What is svo2 saturation

What does it tell us? What are the normal values? How do I use this information clinically? If the amount of oxygen being received by the tissues falls below the amount of oxygen required because of an increased need, or decreased supply , the body attempts to compensate as follows: First Compensation: Cardiac Output increases The cardiac output is increased in an effort to increase the amount of oxygen being delivered to the tissues as shown below.

Tissues begin to remove or extract a higher percentage of oxygen from the arterial blood. This results in a reduced amount of oxygen remaining in the blood as it returns to the right side of the heart decreased SvO2.

If this is not sufficient to meet tissue energy needs, we move to our second compensation. Third Compensation: Anaerobic Metabolism iIncreases If the tissues fail to receive an adequate supply of oxygen, anaerobic metabolism becomes the only mechanism to produce tissue ATP. Why measure it? Top Stories. Getting the data on homelessness. Hospital News. MRT Week has started: Let's celebrate and recognize this essential role in health care. Ensuring patients and Essential Care Partners are heard in palliative care.

But what if we get more sophisticated? First, we could stop giving patients excessive amounts of FiO2 and PaO2 avoiding hyperoxia is good practice anyway.

This would get rid of the PaO2 term, allowing us to use a traditional Fick equation as shown below. Second, we could calculate the cardiac output from this equation, allowing us to account for variables such as hemoglobin and arterial oxygen saturation.

Would that allow calculation of the cardiac output? Plugging these values into the formulae above indicates that random error in all four parameters yields a standard deviation of 1.

This is too imprecise for clinical use. To verify this math, a Monte-Carlo simulation may be performed. This involves generating values for 5, imaginary patients using the values above as well as randomized normal distribution functions 1. This yields a similar albeit slightly higher standard deviation for the calculated cardiac output 1. The calculated values of cardiac output are shown here:. The amount of uncertainty in the example above is actually quite conservative. Therefore, the amount of error likely to occur in the ICU is considerably higher.

The bottom line is that the Fick equation amplifies the amount of random error involved in each of the values entered into it. Even if each individual variable is known with a reasonable margin of error, the calculated cardiac output varies with an unreasonable margin of error. The oxygen extraction ratio is the ratio of the oxygen consumed by the body VO2 to the oxygen delivered to the body DO2. As the amount of oxygen delivered to the body DO2 decreases, a greater fraction of oxygen will be consumed higher oxygen extraction ratio.

This blog has taken a more theoretical approach, due to a lack of direct evidence. Nonetheless, this does appear consistent with available evidence:.

When we evaluate patients, we are continually integrating new data with our pre-conceived notion about what is going on with the patient:. Studies evaluate the performance of tests in isolation, but this isn't the way tests function in reality.

This category only includes cookies that ensures basic functionalities and security features of the website. These cookies do not store any personal information. Non Necessary non-necessary.

Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. It is mandatory to procure user consent prior to running these cookies on your website. Uncategorized uncategorized. Undefined cookies are those that are being analyzed and have not been classified into a category as yet.

Analytics analytics. Analytical cookies are used to understand how visitors interact with the website. These cookies help provide information on metrics the number of visitors, bounce rate, traffic source, etc. It can be very useful if measured before and after changes are made to cardiac medications or mechanical ventilation, particularly in unstable patients. ATP energy is needed for cell function and survival. Tissues require oxygen in order to make ATP energy. If the amount of oxygen being received by the tissues falls below the amount of oxygen required because of an increased need, or decreased supply , the body attempts to compensate as follows:.

First - Cardiac Output is Increased The cardiac output is increased in an effort to increase the oxygen delivery to the tissues as shown below. Oxygen Delivery is the amount of oxygen being sent to the tissues, and is determined by the following:.

If this is not sufficient to meet tissue energy needs;. Tissues begin to remove or extract a higher percentage of oxygen from the arterial blood. This results in a reduced amount of oxygen remaining in the blood as it returns to the right side of the heart decreased SVO 2. If this is not sufficient to meet tissue energy needs; Third - Anaerobic Metabolism Increases.

If the tissues fail to receive an adequate supply of oxygen, anaerobic metabolism becomes the only mechanism to produce tissue ATP. Anaerobic metabolism is inefficient, producing a large amount of metabolic waste e. It also produces a relatively poor supply of ATP.