Table 1.
Pregnant and nonpregnant women response to high altitude hypoxia
|
Nonpregnant |
Pregnant |
|||
|---|---|---|---|---|
| Variables | Sea level | High altitude | Sea level | High altitude |
| Blood gases | ||||
| Po2, mmHg | 93 (9) | 48 (4)* | 98.5 (10) | 53 (3)* |
| Pco2, mmHg | 40 (2.5) | 27 (2.0)* | 32 (3.0) | 23 (1.6)* |
| pH | 7.43 (0.02) | 7.48 (0.03)* | 7.45 (0.02) | 7.495 (0.03)* |
| Saturation, % | 98 (0.8) | 88 (3.0)* | 98.5 (0.7) | 89.9 (2.4)* |
| Hemoglobin, g/dl | 14 (1.6) | 16 (1.7)* | 11.8 (1.4) | 14.3 (1.5)* |
| HCO3, mM | 25.3 (1.2) | 19.9 (1.3)* | 21.7 (1.6) | 17.5 (1.2)* |
| Base excess | 1.37 (0.9) | −0.7 (1.4)* | −0.69 (1.3) | −2.06 (1.3)* |
| O2 content, ml/100 ml whole blood | 1.82 (0.2) | 1.89 (0.2) | 1.58 (0.2) | 1.75 (0.2)* |
| Minute ventilation, l/min | 10.5 (4) | 12.4 (4) | 13.3 (3.8) | 16.7 (7)* |
| Respiratory rate/min | 15.7 (4.8) | 18.9 (5.3) | 18.6 (5.9) | 20.9 (6.6)† |
| Tidal volume, l | 0.7 (0.3) | 0.7 (0.2) | 0.8 (0.3) | 0.8 (0.4) |
| Cardiovascular parameters | ||||
| Cardiac output, l/min | 5.08 (1.04)§ | 4.68 (0.78) | 6.89 (1.04) | 5.60 (1.04)§ |
| Stroke volume, ml | 71.64 (13.78)§ | 70.49 (9.34) | 86.25 (10.73) | 77.74 (12.29)§ |
| Left atrial diameter, mm | 30.70 (1.98)§ | 31.83 (5.10) | 38.24 (4.03) | 35.84 (4.91)§ |
| Heart rate, beats/min | 71.22 (7.85)§ | 66.68 (8.82) | 80.79 (9.31) | 72.32 (10.25)§ |
| LV intraventricular septum during diastole/BSA, 10−3 × m−1 | 4.09 (0.37) | 4.11 (0.67) | 4.14 (0.50) | 4.38 (0.43) |
| LV end-diastolic diameter/BSA, 10−3 × m−1 | 29.81 (2.21) | 28.91 (2.04) | 31.16 (2.84) | 29.93 (2.73) |
| LV posterior wall diameter during diastole/BSA, 10−3 × m−1 | 4.20 (0.37) | 4.17 (0.43) | 4.16 (0.48) | 4.29 (0.50) |
| LV intraventricular septum during systole/BSA, 10−3 × m−1 | 6.50 (0.67)§ | 5.69 (0.70)‡ | 6.08 (0.62) | 6.29 (0.83)§ |
| LV end-systolic diameter/BSA, 10−3 × m−1 | 18.47 (1.63)§ | 19.83 (1.72)‡ | 19.93 (2.05) | 19.17 (2.14) |
| LV posterior wall diameter during systole/BSA, 10−3 × m−1 | 7.28 (0.66) | 6.28 (0.67)‡ | 7.18 (1.02) | 7.19 (0.74)§ |
| Fractional shortening | 0.38 (0.04) | 0.31 (0.03)‡ | 0.36 (0.04) | 0.36 (0.04)§ |
| Ejection fraction | 0.68 (0.05) | 0.59 (0.05)‡ | 0.65 (0.02) | 0.64 (0.05)§ |
| Mean arterial pressure, mmHg | 96.32 (10.42)§ | 92.33 (8.95) | 91.28 (7.51) | 84.81 (6.77)§ |
| Total vascular resistance, dyn·s−1·cm−5 | 1579.36 (272.13) | 1550.99 (207.37) | 1081.95 (168.09)§ | 1247.20 (235.55)§ |
| Global long axis shortening, mm | 15.37 (1.16) | 14.48 (1.21)‡ | 15.67 (1.52) | 15.63 (1.40)§ |
| Global time to shortening, ms | 78.57 (8.65) | 91.42 (13.74)‡ | 80.65 (10.42) | 83.07 (12.15)§ |
| LV mass/BSA, g/m2 | 71.11 (9.16)§ | 66.47 (13.24) | 78.49 (10.49) | 72.71 (13.21) |
*
P < 0.01. †P < 0.05. ‡Denotes statistically significant difference (P < 0.05) between nonpregnant controls at altitude and sea level. §Denotes statistically significant difference (P < 0.05) between pregnant women and nonpregnant controls at their respective altitude. [Table adapted from Kametas et al. (460) and McAuliffe et al. (634).]