A multidisciplinary, international group of experts has recommended changing the way clinicians and patients describe cognitive changes experienced in some patients after anaesthesia and surgery.
The recommendations are being published simultaneously in 6 peer-reviewed journals including, Anesthesiology, Acta Anaesthesologica Scandinavica, Anesthesia & Analgesia, British Journal of Anaesthesia, Canadian Journal of Anesthesia, and the Journal of Alzheimer’s Disease.
Changes in cognitive function after anaesthesia and surgery can take many forms and may last for highly variable periods of time — days to years. Up until now, all these complications have been termed postoperative cognitive dysfunction (POCD).
The experts recommend that a new umbrella term, or nomenclature, for impairment or change in cognition associated with anaesthesia and surgery be given: Perioperative Neurocognitive Disorder (PND).
PND is then further classified as delirium, delayed neurocognitive recovery (dNCR), and mild or major neurocognitive disorder (NCD) after surgery, depending on timing, duration, and magnitude. Patient and/or caregiver subjective assessment of the patient’s cognitive function would also be taken into account.
These recommendations are based on accepted nomenclature that already exists in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5).
“The majority of patients have no apparent cognitive issues after surgery, but some patients describe having what they call ‘brain fog,’ which can last for weeks to months, but then generally clears up after that,” said Roderic G. Eckenhoff, MD, University of Pennsylvania, Philadelphia, Pennsylvania. “There has been no term in the DSM-5 to describe this reversible form of cognitive complaint. Delayed neurocognitive recovery is recommended for what is, in fact, the most common form of PND. These changes in nomenclature will allow physician anaesthesiologists and other medical providers to speak the same language when it comes to postoperative cognitive changes in the elderly. It will help clinicians discuss patient risk and prognosis.”
● Cognitive decline diagnosed preoperatively NCD.
● Any form of an acute event that occurs in the hospital up to 1 week post-procedure or until discharge (whichever occurs first), such as postoperative delirium.
● Cognitive decline with symptoms diagnosed up to 30 days after the procedure (delayed dNCR).
● Cognitive decline with symptoms diagnosed between 30 days and 1 year postoperatively (mild or major NCD).
“Physician anaesthesiologists rarely talk with patients about postoperative cognitive complications following anaesthesia and surgery,” said Dr. Eckenhoff. “Yet, this is the most common complication in older patients. We need to talk with patients about this issue, to prepare them for what may occur as well as allay any fears that this may represent a progressive condition. The new nomenclature will, in part, help us do that.”
Although not explicitly designed for researchers, the new nomenclature also will provide a framework for investigators to examine the incidence, risk factors and natural history of PND, he said.