No abstract

The results of this study suggest that the Ventrain device can ensure sufficient oxygenation and ventilation through a small-bore transtracheal catheter when the airway is open, partly obstructed, or completely closed. Minute ventilation and avoidance of high airway pressures were superior in comparison with traditional hand-triggered jet ventilation, particularly in the event of complete upper airway obstruction.

PurposeDuring 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.MethodsIn 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 (SpO2) of < 70%, ventilation through the AEC was started with Ventrain at an oxygen flow of 15 L·min−1, a frequency of 30 breaths·min−1, and an inspiration/expiration ratio of approximately 1:1. It was continued for ten minutes.ResultsWithin one minute, severe hypoxia was reversed from a median [interquartile range] arterial saturation (SaO2) 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 PaCO2 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.ConclusionVentrain 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.

These data show that the transpulmonary double indicator method may underestimate extravascular lung water and right ventricular preload when the perfusion to parts of the lung is obstructed.

Adequate oxygenation could be provided by jet-like transtracheal ventilation with a simple self-made device using easily available materials. Sufficient ventilation depends on the body weight of the animals.