Postoperative Cognitive Dysfunction (POCD) is a term that may be unfamiliar, but it describes a fairly common phenomenon. It’s a decline in cognitive function that can last weeks or even months after surgery; while it can occur after any type of surgery, it’s seen most often after cardiac procedures.
We spoke to Vero Beach neurologist Dr. S. James Shafer about POCD. “We all have a reservoir of neurons and brain cells that allow us to manage stressors,” says Dr. Shafer. “There are a lot of stressors associated with surgery – the procedure itself, anesthesia, post-surgery medications, sleep deprivation, caloric insufficiencies.” Dr. Shafer explains that patients who are undergoing a cardiac procedure have some level of cerebral dysfunction to begin with, which lowers this reservoir and can make the patient more susceptible to POCD.
Studies of POCD have described changes in brain functioning, specifically in the areas of memory, attention, learning, language, spatial skills, mathematics, motor function, and “executive function,” which is a set of mental processes used for planning, organizing, and paying attention to details. Anxiety or depression is also commonly reported in those with POCD.
A deficit of executive function may have played a part in then-Secretary of State Alexander Haig’s ill-judged claim that he was in control of the government after President Reagan was shot in 1981. Haig had recently had heart surgery and seemed off his game in other instances as well. He resigned in 1982.
POCD does not occur after every cardiac procedure. One study indicates that after coronary artery bypass (a type of open-heart surgery that improves blood flow to the heart), 33 percent of patients experienced POCD in the first week after surgery, with the percentage dramatically decreasing as the weeks and months go by. Dr. Shafer’s experience is that when POCD occurs after a large or complicated procedure, it usually clears up within 4-6 months.
As POCD does not always occur after cardiac surgery, what are the risk factors?
“It depends on the procedure being performed and on the patient themselves,” explains Dr. Shafer. “If the patient smokes, drinks heavily, has diabetes, hypertension, hardening of the arteries, or is sedentary, the risk is higher.” Some studies have drawn a link between POCD and the use of a pulmonary cardio pump (heart-lung machine) during cardiac surgery.
The biggest single risk factor is the age of the patient, with 60 generally being seen as the age when the risk increases. This is due at least in part to the brain losing plasticity – becoming less able to modify its own structures and function – as people age. Along the same lines, people with a prior history of stroke, even if all function has been recovered, have a higher incidence of POCD.
There is conjecture in both the medical and non-medical communities that anesthesia is responsible for the changes in mental function seen in POCD, but Dr. Shafer says, “Anesthesia has very little to no role. It’s just one more piece of the puzzle to aggravate the brain.” This is consistent with a 2005 study that showed POCD is just as likely to occur after operations in which a local or regional anesthetic was used.
Dr. Shafer advises that for a big procedure of any type, patients should prepare as they would for an athletic event. “Rest, eat well, stay hydrated, cut down on the alcohol, and get some good aerobic exercise.” He adds that it would be ideal if smokers stopped smoking, but they should at least try to smoke less. All of this will help to prepare your body for the trauma of surgery, which has been described as akin to being hit by a truck, only with tidier wounds.
When POCD occurs, it is understandably frightening for patients and caregivers. There should be some comfort in knowing that it is a transient condition that will resolve over time, and there are ways to minimize the risk in advance of a planned surgery. Talk to your primary care physician and your surgeon about your specific circumstances.
Dr. Shafer’s office is located at 1155 35th Lane, #100 in Vero Beach; his office phone is 772 569 7039.
