What is mean arterial blood pressure?

Mean arterial pressure (MAP) is a measure of the average arterial pressure over a cardiac cycle. It is calculated by adding the diastolic blood pressure to one-third of the pulse pressure (the difference between systolic and diastolic blood pressures).

$$MAP = DBP + 1/3 (SBP - DBP)$$

MAP is a more accurate reflection of the perfusion of tissues than either systolic or diastolic blood pressure alone. This is because MAP takes into account the effects of both systolic and diastolic blood pressures on blood flow.

MAP is normally between 70 and 100 mmHg. A MAP below 65 mmHg is considered to be low, and a MAP above 110 mmHg is considered to be high.

Low MAP can be caused by a number of conditions, including:

* Heart failure

* Shock

* Dehydration

* Anemia

High MAP can be caused by a number of conditions, including:

* Hypertension

* Kidney disease

* Diabetes

* Obesity

MAP is an important parameter to monitor in critically ill patients. It can help to assess the adequacy of tissue perfusion and to guide treatment decisions.