By: 28 March 2014

Two types of regional anaesthesia do not make patients more prone to falls in the first days after having knee replacement surgery as some have previously suggested, says a new study based on nearly 200,000 patient records.  

Regional forms of anaesthesia, like spinal or epidural (neuraxial) anaesthesia and peripheral nerve blocks (PNB), provide better pain control and faster rehabilitation and fewer complications than general anaesthesia, research shows. But some surgeons avoid using them due to concerns regional anaesthesia 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 anaesthesia not increase the risk of falls, but also spinal or epidural anaesthesia may even decrease the risk compared to general anaesthesia,” said Stavros Memtsoudis, MD, PhD, professor of anaesthesiology and public health and director of critical care services, Hospital for Special Surgery, New York, and lead author of the study, published in Anesthesiology. “This work suggests that fear of in-hospital falls is not a reason to avoid regional anaesthesia for orthopaedic surgery.”

Researchers analysed the types of anaesthesia used in 191,570 knee replacement surgeries in the Premier Perspective database: 76.2 percent of patients had general anaesthesia, 10.9 percent had spinal or epidural anaesthesia, and 12.9 percent had a combination of neuraxial and general anaesthesia. In addition, 12.1 percent of all patients had PNB.

Researchers then analysed the type of anaesthesia used for those who suffered a fall in the hospital. Of patients who had general anaesthesia, 1.62 percent fell, compared to 1.3 percent of those who had neuraxial anaesthesia and 1.5 percent who had general and neuraxial anaesthesia. Patients who also received a PNB 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 anaesthesia and PNB are used far less often than general anaesthesia because of concern that the regional forms – particularly PNB – 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 programmes and are able to reduce the impact of other factors shown to increase fall risk, such as higher narcotic use,” said Dr Memtsoudis.