Chance of falling after knee replacement not increased by regional anesthesia

Research suggests spinal and epidural anesthesia, peripheral nerve blocks safe to use

[February 21, 2014]  CHICAGO — A study based on nearly 200,000 patient records suggests that two types of regional anesthesia do not make patients more prone to falls in the first days after having knee replacement surgery as some have previously suggested. The results of the study were published in the March issue of Anesthesiology.

Regional forms of anesthesia — spinal or epidural (neuraxial) anesthesia and peripheral nerve blocks, or PNB — which numb only the area of the body that requires surgery, provide better pain control and lead to faster rehabilitation and fewer complications than general anesthesia, research shows. But some surgeons avoid using them due to concerns that regional anesthesia may cause motor weakness, making patients more likely to fall when they are walking in the first days after knee replacement surgery.

"We found that not only do these types of anesthesia not increase the risk of falls, but also spinal or epidural anesthesia may even decrease the risk compared to general anesthesia," said Stavros G. Memtsoudis, M.D., Ph.D., lead author of the article and professor of anesthesiology and public health and director of critical care services at the Hospital for Special Surgery, New York, N.Y. "This work suggests that fear of in-hospital falls is not a reason to avoid regional anesthesia for orthopedic surgery."

Researchers analyzed the types of anesthesia used in 191,570 knee replacement surgeries in the Premier Perspective database: 76.2 percent of patients had general anesthesia, 10.9 percent had spinal or epidural anesthesia, and 12.9 percent had a combination of neuraxial and general anesthesia. In addition, 12.1 percent of all patients had peripheral nerve blocks. Researchers then analyzed the type of anesthesia used for those who suffered from an inpatient fall, in other words, in the hospital. Of patients who had general anesthesia, 1.62 percent fell, compared with 1.3 percent of those who had neuraxial anesthesia and 1.5 percent who had general and neuraxial anesthesia. Patients who also received a peripheral nerve block had a fall rate of 1.58 percent.

When patients fall during recovery, they are more likely to have worse outcomes, including more heart and lung problems and higher rates of death within 30 days of surgery. Spinal or epidural anesthesia and peripheral nerve blocks are used far less often than general anesthesia because of concern that regional forms of anesthesia, particularly peripheral nerve blocks, may increase muscle weakness and make patients more prone to falls. However, there has never been a large study based on real-world practices to determine if that is true.

"In this study using data from a wide range of hospital settings, we found this concern seems unfounded, especially because hospitals and physicians performing these procedures use fall-prevention programs and are able to reduce the impact of other factors shown to increase fall risk, such as higher narcotic use," said Dr. Memtsoudis.

[Text from file received from the American Society of Anesthesiologists]

The American Society of Anesthesiologists, founded in 1905, is an educational, research and scientific society with more than 52,000 members, organized to raise and maintain the standards of the medical practice of anesthesiology. The society is committed to ensuring physician anesthesiologists evaluate and supervise the medical care of patients before, during and after surgery to provide the highest quality and safest care every patient deserves.

For more information on the field of anesthesiology, visit the American Society of Anesthesiologists online at asahq.org. To learn more about the role physician anesthesiologists play in ensuring patient safety, visit asahq.org/WhenSecondsCount. To join the social conversation, like ASA on Facebook and follow ASALifeline on Twitter.