October 26, 2006

Fever of uknown origin

A 72YO male with a history of hypertension and recent GI bleeding, was transferred from the MICU on hospital day (HD) 6 after being treated for delayed transfusion hemolytic reaction. His medication at the time of transfer included prednisone tapering dose. He had no known drug allergy. Shortly after, the patient was found to be febrile (101F). Of note he had a left subclavian central venous line and a left radial arterial line which were placed on the day of admission and removed before the transfer.

In addition to a chest radiograph, blood and urine cultures were obtained. On HD#7, gram positive cocci grew in IV/IV cultures bottles. At that time, intravenous (IV) vancomycin and oral rifampin were initiated. On HD#9 methicillin resistant staphylococcus aureus (MRSA) susceptible to vancomycin, sulfamethoxazole-trimethoprim, tetracycline, and gentamicin was identified. Review of systems obtained were significant for fatigue, chills, diaphoresis, and decreased appetite. He also complained of bilateral lower back pain when being positioned in bed. He denied dysuria, neck stiffness, diarrhea nausea, vomiting, cough, and shortness of breath.

On physical examination, the patient was afebrile and his vitals were stable. He was alert and oriented to self, time, and place. He had no meningeal signs, no heart murmurs and no lung crackles. His abdominal exam was unremarkable. He had tenderness on palpation of the right flank region. His left wrist radial arterial line site was indurated and tender.

His white blood cell count was 10,600 with 83% segmented neutrophils.On HD#10, his urine also grew MRSA. A computer tomography scan (CT) of his abdomen/pelvis revealed an asymmetric enlargement with heterogeneous enhancement in the right psoas muscle, likely of an infectious etiology. The left upper extremity duplex showed no deep venous thrombosis to the left arm but superficial thrombophlebitis. Other diagnostic studies were unremarkable. Blood cultures were persistently positive for MRSA.Thus the vancomycin was switched to linezolid (IV) on HD#10 and again to daptomycin(IV) on HD#13.On HD#15 vancomycin was added to daptomycin and rifampin. Finally, the patient had negative blood cultures and was clinically stable on HD#20.The final diagnosis at discharge was right psoas abscess.

In summary it is important to include psoas abscess in the differential diagnosis of patients with bacteremia and be aware of physical findings associated with psoas abscess. It is also important to realize that a combination of antibiotics may be needed for eradication of MRSA bacteremia.

Posted by mmw at 02:44 PM | Comments (0)