Transtracheal High Frequency Jet Ventilation Prevents Aspiration.

Klain M, Keszler H, Stool S Critical Care Medicine 1983 Vol 14 Pages 170-172

Noting that aspiration is a potentially fatal complication of artificial ventilation, the authors present high frequency jet ventilation (HFJV) as an innovative technique to prevent aspiration. 6 anesthetized, paralyzed dogs had 14 g 3-1/4î catheters for jet ventilation introduced between the 1st and 2nd tracheal rings. A mixture of saliva, saline and cardiogreen dye was introduced into the mouth so as to form a pool 1î above the midvocal cord level. When observations confirmed that HFJV prevents aspiration at frequencies of 100/minute and I:E ratios of 1:1, observations were repeated at 1:2, and 1:3 and at rates of 60 and 200/minute. As well, the depth of the pool was gradually increased to between 2 and 3-1/4î and observations repeated. If the ventilator was stopped during effective HFJV, fluid would spill into the trachea usually within 1-3 seconds. The results showed convincingly that HFJV can prevent fluid from entering the larynx from above by causing a continuous gas flow outward through the larynx. This is associated with a low continuous positive airway pressure and excellent blood gases. The effect is unreliable when the HFJV frequency is decreased to 60/minute or inspiration is less than 33% of the breathing cycle. The authors also question whether CPR would interfere with this effect of HFJV.