What is the true blood pressure of a patient positioned 20cm above the phlebostatic axis with a recorded BP of 120/80?

To determine the true blood pressure of a patient positioned 20 cm above the phlebostatic axis with a recorded blood pressure of 120/80 mmHg, it is essential to understand how the position of the patient affects the reading.

Blood pressure measurements are influenced by hydrostatic pressure when a patient is positioned above or below the level of the heart. For every 10 cm of vertical distance from the phlebostatic axis, the pressure changes by approximately 7.5 mmHg. In this case, the patient is positioned 20 cm above the phlebostatic axis, which would increase the recorded blood pressure due to the effects of hydrostatic pressure.

To calculate the true blood pressure, you must subtract the effect of the position from the recorded BP. Since the patient is 20 cm above the reference point, you would adjust the reading downwards by about 15 mmHg (2 x 7.5 mmHg for 20 cm).

Starting with the recorded systolic pressure of 120 mmHg:

120 mmHg - 15 mmHg = 105 mmHg

For the diastolic pressure:

80 mmHg - 15 mmHg = 65 mmHg

This results in a true blood pressure of