RT Journal Article SR Electronic T1 Military gas mask to protect surgeons when performing tracheotomies on patients with COVID-19 JF BMJ Military Health JO BMJ Mil Health FD British Medical Journal Publishing Group SP 214 OP 214 DO 10.1136/bmjmilitary-2020-001547 VO 167 IS 3 A1 Jean-Baptiste Caruhel A1 N Sigaux A1 A Crambert A1 N Donat A1 G Boddaert A1 P Haen A1 C Hoffmann YR 2021 UL http://militaryhealth.bmj.com/content/167/3/214.abstract AB