Figures
- FIGURE 1
Survival stratified by type of respiratory failure and duration of mask-on time (noninvasive ventilation “dose”) in bands of <4, 4–8, 8–16, 16–24 and >24 h. a) All patients, b) hypercapnic respiratory failure patients and c) hypoxaemic respiratory failure patients.
- FIGURE 2
Survival stratified by type of respiratory failure and mask-on time thresholds of <2, <4, <8, <16, <24 and <48 h. a) All patients, b) hypercapnic respiratory failure patients and c) hypoxaemic respiratory failure patients.
- FIGURE 3
Survival stratified by threshold of mask-on time. a) >2 versus <2 h, b) >4 versus <4 h, c) >8 versus <8 h and d) >24 versus <24 h.
- FIGURE 4
Survival stratified by type of respiratory failure and mask-on proportion (mask-on time relative to total therapy duration) calculated as mask-on time/(mask-on time+mask-off time) representing noninvasive ventilation “intensity”. a) All patients, b) hypercapnic respiratory failure patients and c) hypoxaemic respiratory failure patients.
Tables
- TABLE 1
Clinical characteristics of the study cohort
All patients HCRF patients HRF patients p-value Subjects 654 594 60 Age years 64.3 (53.4–71.9) 55.2 (41.5–68.5) 64.9 (55.3–73.9) 0.79 Male:female (% male) 363:291 (55) 317:277 (53) 46:14 (77) <0.001 Diagnoses COPD 375 (57) 360 (61) 15 (25) <0.001 Asthma 35 (5) 34 (6) 1 (2) 0.30 Pneumonia 117 (18) 88 (15) 29 (48) <0.001 LRTI 22 (3) 20 (3) 2 (3) 0.72 Bronchiectasis 27 (4) 26 (4) 1 (2) 0.51 Lung cancer 25 (3) 16 (3) 9 (15) <0.001 Interstitial lung disease 15 (2) 4 (<1) 11 (18) <0.001 Acute pulmonary oedema 41 (6) 35 (6) 6 (10) 0.33 Sleep disordered breathing 171 (26) 158 (27) 13 (22) 0.50 Obesity 243 (37) 231 (31) 12 (20) 0.006 Motor neurone disease 23 (4) 21 (4) 2 (3) 0.77 Admission gas exchange pH 7.43 (7.29–7.40) 7.34 (7.29–7.39) 7.44 (7.39–7.47) <0.001 PaCO2 mmHg 62.1 (53.0–75.0) 65.0 (55.0–76.0) 38.0 (32.5–43.0) <0.001 PaO2/FIO2 220.0 (180.0–258.9) 222.7 (185.7–261.9) 147.2 (79.0–244.5) <0.001 Mortality 68 (10.4) 47 (7.9) 21 (35.0) <0.001 Patients requiring ICU 12 (2) 5 (<1) 7 (12) <0.001 Subsequent mortality 5 (42) 1 (20) 4 (57) 0.30 Usual WHO Functional Class I 43 (7) 32 (5) 11 (18) II 311 (48) 284 (48) 27 (45) <0.001 III 298 (46) 188 (32) 10 (17) IV 98 (15) 86 (15) 12 (20) Data are presented as n, median (interquartile range) or n (%), unless otherwise stated. HCRF: hypercapnic respiratory failure; HRF: hypoxaemic respiratory failure; COPD: chronic obstructive pulmonary disease; LRTI: lower respiratory tract infection; PaCO2: arterial carbon dioxide tension; PaO2: arterial oxygen tension; FIO2: inspiratory oxygen fraction; ICU: intensive care unit; WHO: World Health Organization. p-values refer to differences between HCRF and HRF cohorts.
- TABLE 2
Noninvasive ventilation (NIV) characteristics and parameters
All patients HCRF patients HRF patients p-value Subjects 654 594 60 Duration of NIV therapy# days 2.74 (1.51–4.73) 2.76 (1.53–1.23) 2.25 (1.23–5.95) 0.56 Total mask-on time¶ h 34.0 (18.0–60.0) 34.0 (18.2–60.0) 34.0 (10.0–60.0) 0.42 Proportion of mask-on time % 56.1 (41.2–69.5) 55.2 (41.5–68.5) 65.6 (33.7–85.2) 0.07 Settings Inspiratory pressure cmH2O 18.0 (16.0–22.0) 19.0 (16.0–22.0) 15.0 (12.5–16.8) <0.001 Expiratory pressure cmH2O 10 (8–14) 10 (8–14) 8.5 (6.5–10.0) 0.07 Pressure support cmH2O 8 (5–15) 8 (5–15) 6 (4–11) <0.001 Out-of-protocol cessation of NIV+ 37 (6) 29 (4) 8 (13) 0.02 Intolerance of treatment 20 18 2 Change to palliative treatment intent 12 7 5 0.10 Treatment ineffective 5 4 1 Data are presented as n, median (interquartile range) or n (%), unless otherwise stated. HCRF: hypercapnic respiratory failure; HRF: hypoxaemic respiratory failure. #: overall period where NIV was used (including mask-on and mask-off durations); ¶: cumulative period where the therapy was actually in use; +: therapy was stopped before clinical stability was achieved. p-values refer to differences between HCRF and HRF cohorts.
