Chapter 46. Regional Anesthesia and Cardiovascular Disease
The cardiovascular effects of high thoracic epidural anesthesia (TEA) (T1–T5) include the following except for:
A. An increase in cardiac output
B. Reduction in heart rate and systemic arterial pressure
C. Blunting of the sympathetic response to laryngoscopy
D. Reduction in chest pain in patients with severe coronary artery disease and unstable angina pectoris
A is correct. An increase in cardiac output is not observed with high thoracic epidural anesthesia due to the reduction in chronotropic and inotropic drive to the myocardium.
B is incorrect. A reduction in heart rate and systemic arterial pressure is commonly seen due to reduced sympathetic outflow.
C is incorrect. Licker et al in 1995 reported that patients who received TEA in addition to general anesthesia (GA) had smaller increases in mean arterial pressure and heart rate during laryngoscopy and tracheal intubation than those who received GA only, suggesting that high TEA affords some hemodynamic protection during these maneuvers.
D is incorrect. Blomberg et al in 1989 showed that high TEA relieved chest pain in patients with unstable angina pectoris.
An 85-year-old man with severe long-standing hypertension presents with a hip fracture requiring surgical intervention. Which of the following statements is true regarding anesthesia in this context?
A. Hypertension is not a significant problem as regional anesthesia will prevent the blood pressure rising.
B. Lumbar epidural anesthesia may reduce the risk of coronary ischemia.
C. Severe mitral regurgitation would be an indication for emergency cardiac surgery to be undertaken first.
D. Hypotension is less likely to occur as a result of peripheral vasodilation due to the likely presence of left ventricular hypertrophy and increased force of ventricular contraction.
B is correct. A reduction in ischemic episodes has been demonstrated in elderly patients undergoing surgery for hip fracture who received continuous lumbar epidural analgesia perioperatively.
A is incorrect. Severe long-standing hypertension is associated with a shift in the autoregulatory curve for many vascular beds, resulting in a decrease in end-organ perfusion if blood pressure is allowed to drop too low. Measures to prevent large decreases in blood pressure should be taken, with regard to the patient’s baseline blood pressure.
C is incorrect. Severe mitral regurgitation may be an indication for urgent cardiological assessment and treatment, particularly if it were causing symptoms and signs of heart failure, but would not in itself be an indication for urgent cardiac surgery.