Carbon dioxide elimination during high-frequency jet ventilation for rigidbronchoscopy

Oxygen saturation and carbon dioxide values should be monitored during high -frequency jet ventilation (HFJV). Modern transcutaneous Pco(2) (Ptc(CO2)) measurement allows the estimation of ventilation efficiency. We studied how tests of lung function could predict carbon dioxide elimination during HFJ V. Lung function tests from 180 adult patients undergoing rigid bronchoscop y were analysed as factors affecting carbon dioxide elimination. The lung f unction test results showed a significant relationship with the efficiency of carbon dioxide elimination; the greatest impairment of carbon dioxide el imination was found in patients with combined abnormalities of lung functio n. Further factors associated with difficult carbon dioxide elimination wer e male gender and elevated body weight. Of the patients investigated, 72% h ad normal carbon dioxide elimination, whereas in 23% hypercapnia could be a voided only by increasing the driving pressure. The prevalence of abnormal preoperative lung function test results predicts (sensitivity 76%, positive predictive value 27%) impaired carbon dioxide elimination during jet venti lation and rigid bronchoscopy.