Can quitting smoking before surgery prevent complications?

Photo of patient and nurse after surgery

Quitting smoking one or two months before planned surgery can significantly lower the risk of complications like poor wound healing. Intensive behavioral support (counseling) combined with nicotine replacement therapy can help you quit smoking.

Many people feel nervous before going in for surgery, and quitting smoking is probably the last thing on smokers’ minds – why put yourself through that too? But smokers are much more likely to have complications after surgery, especially poor wound healing.

There are probably several reasons why smoking could affect recovery from surgery: When you breathe in cigarette smoke, your blood absorbs carbon monoxide and nicotine, and the level of oxygen in your blood goes down. But oxygen is very important for the healing of wounds. Also, nicotine makes your heart work harder because it increases your blood pressure and heart rate. Since anesthetics and surgery already affect your circulation and make it harder for your body to get enough oxygen, the associated risks can be higher for people who smoke.

Quitting smoking even right before surgery can increase the amount of oxygen in your body. After 24 hours without smoking, nicotine and carbon monoxide are already gradually broken down in the blood. Your lung function starts improving after about two smoke-free months.

One thing that can make it easier to quit is nicotine replacement therapy (sometimes abbreviated as NRT). It relieves withdrawal symptoms after you stop smoking.

There is less nicotine in nicotine patches or gum than there is in cigarettes and – unlike cigarettes – they don’t increase the level of carbon monoxide in your body.

Four weeks of not smoking can lower the risk of complications

Danish researchers from the – an international research network – looked for studies that tried to find out what happens when people were encouraged to quit smoking before surgery. The researchers found 13 studies in total, involving just over 2,000 people who smoked. Before having surgery, they did things like trying out nicotine replacement therapy, taking part in a cessation (quitting) program, going to special counseling sessions, or reading pamphlets about quitting smoking.

The participants were having different kinds of surgery, including hip or knee replacement surgery, and chest or bowel operations. Only very few of them had heart surgery, and none had lung surgery. But these studies still provided enough information on how smoking affects common complications of surgery, like problems with wound healing.

In two studies, the participants were randomly divided into two groups: One of the groups started weekly counseling sessions and nicotine replacement therapy several weeks before surgery, and the other group didn’t. The first group had fewer wound healing problems:

  • Without counseling and nicotine replacement therapy, about 28 out of 100 people had wound healing problems after surgery.
  • With counseling and nicotine replacement therapy, about 9 out of 100 people had these problems after surgery.

There is no to show whether counseling alone (without nicotine replacement therapy) can decrease this risk of complications. Some of the people who quit smoking before surgery were still not smoking months after the operation, but others started smoking again later.

Thomsen T, Villebro N, Møller AM. Interventions for preoperative smoking cessation. Cochrane Database Syst Rev 2014; (3): CD002294.

IQWiG health information is written with the aim of helping people understand the advantages and disadvantages of the main treatment options and health care services.

Because IQWiG is a German institute, some of the information provided here is specific to the German health care system. The suitability of any of the described options in an individual case can be determined by talking to a doctor. can provide support for talks with doctors and other medical professionals, but cannot replace them. We do not offer individual consultations.

Our information is based on the results of good-quality studies. It is written by a team of health care professionals, scientists and editors, and reviewed by external experts. You can find a detailed description of how our health information is produced and updated in our methods.

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Updated on April 19, 2022

Next planned update: 2025


Institute for Quality and Efficiency in Health Care (IQWiG, Germany)

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