AANA Journal course: Update for nurse anesthetists--Part 4--preoperative cardiac evaluation

This AANA Journal course discusses the American College of Cardiology (ACC) and American Heart Association (AHA) guideline on perioperative cardiovascular evaluation for noncardiac surgery. The intent of the ACC/AHA guideline is to assist clinicians in clinical decision making by describing a range of generally acceptable approaches for the diagnosis, management, and prevention of cardiac diseases. Optimizing the anesthetic management of the cardiac patient undergoing noncardiac surgery is becoming increasingly important: as the percentage of Americans older than 65 years continues to grow, so does the prevalence of cardiac disease in this population. Simply accepting a preoperative cardiology clearance for the cardiac patient undergoing noncardiac surgery provides little information that can be used for risk assessment and management of anesthesia. While national practice patterns vary significantly, there is an important need to standardize cost-effective preoperative cardiac evaluation. By using evidence-based studies, the ACC/AHA guideline delineates methods to objectively categorize cardiovascular risk and use data from the cardiology consultation to refine anesthetic management. Use of the guideline can lead to more efficient evaluation of the noncardiac patient with cardiac disease, which can decrease morbidity, mortality, and cost.

Comparability of the thermodilution cardiac output method: proximal injectate versus proximal infusion lumens

In this study we examined the relationship between cardiac output (CO) measurements obtained from the proximal injectate lumen and the proximal infusion lumen of a thermodilution pulmonary artery catheter. The research was predicated on the belief that a strongly significant relationship would provide the clinician with an alternative lumen for measuring CO. Twenty-one subjects were selected by using a nonprobability convenience sampling method. With ice temperature injectate, four injections were performed into one lumen followed by four injections into the alternate lumen. CO values were computed with installed data management physiologic monitors. A Pearson's Product-Moment Correlation Coefficient was calculated, and the result verified a strong positive correlation between CO values (r = 0.96, p = less than 0.0001). Results of a paired t test demonstrated no statistically significant differences between CO means. These findings lend direction for minimizing the potential risk of catheter contamination associated with the manipulation of intravenous lines containing vasoactive medications. It also may save time for the critical care clinician who is trying to balance tasks such as CO measurements and titration of vasoactive or inotropic medications.