title: Spontaneous retroperitoneal bleeding: a case series.
abstract: BACKGROUND
  We experienced four Japanese patients with spontaneous retroperitoneal bleeding, a rare disease. We categorized the clinical characteristics of spontaneous retroperitoneal bleeding in these patients treated in our hospital and discuss the risk factors of spontaneous retroperitoneal bleeding.
  
  
  METHODS
  Three of the 4 patients did not have a bleeding tendency as indicated by laboratory data obtained at the time of retroperitoneal bleeding. The causative blood vessels were the lumbar and superior gluteal arteries and the internal iliac artery. All patients were receiving an anticoagulant, heparin in one and nafamostat mesilate in the other three patients. Three patients were being treated with hemodialysis or continuous hemodiafiltration when the spontaneous retroperitoneal bleeding occurred. We achieved hemostasis with transcatheter arterial embolization in 3 patients and with surgical hemostasis in 1 patient.
  
  
  CONCLUSIONS
  We suggest that in patients receiving anticoagulant therapy in whom progressive anemia and unstable vital signs are present, spontaneous retroperitoneal bleeding should be considered as a possible cause. Nafamostat mesilate may be one of the risk factors for spontaneous retroperitoneal bleeding.
authors.affiliation: Department of Critical Care Medicine, Graduate School of Medicine, Osaka City University, 1-4-3 Asahimachi, Abenoku, Osaka 545-8585, Japan. yamamura@med.osaka-cu.ac.jp.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Yamamura
authors.forename: Takasei
authors.initials: T
authors.lastname: Morioka
authors.forename: Tomonori
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Kaneda
authors.forename: Yasumitsu
authors.initials: Y
authors.lastname: Mizobata
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000009:adverse effects; D001550:Benzamidines; D004621:Embolization, Therapeutic; D005260:Female; D006146:Guanidines / Q000009:adverse effects; D017583:Hemodiafiltration / Q000009:adverse effects; D006470:Hemorrhage / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy; D006488:Hemostasis, Surgical; D006493:Heparin / Q000009:adverse effects; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D006435:Renal Dialysis / Q000009:adverse effects; D012187:Retroperitoneal Space; D012307:Risk Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D000925:Anticoagulants; D001550:Benzamidines; D006146:Guanidines; D006493:Heparin; C032855:nafamostat