Cardiopulmonary Resuscitation-Reply

Abstract

To the Editor.— In the June 6, 1986, issue of JAMA , Part III of Standards and Guidelines for Cardiopulmonary Resuscitation (CPR) and Emergency Cardiac Care (ECC) 1 recommends endotracheal tube sizes of 7.5 to 8.0 mm in internal diameter for women and 8.0 to 8.5 mm in internal diameter for men. As my colleagues and I showed in our study reported in 1983, 2 the tube sizes recommended are too large. In our study, we examined the relationship between morphologic parameters and cricoid ring size, the cricoid being the smallest fixed cross-sectional area in the upper airway. We determined that for 85 men and 45 women of comparable height, the female cricoid was an average of 2.7 mm smaller than the male cricoid. We also found that cricoid size is a linear function of height (not of weight). We found that an endotracheal tube with an 8.0-mm internal diameter has