Emergency ventilation with the Ventrain through an airway exchange catheter in a porcine model of complete upper airway obstruction.

PURPOSE

During difficult airway management, oxygen insufflation through airway-exchange and intubating catheters (AEC/IC) can lead to life-threatening hyperinflation. Ventrain was originally designed to facilitate emergency ventilation using active expiration through short, small-bore cannulas. Herein, we studied its efficacy (oxygenation and ventilation) and safety (avoidance of hyperinflation) in a long, small-bore AEC.

METHODS

In six anesthetized pigs, the upper airway was obstructed, except for a 100 cm long, 3 mm internal diameter AEC. After apneic desaturation to a peripheral oxygen saturation (SpO) of < 70%, ventilation through the AEC was started with Ventrain at an oxygen flow of 15 L·min, a frequency of 30 breaths·min, and an inspiration/expiration ratio of approximately 1:1. It was continued for ten minutes.

RESULTS

Within one minute, severe hypoxia was reversed from a median [interquartile range] arterial saturation (SaO) of 48 [34-56] % before initiation of Ventrain ventilation to 100 [99-100] % afterward (median difference 54%; 95% confidence interval [CI] 44 to 67; P = 0.028). In addition, hypercarbia was reversed from PaCO of 59 [53-61] mmHg to 40 [38-42] mmHg (median difference of -18 mmHg; 95% CI -21 to -15; P = 0.028). After ten minutes of Ventrain use, peak inspiratory and end-expiratory pressures were lower than during baseline pressure-controlled ventilation (8 [7-9] mmHg vs 12 [10-14] mmHg and -2 [-3 to +1] mmHg vs 4 [2 to 4] mmHg, respectively; P = 0.027 for both). No hemodynamic deterioration occurred.

CONCLUSION

Ventrain provides rapid reoxygenation and effective ventilation through a small-bore AEC in pigs with an obstructed airway. In clinical emergency situations of obstructed airways, this device may be able to overcome problems of unintentional hyperinflation and high intrapulmonary pressures when ventilating through long, small-bore catheters and could therefore minimize the risks of barotrauma and hemodynamic instability.