Medical Pharmacology Chapter 43:  Adult Cardiac Procedures

Chronic Drug Therapy, Previous Surgical, Diagnostic Procedures

•   Chronic Drug Treatment: major points

  •  Do not discontinue ß-adrenoceptor perioperatively because discontinuation may cause:

    •  Worsening angina (including infarction)  

    •  Hypertension 

  •   ß-adrenoceptor blocking drugs may be useful during anesthesia because these agents :

    1. Reduce the likelihood of tachycardia

    2. Have antiarrhythmic properties

    3. Are antihypertensive

    4. May reduce myocardial ischemia

    • Conclusions: ß-adrenoceptor blocking drugs

      • Except for long-acting agents ( e.g., nadolol (Corgard)), patient's usual morning does may be given orally along with preanesthetic medications {IV doses may be administered intraoperatively as needed to control heart rate/angina}

  • Calcium channel blockers:

    •  Generally chronic administration is continued up to the morning of surgery

  • Antihypertensive drugs:

    • Generally these drugs are continued through the night before or the morning of surgery because:

      1. They promote reduced perioperative hemodynamic stress

      2. Of manageable interactions with anesthetic and cardiovascular drugs

      3. Rebound hypertension may occur if antihypertensive drugs are abruptly discontinued (particular noted with clonidine (Catapres))

      4. With angiotensin converting enzyme inhibitors (ACE inhibitors): continue these drugs until surgery and start them again as soon as possible postoperatively

         • Patients on ACE inhibitors probably have an attenuated blood pressure response to catecholamine infusions (increased doses may be required)