Table 1

Clinical studies on target volume during pressure-preset ventilation

Study	Year	Design	Cohort	Target volume setting	Main target volume outcomes^*
Storre et al7 ^†	2006	6-week cross-over RCT (n=10)	OHS^‡	7 ml/kg IBW (n=5), 10 ml/kg IBW (n=5)	Greater reduction in nocturnal PtcCO₂ Comparable effect on polysomnography Comparable effect on quality of life

Janssens et al10 ^†	2009	1-day cross-over RCT (n=12)	OHS^¶	7.5±0.8 ml/kg body weight	Greater reduction in nocturnal PtcCO₂ Worse polysomnography

Ambrogio et al11 ^†	2009	1-day cross-over RCT (n=28)	Mixed^¶	8 ml/kg IBW or 110% of baseline VT	Comparable effect on polysomnography Greater nocturnal minute volume

Crisafulli et al12 ^†	2009	5-day cross-over RCT (n=9)	COPD^‡	8 ml/kg IBW	Comparable improvements in morning PaCO₂ Subjective improvement in sleep efficiency

Oscroft et al13 ^§	2010	8-week cross-over RCT (n=24)	COPD^¶	11.0±3.9 l/min (minute volume)	Comparable effects on: Daytime blood gases Lung function and exercise capacity Quality of life Nocturnal PtcCO₂

Murphy et al14 ^†	2012	3-month RCT (n=46)	OHS^‡	Individual adjustments aimed at achieving control of nocturnal hypoventilation while abolishing obstructive events	Comparable effects on: Daytime PaCO₂ improvements Quality of life Weight loss Comparable improvements in ESS

↵* Compared with conventional pressure-preset non-invasive positive pressure ventilation (NPPV).
↵† Mode for target volume: average volume assured pressure support.
↵‡ Patients naive to any form of NPPV.
↵§ Mode for target volume: intelligent volume assured pressure support.
↵¶ Patients already established on pressure-preset NPPV.
COPD, chronic obstructive pulmonary disease; ESS, Epworth Sleepiness Score; IBW, ideal body weight; OHS, obesity hypoventilation syndrome; PaCO₂, arterial partial pressure of carbon dioxide; PtcCO₂, transcutaneous partial pressure of carbon dioxide; RCT, randomised controlled trial; VT, tidal volume.