Cognitive Impairment After Bypass Surgery

Cognitive Impairment After Bypass Surgery
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Cognitive impairment after bypass surgery is something patients may experience. The patient may not be able to think clearly. For most patients, any cognitive decline does improve within a few months. The cognitive issues, sometimes referred to as post-perfusion syndrome or “pump head” are thought to be caused by the bypass machine.

After Effects of Bypass Surgery

After a patient has a bypass surgery, there is a 5 to 6 percent chance of a stroke. This is the most feared complication. Vision problems can also occur, but tend to improve. Patients may also experience slow thought processes, short-term memory loss and trouble solving problems or making decisions. The risk of cognitive impairment is higher for older patients.

Why Cognitive Impairment Occurs

Why cognitive impairment after bypass surgery occurs is not fully understood, there are some theories about why it happens. Some believe that trauma during surgery may be a cause. Cross clamping to close the aorta can cause small strokes by breaking off plaque into the bloodstream.

Some patients may have a genetic risk. While one has yet to be identified, researchers are currently searching for one. There are several genetic factors associated with cognitive impairment.

The development of small clots may occur when the patient is being supported by the bypass machine during surgery.

Blood flow changes may occur because the bypass machine pumps blood differently. Elderly patients, and others who are susceptible, may experience cognitive impairment because of this.

Coronary artery disease is the cause of a patient needing bypass surgery. This condition may cause cognitive decline similar to that of bypass surgery.

Protecting the Brain

There are some steps that can be taken to protect the brain during surgery. These include:

  • Using different cross-clamp techniques
  • Keeping the brain temperatures cool
  • Aorta ultrasound
  • Managing blood pressure
  • Controlling blood sugar

Coping with Cognitive Impairment

Cognitive impairment tends to improve without intervention, but there are things patients can do to help them cope with it. Patients should always consult with their physician about it. Any issues with vision, thinking clearly, speech or memory should be evaluated because they can be caused by a number of factors. The surgery may not be the cause.

The patient’s doctor may want to test the patient’s cognitive function to determine the kind he or she is experiencing. The patient may be asked to recall words or odd number series, follow the doctor’s finger or have brain imaging done. In most cases, the testing is noninvasive and not painful. These test will be able to show the doctor how well the patient’s brain is working.

Cardiac rehabilitation will help the patient better adjust to life after bypass surgery. This includes getting information on cognitive impairment, diet, exercise and other areas of life the patient may be struggling with.

Depending on the cause and type of cognitive impairment, medications may be beneficial.


American Heart Association. (2011). Bypass Surgery, Coronary Artery. Retrieved on April 14, 2011 from the American Heart Association:

Mayo Clinic. (2010). Mild Cognitive Impairment. Retrieved on April 14, 2011 from the Mayo Clinic:

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