again wonderful as always. In the case of a combined VSD and PDA, what saturation would you use to calculate Qp, Qs and Qeff? Here, for example, saturation in the ascending aorta is 95% and in the descending aorta is 80%.
Great lecture. Seems like your estimate of the contribution of dissolved O2 is off by a factor of 10. The solubility coefficient is routinely estimated at 0.003 mLO2/dl/mmHg whereas you have it at 0.03.
We are both correct. What I have is 0.03 ml O2/L blood/mmHg, a different unit, and the unit best suited for our calculations. The idea here is that we are applying the true Fick equation to calculate flow. Remember that we multiply the denominator by 10 to obtain the O2 content in per L of blood instead of dL: 1.36xHbxSO2 x10. We do the same for the dissolved O2 content. So O2 content in ml O2 per Liter of blood is: (1.36xHbx10xSO2) + (0.03x pO2). If you want it in ml O2 per dL of blood: (1.36xHbxSO2) + (0.003x pO2). For Fick, we use the former to obtain CO in L/min This is a nice reference that corroborates my explanation and the use of 0.03: Murakami T, Horibata Y, Shirai T, et al. Cardiac shunt calculations under 100% oxygen. Catheter Cardiovasc Interv 2011; 78:336.
again wonderful as always. In the case of a combined VSD and PDA, what saturation would you use to calculate Qp, Qs and Qeff? Here, for example, saturation in the ascending aorta is 95% and in the descending aorta is 80%.
Great lecture. Seems like your estimate of the contribution of dissolved O2 is off by a factor of 10. The solubility coefficient is routinely estimated at 0.003 mLO2/dl/mmHg whereas you have it at 0.03.
We are both correct. What I have is 0.03 ml O2/L blood/mmHg, a different unit, and the unit best suited for our calculations. The idea here is that we are applying the true Fick equation to calculate flow. Remember that we multiply the denominator by 10 to obtain the O2 content in per L of blood instead of dL: 1.36xHbxSO2 x10. We do the same for the dissolved O2 content. So O2 content in ml O2 per Liter of blood is: (1.36xHbx10xSO2) + (0.03x pO2).
If you want it in ml O2 per dL of blood: (1.36xHbxSO2) + (0.003x pO2).
For Fick, we use the former to obtain CO in L/min
This is a nice reference that corroborates my explanation and the use of 0.03: Murakami T, Horibata Y, Shirai T, et al. Cardiac shunt calculations under 100% oxygen. Catheter Cardiovasc Interv 2011; 78:336.
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