title: Spontaneous retroperitoneal hematoma: etiology, characteristics, management, and outcome.
abstract: BACKGROUND
  Spontaneous retroperitoneal hematoma (SRH) can be fatal, requiring immediate recognition and intervention. Current literature is limited, providing little direction in patient care.
  
  
  OBJECTIVE
  To describe clinical characteristics of patients with SRH during an 8-year period.
  
  
  METHODS
  Observational cohort study of all consecutive patients 18 years and older with SRH from January 2000 to December 2007. SRH was defined as unrelated to invasive procedures, surgery, trauma, or abdominal aortic aneurysm.
  
  
  RESULTS
  Of 346 patients screened, 89 were eligible. Median age was 72 years; 56.2% were male. Overall, 66.3% were anticoagulated: 41.6% on warfarin, 30.3% heparin, and 11.2% low-molecular-weight heparin; 30.3% were on antiplatelet therapy; 16.5% were taking both anticoagulant and antiplatelet medications; 15.3% were taking neither. Primary presentation to the Emergency Department was seen in 36%; 64% developed SRH during inpatient anticoagulation therapy. The most common symptom was pain: abdominal (67.5%), leg (23.8%), hip (22.5%), and back (21.3%); 10.1% were misdiagnosed upon their initial encounter. Computed tomography (CT) was performed in 98.8%, ultrasound in 22.1%, and magnetic resonance imaging in 3.5%. Of all subjects, 40.4% were managed in an intensive care unit; 24.7% underwent interventional radiology (IR) procedures and 6.7% surgical evacuation; 75.3% received blood transfusion. Mortality was 5.6% within 7 days, 10.1% within 30 days, and 19.1% within 6 months.
  
  
  CONCLUSIONS
  SRH is uncommon but potentially lethal, with a non-specific presentation that can lead to misdiagnosis. One-third of the cohort was not taking anticoagulants. CT was effective at identification. Most patients received aggressive management with transfusion or IR procedures.
authors.affiliation: Department of Emergency Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: Kharmene L
authors.initials: KL
authors.lastname: Sunga
authors.forename: M Fernanda
authors.initials: MF
authors.lastname: Bellolio
authors.forename: Rachel M
authors.initials: RM
authors.lastname: Gilmore
authors.forename: Daniel
authors.initials: D
authors.lastname: Cabrera
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000009:adverse effects; D001803:Blood Transfusion; D016009:Chi-Square Distribution; D003422:Critical Care; D005260:Female; D006406:Hematoma / Q000139:chemically induced / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy*; D006495:Heparin, Low-Molecular-Weight / Q000009:adverse effects; D006801:Humans; D019934:International Normalized Ratio; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000209:etiology*; D010314:Partial Thromboplastin Time; D010975:Platelet Aggregation Inhibitors / Q000009:adverse effects; D015642:Radiology, Interventional; D012187:Retroperitoneal Space; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed; D014859:Warfarin / Q000009:adverse effects
chemical_list: D000925:Anticoagulants; D006495:Heparin, Low-Molecular-Weight; D010975:Platelet Aggregation Inhibitors; D014859:Warfarin