Student study notes from paramedic coursework (2023 to 2024), not medical advice. Verify clinical values against current references and your local protocols.
| EMS etiologies | Setting: ER |
A hypertensive emergency is an acute and severe elevation in blood pressure that leads to target-organ damage, which can affect the heart, lungs, kidneys, brain, or vascular system. Common manifestations include pulmonary edema, cardiac ischemia, acute renal failure, aortic dissection, and eclampsia. In such cases, aggressive blood pressure reduction is critical to prevent further organ damage. In contrast, gradual reduction is recommended for patients without organ damage to prevent complications from low perfusion.
The primary causes of hypertensive emergencies often involve patients with a history of chronic hypertension, typically due to noncompliance with antihypertensive medications or the use of sympathomimetics (e.g., cocaine). The body’s inability to regulate a sudden spike in blood pressure contributes to organ damage, which explains why hypertensive emergencies can occur at lower blood pressure levels in patients without chronic hypertension, and at much higher levels in patients with long-standing hypertension.
Hypotension refers to abnormally low blood pressure, which can occur due to abnormalities in cardiac output or total peripheral vascular resistance. Blood pressure regulation is dependent on both of these factors:
Types of hypotensive shock include:
The autonomic nervous system regulates blood pressure through the balance between the sympathetic and parasympathetic systems. The sympathetic system increases blood pressure by raising heart rate and constricting blood vessels, while the parasympathetic system lowers it by relaxing vessels and decreasing heart rate.
Hypotensive: dizziness, fainting, shock
Hypertensive: severe headache, vision changes, chest pain, seizures
Hypotensive: fluid resuscitation, vasopressors
Hypertensive: antihypertensive medications, monitoring