Definitions

Weaning is the successful separation (or liberation) of the patient from the ventilator. Weaning definitions range from being totally free of MV support to just being free of invasive ventilation [7]. The lack of standard definitions and the varied end

R. Freebairn, FANZCA, FRCPE, FCICM

Intensive Care Services, Hawke’s Bay Hospital, Hastings, New Zealand

Chinese University of Hong Kong, Hong Kong, China e-mail: This email address is being protected from spam bots, you need Javascript enabled to view it

© Springer International Publishing Switzerland 2017 D. Chiumello (ed.), Acute Respiratory Distress Syndrome (ARDS), DOI 10.1007/978-3-319-41852-0_9

points for weaning complicate analysis [7, 8]. Prolonged MV also has a myriad of definitions including MV periods for as brief as 2 days to as long as 29 days [9-11]. A 2004 consensus defined prolonged MV as greater than or equal to 21 consecutive days of MV, for greater than or equal to 6 h/d [10].

The end of the weaning process also lacks agreed definitions and is variously defined as first extubation, successful extubation, unassisted breathing for 24 or 72 h, the first spontaneous breathing trial (SBT) or successful SBT, or an ill-defined “successful weaning” [7, 12-17]. The spectrum of transitioning supportive therapy such as high-flow nasal cannula (HFNC) as adjuncts to weaning adds further complexity [18-21].