Inhaled Nitric Oxide Versus Intravenous Vasodilators in Severe Pulmonary Hypertension After Cardiac Surgery:

Pulmonary hypertension associated with cardiopulmonary bypass and cardiac surgery

BACKGROUND AND AIM

Pulmonary hypertension (PH) is frequently associated with cardiovascular surgery and is a common complication that has been observed after surgery utilizing cardiopulmonary bypass (CPB). The purpose of this review is to explain the characteristics of PH, the mechanisms of PH induced by cardiac surgery and CPB, treatments for postoperative PH, and future directions in treating PH induced by cardiac surgery and CPB using up-to-date findings.

METHODS

The PubMed database was utilized to find published articles.

RESULTS

There are many mechanisms that contribute to PH after cardiac surgery and CPB which involve pulmonary vasomotor dysfunction, cyclooxygenase, the thromboxane A2 and prostacyclin pathway, the nitric oxide pathway, inflammation, and oxidative stress. Furthermore, there are several effective treatments for postoperative PH within different types of cardiac surgery.

CONCLUSIONS

By possessing a deep understanding of the mechanisms that contribute to PH after cardiac surgery and CPB, researchers can develop treatments for clinicians to use which target the mechanisms of PH and ultimately reduce and/or eliminate postoperative PH. Additionally, learning about the most up-to-date studies regarding treatments can allow clinicians to choose the best treatments for patients who are undergoing cardiac surgery and CPB.

Managing Emergency Hypertension in Aortic Dissection and Aortic Aneurysm Surgery

From a disease that just a few decades ago carried an ominous prognosis, aortic dissection has become a highly treatable condition. Similar development has occurred in regard to the treatment of thoracic aortic aneurysms. Treatment options are medical, surgical, or endovascular. Aortic dissection always presents as a hypertensive emergency and requires parenteral antihypertensive agents to control blood pressure (BP) and prevent target organ damage. Diligent control of BP is of utmost importance in order to stop the progression of dissection with possible aortic branch malperfusion. Treatment for hypertensive emergency begins in the intensive care unit and continues during and after surgery. Improved surgical techniques as well as newer, safer agents that reduce BP to acceptable levels have reduced the risk of mortality and improved prognosis in the postoperative period. Nevertheless, mortality rates remain high, and successful management of aortic dissection and aortic aneurysm still poses a clinical challenge.

Exploring an Optimum Intra/Postoperative Management Strategy for Acute Hypertension in the Cardiac Surgery Patient

An estimated 50% of patients undergoing routine cardiac surgery require intravenous antihypertensive therapy to manage life-threatening arterial bleeding, myocardial ischemia, or cardiac failure in the perioperative period. Managing hypertension in this setting can be challenging because of the need to reduce blood pressure while maintaining adequate end organ perfusion. Hypotensive episodes can increase the risk of cardiac complications and end organ hypoperfusion, particularly in patients whose underlying cardiovascular disease has altered autoregulation of blood flow. To decrease the risk of hypertensive or hypotensive episodes, blood pressure is monitored continuously, and short-acting intravenous antihypertensive agents are administered in an effort to target a mean arterial pressure generally within 20% of the patient's baseline value. Efforts to optimize end organ perfusion and avoid recognized adverse drug effects may influence the choice of antihypertensive agents. The ideal agent for postoperative hypertension should have a rapid onset of action, be highly vascular selective, and be rapidly reversible. In addition, it should be safe, with little risk of overshoot hypotension or adverse drug reaction. Precise management of arterial pressure in the perioperative period has the potential to improve clinical outcome by avoiding hypotensive episodes, ensuring adequate end organ perfusion, decreasing the risk of adverse drug effects, and serving as a bridge to definitive long-term therapy for essential hypertension.