Low-flow transtracheal rescue insufflation of oxygen after profound maturation

Background. The objective of this study was to determine whether low-flow transtracheal insufflation of oxygen (TRIO) could rescue an animal from profound desaturation. This temporizing maneuver could be useful during cannot-intubate or -ventilate scenarios by resolving hypoxia without the morbidity associated with more invasive procedures. Methods: Seven swine for a total of 12 runs were studied. Animals were pharmacologically anesthetized, paralyzed, and mechanically ventilated with room air. After disconnection from the ventilator and desaturation to an SPO2 < 50%, low-flow TRIO (2 L/min) was administered for 1 hour. Results. All animals survived and Spo(2) increased to greater than 90% in 23 seconds on average. Pao(2) (mean, 183 mm Hg) remained elevated throughout the runs were studied. Animals were pharmacologically anesthetized, paralyzed, and mechanically ventilated with room air. After disconnection from the ventilator and desaturation to an Spo(2) < 50%, low-flow TRIO (2 L/min) was administered for 1 hour. Results. All animals survived and Spo(2) increased to greater than 90% in 23 seconds on average. Pao(2) (mean, 183 mm Hg) remained elevated throughout the study. Hemodynamic stability was maintained for at least 15 minutes. Conclusion: Low-flow TRIO rescued animals from profound hypoxia and maintained oxygenation for at least 1 hour. Low flow TRIO did not prevent hypercarbia with its subsequent sympathetic activation.