Drugs: Controlled Hypotension

Controlled hypotension is the process of deliberately reducing a patient’s blood pressure (typically, ~30% reduction of baseline MAP) for a therapeutic purpose. This is accomplished by reduction of either SVR or CO.

Indications:

1. Improve visualization of operative field

2. Reduce hemorrhagic loss and transfusions

3. Decreased amount of cauterized tissue

4. Most frequently used in Neurosurgery, Orthopedics, ENT, and Gynecology

Contraindications:

1. Cerebrovascular disease

2. Cardiovascular disease

3. Aortic Stenosis

4. Renal Dysfunction

5. Pregnancy

6. Severe hypovolemia or anemia

Risks:

1. Reduced end-organ perfusion and tissue oxygenation with tissue damage

2. Resultant acidosis

Techniques:

1. Volatile Anesthetics

2. Direct Vasodilators (Sodium Nitroprusside, Nitroglycerin, Hydralazine)

3. Alpha Blockers (Phentolamine)

4. Beta Blockers (Esmolol, Labetalol)

5. Calcium Channel Blockers (Nicardipine)