Table 1.
Failure of High-Flow Nasal Cannula, according to Exposure Duration and Patients’ Characteristics
| Nested Cohorts, n (%) | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| HFNC, d | ⩾0 | ⩾1 | ⩾2 | ⩾3 | ⩾4 | ⩾5 | ⩾6 | ⩾7 | ⩾8 | ⩾9 | ⩾10 | ⩾11 | ⩾12 | ⩾13 | ⩾14 |
| Patients (n) | 557 | 486 | 433 | 349 | 303 | 255 | 224 | 194 | 158 | 129 | 105 | 76 | 60 | 50 | 39 |
| Treatment failure | |||||||||||||||
| All patients | 257 (46) | 195 (40) | 170 (39) | 119 (34) | 99 (33) | 74 (29) | 63 (28) | 55 (28) | 51 (32) | 38 (29) | 31 (30) | 25 (33) | 21 (35) | 19 (38) | 16 (41) |
| Age,* yr | |||||||||||||||
| <50 | 40/110 (36) |
26/93 (28) |
19/77 (25) |
15/64 (23) |
11/53 (21) |
10/49 (20) |
9/43 (21) |
8/39 (21) |
8/33 (24) |
7/27 (26) |
6/21 (29) |
5/14 (36) |
4/12 (33) |
4/11 (36) |
3/9 (33) |
| 50–64 | 97/215 (45) |
72/188 (38) |
64/169 (38) |
43/135 (32) |
37/118 (31) |
27/101 (27) |
23/87 (26) |
20/75 (27) |
18/60 (30) |
13/50 (26) |
10/41 (24) |
8/28 (29) |
6/21 (29) |
6/18 (33) |
5/11 (45) |
| 65–84 | 114/221 (52) |
91/194 (47) |
82/177 (46) |
56/141 (40) |
46/124 (37) |
32/97 (33) |
26/86 (30) |
22/72 (31) |
20/57 (35) |
15/46 (33) |
12/38 (32) |
10/30 (33) |
9/24 (38) |
7/18 (39) |
7/17 (41) |
| ⩾85 | 6/10 (60) |
6/10 (60) |
5/9 (56) |
5/9 (56) |
5/8 (62) |
5/8 (62) |
5/8 (62) |
5/8 (62) |
5/8 (62) |
3/6 (50) |
3/5 (60) |
2/4 (50) |
2/3 (67) |
2/3 (67) |
1/2 (50) |
| Sex | |||||||||||||||
| Male | 174/366 (48) |
131/318 (41) |
114/281 (41) |
78/224 (35) |
65/192 (34) |
48/161 (30) |
43/144 (30) |
38/124 (31) |
36/101 (36) |
25/82 (30) |
19/66 (29) |
14/45 (31) |
13/35 (37) |
11/29 (38) |
10/22 (45) |
| Female | 83/191 (43) |
64/168 (38) |
56/152 (37) |
41/125 (33) |
34/111 (31) |
26/94 (28) |
20/80 (25) |
17/70 (24) |
15/57 (26) |
13/47 (28) |
12/39 (31) |
11/31 (35) |
8/25 (32) |
8/21 (38) |
6/17 (35) |
| BMI,† kg/m2 | |||||||||||||||
| <25 | 39/84 (46) |
29/71 (41) |
27/63 (43) |
18/46 (39) |
16/37 (43) |
14/34 (41) |
13/28 (46) |
11/22 (50) |
11/21 (52) |
8/16 (50) |
7/15 (47) |
6/12 (50) |
6/11 (55) |
5/9 (56) |
4/7 (57) |
| 25–29 | 84/181 (46) |
65/161 (40) |
58/147 (39) |
41/125 (33) |
35/114 (31) |
26/97 (27) |
22/91 (24) |
19/80 (24) |
18/64 (28) |
13/52 (25) |
12/43 (28) |
9/28 (32) |
7/22 (32) |
7/20 (35) |
6/15 (40) |
| 30–34 | 67/138 (49) |
53/122 (43) |
44/105 (42) |
29/83 (35) |
25/75 (33) |
18/62 (29) |
14/52 (27) |
12/43 (28) |
11/34 (32) |
8/30 (27) |
6/25 (24) |
5/18 (28) |
4/12 (33) |
3/10 (30) |
3/9 (33) |
| ⩾35 | 30/80 (38) |
20/68 (29) |
16/58 (28) |
12/47 (26) |
10/36 (28) |
7/28 (25) |
5/21 (24) |
5/20 (25) |
5/17 (29) |
3/12 (25) |
2/9 (22) |
1/7 (14) |
1/6 (17) |
1/4 (25) |
1/3 (33) |
| SpO2:FiO2 | |||||||||||||||
| <190 | 233/448 (52) |
174/383 (45) |
149/346 (43) |
100/273 (37) |
81/242 (33) |
60/203 (30) |
55/185 (30) |
50/163 (31) |
46/135 (34) |
35/110 (32) |
28/90 (31) |
22/66 (33) |
18/51 (35) |
16/43 (37) |
14/34 (41) |
