Thrombocytopenia Preceding Urosepsis in an Otherwise Asymptomatic Patient After Bilateral Retrograde Intrarenal Surgery.

Introduction and Background: Urosepsis is commonly predicted by the systematic inflammatory response syndrome (SIRS) criteria. We report a case of urosepsis preceded only by thrombocytopenia. Case Presentation : An 80-year-old Caucasian female presented with recurrent urinary tract infections, type 1 second-degree heart block (Mobitz I), and chronic deep venous thrombosis for which she was taking apixaban. Computed tomography (CT) revealed a 1.3 cm right upper pole calculus (Hounsfield units (HU) = 704) and a left 5 mm nonobstructing interpolar calculus (HU = 904). A preoperative urine culture was sterile as the patient was on antibiotics. While on antibiotic coverage, the patient underwent bilateral retrograde intrarenal surgery with bilateral stent placement: the procedure time was 188 minutes. She was continued on vancomycin and gentamicin immediately postoperatively. On postoperative day (POD) 1, she was feeling well; her vital signs were within normal limits. However, the hemoglobin and the platelet counts declined from 12.4 to 10.0 g/dL and from 215 to 58/mm³, respectively. Because of the unexplained thrombocytopenia, the patient was kept at the hospital. In the afternoon, she became hypotensive (78/37 mm Hg) and a rapid response was called. She was admitted to the surgical intensive care unit and antibiotics were broadened. On POD 2, the patient met sepsis SIRS criteria with white blood cell (WBC) of 2.9/mm³ and heart rate of 92 bpm. Stone culture was positive for methicillin-resistant Staphylococcus aureus (MRSA). On POD 3, her blood pressure had returned to 116-142/47-84. On POD 5, platelet count recovered to 94/mm³ and WBC to 3.8/mm³. She was discharged on POD 6 with a 2-week ongoing course of intravenous vancomycin. On follow-up 7 weeks postoperatively, she was asymptomatic with WBC of 6.5/mm³ and platelet count of 206/mm³. Follow-up CT demonstrated normal renal anatomy with subcentimeter calculi clustered within the left renal parenchyma and no stones on the right side. Conclusion: This case shows an uncommon non-SIRS presentation of postoperative urosepsis signaled only by thrombocytopenia.