title: [Assessment of a risk scale in patients submitted to coronary artery bypass surgery: analysis of 400 cases].
abstract: OBJECTIVE
  The objective of this paper was to assess a risk scale based on a protocol developed at The Cleveland Clinic Foundation for the coronary artery bypass surgery using preoperative and perioperative parameters and the patient's physiological profile at the admission in the intensive care unit (ICU).
  
  
  METHODS
  In the period between May,1999 and January,2002 part of the patients who underwent coronary artery bypass surgery in the cardiac service of the Hospital Universitário Cajuru of Pontifícia Universidade Católica do Paraná were included in the assessment of the operative risk scale, prospectively and consecutive. During the postoperative assessment a parameter < 6 was associated to less severe cases and parameters above 7 corresponding to more severe cases. For the evaluation of ICU admission, this classification was associated with parameter values < and > 14. Morbidity was classified in major complications as well as less important complications. There were including all patients that it was possible to include all variables of the protocol.
  
  
  RESULTS
  Four hundred patients who underwent surgery, with cardiopulmonary bypass or off-pump coronary bypass, were assessed. There was 22 deaths (5.5%) and 124 patients with major complications (31%). The most common preoperative risk factors were the age between 65 and 74 in 111 cases (27.75%), weight below 65 kg in 106 (26.5%). Diabetes mellitus being treated in 89 cases (22.5%). The cardiopulmonary bypass time was above 160 minutes in 13 cases (6.95%) and intra-aortic balloon pump was used in 11 (2.75%). During the analysis of the ICU admission physiology, the alveolar arterial gradient equal or above 250 mmHg was the parameter found in 334 patients (83.5%), arterial sodium bicarbonate at ICU below 21 mmol/L was identified in 265 patients (66.25%), and the marginal or inadequate cardiovascular performance was observed in 263 patients (65.75%). The major complications occurred in 124 patients (31%) and the low output syndrome was more frequently seen in 64 (51.61%) of the cases. Twenty-two deaths were recorded (5.5%) and the ones with cardiovascular etiology were the most frequent (40.9%). In 370 patients (92.5%) the preoperative assessment showed as a result a parameter equal or below 6 and the ICU admission, the parameter was equal or below 14 in 345 cases (86.25%). Patients with parameters above that, at the preoperative and at the ICU admission, have shown more complications and more deaths.
  
  
  CONCLUSIONS
  It was possible to conclude that the parameters recorded at the preoperative and at the ICU admission were correlated with the probability of death and complications and the ICU admission parameter, associated with the preoperative parameters and intraoperative factors bring more information for the prognostic of death and complications. The adjusted models adequately express the death and complications probabilities estimate, due to the preoperative, intraoperative and ICU admission parameters.
authors.affiliation: Hospital Universitário Cajuru, Pontifícia Universidade Católica do Paraná, Curitiba, PR.
authors.forename: Hélcio
authors.initials: H
authors.lastname: Giffhorn