Delirium is a complex condition that affects up to 80% of critically ill older adults. With varying presentations and multiple causes, this acute disorder requires early nursing care.
“Understanding the pathophysiology of delirium can help nurses identify patients at risk for developing delirium, promote screening, and help implement prevention and treatment strategies,” said Malissa Ann Mulkey, neuroscience clinical nurse specialist, Duke University Hospital, Durham, North Carolina. “Early implementation of nursing strategies has been found to be the most effective delirium treatment.”
On Wednesday, Mulkey and Sonya R. Hardin, dean of the University of Louisville School of Nursing in Kentucky, presented “Surprising Causes of Delirium in Older Adults: What Every Nurse Needs to Know.”
“Delirium is representative of brain failure,” Mulkey said. “As stress on the brain ensues, there are alterations in the neurotransmitters. The greater the stressor, the greater the imbalance. As imbalances occur, they result in changes in electrical activity within the brain. When the overwhelming stress of illness or trauma causes imbalances in neurotransmitters to exceed the brain’s ability to compensate, behavioral symptoms/changes begin to appear.”
During the session, Mulkey and Hardin explained how older age and previous cognitive illness could decrease the brain’s ability to compensate for those imbalances. They also identified potential causes for brain failure, including surgery, illness, medications, alcohol and drug abuse or withdrawal, hypoxemia, acute blood loss, sepsis and trauma.
“The brain’s stress response responsible for delirium includes a dramatic increase in dopamine and a reduction in acetylcholine,” Mulkey said. “These two neurotransmitters are the primary drivers of delirium. Levels of other neurotransmitters such as glutamate, serotonin and GABA determine the type of delirium — hypoactive, hyperactive or mixed.”
They also reviewed nursing interventions that can prevent and treat delirium, such as promoting a day/night schedule in the patient’s room, frequent reorientation, early mobilization, advocating for continuation of home medications, limiting the use of restraints, and minimizing sedative and antipsychotic use.
“Nurses should closely monitor and screen all patients for delirium, not just in the ICU,” Mulkey said. “The longer delirium is present, the harder it is to resolve and the more severe it becomes. Most patients who develop delirium present as quiet and lethargic, and have the highest mortality risk and long-term cognitive deficits.”