The Effects of Low Pressure Domiciliary Non-Invasive Ventilation on Clinical Outcomes in Patients with Severe COPD Regardless Having Hypercapnia

Figures & data

Table 1 Demographic and Clinical Characteristics of Patients at Baseline

N = 32	Mean (SD)	Normocapnic N=13	Hypercapnic N = 19
Age, years	61.6 (9.7)	63 (8.8)	60.6 (10.6)
Male, %	56	54	58
Body-mass index, kg/m2	25.7 (5.7)	24.6 (4.6)	26.5 (6.6)
Normocapnic, % (capillary pCO2 ≤ 6.0 kPa)	41	100	0
FEV1, liters	0.95 (0.47)	1.0 (0.5)	0.9 (0.4)
FEV1 predicted, %	31.8 (11.5)	31.9 (8.5)	31.7(13.5)
FVC, liters	2.68 (0.81)	2.9 (0.9)	2.6 (0.7)
FVC predicted, %	72.8 (19.1)	76.7 (19.1)	70.2 (19.9)
pCO2 capillary, kPa	6.8 (1.5)	5.5 (0.5)	7.8(1.2)
HCO3^− capillary, mmol/l	29.4 (4.0)	26.4 (2.3)	31.5(3.7)
COPD history (years)	6.9 (3.2)	6.5 (3.4)	7.2 (3.1)
Hospital admissions (1 year before NIV)	1.81 (1.9)	1.00 (1.4)	2.37 (2.1)
In hospital days (1 year before NIV)	17.97 (21.4)	9.15 (14.2)	24.00 (23.7)

Note: Data presented are mean (SD) unless otherwise stated.

Abbreviations: FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; HCO₃⁻, capillary bicarbonate; pCO₂, carbon dioxide pressure.

Table 2 Hospital Admissions, Symptoms Scores and pCO₂ Before and After 1 Year NIV

N = 32	1 Year Before, Mean (SD)	1 Year After, Mean (SD)	Mean Difference (SD)	P-value
Hospital admission	1.81 (1.93)	0.81 (1.23)	1.00 (1.48)	0.001
In hospital days	17.97 (21.43)	7.97 (12.85)	10.00 (15.48)	0.001
MRC scores	4.18 (0.70)	3.52 (1.0)	0.66 (1.35)	0.02
CCQ scores	3.3 (0.9)	2.8 (1.3)	0.59 (1.39)	0.03
HADS anxiety	7.2 (3.8)	5.6 (4.25)	1.64 (3.12)	0.01
HADS depression	8.4 (3.7)	6.7 (4.7)	1.64 (3.91)	0.04
Capillary pCO2 kPa	6.8 (1.5)	6.5 (1.2)	0.33 (0.81)	0.03

Note: Data presented are mean (SD) unless otherwise stated.

Abbreviations: CCQ, Clinical COPD Questionnaire scores; HADS, Hospital Anxiety and Depression Scale; MRC, Medical Research Council dyspnea scores; pCO_2, carbon dioxide pressure.

Figure 1 Mean MRC dyspnea score, CCQ score and HADS score at baseline and after 1 year NIV treatment.

Abbreviations: NIV, non-invasive ventilation; MRC, Medical Research Council; CCQ, Clinical COPD Questionnaire; HADS, Hospital Anxiety Depression Scale.

Table 3 NIV Usage, Type, and Setting

N = 32		Mean (SD)
Predominant Use Night	(hours)	6.5 (2.0)
Humidification	%	80
Type of mask (Oronasal)	%	100
IPAP	(cm H2O)	14.9 (2.8)
EPAP	(cm H2O)	5.2 (1.5)

Note: Data presented are mean (SD) unless otherwise stated.

Abbreviations: EPAP, expiratory positive airway pressure; IPAP, inspiratory positive airway pressure; NIV, non-invasive ventilation.

Figure 2 Sleep quality after one year of NIV (n=32). 31% of the patients showed some improvement in sleep quality, 53% did show a very clear improvement.

Figure 3 NIV experience after one year (n=32). 65% experienced NIV as positive, 23% as very positive.