[Indications for thoracic radiography in the preoperative evaluation for elective surgery]

To establish a protocol for ordering chest x-ray films for screening before elective surgery. To study the prevalence of anomalies detected in routinely-ordered chest x-rays, their influence on management of anesthesia and surgery and on the prevention of perioperative complications.

A prospective study of 413 patients undergoing elective surgery over a period of two years. Anomalies detected in chest films were classified as significant or not significant and then as expected or unexpected in function of agreement between the patient's medical history and the image.

A preoperative chest x-ray was obtained for 99.5% of the patients and anomalies were detected in 28.1%, of which 49.1% were significant. The prevalence of anomalies was higher among men over 60 years of age, smokers, those with cardiac or respiratory disease, and those who were classified ASA III-IV. In 6.9% of the cases, the anomalous findings were unexpected based on the patient's history. Findings led to preoperative changes in management in 0.5% of the cases; no delays or cancellations occurred. The frequencies of intraoperative and postoperative complications were 7.9% and 24.6%, respectively.

A preoperative chest x-ray should be ordered only for patients over 60 years of age, smokers of 10 cigarettes/day or more, those with heart or respiratory disease, those who have had contact with tuberculosis and who have not had any other chest x-ray taken within the past year.