Exercise oximetry versus spirometry in the assessment of risk prior to lung resection

Spirometry remains a standard method of assessing patient risk prior to lung resection despite its poor sensitivity and specificity. This study compares the relative ability of standardized exercise oximetry and spirometry--forced expiratory volume in the first second--to predict morbidity and mortality after lung resection.

The study comprised a retrospective review of 396 consecutive patients of whom 299 underwent both oximetry and spirometry. Oximetry was undertaken during standard exercise under the supervision of a single physical therapist. Spirometry identified 46 patients with a forced expiratory volume in the first second of less than 1.5 L who were considered to be high risk. Exercise oximetry was used to identify patients with arterial oxygen desaturation at rest, while walking on level ground, or while climbing two flights of stairs (n = 65).

Compared with spirometry, exercise oximetry more reliably predicted home oxygen requirements (p < 0.001), need of admission to the intensive care unit (p < 0.05), prolonged hospital stay (p < 0.001), and respiratory failure (p < 0.05). Oximetry identified 50% of the patients who died, all of whom had a forced expiratory volume in the first second of greater than 1.5 L. Despite its superior predictive value, the sensitivity of oximetry remained low.

We conclude that standardized exercise oximetry is a superior screen of the high-risk patient than spirometry (forced expiratory volume in the first second) prior to pulmonary resection when there are no other risk factors noted on initial history and physical examination. A prospective, randomized trial is required to substantiate this conclusion.