INTRODUCTION

METHODS
Design and population
Data collection
Statistical analysis

RESULTS
Baseline characteristics
Table 1
Characteristic | 2016 (n = 226) | 2010 (n = 275) | p value |
---|---|---|---|
Age, yr | 68.0 (58.0–77.0) | 69.0 (54.0–75.0) | 0.250 |
Male sexa | 144/226 (63.7) | 160/275 (58.2) | 0.232 |
BMI, kg/m2 | 22.0 (20.0–25.0) | 22.0 (19.0–24.0) | 0.343 |
SAPS II | 51.5 (40.0–62.0) | 50.0 (38.0–64.0) | 0.610 |
Previous tracheostomya | 8/226 (3.5) | 6/275 (2.2) | 0.420 |
NIV at homea | 2/226 (0.9) | 3/275 (1.1) | 1.000 |
Reason for mechanical ventilationa | |||
Acute on chronic respiratory failure | |||
COPD | 6/191 (3.1) | 23/275 (8.4) | 0.030 |
Asthma | 3/191 (1.6) | 3/275 (1.1) | 0.693 |
Other chronic respiratory diseases | 9/191 (4.7) | 19/275 (6.9) | 0.429 |
Acute respiratory failure | |||
ARDS | 16/191 (8.4) | 27/275 (9.8) | 0.629 |
Postoperative | 1/191 (0.5) | 12/275 (4.4) | 0.018 |
Congestive heart failure | 18/191 (9.4) | 16/275 (5.8) | 0.151 |
Aspiration | 21/191 (11.0) | 14/275 (5.1) | 0.020 |
Pneumonia | 48/191 (25.1) | 63/275 (22.9) | 0.582 |
Sepsis | 28/191 (14.7) | 28/275 (10.2) | 0.150 |
Trauma | 1/191 (0.5) | 2/275 (0.7) | 1.000 |
Cardiac arrest | 10/191 (5.2) | 15/274 (5.5) | 1.000 |
Othersb | 7/191 (3.7) | 29/274 (10.5) | 0.007 |
Comac | 20/191 (10.5) | 22/275 (8.0) | 0.412 |
Metabolic | 10/20 (50.0) | 8/22 (36.4) | |
Intoxication | 4/20 (20.0) | 3/22 (13.6) | |
Hemorrhagic stroke | 2/20 (10.0) | 6/22 (27.3) | |
Ischemic stroke | 1/20 (5.0) | 5/22 (22.7) | |
Brain trauma | 2/20 (10.0) | 0/22 (0) | |
Others | 1/20 (5.0) | 0/22 (0) | |
Neuromuscular disease | 3/191 (1.6) | 1/275 (0.4) | 0.310 |
BMI, body mass index; SAPS II, Simplified Acute Physiology Score II; NIV, non-invasive ventilation; COPD, chronic obstructive pulmonary disease; ARDS, acute respiratory distress syndrome.
a Because of missing data, available number of patients were presented as denominator or in bracket.
b Other causes of acute respiratory failure include pulmonary embolism, upper airway obstruction, gastrointestinal bleeding, pneumothorax, hemoptysis and vasculitis, and pulmonary embolism, upper airway obstruction and gastrointestinal bleeding, pulmonary hemorrhage and shock in 2016 and in 2010, respectively.
Management of mechanical ventilation
Table 2
Variable | 2016 (n = 226) | 2010 (n = 275) | p value |
---|---|---|---|
NIV as initial ventilator at ICUa | 3/226 (1.3) | 7/275 (2.5) | 0.523 |
NIV success at ICU | 3/3 (100) | 3/7 (42.9) | 0.200 |
NIV before ICUa | 23/226 (10.2) | 7/275 (2.5) | < 0.001 |
NIV as initial ventilator at ICU | 1/23 (4.3) | 2/7 (28.6) | 0.128 |
Ventilator modeb (days of use per 1,000 days) | |||
ACMV | 86 | 205 | < 0.001 |
PSV | 300 | 215 | < 0.001 |
SIMV | 19 | 12 | 0.058 |
SIMV + PS | 2 | 143 | < 0.001 |
PCV | 540 | 376 | < 0.001 |
APRV | 22 | 4 | < 0.001 |
PRVC | 14 | 33 | < 0.001 |
High frequency | 1 | 0 | 0.433 |
CPAP | 15 | 0 | < 0.001 |
ASV | 1 | 9 | < 0.001 |
Others | 0 | 1 | 0.263 |
Ventilator setting at the first daya,b | |||
TV/PBW, mL/kg | 7.1 (6.3–8.5) [210] | 7.4 (6.2–8.8) [259] | 0.372 |
Peak pressure, cmH2O | 22.0 (17.8–26.0) [190] | 24.0 (19.0–28.0) [249] | 0.011 |
PEEP, cmH2O | 6.0 (5.0–8.0) [214] | 6.0 (5.0–8.0) [265] | 0.141 |
Sedativesa,b | 157/222 (70.7) | 155/272 (57.0) | 0.002 |
Midazolam | 62/222 (27.9) | 129/272 (47.4) | < 0.001 |
Lorazepam | 20/222 (9.0) | 31/272 (11.4) | 0.458 |
Propofol | 37/222 (16.7) | 26/272 (9.6) | 0.021 |
Dexmedetomidine | 75/222 (33.8) | 0/272 (0) | < 0.001 |
Analgesicsa,b | 192/222 (86.5) | 139/272 (51.1) | < 0.001 |
Morphine | 21/222 (9.5) | 53/272 (19.5) | 0.002 |
