Table 2.
Hemodynamic, oxygen and ventilatory parameters
| Variable |
Group 1, H-H |
Group 2, L-H |
Group 3, H-L |
Group 4, L-L |
P value |
|---|---|---|---|---|---|
| ( n = 24) | ( n = 8) | ( n = 17) | ( n = 36) | ||
|
Hemodynamic variables | |||||
| Heart rate (beats/minute) |
|
|
|
|
|
| T0 |
112 (103 to 129) |
111 (77 to 138) |
104 (86 to 126) |
109 (93 to 118) |
0.31 |
| T6 |
114 (101 to 125) |
103 (73 to 127) |
98 (85 to 114) |
103 (88 to 118) |
0.14 |
| Cardiac index (l/minute/m2) |
|
|
|
|
|
| T0 |
3.0 (2.3 to 4.2) |
3.6 (2.7 to 4.6) |
3.0 (2.5 to 5.0) |
3.5 (2.7 to 4.5) |
0.63 |
| T6 |
3.2 (2.2 to 4.3) |
3.3 (2.4 to 3.8) |
3.7 (2.2 to 5.5) |
3.6 (2.8 to 4.3) |
0.75 |
| MAP (mmHg) |
|
|
|
|
|
| T0 |
65.0 (61.0 to 72.8)** |
67.0 (65.3 to 69.5) |
73.0 (68.0 to 82.5)** |
72.0 (64.5 to 77.0) |
0.02 |
| T6 |
69.0 (65.3 to 75.8) |
77.5 (70.5 to 96.0) |
68.0 (63.5 to 72.0) |
71.5 (65.0 to 78.8) |
0.06 |
| CVP (mmHg) |
|
|
|
|
|
| T0 |
14.5 (10.3 to 17.0) |
10.0 (9.0 to 12.8) |
12.0 (8.5 to 15.0) |
10.0 (7.0 to 14.0) |
0.10 |
| T6 |
13.5 (10.0 to 15.8)** |
15.0 (10.0 to 17.0) |
10.0 (5.0 to 12.5)** |
10.0 (7.3 to 13.0) |
0.03 |
| PAOP (mmHg) |
|
|
|
|
|
| T0 |
17.0 (14.0 to 20.0) |
12.5 (10.0 to 15.0) |
17.0 (12.0 to 22.0) |
15.0 (11.0 to 20.0) |
0.52 |
| T6 |
19.0 (15.0 to 24.0)** |
14.5 (10.0 to 19.0) |
13.0 (10.0 to 15.0)** |
16.0 (12.0 to 20.0) |
0.03 |
|
Blood gases and oxygen variables | |||||
| pH |
|
|
|
|
|
| T0 |
7.30 (7.18 to 7.37) |
7.31 (7.22 to 7.40) |
7.34 (7.22 to 7.41) |
7.32 (7.24 to 7.40) |
0.85 |
| T6 |
7.32 (7.20 to 7.36) |
7.35 (7.30 to 7.42) |
7.35 (7.26 to 7.39) |
7.34 (7.30 to 7.39) |
0.33 |
| PaCO2 (mmHg) |
|
|
|
|
|
| T0 |
30.5 (24.1 to 36.6) |
34.2 (24.7 to 36.9) |
31.0 (23.6 to 33.6) |
27.5 (23.7 to 36.5) |
0.81 |
| T6 |
26.1 (22.4 to 32.7) |
31.0 (21.6 to 34.0) |
31.3 (26.8 to 33.6) |
27.5 (21.7 to 32.1) |
0.25 |
| PvmCO2 (mmHg) |
|
|
|
|
|
| T0 |
40.6 (33.9 to 46.5)¶ |
29.5 (25.0 to 35.3) |
39.7 (35.5 to 47.1) 34.3 |
32.8 (27.3 to 40.9)¶ |
0.03 |
| T6 |
38.0 (29.9 to 39.7)¶ |
38.3 (28.0 to 46.2) |
(30.4 to 36.8) |
30.0 (25.5 to 35.5)¶ |
0.02 |
| PvcCO2 (mmHg) |
|
|
|
|
|
| T0 |
38.2 (29.1 to 50.5) |
40.1 (34.2 to 43.4) |
36.7 (35.5 to 47.1) 33.9 |
32.5 (28.1 to 38.4) |
0.12 |
| T6 |
33.7 (28.3 to 36.9) |
33.8 (31.4 to 41.4) |
(30.4 to 36.8) |
29.0 (25.1 to 35.8) |
0.20 |
| PaO2 (mmHg) |
|
|
|
|
|
| T0 |
112.2 (79.3 to 167.3) |
117.1 (77.5 to 139.5) |
115.7 (81.4 to 140.8) |
100 (86.0 to 123.9) |
0.70 |
| T6 |
113.6 (83.0 to 147.3) |
132.5 (109.8 to 197.8) |
105.0 (83.5 to 127.4) |
111.5 (86.2 to 135.7) |
0.34 |
| PaO2/FiO2 (mmHg) |
|
|
|
|
|
| T0 |
188.9 (117.1 to 265.0) |
166.9 (143.8 to 244.1) |
233.7 (184.6 to 314.0) |
214.3 (141.6 to 368.0) |
0.28 |
| T6 |
177.9 (136.4 to 298.4) |
265.0 (185.5 to 383.5) |
239.3 (185.1 to 306.3) |
