[Tracheal gas insufflation associated with mechanical ventilation for CO2 removal].
OBJECTIVE
Tracheal gas insufflation (TGI) either continuously, or at inspiration, or at expiration, is a technique associated with mechanical ventilation aimed to enhance CO2 elimination in favouring washout of anatomical dead space. This article analyses the mechanism of action, the techniques and the effects of TGI in presence of hypercapnia, especially in the fame of ARDS in adults.


METHODS
In addition to some historical or major references, the articles on TGI published over the past five years have been searched in the Medline data base.


METHODS
Articles with data on TGI associated with mechanical ventilation were selected.


METHODS
Data on mechanisms of action, technical and practical aspects of TGI were extracted.


RESULTS
CO2 elimination is increased when the TGI catheter tip is close to the carina, when the gas jet is directed towards the latter, by a continuous gas jet, by a high washing gas volume. The effect on oxygenation is minor. The work of breathing is decreased. An increased intracranial pressure is decreased. Circulatory effects are minor. The major risk is dynamic pulmonary over distension. Local complications include dessiccation and lesion of bronchial mucosa by the gas jet.


CONCLUSIONS
In mechanically ventilated patients, additional TGI is a valuable technique for decreasing anatomical dead space. TGI decreases hypercapnia during mechanical ventilation with limited tidal volumes in permissive hypercapnia. Further clinical studies with large series of patients are required to assess the benefits and the effect of TGI on outcome.
Dorne
R
R
Service de réanimation polyvalente, centre hospitalier Saint-Joseph et Saint-Luc, Lyon, France.
Liron
L
L
Pommier
C
C
D000818:Animals; D002245:Carbon Dioxide; D005740:Gases; D006801:Humans; D007327:Insufflation / Q000379:methods*; D012121:Respiration, Artificial / Q000379:methods*; D014132:Trachea
D005740:Gases; D002245:Carbon Dioxide