Prospective cross-sectional multicenter study on domiciliary noninvasive ventilation in stable hypercapnic COPD patients

Figures & data

Table 1 Clinical and laboratory characteristics of the patients

The number of patients: 266	Mean	SD
Age (years)	64.5	10.3
BMI (kg/m^2)	28.5	7.7
Smoking (pack/yr)	45.5	25.7
FEV1 (%)	34.5	14.3
FEV1/FVC (%)	53.9	10.1
pH	7.41	0.04
PaCO2 (mmHg)	50.97	7.3
PaO2 (mmHg)	73.8	25.2
SaO2 (%)	92.2	5.2
Compliance of NIV (hours/d)	6.3	3
IPAP (cmH2O)	18.1	5.5
EPAP (cmH2O)	5.8	1.3
CAT score	24.3	8
mMRC score	3.9	1.1

Abbreviations: BMI, body mass index; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; PaO₂, partial arterial oxygen pressure; PaCO₂, partial arterial carbon dioxide pressure; SaO₂, oxygen saturation; NIV, noninvasive ventilation; IPAP, inspiratory positive airway pressure; EPAP, expiratory positive airway pressure; CAT, COPD Assessment Test; mMRC, modified Medical Research Council.

Table 2 Distribution of the side effects related to NIV

Side effects	Number (n)	%
Headache	98	36.8
Sleep disruption	81	30.5
Feeling of suffocation	54	20.3
Nasal skin lesion	41	15.4
Conjunctivitis	38	14.3
Extremely high air pressure	37	13.9
Overall side effects	159	59.8

Abbreviation: NIV, noninvasive ventilation.

Table 3 Comparison of the groups with respect to NIV use, type, and setting

The NIV use, type and setting			High-compliance group	Low-compliance group	Total	χ^2	p-value
Predominant period of use	Daytime	N	44	62	106
		%	27.0	61.4	40.2	30.695	0.000a
	Night	N	119	39	158
		%	73.0	38.6	59.8
Mode	ST mode	N	99	35	134
		%	60.7	34.0	50.4	18.074	0.000a
	S mode	N	64	68	132
		%	39.3	66.0	49.6
Humidification system	Yes	N	114	66	180
		%	69.9	64.1	67.7	0.991	0.319
	No	N	49	37	86
		%	30.1	35.9	32.3
Type of mask	Nasal	N	10	10	20
		%	6.1	9.7	7.5	1.159	0.282
	Oronasal	N	153	93	246
		%	93.9	90.3	92.5
IPAP (cmH2O)	High-comp group		163	18.97	5.79	3.531	0.000a
	Low-comp group		103	16.70	4.63
EPAP (cmH2O)	High-comp group		163	5.8	1.39	0.421	0.674
	Low-comp group		102	5.74	1.1
Daytime headache	Yes	N	85	47	132
		%	52.1	45.6	49.6	1.072	0.300
	No	N	78	56	134
		%	47.9	54.4	50.4
Somnolence	Yes	N	51	32	83
		%	31.3	31.1	31.2	0.001	0.970
	No	N	112	71	183
		%	68.7	68.9	68.8

Notes: Two patients had missing data regarding the use of time (daytime/night). Bold is significant.

a p<0.001.

Abbreviations: NIV, noninvasive ventilation; ST, spontaneous time; S, spontaneous; IPAP, inspiratory positive airway pressure; EPAP, expiratory positive airway pressure; comp, compliance.

Table 4 Comparison of the groups in terms of hospitalization and emergency department and ICU admissions within the last year and symptom scoring

Groups	The number of patients	Mean	SD	t	p-value
The number of emergency department admission
High compliance	144	4.4	5.3	−0.207	0.836
Low compliance	75	4.5	4.1
The number of hospitalization
High compliance	135	3.3	3.5	1.488	0.138
Low compliance	85	2.7	2.0
The number of ICU admission
High compliance	76	1.9	1.6	0.755	0.452
Low compliance	40	1.7	1.6
CAT score
High compliance	163	25	7.6	1.771	0.078
Low compliance	103	23	8.5
mMRC score
High compliance	163	3.9	1.1	0.428	0.669
Low compliance	103	3.9	1.1

Notes: High-compliance group (n=163); low-compliance group (n=103).

Abbreviations: ICU, intensive care unit; CAT, COPD Assessment Test; mMRC, modified Medical Research Council.

Table 5 Assessment of the relationship between the compliance of NIV and IPAP levels, BMI, symptom scores and card readout

		BMI (kg/m^2)	mMRC score	CAT score	IPAP (cmH2O)	Compliance of NIV (card readout) (hours/d)
Compliance of NIV (all patients [N=266]; card readout or self-report; hours/d)	r	0.046	0.092	0.163	0.267	0.832
	p-value	0.460	0.134	0.008**	0.000***	0.000***
	N	266	266	266	266	115

Note:

** p<0.01,

*** p<0.001.

Abbreviations: NIV, noninvasive ventilation; IPAP, inspiratory positive airway pressure; BMI, body mass index; mMRC, modified Medical Research Council; CAT, COPD Assessment Test.