treating post-surgery pain before it starts - news

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Methods using preventive analgesia to treat pain after surgery before it

develops

Tuesday, 17-Aug-2004 News-Medical.Net

York University Professor Katz is studying methods of preventing or

significantly reducing pain after surgery by employing preemptive or

preventive analgesia to treat pain before it develops.

“Basically, we are trying to block surgically-induced noxious signals

that can cause a state of central nervous system hypersensitivity in the

spinal cord,” says Katz, “We do this by administering analgesic drugs

via the epidural route before surgery.” He distinguishes between

preemptive analgesia that involves pre-operative treatment only and

preventive analgesia which is a broader concept.

“Chronic post-surgical pain is a tremendous problem,” says Katz, York’s

Canada Research Chair in Health Psychology, “Many patients experience

pain long after they are supposed to have healed.”

Katz says studies show that injuries, including surgical procedures, can

cause a state of central nervous system hypersensitivity that leads to a

heightened experience of pain and even pain arising from a stimulus that

normally is not painful.

“A common example of pain in response to a normally non-painful stimulus

occurs after sunburn,” says Katz, “where a gentle pat on the shoulder or

a warm shower can provoke a powerful pain response.” Katz adds that the

phenomenon of central nervous system hypersensitivity has only

relatively recently been shown to contribute to post-operative pain.

Currently, Katz notes, about one quarter of patients who are seen at

specialty pain clinics are referred because of chronic post-surgical

pain problems. He says that 80 per cent of amputees experience chronic

‘phantom limb’ pain years after amputation, while 30 per cent to 50 per

cent of chest surgery patients report chronic post-surgical pain more

than one year after the operation. Even a relatively minor procedure

such as a hernia repair has a significant incidence of chronic

post-surgical pain. Almost 30 per cent per cent of hernia patients

report pain one year after surgery, although this number drops to nine

per cent after five years.

Recent studies by Katz and his colleagues at the University Health

Network in Toronto have demonstrated that patients who have preemptive

or preventive pain control show significantly less intense post-surgical

pain. In one study pain disability was reduced three weeks after

surgery. “The beneficial effect is no longer apparent after six months,”

says Katz, “but this approach leads to less pain in the days immediately

after surgery which may help patients recover more quickly when they

leave the hospital and return home.” He hopes this research will

ultimately provide major benefits both for patients and the entire

healthcare community.

http://www.yorku.ca