title: Factors associated to hypoxemia in patients undergoing coronary artery bypass grafting.
abstract: BACKGROUND
  Hypoxemia is a frequent pulmonary complication in the postoperative coronary artery bypass graft. Detection of factors associated with their occurrence may indicate patients at risk for this complication, which allows tracing specific therapeutic and consequently reduce morbidity and mortality.
  
  
  OBJECTIVE
  To identify related factors to hypoxemia occurrence in immediate coronary artery bypass graft postoperative.
  
  
  METHODS
  In this retrospective cohort study, we studied 100 patients submitted to elective om-pump artery bypass graft , between April 2010 and December 2011, at a reference university hospital for cardiac surgery in the state of Maranhão. It was considered hypoxemia gas exchange ratio less than or equal to 300 mmHg. Associated variables with perioperative hypoxemia were defined by the Student T test, G or Mann-Whitney tests, Chi-square, or Fisher's exact test and multiple linear regression.
  
  
  RESULTS
  Among studied variables, high body mass index (P=0.036) and smoking (P=0.024) were significantly associated with hypoxemia in the immediate coronary artery bypass graft postoperative. Hypoxemia incidence in this period was 55% and did not affects mechanical ventilation duration and Intensive Care Unit lengh of stay.
  
  
  CONCLUSIONS
  In this sample, body mass index and smoking were associated to hypoxemia. These data reinforce the importance of clinical assessment to identify patients at risk for this complication, considering its high incidence in immediate postoperative period.
authors.forename: Natália Pereira dos
authors.initials: NP
authors.lastname: Santos
authors.forename: Rodrigo Martins
authors.initials: RM
authors.lastname: Mitsunaga
authors.forename: Daniel Lago
authors.initials: DL
authors.lastname: Borges
authors.forename: Marina de Albuquerque Gonçalves
authors.initials: Mde A
authors.lastname: Costa
authors.forename: Thiago Eduardo Pereira
authors.initials: TE
authors.lastname: Baldez
authors.forename: Ilka Mendes
authors.initials: IM
authors.lastname: Lima
authors.forename: Karol Cristina Fonseca
authors.initials: KC
authors.lastname: Moura
authors.forename: Josimary Lima da Silva
authors.initials: JL
authors.lastname: Lula
mesh_terms: D000368:Aged; D015992:Body Mass Index; D002315:Cardiopulmonary Bypass / Q000009:adverse effects; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000209:etiology* / Q000503:physiopathology; D007362:Intensive Care Units; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D059035:Perioperative Period; D011183:Postoperative Complications / Q000209:etiology; D012121:Respiration, Artificial; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D013997:Time Factors