Fentanyl | 46/222 (20.7) | 108/272 (39.7) | < 0.001 |
Remifentanil | 157/222 (70.7) | 30/272 (11.0) | < 0.001 |
Awakening trialc | 76/157 (48.4) | 48/155 (31.0) | 0.002 |
Neuromuscular blockera,b | 45/222 (20.3) | 71/272 (26.1) | 0.136 |
Prone positiona,b | 5/222 (2.3) | 4/272 (1.5) | 0.738 |
Steroida,b | 58/222 (26.1) | 92/272 (33.8) | 0.077 |
Intensive insulin therapya,b | 35/222 (15.8) | 77/272 (28.3) | 0.001 |
NIV, non-invasive ventilation; ICU, intensive care unit; ACMV, volume-cycled assist-control ventilation; PSV, pressure-support ventilation; SIMV, synchronized intermittent mandatory ventilation; PS, pressure-support; PCV, pressure-control ventilation; APRV, airway pressure release ventilation; PRVC, pressure regulated volume control; CPAP, continuous positive airway pressure; ASV, adaptive support ventilation; TV, tidal volume; PBW, predicted body weight; PEEP, positive end-expiratory pressure.
a Because of missing data, available number of patients were presented as denominator or in bracket.
![]() | Figure 1Ventilator mode during the course of invasive mechanical ventilation. Bar graphs represent the daily number of patients who were supported by invasive mechanical ventilation. Line graph represent the daily proportion of each mode of ventilation. Miscellaneous mode includes airway pressure release ventilation, pressure regulated volume control, continuous positive airway pressure, adaptive support ventilation, and high frequency oscillatory ventilator mode. PCV, pressure-control ventilation; ACMV, volume-cycled assist-control ventilation; PSV, pressure-support ventilation; SIMV, synchronized intermittent mandatory ventilation. |
![]() | Figure 2Level of sedation during the course of invasive mechanical ventilation. Bar graphs represent the daily number of patients who were supported by invasive mechanical ventilation and were assessed for sedation and agitation using Richmond Agitation-Sedation Scale (RASS). Deep sedation, light sedation, and agitation are defined by RASS −5 to −3, −2 to 1, and 2 to 4, respectively. |
Acute respiratory distress syndrome
Table 3
Variable | 2016 (n = 16) | 2010 (n = 27) | p value |
---|---|---|---|
Ventilator mode at the first daya | |||
ACMV | 0/15 (0) | 6/27 (22.2) | 0.073 |
PSV | 1/15 (6.7) | 2/27 (7.4) | 1.000 |
SIMV + PS | 0/15 (0) | 2/27 (7.4) | 0.530 |
PCV | 14/15 (93.3) | 15/27 (55.6) | 0.015 |
PRVC | 0/15 (0) | 2/27 (7.4) | 0.530 |
TV/PBW at the first day, mL/kga | 6.8 (5.6–10.2) [13] | 6.5 (5.7–7.8) [26] | 0.648 |
TV/PBW < 6 | 4/13 (30.8) | 8/26 (30.8) | 1.000 |
6 ≤ TV/PBW < 8 | 5/13 (38.5) | 12/26 (46.2) | 0.740 |
8 ≤ TV/PBW < 10 | 0/13 (0) | 3/26 (11.5) | 0.538 |
TV/PBW > 10 | 4/13 (30.8) | 3/26 (11.5) | 0.194 |
Peak pressure at the first day, cmH2Oa | 26.0 (20.8–30.0) [14] | 27.5 (21.0–32.3) [26] | 0.705 |
PEEP at the first day, cmH2Oa | 8.0 (5.0–10.3) [14] | 10.0 (6.0–12.0) | 0.294 |
PEEP < 5 | 2/14 (14.3) | 2/27 (7.4) | 0.596 |
5 ≤ PEEP ≤ 10 | 9/14 (64.3) | 16/27 (59.3) | 1.000 |
PEEP > 10 | 3/14 (21.4) | 9/27 (33.3) | 0.494 |
Sedatives | 16/16 (100) | 24/27 (88.9) | 0.282 |
Analgesics | 16/16 (100) | 15/27 (55.6) | 0.001 |
Neuromuscular blocker | 8/16 (50) | 11/27 (40.7) | 0.752 |
Prone position | 3/16 (18.8) | 2/27 (7.4) | 0.344 |
Inhaled NO | 1/16 (6.25) | No data | |
ECMO | 0/16 (0) | No data |
ACMV, volume-cycled assist-control ventilation; PSV, pressure-support ventilation; SIMV, synchronized intermittent mandatory ventilation; PS, pressure-support; PRVC, pressure regulated volume control; TV, tidal volume; PBW, predicted body weight; PEEP, positive end-expiratory pressure; NO, nitric oxide; ECMO, extracorporeal membrane oxygenation.
