Hong Kong Med J 2008;14(Suppl 5):S27-31
Survey and evaluation of modified oxygen delivery devices used for suspected severe acute respiratory syndrome and other high-risk patients in Hong Kong
KS Khaw, WD Ngan Kee, YH Tam, MK Wong, SWY Lee
Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Shatin, NT, Hong Kong
1. Covering facemasks or nasal cannulae with surgical facemasks generally improved percentage of inspired oxygen (FiO2) but at a risk of increased CO2 rebreathing when a low oxygen flow rate was used.
2. We recommend that at least 5 L/min of oxygen be used for nasal cannula and at least 6 L/min of oxygen be used for facemask when these devices are covered with a surgical facemask.
3. Using a combination of several oxygen delivery devices is unlikely to increase the FiO2 significantly.
4. All the modifications described did not introduce any significant increase in airway resistance.