Tool Boosts Power to Predict Delirium in Adult ICU

A recently developed tool could help doctors stay ahead of the game in preventing delirium in intensive care patients.

Dutch researchers say their delirium prediction model, known as PRE-DELIRIC, was significantly more successful than doctors and nurses at predicting delirium in hospitalized adults.

Preventive measures for delirium can limit its incidence, severity, and duration. While several assessment tools exist for other segments of hospitalized patients, "no evidence-based prediction model for general intensive care patients is available," Mark van den Boogaard, Ph.D., of Radboud University Nijmegen (Netherlands) Medical Centre and his colleagues said (BMJ 2012;344:e420 [doi: 10.1136/bmj.e420]).

General preventive measures in all ICU patients are time consuming, and may expose many patients to unnecessary risks such as adverse events related to drug prophylaxis, the researchers explained.

For PRE-DELIRIC (Prediction of Delirium in ICU Patients), Dr. van den Boogaard and his colleagues defined 10 risk factors that can be easily assessed within 24 hours of admission to the ICU: age, APACHE II (Acute Physiology and Chronic Health Evaluation II) score, admission category, coma, infection, metabolic acidosis, morphine use, sedative use, urea concentration, and urgent admission.

"The use of the PRE-DELERIC model to identify and consequently preventively treat high-risk patients could offer an important contribution to intensive care practice and ensure efficient use of research resources to study only high-risk patients," the researchers said.

Clinically, the model may improve the use of nondrug measures to prevent delirium in high-risk patients, the researchers added. Such measures include improvement of orientation, cognitive stimulation, early mobilization, and listening to music, they said.

In noncritical patients, nondrug preventive measures have been shown to reduce delirium incidence and duration, and haloperidol treatment has lessened severity, duration, and associated length of stay. But for ICU patients, data are hard to come by. PRE-DELIRIC could inform the choice to use prophylactic haloperidol in these patients, the authors said. Existing research (Lancet 2009;373:1874-82) does show that "early mobilisation of mechanically ventilated patients in intensive care, besides other significant effects, resulted in a reduced duration of delirium," Dr. van den Boogaard and his coauthors wrote.

After testing their model for temporal validation, the researchers conducted an external validation study of data from intensive care patients admitted to four Dutch hospitals between Jan. 1 and Sept. 1, 2009. The pooled data included information from 3,056 patients aged 18 years and older, yielding an area under the receiver operating characteristics curve (AUROC) of 0.85. The patients were divided into four risk groups: low, moderate, high, and very high. The sensitivity and specificity were, respectively, 81% and 75% for the group with low-risk group; 62% and 89% for the moderate-risk group; 46% and 95% for the high-risk group; and 30% and 98% for the group with very high risk.

The researchers compared the predictions of patient delirium made by their model to predictions made by doctors and nurses in the hospital, using a convenience sample of 124 patients.

The AUROC for the PRE-DELIRIC model (0.87) was significantly higher than that of the doctors and nurses (0.59).

No significant differences appeared in the predictions of intensive care nurses compared with student intensive care nurses or among intensivists, fellow-intensivists, and residents, the researchers said.

The PRE-DELIRIC model is being used in daily practice in the hospital where the model was developed, the researchers said. "Intensive care patients with a high risk of delirium (at least a 50% PRE-DELIRIC score), and patients with dementia or alcohol misuse, receive preventive measures. The optimal cut-off point of the PRE-DELIRIC model and the most effective delirium preventive interventions for intensive care patients need to be studied in the near future."

The findings were limited by the static nature of the model, which does not account for changes in health status that might affect the odds of developing delirium, the researchers noted.

The researchers reported having no financial conflicts of interest.

A recently developed tool could help doctors stay ahead of the game in preventing delirium in intensive care patients.

Dutch researchers say their delirium prediction model, known as PRE-DELIRIC, was significantly more successful than doctors and nurses at predicting delirium in hospitalized adults.

Preventive measures for delirium can limit its incidence, severity, and duration. While several assessment tools exist for other segments of hospitalized patients, "no evidence-based prediction model for general intensive care patients is available," Mark van den Boogaard, Ph.D., of Radboud University Nijmegen (Netherlands) Medical Centre and his colleagues said (BMJ 2012;344:e420 [doi: 10.1136/bmj.e420]).

General preventive measures in all ICU patients are time consuming, and may expose many patients to unnecessary risks such as adverse events related to drug prophylaxis, the researchers explained.

For PRE-DELIRIC (Prediction of Delirium in ICU Patients), Dr. van den Boogaard and his colleagues defined 10 risk factors that can be easily assessed within 24 hours of admission to the ICU: age, APACHE II (Acute Physiology and Chronic Health Evaluation II) score, admission category, coma, infection, metabolic acidosis, morphine use, sedative use, urea concentration, and urgent admission.

