Arterial oxygen partial pressure and cardiovascular surgery in elderly patients

Abstract

Arterial blood gas assessment is still routinely performed in candidates for a cardiovascular surgery. Whether sampling arterial blood is useful in an elderly patient with a near normal lung function and who meets all other criteria for operability, is unknown. Therefore, it was our purpose to provide reference values for arterial blood gases in these patients and to examine how the level of arterial oxygen partial pressure (PaO2) might influence postoperative outcome. We retrospectively studied arterial blood gases in 201 patients, aged 2 70-92 years with normal or near normal ventilatory function awaiting a planned cardiovascular surgery. PaO2 averaged 81.6±7.6 mmHg 2 and PaCO2 averaged 37.7±3.2 mmHg. Both were independent of age. Factors associated with mortality according to bivariate analysis 2 were: gender (female), type of surgery (valve replacement), and a low PaO2 with strictly no ventilatory abnormality. In conclusion, PaO2 values in elderly patients with cardiac disease and normal ventilatory function are greater than those obtained by extrapolation from healthy younger subjects. PaO2 measurement should be recommended prior to cardiovascular surgery in elderly patients since a low PaO2 with strictly normal ventilatory function is significantly associated with an increased risk for postoperative mortality.