STUDY OBJECTIVE: To test the efficacy of several modes of continuous-flow insufflation on the maintenance of physiologic parameters in a model of respiratory arrest, and the effect of these modes on neurologic outcome. METHODS: Anesthetized dogs were slowly infused with tetrodotoxin over 75 minutes to the point of respiratory arrest. We used two different modes of continuous-flow insufflation: endobronchial insufflation (EI) of air 3 cm distal to the carina (.25 or 1.0 L.kg-1.min-1); and tracheal insufflation of oxygen (TRIO) 1 cm proximal to the carina (.08 or .2 L.kg-1.min-1). RESULTS: EI at either flow rate provided ventilation sufficient to allow the dogs to recover effective spontaneous breathing and be removed from ventilation after 4 hours. By this time, almost all cardiovascular variables and blood gas values were normal. TRIO at .2 L.kg-1.min-1 also resulted in successful recovery, although Pa02, as well as systemic and pulmonary arterial pressures and vascular resistances, remained increased at the end of the 4-hour period. TRIO at the low flow rate, however, resulted in deterioration of blood gas values and systemic arterial pressure; dogs required conventional mechanical ventilation after 45 minutes of low-flow TRIO. CONCLUSION: EI can be used to maintain oxygenation in acute respiratory arrest when conventional techniques are not feasible; TRIO at .2 L.kg-1.min-1 is also effective.
STUDY OBJECTIVE: To test the efficacy of several modes of continuous-flow insufflation on the maintenance of physiologic parameters in a model of respiratory arrest, and the effect of these modes on neurologic outcome. METHODS: Anesthetized dogs were slowly infused with tetrodotoxin over 75 minutes to the point of respiratory arrest. We used two different modes of continuous-flow insufflation: endobronchial insufflation (EI) of air 3 cm distal to the carina (.25 or 1.0 L.kg-1.min-1); and tracheal insufflation of oxygen (TRIO) 1 cm proximal to the carina (.08 or .2 L.kg-1.min-1). RESULTS: EI at either flow rate provided ventilation sufficient to allow the dogs to recover effective spontaneous breathing and be removed from ventilation after 4 hours. By this time, almost all cardiovascular variables and blood gas values were normal. TRIO at .2 L.kg-1.min-1 also resulted in successful recovery, although Pa02, as well as systemic and pulmonary arterial pressures and vascular resistances, remained increased at the end of the 4-hour period. TRIO at the low flow rate, however, resulted in deterioration of blood gas values and systemic arterial pressure; dogs required conventional mechanical ventilation after 45 minutes of low-flow TRIO. CONCLUSION: EI can be used to maintain oxygenation in acute respiratory arrest when conventional techniques are not feasible; TRIO at .2 L.kg-1.min-1 is also effective.
Authors: Sophia Villiere; Ko Nakase; Richard Kollmar; Hamid Arjomandi; Jason Lazar; Krishnamurthi Sundaram; Joshua B Silverman; Michael Lucchesi; David Wlody; Mark Stewart Journal: Laryngoscope Investig Otolaryngol Date: 2018-08-09