[Hypercapnea during facial surgery under local anesthesia]

Abstract

We examined the ventilation of patients whose faces were draped during facial surgery under local anesthesia. Ten patients who underwent eye surgery received hydroxyzine 25 mg and pentazocine 15 mg i.m. before local anesthesia. Arterial blood samples and end-tidal respiratory gases from nasal cannulae were collected at the following selected times: before draping their faces, 10 min, 30 min, 60 min after draping, and after the drapes were removed. Both arterial carbon dioxide tension (42 +/- 1 mmHg before draping and 46 +/- 1 mmHg at 10 min) and end-tidal carbon dioxide tension (33 +/- 2 mmHg before draping and 36 +/- 1 mmHg at 10 min) were elevated significantly after their faces were draped. Hypercapnea was completely eliminated by suctioning the expired gases. It is concluded that hypercapnea is inevitable during face or neck surgery under local anesthesia, and that the expired gases should be monitored and removed.