Controlled hypotension

Controlled Hypotension

Controlled hypotension is a medical technique used to deliberately lower a patient's blood pressure during surgical procedures. This practice is employed to reduce bleeding and improve the surgical field visibility, thereby facilitating a safer and more efficient operation. Controlled hypotension is particularly useful in surgeries where blood loss is a significant concern, such as in orthopedic surgery, neurosurgery, and cardiovascular surgery.

Mechanism

Controlled hypotension is achieved through the administration of pharmacological agents that reduce systemic vascular resistance or cardiac output, leading to a decrease in arterial blood pressure. Commonly used agents include vasodilators, beta-blockers, and calcium channel blockers.

Pharmacological Agents

• Vasodilators: These drugs, such as sodium nitroprusside and nitroglycerin, work by relaxing the smooth muscles in blood vessels, leading to vasodilation and reduced blood pressure.
• Beta-blockers: Medications like esmolol and labetalol decrease heart rate and cardiac output, contributing to lower blood pressure.
• Calcium channel blockers: Agents such as nicardipine and verapamil inhibit calcium ion influx in vascular smooth muscle, causing vasodilation.

Indications

Controlled hypotension is indicated in surgeries where minimizing blood loss is critical. It is also used in procedures where a bloodless field is necessary for precision, such as in microsurgery and endoscopic sinus surgery.

Risks and Complications

While controlled hypotension can be beneficial, it carries potential risks, including:

• Hypoperfusion: Excessive lowering of blood pressure can lead to inadequate blood flow to vital organs, resulting in ischemia.
• Organ Dysfunction: Prolonged hypotension may cause dysfunction in organs such as the kidneys and brain.
• Cardiovascular Instability: Patients with pre-existing cardiovascular conditions may experience adverse effects.

Monitoring

Continuous monitoring of the patient's vital signs is crucial during controlled hypotension. Invasive blood pressure monitoring and central venous pressure measurements are often employed to ensure patient safety.

Also see

• Anesthesia
• Blood pressure
• Surgical procedures
• Pharmacology

Resources

Latest articles - Controlled hypotension

• Most recent articles
• Ongoing trials

Source: Data courtesy of the U.S. National Library of Medicine. Since the data might have changed, please query MeSH on Controlled hypotension for any updates.

‎