Jet Ventilation Using Fiberoptic Bronchoscopes

Abstract

A fiberoptic bronchoscope is used to facilitate tracheal intubation in cases of difficult direct laryngoscopy.Occasionally, difficulty is encountered in advancing the endotracheal tube after the fiberoptic bronchoscope has been introduced into the trachea. This study tested the feasibility of providing jet ventilation through the suction channel of the fiberoptic bronchoscope as an interim measure under those or similar circumstances. Three commercial models of fiberoptic bronchoscopes with suction channels of 1.2-, 1.5-, and 2-mm diameter, respectively, were tested in a mechanical test lung at varying compliances and resistances using a jet injector connected to an oxygen source at 50 psi. The fiberoptic bronchoscope with the 2-mm suction channel was also studied in seven adult patients who were anesthetized and paralyzed. Jet ventilation was manually performed at the rate of 12/min for 10 min. In the mechanical test lung, the tidal volumes with 1.2-, 1.5-, and 2-mm suction channels were as follows: 280 mL, 490 mL, and 880 mL, respectively, at a compliance of 50 mL/cm H2 O and normal resistance; 260 mL, 470 mL, and 820 mL, respectively, at a compliance of 50 mL/cm H2 O and high resistance to simulate bronchospasm; 130 mL, 270 mL, and 890 mL, respectively, at a compliance of 20 mL/cm H2 O and normal resistance; 120 mL, 220 mL, and 810 mL, respectively, at a compliance of 20 mL/cm H2 O and high resistance. In anesthetized, paralyzed patients, oxygen saturation was 96% or more throughout the study. PaO2, PaCO2, and pHa at the end of 10 min of jet ventilation were 374 +/- 121 mm Hg, 36 +/- 12 mm Hg, and 7.41 +/- 0.05, respectively. We conclude that effective jet ventilation can be provided using fiberoptic bronchoscopes with a suction channel 2 mm in diameter in most anesthetized, paralyzed adult patients. From the results in the mechanical lung, we also predict that effective jet ventilation can be performed in patients with normal compliance and airway resistance using a fiberoptic bronchoscope with a suction channel 1.2 mm in diameter. (Anesth Analg 1995;80:384-7)