Evaluation of rebreathing in patients undergoing cataract surgery.

Ten patients undergoing elective cataract surgery with local anesthesia were evaluated for rebreathing using mass spectrometry and arterial blood gas analysis. Results showed a 10 or 51 oxygen-air mixture with an inspired oxygen concentration of 50% (FIO2) administered via a face tent maintained normal blood gases and a satisfactorily low inspired carbon dioxide (FICO2) in conscious patients who were free of lung disease.