Abstract:To observe the impact of high-frequency jet ventilation to blood gas of elderly patients undergoing painless fiberoptic bronchoscopy.?Methods?102 patients were randomly divided into observation group and control group. Frequency of 60 jet per minute was used in observation group, and 25 jet in control group. Arteria cruralis blood was sent for blood gas analysis. Bucking, respiratory depress, body dynamic response, carbon dioxide accumulation were recordered.?Results?Between the two groups, the difference of PaO2, PaCO2, SaO2 before aneasthesia and after jet ventilation for 10 minutes was not significant (P > 0.05). In each group, PaO2, PaCO2, SaO2 rised apparently after jet ventilation for 10 minutes (P < 0.05). 4 patients with carbon dioxide accumulation were recordered in observation group and 7 in control group. But PaCO2 < 65 mmHg in every patients, and the difference between the two groups was not significant (P > 0.05).?Conclusion?High-frequency jet ventilation in painless fiberoptic bronchoscopy can provide satisfied oxygen supply, but can not prevent carbon dioxide accumulation on account of respiratory depression. The problem should be pay attention to.