Spinal anesthesia improves hip, knee replacement outcomes

A HIGHLY underutilized anesthesia technique called neuraxial anesthesia, also known as spinal or epidural anesthesia, improves outcomes in patients undergoing hip or knee replacement, according to a new study by researchers at Hospital for Special Surgery. The study, which appears in the May issue of the journal Anesthesiology, found that neuraxial anesthesia, a type of regional anesthesia, reduced morbidity, mortality, length of hospital stay and costs when compared with general anesthesia.

“The influence that the type of anesthetic can have on perioperative outcomes has been vastly underestimated. Indeed, our study suggests that the type of anesthesia chosen may have important impacts on all kind of medical and economic outcomes in orthopedic surgical patients,” said Stavros Memtsoudis, M.D., Ph.D., director of Critical Care Services at Hospital for Special Surgery, New York City. “It is not something to be taken lightly.” The findings of this comparative effectiveness research could be applied to over one million patients undergoing joint arthroplasty in the United States each year.

Using neuraxial anesthesia over general anesthesia reduced the risk of pulmonary compromise by twofold in knee replacement patients and over threefold in hip replacement patients. “When one considers the modest decrease in risk of adverse outcomes associated with the use of a number of widely used medications such as anti-cholesterol drugs, the effect sizes seen in this study are really impressive,” said Dr. Memtsoudis.

Neuraxial anesthesia involves injecting medication into fatty tissue that surrounds the nerve roots in the spine (known as an epidural) or into the cerebrospinal fluid that surrounds the spinal cord. Currently, the majority of joint replacements in the United States are performed under general anesthesia. Anesthesiologists at the Hospital for Special Surgery, however, use regional anesthesia for over 90% of hip and knee replacements. In the past, several small studies have shown that compared with general anesthesia, regional anesthesia reduces intraoperative blood loss and the need for blood transfusions.

In the new study, researchers at Hospital for Special Surgery conducted a retrospective review of hip and knee replacements performed between 2006 and 2010 in the United States using data collected by Premier Perspective. This administrative database contains discharge information from approximately 400 acute care hospitals located throughout the United States.

Information on the type of anesthesia used was available in 71.4% of 528,495 patients. Eleven percent received neuraxial anesthesia, 14.2% received combined neuraxial and general anesthesia, and 74.8% received general anesthesia. Thirty-day mortality was significantly higher in patients who received general anesthesia, 0.18%, compared with those who received neuraxial, 0.10%, or neuraxial-general, 0.10%.Nike Mercurial Superfly