Table of Contents
What is a normal DO2 to VO2 ratio?
Evidence will be presented that blood flow is scaled according to a tissue specific ratio of oxygen delivery (DO2) to oxygen consumption (VO2). For the brain DO2 is approximately three times VO2, for heart muscle DO2 is 1.5 to 1.6 times VO2 and is very similar for skeletal muscle for moderate exercise.
What does low sv02 mean?
If SvO2 decreases, it indicates that the tissues are extracting a higher percentage of oxygen from the blood than normal. In otherwords, a decreased SvO2 indicates that the cardiac output is not high enough to meet tissue oxygen needs.
How is d02 calculated?
DO2 = CO x (sO2 x ceHb x 1.39) + (PaO2 x 0.03) Potential oxygen carrying capacity – determined by total Hb concentration [ctHb, measured in ABG – measures all species of Hb, including carboxyHb].
What does high oxygen extraction mean?
The amount of oxygen delivered to the myocardium is greater than the amount that is actually taken up (oxygen consumed) by the myocardium to support oxidative metabolism. Compared to most organs of the body (see table below), the oxygen extraction of the heart is relatively high.
What is VO2 in ECMO?
Metabolism is measured by measuring the amount of oxygen consumed per minute, which is called VO2. The rate of metabolism for adults at rest is 3cc/kg/min or 120c/min/m2 for a typical adult (children 4cc/kg, infants 5cc/kg.).
What is the normal cardiac output?
What is a normal cardiac output? A healthy heart with a normal cardiac output pumps about 5 to 6 litres of blood every minute when a person is resting.
What is a normal venous pO2?
TABLE I: Arterial and venous blood gas reference range
| Arterial | Venous | |
|---|---|---|
| pCO2 (mmHg) | 35 -45 | 41 – 51 |
| Bicarbonate (mmol/L) | 22-28 | 23-29 |
| PO2 (kPa) | 10.6 – 13.3 | 4.0 -5.3 |
| pO2 (mmHg) | 80-100 | 30 -40 |
How do you calculate oxygen consumption?
The best fitting formula is expressed as: VO2(ass) = (157.3 x BSA + 10.0 x Sex – 10.5 x In Age + 4.8) ml. min-1, where ln Age = the natural logarithm of the age. This formula was validated prospectively in 60 patients. A non-significant difference between VO2(ass) and VO2(dd) was found; mean 2.0 +/- 23.4 ml.
What does oxygen extraction ratio mean?
Abstract. Oxygen extraction fraction (OEF) is defined as the ratio of blood oxygen that a tissue takes from the blood flow to maintain function and morphological integrity. OEF reflects the efficiency of oxygen utilization by the tissue and, therefore, is a hemodynamic measure in brain ischemia.
What’s a normal stroke volume?
Stroke volume is the difference between end-diastolic and end-systolic volumes; it is the volume ejected with each heart beat. The normal range is 50 to 100 ml. In the ICU, stroke volume is usually measured by a pulmonary artery catheter and is reported as cardiac output.