Table 3.
Measured and calculated cardiovascular variables in 12 dorsally recumbent anesthetized pigs ventilated with either apneustic anesthesia ventilation (AAV) or conventional mechanical ventilation (CMV) in random order at baseline (T0), 30 min (T30), and 60 min (T60).
| Variable | Order | AAV | CMV | Mode effect | Order effect | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| T0 | T30 | T60 | T0 | T30 | T60 | AAV | CMV | |||
| HR (beats min−1) | AAV → CMV | 117 ± 7 | 118 ± 5 | 118 ± 4 | 101 ± 4 | 95 ± 5 | 95 ± 5 | < 0.0001 | 0.1604 | 0.1652 |
| CMV → AAV | 135 ± 8 | 131 ± 9 | 127 ± 9 | 112 ± 11 | 110 ± 14 | 110 ± 14 | ||||
| MAP (mmHg) | AAV → CMV | 61 ± 3 | 61 ± 2 | 63 ± 4 | 70 ± 2 | 73 ± 3 | 73 ± 4 | < 0.0001 | 0.1751 | 0.0027 |
| CMV → AAV | 58 ± 2 | 71 ± 4 | 69 ± 3 | 83 ± 3 | 83 ± 3 | 84 ± 2 | ||||
| MPAP (mmHg) | AAV → CMV | 24 ± 1 | 24 ± 1 | 24 ± 1 | 24 ± 2 | 23 ± 1 | 24 ± 1 | 0.4465 | 0.5367 | 0.4646 |
| CMV → AAV | 24 ± 2 | 23 ± 1 | 23 ± 1 | 23 ± 1 | 23 ± 1 | 23 ± 1 | ||||
| PAOP (mmHg) | AAV → CMV | 13 ± 1 | 13 ± 1 | 13 ± 1 | 6 ± 1 | 7 ± 1 | 7 ± 1 | < 0.0001 | 0.5165 | 0.0991 |
| CMV → AAV | 14 ± 1 | 13 ± 1 | 13 ± 1 | 5 ± 0 | 5 ± 1 | 5 ± 1 | ||||
| CI (mL min−1 kg−1) | AAV → CMV | 68 ± 4 | 70 ± 3 | 73 ± 4 | 106 ± 6 | 108 ± 7 | 119 ± 5 | < 0.0001 | 0.0117 | 0.1499 |
| CMV → AAV | 77 ± 4 | 85 ± 5 | 83 ± 7 | 106 ± 5 | 99 ± 3 | 109 ± 5 | ||||
| SVI (mL beat−1 kg−1) | AAV → CMV | 0.61 ± 0.06 | 0.58 ± 0.03 | 0.62 ± 0.03 | 1.09 ± 0.06 | 1.19 ± 0.07 | 1.31 ± 0.06 | < 0.0001 | 0.6843 | 0.0009 |
| CMV → AAV | 0.57 ± 0.02 | 0.65 ± 0.02 | 0.66 ± 0.02 | 0.98 ± 0.08 | 0.98 ± 0.12 | 1.06 ± 0.10 | ||||
| SVR (dyne sec cm−5) | AAV → CMV | 1,683 ± 146 | 1,698 ± 89 | 1,622 ± 115 | 1,226 ± 92 | 1,304 ± 139 | 1,145 ± 88 | < 0.0001 | 0.2014 | 0.0440 |
| CMV → AAV | 1,423 ± 74 | 1,575 ± 90 | 1,547 ± 55 | 1,499 ± 134 | 1,579 ± 107 | 1,453 ± 112 | ||||
| PVR (dyne sec cm−5) | AAV → CMV | 313 ± 24 | 317 ± 16 | 285 ± 28 | 322 ± 36 | 297 ± 23 | 272 ± 20 | 0.0002 | 0.0104 | 0.7656 |
| CMV → AAV | 235 ± 23 | 210 ± 13 | 226 ± 20 | 319 ± 27 | 332 ± 27 | 294 ± 25 | ||||
| DO2I (ml min−1 kg−1) | AAV → CMV | 9.0 ± 0.7 | 9.2 ± 0.5 | 9.4 ± 0.7 | 13.2 ± 0.5 | 13.0 ± 1.1 | 14.2 ± 0.8 | < 0.0001 | 0.1756 | 0.8828 |
| CMV → AAV | 9.7 ± 0.6 | 10.4 ± 0.6 | 10.0 ± 0.8 | 13.8 ± 0.8 | 12.6 ± 0.4 | 13.8 ± 0.7 | ||||
| O2ER | AAV → CMV | 0.50 ± 0.03 | 0.51 ± 0.03 | 0.52 ± 0.04 | 0.37 ± 0.01 | 0.40 ± 0.01 | 0.41 ± 0.01 | < 0.0001 | 0.4813 | 0.0737 |
| CMV → AAV | 0.51 ± 0.03 | 0.50 ± 0.02 | 0.47 ± 0.02 | 0.33 ± 0.02 | 0.34 ± 0.01 | 0.36 ± 0.01 | ||||
All values are mean ± standard error of the mean. The two right-most columns provide p-values for the overall effects of mode of ventilation and order of mode application determined by data modeling with repeated measures ANOVA.
HR, heart rate; MAP, mean arterial pressure; MPAP, mean pulmonary artery pressure; PAOP, pulmonary artery occlusion pressure; CI, cardiac index; SVI, stroke volume index; SVR, systemic vascular resistance; PVR, pulmonary vascular resistance; DO2I, oxygen delivery index; O2ER, oxygen extraction ratio. For each variable, data are given for each order of mode application: AAV followed by CMV (AAV → CMV) and CMV followed by AAV (CMV → AAV).