Medical Image of the Week: Pericardial Effusion in a Setting of Bacterial Endocarditis

Figure 1. Single portable semi-upright chest radiograph with findings of an enlarged cardiomediastinal silhouette, and indistinctness of the perihilar vasculature.

Figure 2. Axial contrast enhanced computed tomography—soft tissue windows. A large concentric rim (fluid density) surrounds all four chambers of the heart, consistent with a pericardial effusion. Notice how the right ventricle is normal, which can be collapsed in cardiac tamponade.

A 25-year-old man with an extensive history of intravenous drug abuse presents to the hospital with worsening shortness of breath and fevers for two weeks. In the emergency department, he was initially provided breathing treatments including ipratropium/albuterol and methylprednisolone. As the patient still required supplemental oxygen, a chest radiograph was performed to evaluate for an underlying infectious etiology.

However, the chest radiograph portrayed an enlarged cardiomediastinal silhouette in a “water-bottle” appearance and obscuration of the hilar vessels (Figure 1). Given these findings, there was a high concern for a pericardial effusion, and the physicians opted for further cross-sectional imaging. The contrast enhanced computed tomography (CT) images confirmed the aforementioned diagnosis (Figure 2). As blood cultures eventually grew Staphylococcus aureus, and given the patient’s extensive history of intravenous drug abuse, there was a high suspicion for bacterial endocarditis. A subsequent echocardiogram verified several valvular vegetations in keeping with endocarditis. The patient’s vitals remained stable throughout the hospital course, and he was continued on long-term antibiotic therapy.

Chest radiographs are often unreliable in depicting pericardial effusions, as they require at least 200 mL of pericardial fluid to portray an enlarged cardiomediastinal silhouette (1).  As fluid continues to accumulate in the pericardial space, the increase in pericardial pressure on the chambers can eventually lead to cardiac tamponade—a form of cardiogenic shock (2). Cardiac tamponade will result in a decrease in stroke volume, decreased blood pressure, and ultimately a diminished cardiac output; all of which require immediate intervention (2). Echocardiography remains the imaging modality of choice given its portability and high sensitivity in diagnosing pericardial fluid (3).

Amrit Hansra, MD

Department of Medical Imaging

University of Arizona

Tucson, AZ

References

1. Restrepo CS, Lemos DF, Lemos JA, et al. Imaging findings in cardiac tamponade with emphasis on CT. Radiographics. 2007 Nov-Dec;27(6):1595-610. [CrossRef] [PubMed]
2. Spodick DH. Acute cardiac tamponade. N Engl J Med. 2003 Aug 14;349(7):684-90. [CrossRef] [PubMed]
3. Chong HH, Plotnick GD. Pericardial effusion and tamponade: evaluation, imaging modalities, and management. Compr Ther. 1995 Jul;21(7):378-85. [PubMed] 

Cite as: Hansra A. Medical image of the week: pericardial effusion in a setting of bacterial endocarditis. Southwest J Pulm Crit Care. 2016 Mar;12(3):110-1. doi: http://dx.doi.org/10.13175/swjpcc009-16 PDF

Medical Image of the Week: Diffuse Gastric Bleeding and ALL

Figure 1. Technetium 99m tagged RBC scan showing abnormal radio tracer accumulation throughout the stomach (Panel A), and subsequently passing into the small bowel (Panel B).

A 26-year-old man with a medical history significant for acute lymphoblastic leukemia (ALL) presented with hypovolemic shock secondary to large volume hematemesis. The patient was diagnosed with ALL and treated with high dose chemotherapy followed by peripheral blood stem cell transplant from a matched unrelated donor one year prior to presentation. His treatment course was complicated by grade 4 acute graft versus host disease (GVHD) and CMV colitis. Blood work on admission showed hemoglobin of 6.4 g/dL and a leukocytosis. Patient was intubated for airway protection, transferred to ICU, and EGD was performed, which revealed diffusely friable mucosa, inflammation, and ulcerations throughout the gastric mucosa with only a few areas of normal appearing mucosa. Additionally, areas of spontaneous bleeding were seen. Selective arteriography within the right gastric and gastroduodenal arteries showed no active extravasation from the stomach or duodenum. However the gastroepiploic and right gastric arteries were prophylactically embolized. Subsequently, a technetium 99m tagged RBC scan demonstrated abnormal radio-tracer accumulation throughout the stomach with subsequent passage into the small bowel (Figure 1). The patient continued to have refractory gastric bleeding even with an increased dose of cyclosporine. Surgical measures including gastrectomy were discussed with the family. However, the family decided on comfort care. The patient died the following day.

Although gastric bleeding is rare in ALL patients in general, it is more commonly associated with certain condition such as GVHD and colitis following allogeneic stem cell transplantation (SCT). One of the retrospective studies with 447 SCT patients showed that 21.1% of study population experienced major GI bleeding, requiring transfusions or surgical intervention. Also, their mortality was shown to be twice higher than patients without bleeding complication, although most cases of bleeding were mild and occurred in the peri-transplant period with concurrent severe thrombocytopenia (1).

Hemorrhagic complications occur predominantly during the first month of post transplant, and bleeding is more commonly associated with allogeneic SCT compared to autologous SCT (2). This is mainly secondary to GVHD with gastrointestinal involvement, which leads to destruction and fragility of the epithelium as well as hyper-perfusion and proliferation of the blood vessels. As such, the risk of hemorrhage in patients with acute and chronic GVHD greater than grade I was 2.9 and 4.2 fold higher, respectively, and these patients had 10.8 fold higher risk of severe bleeding. The risk of bleeding is further increased by CMV infection, which infects vascular endothelial cells, narrows capillary lumens, and leads to ischemia and ulceration of gastric mucosa (3). The combination of GVHD and CMV infection could have synergistically damaged the gastric mucosa leading to severe refractory bleeding in our case.

Onyemaechi Okolo MD¹, Seongseok Yun MD PhD¹, Faiz Anwer MD, FACP²

¹Department of Medicine

²Department of Hematology & Oncology, Blood & Bone Marrow Transplantation Program

University of Arizona

Tucson, AZ, 85721

References

1. Pihusch R, Salat C, Schmidt E, Göhring P, Pihusch M, Hiller E, Holler E, Kolb HJ. Hemostatic complications in bone marrow transplantation: a retrospective analysis of 447 patients. Transplantation. 2002;74(9):1303-9. [CrossRef] [PubMed]
2. Törnebohm E, Lockner D, Paul C. A retrospective analysis of bleeding complications in 438 patients with acute leukaemia during the years 1972-1991. Eur J Haematol. 1993;50(3):160-7. [CrossRef] [PubMed]
3. Cheung AN, Ng IO. Cytomegalovirus infection of the gastrointestinal tract in non-AIDS patients. Am J Gastroenterol. 1993;88(11):1882-6. [PubMed]

Cite as: Okolo O, Yun S, Anwer F. Medical image of the week: diffuse gastric bleeding and ALL. Southwest J Pulm Crit Care. 2016;12(3):108-9. doi: http://dx.doi.org/10.13175/swjpcc010-16 PDF