Liberation from mechanical ventilation
Table 4
Variable | 2016 (n = 223) | 2010 (n = 272) | p value |
---|---|---|---|
Weaning trya | 135/189 (71.4) | 167/272 (61.4) | 0.029 |
Method at first attemptb | |||
GRS | 93/135 (68.9) | 18/167 (10.8) | < 0.001 |
SBT | 42/135 (31.1) | 149/167 (89.2) | < 0.001 |
Planned extubationb | 104/135 (77.0) | 135/167 (80.8) | 0.477 |
Accidental extubationa,c | 2/181 (1.1) | 27/266 (10.2) | < 0.001 |
Reintubationd | 21/106 (19.8) | 31/162 (19.1) | 1.000 |
After planned extubation | 21/104 (20.2) | 24/135 (17.8) | 0.739 |
After accidental extubation | 0/2 (0) | 7/27 (25.9) | 1.000 |
Reintubation within 2 day | 14/21 (66.7) | 27/31 (87.1) | 0.095 |
NIV after extubationd | 8/106 (7.5) | 16/162 (9.9) | 0.663 |
HFNC after extubationd | 34/106 (32.1) | No data | |
Tracheostomya,c | 27/181 (14.9) | 42/266 (15.8) | 0.894 |
Before extubation | 18/27 (66.7) | 31/42 (73.8) | 0.592 |
After reintubation | 9/27 (33.3) | 11/42 (26.2) | 0.592 |
Time to tracheostomy, day | 7.0 (4.0–15.0) | 8.5 (13.0–18.0)e | 0.014 |
PDT | 13/27 (48.1) | 5/42 (11.9) | 0.002 |
Values are presented as median (interquartile range) or number (%). GRS method included pressure-support ventilation (PSV), synchronized intermittent mandatory ventilation (SIMV) and SIMV with pressure-support. SBT method included T-piece, continuous positive airway pressure, and PSV less than 7 cmH2O.
GRS, gradual reduction of ventilatory support; SBT, spontaneous breathing trial; NIV, non-invasive ventilation; HFNC, high-flow nasal cannula; PDT, percutaneous dilatational tracheostomy.
a Because of missing data, available number of patients were presented as denominator or in bracket.
Clinical outcomes
Table 5
Variable | 2016 (n = 226) | 2010 (n = 275) | p value |
---|---|---|---|
ICU mortality | 71/226 (31.4) | 98/275 (35.6) | 0.343 |
Pneumonia | 20/48 (41.7) | 20/63 (31.7) | 0.322 |
Sepsis | 14/28 (50.0) | 12/28 (42.9) | 0.789 |
Aspiration | 2/21 (9.5) | 4/14 (28.6) | 0.191 |
ARDS | 8/16 (50.0) | 17/27 (63.0) | 0.526 |
28-Day mortalitya | 68/192 (35.4) | 93/273 (34.1) | 0.767 |
Hospital mortalitya | 88/200 (44.0) | 112/269 (41.6) | 0.637 |
ICU LOS, day | 9.0 (5.0–15.0) | 10.0 (5.0–19.0) | 0.054 |
Hospital LOSa, day | 21.0 (11.0–42.0) [199] | 23.0 (12.0–41.0) [269] | 0.528 |
Ventilator-free days | 18.00 (0.0–23.0) | 14.0 (0.0–23.0) | 0.534 |
Complicationsa | |||
Sepsis | 48/219 (21.9) | 132/261 (50.6) | < 0.001 |
RRT | 57/219 (26.0) | 62/261 (23.8) | 0.596 |
ARDS | 42/219 (19.2) | 59/270 (21.9) | 0.501 |
VAP | 20/219 (9.1) | 20/239 (8.4) | 0.869 |
Barotrauma | 5/219 (2.3) | 11/261 (4.2) | 0.311 |
Organ failure | |||
Cardiovascular | 140/219 (63.9) | 172/261 (65.9) | 0.701 |
Respiratory | 175/214 (81.8) | 216/268 (80.6) | 0.815 |
Hematologic | 73/209 (34.9) | 89/248 (35.9) | 0.845 |
Renal | 78/216 (36.1) | 85/251 (33.9) | 0.627 |
Hepatic | 36/209 (17.2) | 27/245 (11.0) | 0.076 |
ICU-acquired weakness | 11/219 (5.0) | 2/275 (0.7) | 0.004 |
Delirium | 82/219 (37.4) | 22/275 (8.0) | < 0.001 |

DISCUSSION

KEY MESSAGE
