Current Practices in Home Mechanical Ventilation for Chronic Obstructive Pulmonary Disease: A Real-Life Cross-Sectional Multicentric Study

Figures & data

Figure 1 Flow chart.

Table 1 Patients’ Characteristics (n=569)

Sex: Male/Female, n (%)	407 (71.5%)/162 (28.5%)
Age (years), median [1Q-3Q]	72 [64–79]
BMI (kg/m^2), median [1Q-3Q]	29 [24–33]
<18.5	31 (5.5%)
18.5–24.9	119 (20.9%)
25–29.9	173 (30.4%)
30–34.9	127 (22.3%)
35–39.9	74 (13.0%)
>40	45 (7.9%)
Level of autonomous self-care, n (%)
Autonomous	380 (66.8%)
Partially dependent	173 (30.4%)
Totally dependent	16 (2.8%)
Smoking status, n (%)
Never smoker	97 (17.1%)
Current smoker	124 (21.8%)
Former smoker	347 (61.1%)
Smoking burden (Pack/years), median [1Q-3Q]	45 [30–60]
Functional features (Post bronchodilator), median [1Q-3Q]
FEV1 (% predicted)	39.0 [29.8–52.5]
FVC (% predicted)	65.0 [55.1–76.0]
FEV1/FVC	52.5 [38.9–62.0]
Exacerbations in the preceding 12 months, n (%)	(n=568)
0	259 (45.6%)
1–2	230 (40.5%)
>2	79 (13.9%)
Dyspnea (mMRC scale), n (%)
0	11 (1.9%)
1	98 (17.2%)
2	253 (44.5%)
3	134 (23.6%)
4	73 (12.8%)
Sleep study, n (%)
No sleep study	196 (34.5%)
No OSA	110 (19.3%)
Mild OSA (AHI 5–15/h)	91 (16.0%)
Moderate to Severe OSA (AHI ≥15/h)	172 (30.2%)
Months on HMV, median [1Q-3Q]	27.0 [13.0–56.0]
Respiratory rehabilitation, n (%)
No	262 (46.1%)
In the past, but not in the preceding year	156 (27.4%)
Yes (in the preceding year)	151 (26.5%)
Evaluation by Palliative Care Team, n (%)
Yes	23 (4.0%)
No	546 (96.0%)

Abbreviations: BMI, body mass index; FVC, forced vital capacity; FEV1, forced expiratory volume in one second; mMRC, modified Medical Research Council; OSA, obstructive sleep apnea; AHI, Apnea Hypopnea Index.

Table 2 Differences in Clinical Characteristics, Criteria for Initiation and Adaptation Settings in Patients Started in Stable and Post Exacerbation