253.5 (181.6 to 368.0) |
0.17 |
| Lactate (mmol/l) |
|
|
|
|
|
| T0 |
4.3 (2.0 to 7.9) |
2.9 (2.0 to 9.7) |
2.7 (1.5 to 3.9) |
2.9 (1.7 to 4.7) |
0.16 |
| T6 |
3.3 (2.1 to 6.8)**¶ |
2.9 (1.1 to 7.1) |
1.3 (0.9 to 2.3)** |
2.0 (1.0 to 3.5)¶ |
0.002 |
| ScvO2 (%) |
|
|
|
|
|
| T0 |
64.0 (54.7 to 75.1) |
66.8 (59.7 to 74.5) |
73.0 (70.8 to 76.7) |
67.1 (62.1 to 75.9) |
0.36 |
| T6 |
70.8 (66.4 to 73.5) |
73.4 (69.3 to 78.0) |
72.3 (67.2 to 75.9) |
76.0 (60.0 to 77.9) |
0.53 |
| SvO2 (%) |
|
|
|
|
|
| T0 |
66.0 (56.8 to 71.4) |
68.0 (54.9 to 81.0) |
68.1 (57.0 to 71.0) |
69.7 (62.1 to 75.9) |
0.39 |
| T6 |
69.0 (63.3 to 72.9) |
70.6 (63.4 to 73.8) |
71.2 (64.4 to 75.1) |
68.0 (58.7 to 74.3) |
0.77 |
| Oxygen extraction ratio |
|
|
|
|
|
| T0 |
34.7 (28.3 to 44.3) |
30.8 (22.7 to 38.4) |
29.4 (25.0 to 36.8) |
30.7 (24.9 to 37.5) |
0.36 |
| T6 |
29.8 (26.4 to 36.6) |
30.2 (24.9 to 31.3) |
29.3 (24.1 to 33.3) |
30.7 (23.4 to 39.3) |
0.68 |
| Pv-aCO2 (mmHg) |
|
|
|
|
|
| T0 |
8.2 (7.0 to 10.6)*¶ |
1.4 (1.1 to 5.3)*φ |
6.3 (6.1 to 7.2)φξ |
2.7 (2.0 to 4.0)¶ξ |
<0.001 |
| T6 |
7.6 (6.4 to 9.4)**¶ |
8.6 (6.5 to 11.7)φΨ |
3.5 (0.9 to 4.3)**φ |
3.3 (2.2 to 4.1)¶Ψ |
<0.001 |
| Pvc-aCO2 (mmHg) |
|
|
|
|
|
| T0 |
9.7 (7.0 to 12.1)¶ |
4.6 (3.3 to 6.1) |
7.3 (4.6 to 9.1) |
4.4 (2.7 to 5.4)¶ |
<0.001 |
| T6 |
7.0 (5.8 to 9.7) |
8.5 (5.6 to 9.6)Ψ |
4.4 (2.1 to 5.5) |
4.0 (1.7 to 5.4)Ψ |
0.003 |
|
Ventilatory parameters | |||||
| Mechanical ventilation |
|
|
|
|
|
| T0 |
24 |
5 |
11 |
23 |
0.01 |
| T6 |
24 |
5 |
11 |
23 |
0.01 |
| PEEP (mmHg), n |
|
|
5.0 (5.0 to 8.0), 11 |
6.0 (5.0 to 8.0), 23 |
0.48 |
| T0 |
6.0 (5.0 to 8.0), 24 |
5.0 (5.0 to 6.0), 5 |
5.0 (5.0 to 8.0), 11 |
8.0 (5.0 to 10.0), 23 |
|
| T6 |
6.5 (5.0 to 8.0), 24 |
5.0 (5.0 to 7.5), 5 |
|
|
|
| Tidal volume (ml/kg) |
|
|
|
|
|
| T0 |
7.1 (6.3 to 7.7) |
7.3 (6.3 to 7.6), 5 |
7.0 (6.5 to 8.0), 11 |
7.5 (6.6 to 8.0), 23 |
0.65 |
| T6 | 7.2 (6.3 to 7.9) | 7.2 (6.6 to 7.6), 5 | 7.5 (6.8 to 8.0), 11 | 7.5 (6.9 to 8.0), 23 | 0.65 |
Data presented as mean (25 to 75% interquartile range). CVP, central venous pressure; FiO2, oxygen inspired fraction; MAP, mean arterial pressure; PaCO2, arterial carbon dioxyde pressure; PaO2, arterial oxygen pressure; PAOP, pulmonary artery occlusion pressure; PEEP, positive end-expiratory pressure; Pv-aCO2, mixed venous-to-arterial carbon dioxide difference; Pvc-aCO2, central venous-to-arterial carbon dioxide difference; PvcCO2, central venous carbon dioxide pressure; PvmCO2, mixed venous carbon dioxide pressure; ScvO2, central venous oxygen saturation; SvO2, mixed venous oxygen saturation; T0, time 0; T6, 6 hours after Time 0. *P <0.05 for Groups 1 vs. 2; **P <0.05 for Groups 1 vs. 3; ¶P <0.05 for Groups 1 vs. 4; φP <0.05 for Groups 2 vs. 3; ΨP <0.05 for Groups 2 vs. 4; and ξP <0.05 for Groups 3 vs. 4.