Validity of scoring systems to predict risk of prolonged mechanical ventilation after coronary artery bypass graft surgery.
OBJECTIVE
Two scoring systems, (the Spivack scoring system [SSS] and the cardiac risk score [CRS]), have been proposed to predict the risk of prolonged mechanical ventilation (PMV) after coronary artery bypass graft surgery (CABG). The primary objective of this study was to validate the efficacy of these scoring systems to predict the risk of PMV.


METHODS
Prospective observational study.


METHODS
Cardiovascular surgical ICU.


METHODS
Three hundred forty-eight patients underwent CABG. Following surgery, patients were extubated by a standardized respiratory weaning protocol.


RESULTS
Forty-nine percent of patients had SSS > 0 and had significantly longer duration of mechanical ventilation. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the SSS for failure to extubate at 48 h are 80, 49, 9%, and 98%, respectively. Two hundred thirty-two patients (67.5%), 101 patients (29%), and 12 patients (3.5%) had a CRS of 0 to 4, 5 to 8, and > 8, respectively. Patients with lower scores had shorter duration of mechanical ventilation. The sensitivity, specificity, PPV, and NPV of the CRS for failure to extubate at 10 h are 42, 73, 47% and 69%, respectively.


CONCLUSIONS
The SSS may be used as a preoperative screening tool. A simple questionnaire that includes history of unstable angina, diabetes, congestive heart failure, and smoking prior to hospital admission can be used to calculate the SSS. Patients with SSS <or= 0 are at low risk for PMV and can proceed to surgery without further evaluation.
Physician Research Network, Methodist Healthcare University Hospital, Memphis, TN, USA. yende@juno.com
Sachin
S
Yende
Richard
R
Wunderink
D001026:Coronary Artery Bypass; D003422:Critical Care; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007902:Length of Stay; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D012121:Respiration, Artificial; D015300:Ventilator Weaning