Table 1.

Baseline values between groups

	Cough peak flow ≤70 L/minute			Cough peak flow >70 L/minute
	NIV (n = 108)	Control (n = 72)	p Valuea	NIV (n = 71)	Control (n = 105)	p Valuea	p Valueb
Age, years	73 ± 12	74 ± 13	0.68	67 ± 14	58 ± 19	<0.01c	<0.01c
Females/males, n	32/76	33/39	0.04c	12/59	27/78	0.20	<0.01c
Reason for intubation
AECOPD	74	31	<0.01c	46	26	<0.01c	<0.01c
Pneumonia	26	32	0.01c	13	36	0.03c	0.42
ARDS	2	5	0.12	9	22	0.23	<0.01c
Asthma	2	0	0.52	1	5	0.40	0.17
Other	4	4	0.72	2	16	0.01c	0.04c
APACHE II score
Upon admission	24 ± 6	23 ± 6	0.46	21 ± 6	19 ± 7	0.02c	<0.01c
At extubation	13 ± 3	13 ± 3	0.65	12 ± 3	11 ± 3	0.02c	<0.01c
Intubation period before extubation, days	8 ± 12	7 ± 5	0.44	7 ± 5	5 ± 4	<0.01c	0.01c
Cough peak flow, L/minute	48 ± 14	44 ± 15	0.07	98 ± 34	108 ± 29	0.04c	<0.01c
Hemoglobin, g/dl	10.8 ± 2.3	10.4 ± 2.2	0.26	11.3 ± 2.5	11.3 ± 2.4	0.97	0.01c
Secretions, ml/24 h	75 ± 45	85 ± 54	0.18	72 ± 49	77 ± 73	0.61	0.56
Suction frequency/24 h	11 ± 4	13 ± 4	<0.01c	12 ± 4	12 ± 4	0.71	0.96
GCS score	14.7 ± 1.2	14.2 ± 1.8	0.06	14.9 ± 0.1	14.9 ± 0.1	0.80	<0.01c
Physiological parameters at extubation
pH	7.42 ± 0.05	7.43 ± 0.05	0.30	7.45 ± 0.05	7.46 ± 0.05	0.25	<0.01c
PaCO2, mmHg	51 ± 13	45 ± 13	<0.01c	48 ± 11	39 ± 10	<0.01c	<0.01c
PaO2/FiO2	222 ± 63	269 ± 86	<0.01c	225 ± 55	265 ± 94	<0.01c	0.33
Respiratory rate, breaths/minute	23 ± 5	23 ± 5	0.65	23 ± 6	22 ± 5	0.09	0.44
Rapid shallow breathing index	60 ± 27	66 ± 24	0.12	55 ± 21	48 ± 23	0.06	<0.01c
Heart rate, beats/minute	99 ± 16	93 ± 16	0.02c	100 ± 17	94 ± 15	0.01c	0.96
Mean arterial pressure, mmHg	93 ± 13	90 ± 12	0.18	94 ± 12	93 ± 12	0.53	0.40

Abbreviations: APACHE II Acute Physiology and Chronic Health Evaluation II, NIV Noninvasive ventilation, AECOPD Acute exacerbation of chronic obstructive pulmonary disease, ARDS Acute respiratory distress syndrome, GCS Glasgow Coma Scale, PaCO ₂ Partial pressure of carbon dioxide in arterial blood, PaO ₂ /FiO ₂ Ratio of partial pressure of arterial oxygen to fraction of inspired oxygen

^aDifference in NIV versus control

^bDifference in weak versus strong cough

^c p < 0.05