The Application of Biomedical Engineering Techniques to the Diagnosis and Management of Tropical Diseases: A Review <s> Ultrasound <s> In a prospective study, the relationship between the clinical severity of dengue haemorrhagic fever (DHF) and the sonographic findings was examined. The study comprised 73 cases classified as mild (grades I–II) and 75 as severe (grades III–IV). Ultrasonography in the mild group revealed pleural effusions in 30 %, ascites in 34 %, gallbladder wall thickening in 32 %, hepatomegaly in 49 %, splenomegaly in 16 %, and pancreatic enlargement in 14 %. In the severe group, pleural effusions, ascites and gallbladder wall thickening were found in 95 %, pararenal and perirenal fluid collections in 77 %, hepatic and splenic subcapsular fluid collections in 9 %, pericardial effusion in 8 %, hepatomegaly in 56 %, splenomegaly in 16 %, and pancreatic gland enlargement in 44 %. Ultrasound may be useful for early prediction of the severity of DHF in children. <s> BIB001 </s> The Application of Biomedical Engineering Techniques to the Diagnosis and Management of Tropical Diseases: A Review <s> Ultrasound <s> This study was performed to find out whether ultrasound is an important adjunct to clinical and laboratory profile in diagnosing dengue fever or dengue haemorrhagic fever and to further determine whether ultrasound is useful in predicting the severity of the disease. Ultrasound was performed on 128 patients (2-9 years) with clinical suspicion of dengue fever. Serological tests were performed to confirm the diagnosis. 40 patients were serologically negative for dengue fever and later excluded from the study. Of the remaining 88 serologically positive cases, 32 patients underwent ultrasound on second to third day, repeated on fifth to seventh day of fever and in 56 patients ultrasound was done only on fifth to seventh day of fever. Of the 32 patients who underwent the study on second to third day of fever, all showed gall bladder wall thickening and pericholecystic fluid, 21% had hepatomegaly, 6.25% had splenomegaly and right minimal pleural effusion. Follow-up ultrasound on fifth to seventh day revealed ascites in 53% left pleural effusion in 22% and pericardial effusion in 28%. Of the 56 patients who underwent the study on fifth to seventh day of fever for the first time all had gall bladder wall thickening, 21% had hepatomegaly, 7% had splenomegaly, 96% had ascites, 87.5% had right pleural effusion, 66% had left pleural effusion and 28.5% had pericardial fluid. To conclude, in an epidemic of dengue, ultrasound features of thickened gall bladder wall, pleural effusion and ascites should strongly favour the diagnosis of dengue fever. <s> BIB002 </s> The Application of Biomedical Engineering Techniques to the Diagnosis and Management of Tropical Diseases: A Review <s> Ultrasound <s> BACKGROUND ::: Although plasma leakage is the major cause of mortality and morbidity in patients with dengue hemorrhagic fever (DHF), a detailed assessment of the natural course of this process is still lacking. We employed serial ultrasound examination to delineate the locations and the timing of plasma leakage and to evaluate the usefulness of ultrasound in detecting plasma leakage in DHF. ::: ::: ::: METHOD ::: Daily ultrasound examinations of the abdomen and right thorax were performed in 158 suspected dengue cases to detect ascites, thickened gall bladder wall and pleural effusions. Cases were classified into dengue fever (DF), DHF or other febrile illness (OFI) based on serology and evidence of plasma leakage including hemoconcentration and pleural effusion detected by chest radiograph. ::: ::: ::: RESULTS ::: Ultrasonographic evidence of plasma leakage was detected in DHF cases starting from 2 days before defervescence and was detected in some cases within 3 days after fever onset. Pleural effusion was the most common ultrasonographic sign of plasma leakage (62% of DHF cases one day after defervescence). Thickening of the gallbladder wall and ascites were detected less frequently (43% and 52% of DHF cases respectively) and resolved more rapidly than pleural effusions. The size of pleural effusions, ascites and gall bladder wall thickness in DHF grade I and II were smaller than those of grade III patients. Ultrasound detected plasma leakage in 12 of 17 DHF cases who did not meet the criteria for significant hemoconcentration. ::: ::: ::: CONCLUSIONS ::: Ultrasound examinations detected plasma leakage in multiple body compartments around the time of defervescence. Ultrasonographic signs of plasma leakage were detectable before changes in hematocrits. Ultrasound is a useful tool for detecting plasma leakage in dengue infection. <s> BIB003
The critical stage in dengue occurs when the capillary permeability increases which leads to plasma leakage and therefore loss of plasma volume. The presence of pleural effusion and ascites are often used to determine the degree of plasma leakage. These are clinically detectable through physical examination techniques such as auscultatory percussion, and imaging techniques such as chest radiography, and also abdominal and thoracic ultrasonic imaging. Accordingly, several studies have used ultrasound as an aid for diagnosing dengue disease BIB003 BIB002 BIB001 . In the study by Srikiatkhachorn et al. BIB003 ultrasound has been employed to delineate the locations and the timing of plasma leakage in DHF. In the study, one hundred fifty-eight suspected dengue cases classified as DF, DHF, or other Febrile Illness (OFI) based on serology and evidence of plasma leakage including hemoconcentration and pleural effusion, were investigated. Ultrasound examinations of the abdomen and right thorax of patients were performed to detect ascites, thickened gall bladder wall, and pleural effusions. The results indicated that the timing of the plasma leakage was around the time of defervescence. The Pleural effusion was the most common ultrasonographic sign of plasma leakage while the thickening of the gallbladder wall and ascites were not associated as much in determining the plasma leakage. Significantly, plasma leakage of 12 out of 17 DHF cases who did not meet the WHO criteria for hemoconcentration signs was detected by ultrasound. The study concluded that ultrasound imaging is a useful tool for detecting plasma leakage in dengue infection. Another study by Venkata et al. BIB002 was conducted to determine the importance of the ultrasound to clinical and laboratory profiles in diagnosing DF or DHF and to determine the usefulness of ultrasound in predicting the severity of the disease. One hundred twenty-eight suspected dengue patients (40 serologically negative for dengue fever and 88 serologically positive cases) were studied. Results of 32 patients from the 88 cases who were examined on the second to third day and repeated on fifth to seventh day showed that 100% had gall bladder wall thickening and pericholecystic fluid. Follow-up ultrasound on the fifth to seventh day showed ascites in 53%, left pleural effusion in 22%, and pericardial effusion in 28%. The results of the remaining 56 patients who were examined on the fifth to seventh day of fever for the first time showed that 100% had gall bladder wall thickening, 96% had ascites, 87.5% had right pleural effusion, and 66% had left pleural effusion. Contrary to the previous study, this study reported that thickened gall bladder wall, pleural effusion, and ascites should strongly favour the diagnosis of dengue fever. In a separate work by Setiawan et al. BIB001 , a study was conducted to examine the relationship between the clinical severity of 148 DHF patients (73 grades I and II; 75 grades III and IV) and their sonographic findings. Ultrasonography results revealed that the main features presented with grades I and II DHF patients were hepatomegaly 49%, ascites 34%, gallbladder wall thickening 32%, and pleural effusions 30%. On the other hand, the main features detected in DHF patients grades III and IV groups were pleural effusions, ascites and gallbladder wall thickening 95%, pararenal and perirenal fluid collections 77%, hepatomegaly 56%, and pancreatic gland enlargement 44%. The study concluded that ultrasound may be useful for early prediction of the severity of DHF.