title: Incidence and risk factors of gastrointestinal bleeding in mechanically ventilated patients.
abstract: BACKGROUND
  The widespread use of gastrointestinal bleeding prophylaxis in critically ill patients was one of the most controversial issues. Since few studies reported the incidence of gastrointestinal bleeding in mechanically ventilated patients, this study aimed to identify the incidence and risk factors related to gastrointestinal bleeding in patients undergoing mechanical ventilation for more than 48 hours.
  
  
  METHODS
  A total of 283 ICU patients who had received mechanical ventilation for longer than 48 hours at a provincial hospital affiliated to Shandong University from January 1, 2007 to December 31, 2009 were analyzed retrospectively. Those were excluded from the study if they had a history of gastrointestinal bleeding or ulceration, recent gastrointestinal surgery, brain death and active bleeding from the nose or throat. Demographic data of the patients included patient age, diagnosis on admission, duration of ICU stay, duration of ventilation, patterns and parameters of ventilation, ICU mortality, APACHE II score, multiple organ dysfunction, and indexes of biochemistry, kidney function, liver function and coagulation function. Risk factors of gastrointestinal bleeding were analyzed by univariate analysis and multiple logistic regression analysis.
  
  
  RESULTS
  In the 242 patients who were given mechanical ventilation longer than 48 hours, the incidence of gastrointestinal bleeding was 46.7%. The bleeding in 3.3% of the patients was clinically significant. Significant risk factors were peak inspiratory pressure ≥30cmH2O, renal failure, liver failure, PLT count<50×10(9)/L and prolonged APTT. Enteral nutrition had a beneficial effect on gastrointestinal bleeding. However, the multiple logistic regression analysis revealed that the independent risk factors of gastrointestinal bleeding were as follows: high pressure ventilator setting ≥ 30cmH2O(RR=3.478, 95%CI=2.208-10.733), renal failure(RR=1.687, 95%CI = 1.098-3.482), PLT count<50×1 0(9)/L (RR=3.762, 95%CI=2.346-14.685), and prolonged APTT(RR=5.368, 95%CI=2.487-11.266). Enteral nutrition(RR=0.436, 95%CI= 0.346-0.764) was the independent protective factor.
  
  
  CONCLUSIONS
  The incidence of gastrointestinal bleeding was high in the patients who received mechanical ventilation, and bleeding usually occurred within the first 48 hours. High pressure ventilator setting, renal failure, decreased PLT count and prolonged APTT were the significant risk factors of gastrointestinal bleeding. However, enteral nutrition was the independent protective factor.
authors.affiliation: MICU, Provincial Hospital Affiliated to Shandong University, Jinan 250021, China (Chu YF, Meng M, Jiang JJ, Zhang JC, Ren HS, Wang CT); Longkou People's Hospital, Longkou, 265701, China(Jiang Y).
authors.forename: Yu-Feng
authors.initials: YF
authors.lastname: Chu
authors.affiliation: MICU, Provincial Hospital Affiliated to Shandong University, Jinan 250021, China (Chu YF, Meng M, Jiang JJ, Zhang JC, Ren HS, Wang CT); Longkou People's Hospital, Longkou, 265701, China(Jiang Y).
authors.forename: Yi
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: MICU, Provincial Hospital Affiliated to Shandong University, Jinan 250021, China (Chu YF, Meng M, Jiang JJ, Zhang JC, Ren HS, Wang CT); Longkou People's Hospital, Longkou, 265701, China(Jiang Y).
authors.forename: Mei
authors.initials: M
authors.lastname: Meng
authors.affiliation: MICU, Provincial Hospital Affiliated to Shandong University, Jinan 250021, China (Chu YF, Meng M, Jiang JJ, Zhang JC, Ren HS, Wang CT); Longkou People's Hospital, Longkou, 265701, China(Jiang Y).
authors.forename: Jin-Jiao
authors.initials: JJ
authors.lastname: Jiang
authors.affiliation: MICU, Provincial Hospital Affiliated to Shandong University, Jinan 250021, China (Chu YF, Meng M, Jiang JJ, Zhang JC, Ren HS, Wang CT); Longkou People's Hospital, Longkou, 265701, China(Jiang Y).
authors.forename: Ji-Cheng
authors.initials: JC
authors.lastname: Zhang
authors.affiliation: MICU, Provincial Hospital Affiliated to Shandong University, Jinan 250021, China (Chu YF, Meng M, Jiang JJ, Zhang JC, Ren HS, Wang CT); Longkou People's Hospital, Longkou, 265701, China(Jiang Y).
authors.forename: Hong-Sheng
authors.initials: HS
authors.lastname: Ren
authors.affiliation: MICU, Provincial Hospital Affiliated to Shandong University, Jinan 250021, China (Chu YF, Meng M, Jiang JJ, Zhang JC, Ren HS, Wang CT); Longkou People's Hospital, Longkou, 265701, China(Jiang Y).
authors.forename: Chun-Ting
authors.initials: CT
authors.lastname: Wang
keywords: Gastrointestinal bleeding; Mechanical ventilation; Risk factors