Why do patients with uremia experience low blood pressure?
Apr 24, 2022
Source: Cainiu Health
Dr. Zhao Xinju
Introduction
Hypotension in patients with uremia can result from various causes, including bradycardia, dehydration, hypovolemia, and vascular dysfunction. Reduced cardiac output leads to low blood pressure. Dehydration decreases intravascular volume, resulting in hypotension. Significant blood loss or concurrent acute myocardial infarction impairs cardiac contractility, thereby causing hypotension. Additionally, allergic reactions induce vasodilation, which can also lead to hypotension.
Hypotension in patients with uremia may result from bradycardia, dehydration, hypovolemia, or vascular dysfunction, among other causes. Specific explanations are as follows:
1. Bradycardia
Cardiac output directly influences blood pressure. Excessively high cardiac output leads to hypertension, whereas insufficient cardiac output results in hypotension.
2. Dehydration
Dehydration reduces intravascular volume, thereby lowering blood pressure. This is especially common during summer months, when hot weather and inadequate fluid intake predispose patients to dehydration and subsequent hypotension.
3. Hypovolemia
In uremic patients, acute massive blood loss or large-area acute myocardial infarction can impair myocardial contractility. When the heart contracts weakly, it fails to pump blood effectively, leading to hypovolemia and consequent hypotension.
4. Vascular Dysfunction
In cases of allergy, uremic patients may develop vascular dysfunction characterized by excessive vasodilation, resulting in hypotension; severe cases may progress to anaphylactic shock.
