Interfaces and ventilator settings for long-term noninvasive ventilation in COPD patients

Figures & data

Figure 1 Flow chart of study design and patient recruitment.

Abbreviation: ABG, arterial blood gas.

Table 1 Demographic data and lung function parameters

Variable	N=123	Min	Max
Female (%)	44.7 (55)	–	–
Age (years)	66.4±7.9	48.7	85.1
BMI (kg/m^2)	27.6±7.8	14.4	54.7
Pack-years	55.4±25.4	12	150
NIV use (years)	2.3±2.8	0.1	15.1
Use of LTOT (%)	80.5 (99)	–	–
History of IMV due to ARF (%)	26.8 (33)	–	–
NIV initiation after
Acute exacerbation	60.2 (74)	–	–
Weaning from IMV	4.1 (5)	–	–
Chronic hypercapnia	35.7 (44)	–	–
FEV1 (% predicted)	34.1±13.1*	–	–
FVC (% predicted)	56.2±15.4*	–	–
FEV1/FVC (%)	50.1±16.5*	–	–
RV (% predicted)	213±77.1*	–	–
TLC (% predicted)	110±29.9*	–	–
DLCO (% predicted)	59.6±16.1**	–	–
PCO2 (mmHg)	47.2±7.7***	–	–
PO2 (mmHg)	64.5±12.4***	–	–
pH value	7.4±0.03***	–	–
HCO3^− (mmol/L)	27.7±3.3***	–	–

Notes: Data presented as mean ± standard deviation or % of patients (n=); data in brackets represent n=x.

* n=51.

** n=42.

*** n=92. The “–” symbols indicate not applicable.

Abbreviations: Min, minimum; Max, maximum; BMI, body mass index; NIV, noninvasive ventilation; LTOT, long-term oxygen therapy; IMV, invasive mechanical ventilation; ARF, acute respiratory failure; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; RV, residual volume; TLC, total lung capacity; DLCO, diffusing capacity for carbon monoxide; PCO₂, partial pressure of carbon dioxide; PO₂, partial pressure of oxygen; HCO₃⁻, bicarbonate.

Table 2 Ventilation settings and interfaces

Variable	N=123
IPAP (mbar)	23.2±4.6
EPAP (mbar)	5.8±1.3
BR/minute	16.7±2.4
PSV (%)	52.8 (65)
aPCV (%)	47.2 (58)
Full-face mask	77.2 (95)
Nasal mask	22.8 (28)
Active exhalation valve	32.5 (40)
Active humidification	87.0 (107)
NIV compliance (hours/day)	6.5 (121)

Note: Data presented as mean ± standard deviation or % of patients (n=); data in brackets represent n=x.

Abbreviations: IPAP, inspiratory positive airway pressure; EPAP, expiratory positive airway pressure; BR, breathing rate; PSV, pressure support ventilation; aPCV, assisted pressure-controlled ventilation; NIV, noninvasive ventilation.

Figure 2 Distribution of oro-nasal masks (FFMs, dark gray) and NMs (light gray) in different subgroups of patients.

Note: Blue horizontal line indicates overall mean percentage of patients with FFM.
Abbreviations: FFM, full-face mask; NM, nasal mask; BMI, body mass index (in kg/m²); CRF, chronic respiratory failure; SAS, sleep apnea syndrome; ARF, acute respiratory failure; IPAP, inspiratory positive airway pressure.

Figure 3 NIV adherence of patients with FFMs or NMs in varying IPAP ranges.

Note: NIV adherence is presented in mean hours/day.

Abbreviations: NIV, noninvasive ventilation; NM, nasal mask; IPAP, inspiratory positive airway pressure; FFM, full-face mask.

Figure 4 Daytime PaCO₂ in relation to different IPAP ranges and interfaces.

Note: Patients with acute exacerbation were excluded.

Abbreviations: PaCO₂, arterial pressure of carbon dioxide; IPAP, inspiratory positive airway pressure; FFM, full-face mask; NM, nasal mask.

Figure 5 Distribution of NIV equipment and settings according to IPAP range.

Notes: Group A (A): IPAP <21 mbar, Group B (B): IPAP 21–25 mbar (B) and Group C (C): IPAP >25 mbar. Number of patients with FFMs: A=31, B=32 and C=32; with NMs: A=11, B=12 and C=6; with AV: A=6, B=11 and C=23; with Hum: A=39, B=39 and C=29 and with aPCV: A=9, =22 and C=27.
Abbreviations: NIV, noninvasive ventilation; IPAP, inspiratory positive airway pressure; FFM, full-face mask; NM, nasal mask; AV, active valve circuit; Hum, active humidification; aPCV, assisted pressure-controlled ventilation.