	Initiation During Chronic Stable Disease (n=287)	Initiation During or Immediately Following Exacerbation (n=282)
Sex: Male, n (%)	214 (74.6)	193 (68.4)	p=0.1
Age (years), median [1Q-3Q]	71 [64–78]	73 [65–79]	p=0.08
BMI (kg/m^2), median [1Q-3Q]	29 [25–34]	28 [23–33]	p=0.04*
Smoking status, n (%) Ever smokers	247 (86.1)	224 (79.7)	p=0.04*
Functional features (Post bronchodilator), median [1Q-3Q] FEV1 (% predicted) FEV1/FVC	40.0 [29.0–54.0] 53.0 [40.5–62.0]	39.0 [30.0–51.0] 52.3 [37.6–62.0]	p=0.62 p=0.55
Sleep study
No sleep study	66 (23.0)	130 (46.1)	p<0.001*
Sleep study	221 (77.0)	152 (53.9)	p=0.005*
No OSA	53 (24.0)	57 (37.5)
Mild OSA (AHI 5–15/h)	52 (23.5)	39 (25.7)
Moderate to Severe OSA (AHI ≥15/h)	116 (52.5)	56 (36.8)
Criteria for starting HMV
Daytime PaCO2 ≥ 55 mmHg	116 (40.4)	39 (13.8)	p<0.001*
Daytime PaCO2 50–54 mmHg + 2 exacerbations with HRF treated with NIV in the previous 12 months	21 (7.3)	85 (30.2)
Overlap (COPD+OSA) + daytime PaCO2 >45 mmHg	74 (25.8)	36 (12.8)
Failure to wean from NIV after exacerbation	0 (0)	114 (40.4)
Overlap (COPD+OSA) with nocturnal desaturation unresponsive to C/APAP and/or supplemental oxygen	47 (16.4)	4 (1.4)
Daytime PaCO2 50–54 mmHg + nocturnal desaturation (sat<88% during ≥5 consecutive minutes) unresponsive to supplemental oxygen	29 (10.1)	4 (1.4)
Adaptation setting
Inpatient (during exacerbation)	0 (0)	270 (95.7)	p<0.001*
Outpatient with daytime titration (not less than 1 hour on NIV)	168 (58.5)	9 (3.2)
Outpatient prescription and home initiation	91 (31.7)	3 (1.1)
Elective inpatient period	22 (7.7)	0 (0)
Laboratory titration with full night polysomnography	6 (2.1)	0 (0)
Ventilator parameters, median [1Q-3Q]
IPAP (cmH2O)	19.0 [16.0–22.0]	19.5 [16.0–22.0]	p=0.29
PS (cmH2O)	12.0 [9.0–16.0]	12.0 [10.0–16.0]	p=0.047*
Months on HMV, median [1Q-3Q]	27 [13–60]	27 [14–53]	p=0.77
Ventilator usage, median [1Q-3Q]	8.0 [6.4–10]	8.0 [7.0–10.0]	p=0.26
Current PaCO2 (mmHg), median [1Q-3Q]	45 [42–51]	45 [41–49]	p=0.46
Current HCO3 (mmol/L), median [1Q-3Q]	28 [27–31]	29 [27–31]	p=0.91

Note: * Statistically significant difference (p<0.05).

Abbreviations: PaCO2, arterial partial pressure of carbon dioxide; COPD, chronic obstructive pulmonary disease; OSA, obstructive sleep apnea; HRF, hypercapnic respiratory failure; C/APAP, continuous or automatic positive airway pressure; NIV, noninvasive ventilation; IPAP, inspiratory positive airway pressure; PS, pressure support.

Table 3 Current Oxygen Requirements and Ventilation Characteristics (n=569)

Current daytime oxygen, n (%)	318 (55.9%)
Flow rate (L/min), median [1Q-3Q]	1.0 [1.0–2.0]
Current nighttime oxygen, n (%)	385 (67.7%)
Flow rate (L/min), median [1Q-3Q]	2.0 [1.0–2.0]
Ventilator mode, n (%)
Bi-level spontaneous/timed	525 (92.3%)
Bi-level + target volume ventilation	19 (3.3%)
Bi-level spontaneous	18 (3.2%)
Bi-level + target volume ventilation+ auto EPAP	6 (1.0%)
Bi-level timed	1 (0.2%)
Predominant interface, n (%)
Oro-nasal mask	522 (91.7%)
Nasal mask	42 (7.4%)
Total face mask	3 (0.5%)
Nasal pillows	2 (0.4%)
Tracheostomy	0 (0%)
Ventilator parameters, median [1Q-3Q]
IPAP (cmH2O)	19.0 [16.0–22.0]
EPAP (cmH2O)	6.5 [6.0–8.0]
BURR (bpm) (n=506)	15 [14–16]
Volume (assured) mL (n=25)	550.0 [465.0–562.5]
Humidifier, n (%)	224 (39.4%)
Ventilator usage, median [1Q-3Q]	8.0 [7.0 −10.0]
≥ 5h/day, n (%)	526 (92.4%)
≥12h/day, n (%)	58 (10.2%)
Current PaCO2 (mmHg), median [1Q-3Q]	45.0 [42.0–50.0]
≤48 mmHg, n (%)	388 (68.2%)
≤45 mmHg, n (%)	291 (51.1%)
Current HCO3 (mmol/L), median [1Q-3Q]	28.0 [27.0–31.0]

Abbreviations: IPAP, inspiratory positive airway pressure; EPAP, expiratory positive airway pressure; BURR, back up respiratory rate; HMV, home mechanical ventilation; PaCO2, arterial partial pressure of carbon dioxide; HCO3, serum bicarbonate.