[Ventilation effects of added jet air flows in different directions during expiratory phase on dogs with steam inhalation injury].
Nine dogs injured by inhaling steam were subjected to high frequency jet ventilation. Jet airflows of different directions were added during the expiratory phase, and their effects on respiration, circulation and improvment in ventilation efficiency of dogs with inhalation injury were compared, and the assessment of the mechanism of high frequency two-way jet ventilation in the trachea was made. According to the direction of added airflow during expiratory phase, the animal models were classified into three groups: Model A, the control group, without any added airflow; Model B, airflow opposite to the direction of ventilation was added; Model C, airflow of the same direction was added. The results showed: 1. Model B, with its CO2 elimination (Vco2) increased significantly (P < 0.01) and PaCO2 decreased significantly (P < 0.01), was preferable to Model A. This might be due to the reduction of dead space. 2. Model C, although there was slightly reduced anatomical and physiological dead space as compared with model A, showed worse ventilation effects. The mechanism was probably related to increase in PEEP (from 0.20 +/- 0.10 to 0.59 +/- 0.08 kPa) and FRC (from 433 +/- 59 to 504 +/- 7.0 ml). It is suggested that high frequency two-way jet ventilation is preferable for the treatment of inhalation injury with type 1 respiratory failure rather than high frequency ventilation with PEEP.
Zhou
S
S
Jiangxi Medical College, Nanchang.
Cao
Y
Y
Guo
G
G
D000818:Animals; D002059:Burns, Inhalation / Q000150:complications / Q000628:therapy*; D004285:Dogs; D005260:Female; D006611:High-Frequency Jet Ventilation / Q000379:methods; D008297:Male; D012131:Respiratory Insufficiency / Q000209:etiology / Q000628:therapy*