From the Guidelines
Hypotension is primarily caused by vasodilation, hypovolaemia, bradycardia, and low cardiac output, which are all modifiable causes that can be treated with targeted interventions. According to the most recent and highest quality study 1, these underlying physiological processes can act alone or in combination to result in hypotension. The study recommends that treatment of hypotension be based on presumed underlying causes, including vasodilation, hypovolaemia, bradycardia, and low cardiac output, with a strong recommendation and high-quality evidence.
Causes of Hypotension
- Vasodilation: can be reversed by vasopressors such as phenylephrine or norepinephrine
- Hypovolaemia: can be treated with intravascular fluid administration using crystalloid and colloid solutions or blood
- Bradycardia: can be pharmacologically managed with anticholinergic agents such as atropine or glycopyrronium
- Low cardiac output: can be treated with positive inotropic agents such as dobutamine or epinephrine
The symptoms of hypotension arise because insufficient blood pressure means reduced oxygen and nutrient delivery to the brain and other vital organs, resulting in dizziness, lightheadedness, fainting (syncope), blurred vision, fatigue, nausea, difficulty concentrating, and in severe cases, shock. While other studies, such as 1, discuss hypotension in the context of heart failure and beta-blocker therapy, the most recent and highest quality study 1 provides a comprehensive overview of the causes and treatment of hypotension.
From the FDA Drug Label
Hypotension: At lower infusion rates, if hypotension occurs, the infusion rate should be rapidly increased until adequate blood pressure is obtained. If hypotension persists, dopamine HCl should be discontinued and a more potent vasoconstrictor agent such as norepinephrine should be administered. Weaning: When discontinuing the infusion, it may be necessary to gradually decrease the dose of dopamine HCl while expanding blood volume with intravenous fluids. Sudden cessation may result in marked hypotension Administration of phenytoin to patients receiving dopamine HCl has been reported to lead to hypotension and bradycardia
Hypotension causes associated with dopamine (IV) administration include:
- Low infusion rates: Hypotension may occur at lower infusion rates.
- Sudden cessation: Stopping the infusion abruptly may result in marked hypotension.
- Drug interactions: Concomitant administration of certain medications, such as phenytoin, may lead to hypotension. 2 2
From the Research
Hypotension Causes
The provided studies do not directly address the causes of hypotension. However, they discuss the treatment and management of hypertension and heart failure, which can be related to hypotension in some cases.
- The studies mention various factors that can contribute to heart failure, such as coronary artery disease, hypertension, and diabetes mellitus 3, 4, 5, 6.
- They also discuss the importance of blood pressure control in preventing cardiovascular events, such as myocardial infarction and stroke 4, 6.
- Additionally, the studies highlight the role of certain medications, including ACE inhibitors, beta blockers, and diuretics, in managing hypertension and heart failure 7, 3, 4, 5, 6.
Related Factors
While the studies do not directly address hypotension causes, they mention some related factors, such as:
- Low blood pressure as a potential side effect of certain medications, like beta blockers and ACE inhibitors 3, 6.
- The importance of careful dose titration and monitoring to avoid hypotension when using these medications 6.
- The potential benefits of combining different medications to achieve better blood pressure control and reduce the risk of cardiovascular events 5, 6.