Hypoxemia after myocardial revascularization: analysis of risk factors.
OBJECTIVE
Severe hypoxemia is complication frequently seen in the immediate postoperative period of myocardial revascularization (MR), increasing the duration of mechanical ventilation, the incidence of pulmonary infections, hospital costs, and mortality. The objective of this study was to identify predictive factors of severe hypoxemia in patients undergoing MR.


METHODS
Four-hundred and eighty-one adult patients undergoing elective MR between October 2003 and March 2004 were enrolled in this study. Severe hypoxemia was defined as PaO2/FiO2 < 150 upon admission to the ICU. The Chi-square test, Student's t or Wilcoxon test, followed by multivariate analysis and logistic regression (LR) for parameters with p < 0.25 in the univariate analysis, were used for the statistical analysis. A p > 0.2 was required to exclude the parameter from the LR model, and a p < 0.1 was considered significant.


RESULTS
Time for extubation was greater in patients with severe hypoxemia (p < 0.001). Multivariate analysis identified age (p = 0.081), weight (p = 0.001), need of prolonged CBP (p = 0.033), and left ventricular dysfunction (p = 0.082) as independent predictors of severe hypoxemia.


CONCLUSIONS
Older and overweighted patients, those with left ventricular dysfunction, and those who needed CPB presented an increased risk of severe hypoxemia after MR. In those patients, the use of perioperative ventilatory strategies, with elevated positive expiratory pressures and alveolar recruitment maneuver should be considered to prevent postoperative pulmonary dysfunction.
Serviço de Anestesiologia e Terapia Intensiva Cirúrgica do Instituto do Coração (InCor) - Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HC-FMUSP), São Paulo, SP.
Tais Felix
TF
Szeles
Eduardo Muracca
EM
Yoshinaga
Wellington
W
Alenca
Marcio
M
Brudniewski
Flávio Silva
FS
Ferreira
José Otavio Costa Júnior
JO
Auler
Maria José Carvalho
MJ
Carmona
Luiz Marcelo Sá
LM
Malbouisson
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D009204:Myocardial Revascularization / Q000009:adverse effects*; D012307:Risk Factors