title: Measurement of peritoneal fluid urea nitrogen and creatinine levels is useful to detect iatrogenic urinary tract leakage in colorectal surgery.
abstract: BACKGROUND
  Increased peritoneal drainage after colorectal surgery is a common problem. Measurement of peritoneal fluid urea nitrogen (UN) and creatinine (Cr) is a diagnostic tool to detect the urinary tract leakage (UTL). We evaluated its application in colorectal surgery.
  
  
  METHODS
  We conducted a retrospective chart review study. We enrolled patients with iatrogenic UTL, and measured their UN and Cr levels in peritoneal fluid and compared them with those in blood and urine. Meanwhile, we assigned patients without UTL to a control group and compared clinical parameters of both groups.
  
  
  RESULTS
  Twenty-three patients with iatrogenic UTL were recruited. The overall incidence was 0.5%. UN level in peritoneal fluid (322 ± 56 mg/dL) was significantly higher than that in blood (18.7 ± 4.0 mg/dL, p < 0.001); Cr level in peritoneal fluid (69.7 ± 14.3 mg/dL) was also significantly higher than that in blood (1.5 ± 0.5 mg/dL, p < 0.001). UN level in peritoneal fluid was significantly higher in the iatrogenic UTL group than in the control group (322 mL/dL vs. 9.3 mL/dL, p < 0.001); Cr level in peritoneal fluid was also significantly higher (69.7 mg/dL vs. 0.98 mg/dL, p < 0.001).
  
  
  CONCLUSIONS
  When increased peritoneal drainage is found postoperatively in colorectal surgery, measurement of UN and Cr levels in peritoneal fluid can be a useful diagnostic tool to determine intraperitoneal iatrogenic UTL.
authors.affiliation: Division of Colorectal Surgery, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, ROC.
authors.forename: Jui-Ho
authors.initials: JH
authors.lastname: Wang
authors.affiliation: Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan, ROC.
authors.forename: Ya-Hsin
authors.initials: YH
authors.lastname: Kung
authors.affiliation: Division of Colorectal Surgery, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, ROC.
authors.forename: Tai-Ming
authors.initials: TM
authors.lastname: King
authors.affiliation: Division of Colorectal Surgery, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, ROC.
authors.forename: Min-Chi
authors.initials: MC
authors.lastname: Chang
authors.affiliation: Division of Colorectal Surgery, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, ROC; Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan, ROC. Electronic address: ss851124@gmail.com.
authors.forename: Chao-Wen
authors.initials: CW
authors.lastname: Hsu
mesh_terms: D000328:Adult; D000368:Aged; D001202:Ascitic Fluid / Q000737:chemistry*; D003107:Colorectal Surgery / Q000009:adverse effects*; D003404:Creatinine / Q000032:analysis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009584:Nitrogen / Q000032:analysis*; D012189:Retrospective Studies; D014508:Urea / Q000032:analysis*; D014570:Urologic Diseases / Q000175:diagnosis* / Q000209:etiology
chemical_list: D014508:Urea; D003404:Creatinine; D009584:Nitrogen
keywords: creatinine; peritoneal fluid; urea nitrogen; urinary tract leakage