Table 2 Characteristics of critically ill patients without ARDS receiving mechanical ventilation, comparison of survivors and non-survivors
|  | All (n = 935) | Survivors (n = 738) | Non-survivors (n = 197) | p valuea |
|---|---|---|---|---|
Ventilator settings | ||||
Mode of ventilation | Â | Â | Â | Â |
 Volume-controlled | 116/849 (13.7) | 85/657 (12.9) | 31/192 (16.1) | 0.075 |
 Pressure-controlled | 193/849 (22.7) | 151/657 (23.0) | 42/192 (21.9) | |
 Pressure support | 80/849 (9.4) | 68/657 (10.4) | 12/192 (6.3) | |
 SIMV | 223/849 (26.3) | 178/657 (27.1) | 45/192 (23.4) | |
 BiPAP/APRV | 185/849 (21.8) | 138/657 (21.0) | 47/192 (24.5) | |
 ASV | 17/849 (2.0) | 16/657 (2.4) | 1/192 (0.5) | |
 PAV | 0/849 (0.0) | 0/657 (0.0) | 0/192 (0.0) | |
 NAVA | 1/849 (0.1) | 1/657 (0.2) | 0/192 (0.0) | |
 VAPS | 8/849 (0.9) | 4/657 (0.6) | 4/192 (2.1) | |
 PRVC | 23/849 (2.7) | 14/657 (2.1) | 9/192 (4.7) | |
 Other | 3/849 (0.4) | 2/657 (0.3) | 1/192 (0.5) | |
Ventilatory variables | Â | Â | Â | Â |
 Maximum airway pressure (cm H2O) | 18.0 (15.0–22.0) | 18.0 (15.0–22.0) | 20.0 (16.0–24.0) | 0.001 |
 Plateau pressure (cm H2O)b | 16.0 (13.0–20.0) | 15.0 (12.0–19.0) | 17.0 (14.0–21.0) | 0.005 |
 No of patients | 343/935 (36.7) | 259/738 (35.1) | 113/197 (57.4) | < 0.001 |
 Tidal volume (ml) | 500 (440–575) | 500 (450–580) | 500 (414–568) | 0.229 |
 Tidal volume (ml/kg PBW) | 7.9 (6.8–9.1) | 7.9 (6.8–9.1) | 8.1 (6.7–9.2) | 0.622 |
  Controlled vent mode | 7.7 (6.7–8.9) | 7.7 (6.8–8.9) | 7.8 (6.4–9.2) | 0.958 |
  Spontaneous vent mode | 8.0 (6.8–9.2) | 7.9 (6.8–9.2) | 8.1 (6.9–9.3) | 0.616 |
  p value (controlled vs. spontaneous) | 0.089 | 0.161 | 0.340 |  |
  ≤ 7 | 242/811 (29.8) | 188/627 (30.0) | 54/184 (29.3) | 0.181 |
  7–8 | 347/811 (42.8) | 271/627 (43.2) | 76/184 (41.3) | |
  9–10 | 161/811 (19.9) | 116/627 (18.5) | 45/184 (24.5) | |
  > 10 | 61/811 (7.5) | 52/627 (8.3) | 9/184 (4.9) | |
 PEEP (cm H2O) | 5.0 (5.0–8.0) | 5.0 (5.0–8.0) | 6.0 (5.0–8.0) | 0.004 |
  ≤ 5 | 450/830 (54.2) | 365/642 (56.9) | 85/188 (45.2) | 0.003 |
  6–8 | 253/830 (30.5) | 185/642 (28.8) | 68/188 (36.2) | |
  9–10 | 86/830 (10.4) | 57/642 (8.9) | 29/188 (15.4) | |
  > 10 | 41/830 (4.9) | 35/642 (5.5) | 6/188 (3.2) | |
 Driving pressure (cm H2O) | 12.0 (9.0–15.0) | 12.0 (9.0–15.0) | 13.0 (10.0–16.0) | 0.020 |
 Respiratory rate (bpm) | 15.0 (12.0–18.0) | 15.0 (12.0–18.0) | 15.0 (12.0–18.0) | 0.753 |
 FiO2 | 0.5 (0.4–0.6) | 0.4 (0.4–0.5) | 0.5 (0.4–0.7) | < 0.001 |
 Static compliance (ml/cm H2O) | 54.2 (36.9–77.1) | 55.4 (40.0–84.0) | 54.3 (32.4–76.3) | 0.121 |
 Indexed static compliance (ml/cm H2O PBW) | 0.83 (0.65–1.27) | 0.85 (0.66–1.33) | 0.80 (0.49–1.09) | 0.069 |
 Minute ventilation (l/min) | 7.4 (6.2–8.9) | 7.5 (6.2–8.9) | 7.2 (6.1–8.9) | 0.409 |
Vital signs | Â | Â | Â | Â |
SpO2 (%) | 99 (97–100) | 99 (98–100) | 98 (95–100) | < 0.001 |
Heart rate (bpm) | 87 (75–100) | 85 (73–98) | 95 (80–110) | < 0.001 |
Mean arterial pressure (mmHg) | 78 (69–90) | 79 (70–92) | 73 (64–86) | < 0.001 |
etCO2 (mmHg) | 36 (30–42) | 36 (30–41) | 36 (30–45) | 0.976 |
VD/V *T | 20.0 (10.5–28.5) | 19.2 (9.3–25.9) | 21.5 (12.4–33.6) | 0.077 |
Laboratory data | ||||
PaO2/FiO2 (mmHg) | 261 (165–367) | 285 (187–393) | 232 (139–342) | < 0.001 |
PaCO2 (mmHg) | 38.0 (34.0–45.0) | 37.5 (34.0–45.0) | 40.0 (35.0–52.0) | 0.003 |
pH | 7.36 (7.30–7.42) | 7.37 (7.31–7.43) | 7.34 (7.25–7.41) | < 0.001 |
HCO3 (mEq/l) | 22.0 (20.0–25.0) | 22.0 (20.0–25.0) | 22.0 (18.0–25.0) | 0.090 |
Clinical outcome | Â | Â | Â | Â |
Duration of ventilation (days) | 2 (1–4) | 2 (1–4) | 2 (1–4) | 0.974 |
ICU length of stay (days) | 4 (2–10) | 3 (2–8) | 8 (3–16) | < 0.001 |
Hospital length of stay (days) | 16 (9–35) | 16 (9–34) | 17 (7–37) | 0.583 |