There has been an ongoing conversation regarding anesthetic choice for total hip and total knee arthroplasty. Multiple studies have indicated that regional anesthetic has a protective quality as measured by less blood loss, better neurologic outcome, lower hospital stay, and mortality. The primary criticism of this data has been that the studies have been small.

This month's edition of Anesthesiology carries a study aimed at addressing the question of whether anesthetic choice matters. Memtsoudis and colleagues collected data on over 380,000 patients for total hip and knee arthroplasty. The data was obtained via an administrative database and was spread across approximately 400 hospitals in the United States. Demographic data between regional and general patients were comparable with the exception that those receiving regional were slightly older. Outcomes of importance included lower 30 day mortality, lower rate of prolonged hospitalization, and reduced rate of in-hospital complication, all among patients receiving regional anesthetic.

A couple thoughts stand out when I look at this data. First, it appears that regional vs general is relatively unimportant to any individual patient but is significant when applied to a large group of patients. Let's look at pulmonary embolism to highlight what I'm looking at. PE occured in 0.35% of regional patients, 0.44% of general patients. Any practitioner would be hard pressed to make the case that one route is better than the other for any one patient based on those numbers. However, among a large group of patients the difference becomes important. The odds of a regional patient having a PE are 24% lower than those for a general patient. That translates to a 24% reduction in odds for requiring therapy for PE. From a resource utilization point of view, it becomes obvious which route a payer or facility would prefer. Second, this study highlights the utility of an EMR. The difference in ability to collect and interpret this sort of data electronically vs by paper chart is night and day. More and more of this type of data is appearing in our literature. It is through analyzing this sort of data that I see anesthesia providing a palpable service to the hospital.