Hypertension in the post-bypass patient

Hypertension in the post-operative cardiothoracic patient

High blood pressure can also be a major problem in this population. This issue was explored in Question 10 from the first paper of 2008.

Why, you ask?

  • Increased bleeding risk - particularly from the aortic cannulation site
  • Extension of an arterial dissection
  • Increased afterload and thus increased LV workload
    • Thus, increased risk of ischaemia
    • Increased risk of cardiac failure due to decompensated LV failure
  • Increased stress on grafted valves or repaired aortic root
  • Worsening of existing mitral regurgitation
  • Increased need for sedation
  • Bleeding from aortic cannulation site

Causes of hypertension in the post-cardiothoracic surgical patient

  • Pain
  • Inadequate sedation in a partially paralysed patient
  • Pre-existing hypertension, and the perioperative cessation or regular medications
  • Artifactual hypertension (measurement error)
  • Unintelligent use of vasopressors
  • The sudden improvement of aortic flow following the repair of a stenotic aortic valve, which exposes the systemic circulation to being bullied by a massively hypertrophied left ventricle.

References

Frederick A. Hensley, Jr., M.D., Donald E. Martin, M.D.,  Glenn P. Gravlee, M.D. A Practical Approach to Cardiac Anaesthesia, 3rd ed. Sibylle A. Ruesch and Jerrold H. Levy. CHAPTER 9. The Postcardiopulmonary Bypass Period: A Systems Approach. 2003 by LIPPINCOTT WILLIAMS & WILKINS

André, Arthur C. St, and Anthony DelRossi. "Hemodynamic management of patients in the first 24 hours after cardiac surgery." Critical care medicine 33.9 (2005): 2082-2093.

Estafanous, Fawzy G., and Robert C. Tarazi. "Systemic arterial hypertension associated with cardiac surgery.The American journal of cardiology 46.4 (1980): 685-694.

Roberts, A. J., et al. "Systemic hypertension associated with coronary artery bypass surgery. Predisposing factors, hemodynamic characteristics, humoral profile, and treatment." The Journal of thoracic and cardiovascular surgery 74.6 (1977): 846-859.