Table 1. Lung volume recruitment and pulmonary function during admissions due to asthma exacerbation.

Variables, 1991-2009		1991	1994		2006	2008	April 1, 2009
			(3 mo. after the start of NIV)			(1.5 mo. before the incident)
Pulmonary function
	VC, L (%)	1.00 (37)	1.32 (49)		1.2 (51)
	FEV1, L (%)	0.70 (30)	0.92 (41)		0.6 (34)
	Albuterol	0.80 (34)			0.7 (38)
	FEV1/VC, %	70	70		51
	Albuterol, %	78			58
	TLC, L (%)	3.00 (65)	3.38 (74)		3.47 (77)
	ITGV, L (%)	2.30 (90)			2.53 (99)
	Raw, kPa.L-1.s (n)	0.56 (0.3)	0.57 (0.3)
Blood gas analysis		arterial	arterial		capillary	capillary	capillary
	pH	7.37	7.39		7.40	7.42	7.44
	PCO2, mmHg	52	48.0		45	44	51
	Bic, mmol/L	31	30		27.9	28.0	31.6
	PO2, mmHg	52	61		61	61	59
	SO2, %	85	90		91	91	90
	SpO2, %				95	94	93
Variables, 2004-2009LVR-related measurements		2004	2005		2006	2007	2009
			(prior to the start of AS)	(3 mo. after the start of AS)
	PCF unassisted, L/s	2.20	2.25	2.50	3.08	2.83	--
	PCF after MIC, L/s		2.75	3.50	4.08	4.00	--
	RR, min-1		16	18	22	16	20-24

^mo.: months

^NIV: noninvasive ventilation; incident: acquisition of pneumothorax

^ITGV: intrathoracic gas volume

^Raw: airway resistance

^Bic: bicarbonate

^PCO₂: carbon dioxide tension

^PO₂: oxygen tension

^SO₂: oxygen saturation

^LVR: lung volume recruitment

^PCF: peak cough flow

^MIC: maximum insufflation capacity