GENEVA, Jan 21 — Patients who stop smoking at least four weeks before an operation significantly reduce the risk of having postsurgical complications because their blood flow improves, according to a study published yesterday.

The World Health Organisation (WHO) study argued that minor or non-essential operations on regular smokers could be delayed to give them time to quit and thereby improve outcomes such as wound healing and heart function.

The WHO study, conducted in cooperation with the University of Newcastle, Australia and the World Federation of Societies of Anaesthesiologists (WFSA), found that every additional tobacco-free week beyond the four weeks improved health outcomes by 19 per cent.

"The report provides evidence that there are advantages to postponing minor or non-emergency surgery to give patients the opportunity to quit smoking, resulting in a better health outcome,” Dr Vinayak Prasad, head of the No Tobacco unit at WHO, said in a statement.

The study found that nicotine and carbon monoxide, both present in cigarettes, can decrease oxygen levels and greatly increase risk of heart-related complications.

It said the damage on lungs from tobacco smoke also made it difficult for the proper amount of air to flow through, and found that smoking could delay wound healing because of its distorting effect on the patient's immune system.

"Smoking just one cigarette decreases the body's ability to deliver necessary nutrients for healing after surgery,” it said.

WHO said that all countries should build cessation programmes and educational campaigns into their health systems to spread awareness and help people to quit smoking. — AFP-Relaxnews