Patients undergoing cardiac surgery are at increased risk for developing postoperative delirium (POD) in the ICU. POD is a form of cognitive dysfunction that affects attention, environmental awareness, cognition, and perception.

There are three forms of delirium, which is a complex syndrome. Patients with the hyperactive form may experience disturbances in their sleep/wake cycle, become confused and experience delusions or hallucinations, and appear restless and agitated. Those with the hypoactive form may appear restless or withdrawn, lethargic, and less responsive after surgery. Some patients may show signs of both types of delirium, known as mixed motor type.

POD occurs in 15 to 53% of surgical patients over age 65. But the incidence of delirium can be as high as 85% in mechanically ventilated patients, according to a review study in the Journal of the American Heart Association. The study noted that patients undergoing transcatheter aortic valve replacement (TAVR) are also at high risk for delirium, especially patients undergoing nontransfemoral TAVR.

What Did the Study Find?

Delirium is often temporary, but it can be detrimental to recovery, leading to longer hospital stays, increased hospital costs, and an increased mortality risk. Previous studies estimate that healthcare costs attributable to delirium disorders total roughly $152 billion annually nationally. Because it is estimated that between 30 to 40% of delirium cases are preventable, reducing preventable cases could save up to $60 billion per year.

To reduce healthcare costs and optimize patient outcomes, nonpharmacological methods have been shown to reduce delirium in non-ICU settings, such as weaning patients off the ventilator early, reducing sedation, and early mobilization. Could similar methods be employed in the CICU? The study’s authors recommend implementing delirium prevention protocols in the CICU that are becoming increasingly common in other areas of the hospital, such as:

• Screening for delirium with an assessment tool, such as the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU), recommended by the Society of Critical Care Medicine or the 3D-CAM, takes three minutes to implement. Conducting a delirium screening assessment can quickly be done on daily rounds.

• Orient surgical patients to time and place using clocks and calendars and verbal reminders, such as, “Today is Monday. It’s 1:30 in the afternoon. You’re in the hospital for a TAVR procedure.”

• Promoting physiologic sleep by turning the lights off at night, keeping the room quiet by closing doors, dimming hallway lights, decreasing alarm volumes, and giving patients eye masks and earplugs.

• Avoiding delirium-promoting pharmacological agents, such as benzodiazepines, opiates, and diphenhydramine, when possible.

• Provide surgical patients with eyeglasses and hearing aids in the CICU as soon as possible.

• Removing a urinary catheter as soon as possible after surgery.

• Promoting early mobilization with occupational and physical therapy interventions and adopting mobile-friendly devices, such as subclavian intra-aortic balloon pumps and active fixation temporary pacemakers when feasible.

Why Does the Study Matter?

Just as non-cardiac ICUs have developed and championed programs for decreasing delirium, “the CICU needs to develop similar strategies for its unique patients (including those requiring mechanical support and other hardware-related causes of immobility). Specific examples of such strategies would include active fixation temporary pacemakers that can facilitate ambulation and brachial intra-aortic balloon pump placement for patients requiring more prolonged ventricular support,” the authors wrote.

The authors suggest that future research is necessary to tailor delirium prevention to complex cardiac patients in the CICU. For more information on postoperative delirium prevention protocols, visit the Hospital Elder Life Program and the Society for Critical Care Medicine.