In the mid-1900s, surgeons often hesitated to do even simple operations on people over age 50. Times have changed. Now, more than one third of all operations in the United States are done on people aged 65 or over.

However, age does increase the risk of complications during and after surgery. For example, older people are much more likely than younger people to develop delirium after surgery. They are also more likely to have serious complications from bed rest, which may occur after surgery. These complications include

• Blood clots

• Loss of muscle

• Pneumonia

• Urinary tract infections

The risk of death during or after surgery also increases with age. More than three quarters of deaths in the period immediately after surgery occur in older people. Further, when emergency surgery is done or when surgery involves the chest or abdomen, the risk of death increases in all age groups, but much more so for the older age group.

Although age itself is a risk factor, overall health and the presence of certain disorders increase surgical risk far more than age does. Having had a heart attack within 6 months of a surgical procedure greatly increases risk, as does poorly controlled heart failure. For example, heart failure, undernutrition (which is common among older people who live in institutions), and particularly severe or increasing chest pain (unstable angina) increase the risk of surgery in older people. Lung problems, such as chronic obstructive pulmonary disease, are of some concern when determining the risks of surgery, particularly among smokers. Impaired kidney function, type 1 diabetes, previous strokes or transient ischemic attacks, and problems with mental function, such as dementia, may also increase the risk.

Certain surgical procedures pose more risk than others. For example, surgery involving the abdomen or chest, removal of the prostate, and major surgery on a joint (such as hip replacement) rank high on the list of risky procedures. Many procedures that older people commonly undergo, such as cataract surgery and surgery on small joints, pose lower risk. If an older person is generally well, most operations, including ones considered to be higher risk, can be done safely.

When the risks of surgery are high, they still may be outweighed by the potential benefits. For example, surgery that involves some risk of death, such as repair of a large aortic aneurysm, should be considered if the person is expected to live for another 8 to 10 years because such aneurysms increase the risk of death if they are not repaired. However, such surgery should probably be avoided if other illnesses limit life expectancy to only 1 to 2 years.

When the risks of surgery are low, the low risk may be outweighed by a lack of benefit. For example, some people believe that the risk of even more minor procedures (for example, a skin graft of a pressure sore), which usually is very low, is still much too great to justify putting a person with advanced dementia through such an operation.