Delirium Often Not Identified in Postsurgical Cardiac Patients

Separate studies find a need to pay more attention to delirium

Two clinical nurse specialists at Cleveland Clinic—Jennifer Colwill, DNP, APRN, MSN, CCNS, PCCN, of the Sydell and Arnold Miller Family Heart and Vascular Institute Stepdown Cardiothoracic Surgical Unit, and Myra Cook, DNP, APRN, ACNS-BC, CCRN-CSC, APRN/PA coordinator in the Cardiovascular ICU, Heart and Lung Transplant Stepdown Unit—completed separate reality research projects on recognition of delirium. Both studies revealed that nurses often failed to recognize hypoactive delirium (characterized by lethargy and sedation) in postsurgical patients.

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“It is well-documented that delirium is linked to poor outcomes in critically ill patients,” says Dr. Cook. Adds Dr. Colwill, “In older patients, it is linked to falls, infections and mortality. In postsurgical patients with cardiovascular disease, it is associated with a longer time to recovery and functional and cognitive impairments. The longer patients are delirious, the longer it takes them to get back to baseline, even after discharge.” For these reasons, it is important that delirium be recognized early, well managed, and prevented if possible.

Study methods

Dr. Cook decided to perform her study after noticing that delirium rates in the 76-bed cardiothoracic ICU at Cleveland Clinic were far below those found in similar patient populations. “I was concerned that we were underrecognizing delirium, which it turns out we were,” she says. The prospective study included 210 paired APRN and nurse assessments conducted during routine care in the ICU over three months. Dr. Cook, serving as the APRN, noted 24 instances of delirium in the patient population, particularly hypoactive delirium, compared to 13 instances recorded by nurses on the unit. Dr. Cook and the nurses used an ICU-specific version of the Confusion Assessment Method (CAM) screening tool, and the lack of inter-rater agreement was statistically significant.

Likewise, Dr. Colwill found there was poor inter-rater agreement based on individuals Brief CAM (bCAM) components between APRN-nurse dyads in regard to observation of altered mental status, inattention, altered level of consciousness, and disorganized thinking in her study of 555 bCAM observations. Twenty-four patients were positive for delirium based on her assessment as APRN, yet nurses in the acute care postoperative ward identified only four patients with delirium.

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Research implications for practice and education

Both researchers indicated that it can be difficult to detect hypoactive delirium symptoms in post-surgical patients since behaviors associated with this state are less visible than signs of hyperactive delirium (characterized by agitation and, sometimes, aggressive behavior). In addition, if nurses do not answer the first question on the bCAM tool correctly—which asks if the patient has had fluctuations or alternations in mental status—patients may easily be falsely identified as negative for delirium. “Nurses may only look at the patient’s status from the start of their shift or from the handoff from ICU rather than at baseline assessments (before hospital admission) for comparison,” reports Dr. Colwill. “And if you say no to the first question on the bCAM, then you don’t need to finish the assessment.”

“We need to raise awareness and test strategies that will improve recognition by nurses in everyday clinical practice,” states Dr. Cook. Both researchers believe that multimodal education of nurses would be ideal, involving interactive case studies, simulations and didactic lectures. In addition, they say that implementing standardized processes—such as doing a better job of documenting mental status fluctuations in the electronic medical record—and operational supports are essential to improved recognition.