title: Association Between Intraoperative Low Blood Pressure and Development of Surgical Site Infection After Colorectal Surgery: A Retrospective Cohort Study.
abstract: OBJECTIVE
  We tested the primary hypothesis that surgical site infections (SSIs) are more common in patients who had longer periods of intraoperative low blood pressure. Our secondary hypothesis was that hospitalization is prolonged in patients experiencing longer periods of critically low systolic blood pressure (SBP) and/or mean arterial pressure (MAP).
  
  
  BACKGROUND
  Hypotension compromises local tissue perfusion, thereby reducing tissue oxygenation. Hypotension might thus be expected to promote infection, but the extent to which low blood pressure contributes remains unclear.
  
  
  METHODS
  We considered patients who had colorectal surgery lasting at least 1 hour at the Cleveland Clinic between 2009 and 2013. The duration of hypotensive exposure and development of SSI was assessed with logistic regression; the association between hypotensive exposure and duration of hospitalization was assessed with Cox proportional hazard regression.
  
  
  RESULTS
  A total of 2521 patients were eligible for analysis. There was no adjusted association between SBP hypotension < 80 mm Hg and SSI, with an estimated odds ratio (95% confidence interval) of 0.97 (0.81, 1.17) per 5-minute increase in SBP hypotension (P = 0.54). There was also no adjusted association between MAP hypotension time and SSI, with estimated odds ratio of 0.97 (0.81, 1.17) for a 5-minute increase in MAP hypotension < 55 mm Hg time (P = 0.71). There was no association between duration of hypotension and time to discharge.
  
  
  CONCLUSIONS
  Intraoperative hypotension does not seem to be a clinically important predictor of SSI after colorectal surgery, probably because the outcomes are overwhelmingly determined by other baseline and surgical factors-and perhaps postoperative hypotension.
authors.affiliation: *Department of Outcomes Research Anesthesiology Institute, Cleveland Clinic, Cleveland, OH†Department of Anesthesiology and Reanimation, Merzifon Military Hospital, Amasya, Turkey‡Department of Outcomes Research, Anesthesiology Institute, Cleveland Clinic, Cleveland, OH§Departments of Quantitative Health Sciences and Outcomes Research, Cleveland Clinic, Cleveland, OH¶Department of Colorectal Surgery, Digestive Disease Institute, Cleveland Clinic, Cleveland, OH.
authors.forename: Rovnat
authors.initials: R
authors.lastname: Babazade
authors.forename: Huseyin O
authors.initials: HO
authors.lastname: Yilmaz
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Zimmerman
authors.forename: Luca
authors.initials: L
authors.lastname: Stocchi
authors.forename: Emre
authors.initials: E
authors.lastname: Gorgun
authors.forename: Hermann
authors.initials: H
authors.lastname: Kessler
authors.forename: Daniel I
authors.initials: DI
authors.lastname: Sessler
authors.forename: Andrea
authors.initials: A
authors.lastname: Kurz
authors.forename: Alparslan
authors.initials: A
authors.lastname: Turan
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D019072:Antibiotic Prophylaxis; D002400:Cathartics / Q000008:administration & dosage; D013505:Digestive System Surgical Procedures; D005260:Female; D006801:Humans; D007022:Hypotension / Q000150:complications*; D015994:Incidence; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009820:Ohio / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D013530:Surgical Wound Infection / Q000453:epidemiology*
chemical_list: D000900:Anti-Bacterial Agents; D002400:Cathartics