accuracy of 63.3% with statistically non-significant correlation between CTPA and CUS in the diagnostic validity of PE.
Out of the 18 patients with PE, 9 (50%) had DVT, while 9 (50%) did not. Out of the 12 patients with No PE, 2 (16.7%) had DVT, whereas 10 (83.3%) did not. With no statistically significant p value (0.063) (P significant at p<0.05).
Nine (30%) out of the 30 suspected cases with PE had RT ventricular dysfunction, whereas 21 (70%) did not. Out of these 9 patients with RT ventricular dysfunction, 8 (88.9%) had PE, while 1 (11.1%) did not. Out of the 21 patients with no RT ventricular dysfunction, 10 (47.6%) had PE, whereas 11 (52.4%) did not. With statistically significant p value (0.049) (P significant at p<0.05).
Rt ventricular dysfunction by transthoracic echocardiography in comparison to the gold standard CTPA showed to be true positive in 8 patients (26.6%), false positive in one patient (3.3%), true negative in 11 patients (36.3%), and false negative in 10 patients (33.3%) with an overall sensitivity of 44.4%, specificity of 91.6%, PPV of 88.8%, NPV of 52.3%, and accuracy of 63.3% with statistically significant correlation between CTPA and Rt ventricular dysfunction by transthoracic echocardiography in the diagnostic validity of PE.
Out of the 18 patients with PE, 8 (44.4%) had Rt ventricular dysfunction, while 10 (55.6%) did not. Out of the 12 patients with no PE, 1 (8.3%) had Rt ventricular dysfunction, whereas 11 (91.7%) did not.
Although this is not the aim of our study, but our results supported the same theory of Nazerian et al., as the sensitivity of LUS, echocardiography, and CUS combined were 94% while specificity (66.6 %) were much lower than of LUS alone.