Long-term non-invasive ventilation reduces readmissions in COPD patients with two or more episodes of acute hypercapnic respiratory failure

Figures & data

Table 1 Baseline characteristics of the 20 included patients, intended to treat

	Unit	Mean (±SD)
Age	Years	66.0 (±6.5)
NIV settings
BPM	per minute	12.9 (±2.5)
IPAPmin	cm H2O	13.8 (±3.7)
IPAPmax	cm H2O	17.5 (±3.3)
EPAP	cm H2O	5.4 (±0.7)
T i		1.3 (±0.2)
V t	mL	554.3 (±136.7)
PC/AVAPS	n	10/10
Lung function
FEV1	L	0.67 (±0.44)
FEV1	% pred	27.8 (±16.2)
FVC	L	1.77 (±0.66)
MRC	Median (IQR)	4 (±1)
Pack years		44.6 (±18.8)
BMI	kg/m^2	23.7 (±6.8)
SpO2	%	93.4 (±3.1)
Oxygen supply	L	2.4 (±3.2)
Arterial gas values confirming AHRF
pH		7.26 (±0.07)
P a,CO2	kPa	11.3 (±1.8)
P a,O2	kPa	8.5 (±1.7)
stBE	mmol/L	11.2 (±5.4)
Medication and therapy
LAMA	n (%)	17 (85)
LABA	n (%)	18 (90)
ICS	n (%)	16 (80)
OCS	n (%)	4 (20)
Theophylline	n (%)	4 (20)
Rehabilitation	n (%)	11 (55)
LTOT	n (%)	18 (90)

NIV: non-invasive positive pressure ventilation; BPM: breaths per minute; IPAP: inspiratory positive airway pressure; EPAP: expiratory positive airway pressure; T _i: inspiratory time; V _t: ventilated volume per minute; PC: pressure control; AVAPS: average volume assured pressure ventilation; FEV₁: forced expiratory volume in one second; FVC: forced vital capacity; MRC: Medical Research Council dyspnea score; IQR: interquartile range; BMI: body mass index; SpO₂: peripheral oxygen saturation; AHRF: acute hypercapnic respiratory failure; P _a,CO2 : arterial carbon dioxide tension; P _a,O2 : arterial oxygen tension; stBE: standard base-excess concentration in arterial blood; LAMA: long-acting muscarinic antagonists; LABA: long-acting β₂ agonists; ICS: inhaled corticosteroids; OCS: oral corticosteroids; LTOT: long-term oxygen therapy.

Table 2 Per protocol analysis on the 16 patients who were still alive 1 year after LTNIV initiation

Per protocol: variables at LTNIV initiation vs. after 1 year with LTNIV, n=16
		Prior to LTNIV	After 1 year with LTNIV
	Unit	Mean (±SD)	Mean (±SD)	p
FEV1	L	0.73 (±0.48)	0.71 (±0.44)	0.94
FEV1	% pred	30.7 (±16.7)	29.9 (±16.9)	0.93
FVC	L	1.77 (±0.66)	1.68 (±0.64)	0.78
LTOT	n (%)	14 (87.5)	11 (68.8)	0.20
pH		7.40 (±0.04)	7.42 (±0.03)	0.17
P a,CO2	kPa	7.6 (±1.7)	6.7 (±1.4)	0.11
P a,O2	kPa	9.0 (±2.1)	9.0 (±1.8)	0.98
stBE	mmol/L	7.4 (±5.5)	7.0 (±5.5)	0.76
AHRF admissions	n/year	2.4 (±0.6)	0.4 (±0.6)	<0.0001
Admissions	n/year	5.2 (±3.5)	1.9 (±3.2)	0.0092
Admission days	n/year	42.6 (±27.3)	11.9 (±22.3)	0.0015

LTNIV: long-term non-invasive positive pressure ventilation; FEV₁: forced expiratory volume in one second; FVC: forced vital capacity; LTOT: long-term oxygen therapy; P _a,CO2 : arterial carbon dioxide tension; P _a,O2 : arterial oxygen tension; stBE: standard base-excess concentration in arterial blood; AHRF: acute hypercapnic respiratory failure.

Fig. 1 Number of admissions with AHRF, admissions to a pulmonary department per se, and days admitted for the 16 per protocol patients.