We are sometimes asked whether the BP-2000 Blood Pressure Analysis System can be used to measure the blood pressure of anesthetized animals. The answer is a qualified Yes.
Although most researchers use conscious animals, when first developing the instrument we used anesthetized mice for convenience, with good results. And a researcher using the instrument to measure mouse blood pressure did extensive experimentation with anesthetized mice, and got excellent results.
In fact, using anesthesia can make measuring the blood pressure easier and more accurate, because animal movements are reduced or eliminated, thus making it easier to analyze the signal.
Of course, whatever physiological side effects the anesthesia has may affect the results. For example, the anesthesia may lower the heart rate and blood pressure. However if you are comparing two different groups, you would expect the blood pressure would be lower in both, but the difference in the two groups should be measurable.
The only possible problem is that if one of the side effects is to reduce blood flow to the tail, you might have difficulty getting a good enough signal to measure the blood pressure, since the BP-2000 relies on tail blood flow as it primary signal.