🩺 What Does the Number in Parentheses Next to Blood Pressure Mean?🤔

That’s a common question from new nurses. Did you explain about the mean arterial pressure (MAP)?

Blood pressure is one of the most familiar vital signs. It’s even asked about in the anesthesiology board exam and the perioperative management team certification exam. Patients and nurses often bring it up, so we should understand it clearly.

That’s mine—today’s blood pressure.

It hurts to hear that… especially from the source of my stress!

Exactly. Clinically, we often aim for a MAP ≥ 65 mmHg. In elderly patients, vasopressors are frequently needed. For patients with chronic hypertension, an even higher MAP may be necessary.

That’s because I’m still young.

Systolic blood pressure (SBP): pressure when the heart contracts, the “upper number.”
Diastolic blood pressure (DBP): pressure when the heart relaxes, the “lower number.”

That’s what people usually think, but it’s not that simple.

This comes from the fact that about two-thirds of the cardiac cycle is spent in diastole.
Exactly. Automated monitors use oscillometric algorithms, so the displayed MAP may differ slightly, but it’s close.

Sure. MAP is the driving pressure that pushes blood into the organs. To keep organs functioning, we need at least about 60–65 mmHg. Normally MAP is around 70–100 mmHg. If MAP drops below this range for long, organ perfusion can fail.

Brain → risk of ischemia
Kidneys → oliguria or anuria
Heart → myocardial ischemia

This can become life-threatening. Short, mild drops may not cause immediate harm, but prolonged or severe drops are dangerous—especially in elderly patients with less reserve.

That’s transient MAP drop → temporary cerebral ischemia → dizziness. Stand up slowly, especially elderly patients—they can faint and fracture bones.

If MAP remains low, organ dysfunction develops. Particularly kidney failure, brain ischemia, and myocardial ischemia are critical.

Exactly.

Tachycardia = the heart trying to maintain cardiac output.
Cold extremities = vasoconstriction, shunting blood away from skin to protect brain and heart.

Not always. You need to identify the cause.

There are many causes of shock: hypovolemic shock (including hemorrhagic shock), cardiogenic shock such as myocardial infarction, obstructive shock like pulmonary embolism, and distributive shock due to conditions such as sepsis, anaphylaxis, or neurogenic shock (where the blood vessels are dilated). Treatment must be tailored to the underlying cause, otherwise the patient’s condition may worsen.

Some people just silence the alarm and push ephedrine or phenylephrine without thinking. That’s absolutely wrong. You must treat the underlying cause.

…I’m not naming names.

Exactly. If MAP falls, organs like brain, kidney, liver, and heart lose adequate perfusion, impairing oxygen delivery and organ function.

Yes, especially in elderly patients with hypertension and comorbidities. That’s why appropriate fluids, transfusion, and vasopressors are needed. Blood pressure and hemodynamic management are deep topics—we can’t cover everything in one session. Keep asking questions!