Determination of endotracheal tube size from the chest film
Yokoyama, K.; Yoshida, S.; Nomoto, H.; Suzuki, T.
Masui. Japanese Journal of Anesthesiology 29(6): 553-557
1980
ISSN/ISBN: 0021-4892 PMID: 7401299 Document Number: 156949
There is no clear method to determine a suitable endotracheal tube size in the adult. Tracheal size and endotracheal tube size were determined in 120 surgical patients (20-70 yr old). The patients did not have any chest complication. Anterior-posterior chest X-ray with deep inspiration was taken in every patient. Tracheal diameter was measured at the lower edge of 6th cervical spine. Sixty percent of tracheal diameter on the chest film was used for the blue line Portex endotracheal tube (ID ratio (=0.74) and cuff space. This endotracheal tube size had a good fitness in every patient. Initial intra-cuff volume necessary was around 2 ml. With 15 cm H2O airway pressure, intra-cuff pressure did not increase over 25 cm H2O during 2 h of anesthesia under halothane-N2O-O2. This low cuff pressure does not disturb the blood flow of tracheal mucous membrane. Low initial intra-cuff volume is essential to maintain the low cuff pressure. Low intra-cuff volume is obtained only from the suitable endotracheal tube size. Endotracheal tube size (ID) should be about 60% of tracheal diameter measured at chest film.