How Do Smoking and Alcohol Affect Anesthesia?

One of the questions we ask during an anesthesia assessment is about smoking and alcohol.

Some patients find it hard to understand why, because smoking and alcohol are usually associated with general health rather than with an operation.

From the point of view of anesthesia, however, both can directly affect the safety of surgery, the course of recovery and the risk of complications.

Why does smoking affect anesthesia?

Smoking does not affect only the lungs. It affects the airways, the cardiovascular system, wound healing and the immune system.

During anesthesia it is the respiratory consequences that matter most. In people who smoke:

• The airways can be more reactive
• Mucus production can increase
• The cough reflex can change
• The oxygen-carrying capacity of the lungs can fall

Certain risks during and after anesthesia can therefore be higher.

Are risks after surgery higher in smokers?

Yes. Scientific studies show that smoking increases the frequency of certain complications. For example:

• Lung infections
• Pneumonia
• Breathing difficulties
• Delayed wound healing
• Wound infections

can be more common in people who smoke. This becomes more marked in thoracic surgery, cardiac surgery and major abdominal operations.

Is it worth stopping before surgery?

Absolutely. One of the questions patients ask most often is: "I have smoked for years. What difference will stopping now make?"

In fact the benefits begin sooner than expected. Within the first hours:

• The carbon monoxide level in the blood falls
• Oxygen transport begins to improve
• The circulation is positively affected

Within weeks:

• Lung function can improve
• Mucus production can fall
• Respiratory complications can decrease

How long before surgery should you stop?

There is no single magic period. In general:

• Even stopping a few days beforehand helps
• Stopping a few weeks beforehand helps more
• Stopping for longer reduces the risk further

Whatever time remains before your operation, stopping smoking is usually a positive step.

Are e-cigarettes and shisha safer?

No. These products also affect the respiratory system, and patients who use them should say so during the anesthesia assessment.

What matters for anesthesia is not only cigarettes. All inhaled nicotine and tobacco products should be taken into account.

Does alcohol affect anesthesia?

Yes, and often more than people assume. Alcohol can:

• Affect liver function
• Change drug metabolism
• Affect heart rhythm
• Increase the tendency to bleed

Regular alcohol use therefore matters in anesthesia planning.

Is anesthesia planned differently for regular drinkers?

In some cases, yes. In people with long-term, heavy alcohol use:

• The response to the drugs used can change
• Higher drug requirements can appear
• Withdrawal symptoms can develop

Alcohol use should therefore always be shared honestly. The aim is not to judge, but to plan anesthesia safely.

Can you drink alcohol before surgery?

Generally it is not advised. Heavy drinking in the days before an operation in particular can cause:

• Fluid loss
• Cardiac rhythm disturbances
• Unstable blood sugar

All of which can affect the operation and the anesthesia unfavourably.

Is "I drink socially" enough?

Usually not. What matters for anesthesia is:

• How often you drink
• How much you drink
• Whether use is regular

Giving information as clearly as possible during the assessment is helpful.

What if both are used together?

The risks can compound each other. In particular:

• Respiratory problems
• Cardiovascular problems
• Wound healing problems

can become more pronounced. Both habits should therefore be assessed before surgery.

Do smoking and drinking prevent surgery?

No. On their own they do not mean an operation cannot be performed. But the anesthesia team needs to know.

Safe anesthesia begins with reducing surprises. The more information we have, the more accurately we can plan.

What can you do for a safe operation?

Before surgery:

• Say so if you smoke
• Mention e-cigarettes or shisha
• Share how often you drink
• Do not hide the amount

This information is not used against you. It is used for your safety.