| ⩾190 | 24/109 (22) |
21/103 (20) |
21/87 (24) |
19/76 (25) |
18/61 (30) |
14/52 (27) |
8/39 (21) |
5/31 (16) |
5/23 (22) |
3/19 (16) |
3/15 (20) |
3/10 (30) |
3/9 (33) |
3/7 (43) |
2/5 (40) |
| Patient characteristics | |||||||||||||||
| DNI‡ | 45 (8) | 43 (9) | 38 (9) | 38 (11) | 37 (12) | 34 (13) | 33 (15) | 31 (16) | 28 (18) | 26 (20) | 22 (21) | 17 (22) | 13 (22) | 11 (22) | 9 (23) |
| Comorbidities§ | |||||||||||||||
| 0 | 265 (48) | 226 (46) | 204 (47) | 161 (46) | 141 (47) | 117 (46) | 101 (45) | 88 (45) | 71 (45) | 59 (46) | 45 (43) | 34 (45) | 29 (48) | 26 (52) | 18 (46) |
| 1 | 172 (31) | 155 (32) | 137 (32) | 109 (31) | 92 (30) | 75 (29) | 67 (30) | 56 (29) | 48 (30) | 37 (29) | 33 (31) | 24 (32) | 15 (25) | 10 (20) | 9 (23) |
| 2 | 96 (17) | 85 (17) | 76 (18) | 65 (19) | 57 (19) | 50 (20) | 45 (20) | 39 (20) | 30 (19) | 25 (19) | 20 (19) | 15 (20) | 13 (22) | 11 (22) | 10 (26) |
| 3 | 24 (4) | 20 (4) | 16 (4) | 14 (4) | 13 (4) | 13 (5) | 11 (5) | 11 (6) | 9 (6) | 8 (6) | 7 (7) | 3 (4) | 3 (5) | 3 (6) | 2 (5) |
| Outcomes | |||||||||||||||
| Initiated on IMV | 223 (40) | 161 (33) | 139 (32) | 88 (25) | 68 (22) | 44 (17) | 36 (16) | 28 (14) | 26 (16) | 15 (12) | 12 (11) | 11 (14) | 10 (17) | 10 (20) | 9 (23) |
| Died | 132 (24) | 117 (24) | 105 (24) | 74 (21) | 62 (20) | 50 (20) | 42 (19) | 38 (20) | 35 (22) | 31 (24) | 25 (24) | 19 (25) | 15 (25) | 13 (26) | 10 (26) |
| Died without intubation | 34 (6) | 34 (7) | 31 (7) | 31 (9) | 31 (10) | 30 (12) | 27 (12) | 27 (14) | 25 (16) | 23 (18) | 19 (18) | 14 (18) | 11 (18) | 9 (18) | 7 (18) |
| Initiated on NIV | 110 (20) | 70 (14) | 51 (12) | 37 (11) | 31 (10) | 19 (7) | 18 (8) | 14 (7) | 14 (9) | 8 (6) | 8 (8) | 6 (8) | 6 (10) | 6 (12) | 6 (15) |
| Weaned off HFNC | 300 (54) | 291 (60) | 263 (61) | 230 (66) | 204 (67) | 181 (71) | 161 (72) | 139 (72) | 107 (68) | 91 (71) | 74 (70) | 51 (67) | 39 (65) | 31 (62) | 23 (59) |
Definition of abbreviations: BMI = body mass index; DNI = do-not-intubate orders; HFNC = high-flow nasal cannula; IMV = invasive mechanical ventilation; NIV = noninvasive ventilation; SpO2:FiO2 = ratio of peripheral arterial oxygen saturation (SpO2) to the fraction of inspired oxygen (FiO2) (a value of 190 is equivalent to a ratio of partial pressure of arterial oxygen [PaO2] to FiO2 of 150 mm Hg [5]).
All outcomes are reported as cumulative incidences by Study Day 28. By that time frame, all patients who did not die and were not intubated were successfully weaned off HFNC.
Age was missing for one patient.
Body mass index was missing for a total of 74 (13.3%) patients.
This number combines patients who had do-not-intubate orders at enrollment and those whose ceiling of care was lowered after enrollment.
Prospectively defined and collected comorbidities were chronic heart disease, chronic lung disease, chronic kidney disease, severe liver disease, diabetes, and active malignancy.