Table 1.
Gas exchange and haemodynamics
| Parameter | Therapy | ANOVA (P=) | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Group | Mode | 20′ | 40′ | 60′ | Seq | Group | Mode | Time | Mixed |
| MAP (mmHg) | 0.335 | 0.228 | 0.329 | 0.070 | 0.188 | ||||
| Norm | VCV | 80 ± 13 | 76 ± 13 | 72 ± 14 | |||||
| FCV | 74 ± 15 | 73 ± 17 | 78 ± 28 | ||||||
| Hypo | VCV | 65 ± 20 | 65 ± 20 | 63 ± 22 | |||||
| FCV | 69 ± 17 | 67 ± 17 | 64 ± 17 | ||||||
| MPAP (mmHg) | 0.292 | 0.854 | 0.392 | 0.946 | 0.962 | ||||
| Norm | VCV | 28 ± 8 | 26 ± 8 | 27 ± 7 | |||||
| FCV | 27 ± 8 | 27 ± 6 | 27 ± 4 | ||||||
| Hypo | VCV | 27 ± 7 | 28 ± 6 | 28 ± 5 | |||||
| FCV | 26 ± 7 | 25 ± 6 | 25 ± 7 | ||||||
| CVP (mmHg) | 0.380 | 0.066 | 0.368 | 0.738 | 0.875 | ||||
| Norm | VCV | 4 ± 4 | 4 ± 4 | 5 ± 5 | |||||
| FCV | 4 ± 3 | 3 ± 2 | 4 ± 2 | ||||||
| Hypo | VCV | 2 ± 1 | 2 ± 2 | 2 ± 2 | |||||
| FCV | 1 ± 2 | 2 ± 3 | 1 ± 2 | ||||||
| CO (l/min) | 0.744 | 0.102 | 0.456 | 0.540 | 0.369 | ||||
| Norm | VCV | 7.26 ± 1.95 | 7.19 ± 1.53 | 7.51 ± 1.21 | |||||
| FCV | 7.22 ± 1.46 | 7.1 ± 1.42 | 6.82 ± 1.67 | ||||||
| Hypo | VCV | 8.59 ± 3.74 | 8.68 ± 2.75 | 8.88 ± 2.57 | |||||
| FCV | 8.95 ± 2.64 | 8.91 ± 2.37 | 8.76 ± 2.24 | ||||||
| EVLW (mL) | 0.868 | 0.106 | 0.764 | 0.146 | 0.646 | ||||
| Norm | VCV | 446 ± 69 | 455 ± 62 | 448 ± 61 | |||||
| FCV | 438 ± 41 | 439 ± 41 | 438 ± 44 | ||||||
| Hypo | VCV | 559 ± 179 | 536 ± 158 | 499 ± 127 | |||||
| FCV | 562 ± 203 | 560 ± 169 | 530 ± 180 | ||||||
| ITBV (mL) | 0.008 | 0.210 | 0.929 | 0.879 | 0.949 | ||||
| Norm | VCV | 582 ± 167 | 566 ± 141 | 605 ± 173 | |||||
| FCV | 587 ± 222 | 574 ± 240 | 560 ± 205 | ||||||
| Hypo | VCV | 502 ± 90 | 484 ± 88 | 487 ± 96 | |||||
| FCV | 501 ± 128 | 501 ± 118 | 540 ± 181 | ||||||
| GEDV (mL) | 0.008 | 0.220 | 0.999 | 0.974 | 0.882 | ||||
| Norm | VCV | 466 ± 134 | 450 ± 114 | 484 ± 138 | |||||
| FCV | 470 ± 177 | 459 ± 192 | 449 ± 164 | ||||||
| Hypo | VCV | 407 ± 70 | 387 ± 70 | 390 ± 77 | |||||
| FCV | 401 ± 103 | 401 ± 94 | 432 ± 145 | ||||||
| SVR (dyn*s/cm5) | 0.251 | 0.156 | 0.759 | 0.090 | 0.870 | ||||
| Norm | VCV | 955 ± 294 | 878 ± 284 | 805 ± 236 | |||||
| FCV | 1100 ± 436 | 858 ± 254 | 940 ± 242 | ||||||
| Hypo | VCV | 736 ± 433 | 726 ± 410 | 682 ± 392 | |||||
| FCV | 717 ± 306 | 720 ± 319 | 700 ± 325 | ||||||
| Noradrenalin (mg/h) | 0.607 | 0.031 | 0.912 | 0.534 | 0.790 | ||||
| Norm | VCV | 0.28 ± 0.50 | 0.78 ± 1.39 | 0.28 ± 0.50 | |||||
| FCV | 0.23 ± 0.39 | 0.27 ± 0.48 | 0.28 ± 0.48 | ||||||
| Hypo | VCV | 1.94 ± 2.19 | 2.04 ± 2.22 | 2.25 ± 2.59 | 0.054 | ||||
| FCV | 2.12 ± 2.15 | 2.18 ± 2.28 | 2.19 ± 2.55 | 0.022 | |||||
| Hb (mmol/L) | 0.483 | 0.302 | 0.212 | 0.678 | 0.695 | ||||
| Norm | VCV | 5.81 ± 0.91 | 5.64 ± 0.95 | 5.75 ± 1 | |||||
| FCV | 5.92 ± 1.05 | 5.78 ± 1.07 | 5.69 ± 0.85 | ||||||
| Hypo | VCV | 5.19 ± 0.97 | 5.11 ± 0.98 | 5.14 ± 0.91 | |||||
| FCV | 5.46 ± 0.95 | 5.45 ± 0.94 | 5.44 ± 0.87 | ||||||
| Shunt (%) | 0.944 | 0.103 | 0.097 | 0.050 | 0.114 | ||||
| Norm | VCV | 32.8 ± 11.1 | 29.8 ± 8.9 | 29.9 ± 10.2 | |||||
| FCV | 32.5 ± 8.2 | 32.2 ± 7.7 | 30.8 ± 8.2 | ||||||
| Hypo | VCV | 41.7 ± 11.3 | 40.2 ± 11.6 | 38.3 ± 10.4 | |||||
| FCV | 37 ± 9.8 | 37.7 ± 10.5 | 39.6 ± 12.1 | ||||||
Values in mean ± standard deviation; Statistical P values according to linear mixed-effects repeated measures ANOVA with with-in subject factors: mode of ventilation (volume or flow-controlled ventilation) and time of therapy in minutes; and between subject factors group of therapy (normovolaemia or hypovolaemia) and randomisation sequence (volume or flow-controlled ventilation first). Significance was accepted for P < 0.05. Statistical analysis was performed in R statistical programming language and the package lme4
FCV flow-controlled ventilation, VCV volume-controlled ventilation, MAP mean arterial pressure, MPAP mean pulmonary arterial pressure, CVP central venous pressure, CO cardiac output, EVLW extravascular lung water, ITBV intrathoracic blood volume, GEDV global end-diastolic volume, SVR systemic vascular resistance, Hb haemoglobin, Shunt intrapulmonary shunt