What defines a narrow pulse pressure?

From the Guidelines

A narrow pulse pressure is defined as a difference of less than 25 mmHg between systolic and diastolic blood pressure, as suggested by the context of managing patients with extracorporeal cardiopulmonary resuscitation 1. Pulse pressure is calculated by subtracting the diastolic pressure from the systolic pressure (PP = SBP - DBP).

• For example, if someone has a blood pressure of 100/85 mmHg, their pulse pressure would be 15 mmHg, which is considered narrow.
• Narrow pulse pressure can indicate several serious medical conditions including cardiac tamponade, severe heart failure, cardiogenic shock, hypovolemic shock, or aortic stenosis. It occurs when either the systolic pressure decreases (due to reduced stroke volume or cardiac output) or the diastolic pressure increases, causing the two values to move closer together.
• This narrowing reflects compromised cardiovascular function, specifically reduced stroke volume or increased peripheral vascular resistance. When assessing a patient with narrow pulse pressure, it's essential to consider their overall clinical picture, as this finding often requires urgent medical attention, especially if accompanied by symptoms like dizziness, fatigue, or shortness of breath 1.
• Normal pulse pressure typically ranges from 40 to 60 mmHg in healthy adults. In the context of peripherally cannulated patients, a narrow pulse pressure from the right radial arterial line suggests a mixing point proximal to the innominate artery 1.
• Management of such conditions may include increasing ECMO flow to move the mixing point proximally, manipulating ventilator settings to improve oxygenation, or inserting an additional cannula 1.

From the Research

Definition of Narrow Pulse Pressure

• Narrow pulse pressure is generally defined as a pulse pressure of less than 40 mmHg 2, 3.
• Pulse pressure is calculated as the difference between systolic and diastolic blood pressure values 4.
• A narrowed pulse pressure has been identified as an independent predictor of critical administration threshold (CAT+) hemorrhage requiring surgical or endovascular control in trauma patients 3.

Clinical Relevance of Narrow Pulse Pressure

• Narrow pulse pressure is associated with significant transfusion and need for emergent surgery in hemodynamically stable trauma patients 2.
• Low pulse pressure has been linked to increased mortality rates in patients with mild to advanced heart failure 4.
• A narrowed pulse pressure is an independent early predictor of active hemorrhage requiring blood product transfusion and intervention for hemorrhage control in nonhypotensive patients 3.

Key Findings

• Studies have shown that pulse pressure decreases as the severity of heart failure worsens 4.
• A pulse pressure cutoff of 55 mmHg has been identified as a significant predictor of active hemorrhage in patients 61 years or older, while a cutoff of 40 mmHg is significant for patients 16 to 60 years old 3.
• The predicted probability of active hemorrhage increases as pulse pressure narrows 3.