[Arterial blood gas changes in patients with malignant airway obstruction treated with Nd-YAG laser under local anesthesia].

The purpose of this report is to observe the changes in arterial blood gas in patients with malignant airway obstruction treated with Nd-YAG laser under local anesthesia. Nine inoperable lung cancers (7 primary, 2 metastatic) with tracheal and/or bronchial obstruction were studied. Recanalization of the obstructing airway was the goal of Nd-YAG laser treatment. Arterial blood gas levels were measured at rest, post-bronchoscopy, during treatment with Nd-YAG laser, immediately after treatment, and at each hour post-treatment for 5 hours. Blood samples were obtained from a cannula that had already been inserted into the radial artery. A significant decrease in PaCO2 levels was noted after bronchoscopy (12.1 +/- 7.47 mmHg, p less than 0.005), during laser phot resection (16.9 +/- 6.37 mmHg, p less than 0.001), immediately (17.7 +/- 8.51 mmHg, p less than 0.001) and at 1 hour (12.4 +/- 14.01 mmHg, p less than 0.05) after the Nd-YAG laser treatment. No significant changes (p greater than 0.05) in PaCO2 levels were found at 2, 3, 4, 5 hours after treatment. Both PaCO2 and PH showed no significant changes during the process. Because of the marked decline in PaCO2 during and after the Nd-YAG laser treatment, it is suggested that oxygen supplementation should be considered, particularly in hypoxemic patients.