"The use of the PRE-DELERIC model to identify and consequently preventively treat high-risk patients could offer an important contribution to intensive care practice and ensure efficient use of research resources to study only high-risk patients," the researchers said.

Clinically, the model may improve the use of nondrug measures to prevent delirium in high-risk patients, the researchers added. Such measures include improvement of orientation, cognitive stimulation, early mobilization, and listening to music, they said.

In noncritical patients, nondrug preventive measures have been shown to reduce delirium incidence and duration, and haloperidol treatment has lessened severity, duration, and associated length of stay. But for ICU patients, data are hard to come by. PRE-DELIRIC could inform the choice to use prophylactic haloperidol in these patients, the authors said. Existing research (Lancet 2009;373:1874-82) does show that "early mobilisation of mechanically ventilated patients in intensive care, besides other significant effects, resulted in a reduced duration of delirium," Dr. van den Boogaard and his coauthors wrote.

After testing their model for temporal validation, the researchers conducted an external validation study of data from intensive care patients admitted to four Dutch hospitals between Jan. 1 and Sept. 1, 2009. The pooled data included information from 3,056 patients aged 18 years and older, yielding an area under the receiver operating characteristics curve (AUROC) of 0.85. The patients were divided into four risk groups: low, moderate, high, and very high. The sensitivity and specificity were, respectively, 81% and 75% for the group with low-risk group; 62% and 89% for the moderate-risk group; 46% and 95% for the high-risk group; and 30% and 98% for the group with very high risk.

The researchers compared the predictions of patient delirium made by their model to predictions made by doctors and nurses in the hospital, using a convenience sample of 124 patients.

The AUROC for the PRE-DELIRIC model (0.87) was significantly higher than that of the doctors and nurses (0.59).

No significant differences appeared in the predictions of intensive care nurses compared with student intensive care nurses or among intensivists, fellow-intensivists, and residents, the researchers said.

The PRE-DELIRIC model is being used in daily practice in the hospital where the model was developed, the researchers said. "Intensive care patients with a high risk of delirium (at least a 50% PRE-DELIRIC score), and patients with dementia or alcohol misuse, receive preventive measures. The optimal cut-off point of the PRE-DELIRIC model and the most effective delirium preventive interventions for intensive care patients need to be studied in the near future."

The findings were limited by the static nature of the model, which does not account for changes in health status that might affect the odds of developing delirium, the researchers noted.

The researchers reported having no financial conflicts of interest.

A recently developed tool could help doctors stay ahead of the game in preventing delirium in intensive care patients.

Dutch researchers say their delirium prediction model, known as PRE-DELIRIC, was significantly more successful than doctors and nurses at predicting delirium in hospitalized adults.

Preventive measures for delirium can limit its incidence, severity, and duration. While several assessment tools exist for other segments of hospitalized patients, "no evidence-based prediction model for general intensive care patients is available," Mark van den Boogaard, Ph.D., of Radboud University Nijmegen (Netherlands) Medical Centre and his colleagues said (BMJ 2012;344:e420 [doi: 10.1136/bmj.e420]).

General preventive measures in all ICU patients are time consuming, and may expose many patients to unnecessary risks such as adverse events related to drug prophylaxis, the researchers explained.

For PRE-DELIRIC (Prediction of Delirium in ICU Patients), Dr. van den Boogaard and his colleagues defined 10 risk factors that can be easily assessed within 24 hours of admission to the ICU: age, APACHE II (Acute Physiology and Chronic Health Evaluation II) score, admission category, coma, infection, metabolic acidosis, morphine use, sedative use, urea concentration, and urgent admission.

"The use of the PRE-DELERIC model to identify and consequently preventively treat high-risk patients could offer an important contribution to intensive care practice and ensure efficient use of research resources to study only high-risk patients," the researchers said.

Clinically, the model may improve the use of nondrug measures to prevent delirium in high-risk patients, the researchers added. Such measures include improvement of orientation, cognitive stimulation, early mobilization, and listening to music, they said.

In noncritical patients, nondrug preventive measures have been shown to reduce delirium incidence and duration, and haloperidol treatment has lessened severity, duration, and associated length of stay. But for ICU patients, data are hard to come by. PRE-DELIRIC could inform the choice to use prophylactic haloperidol in these patients, the authors said. Existing research (Lancet 2009;373:1874-82) does show that "early mobilisation of mechanically ventilated patients in intensive care, besides other significant effects, resulted in a reduced duration of delirium," Dr. van den Boogaard and his coauthors wrote.

After testing their model for temporal validation, the researchers conducted an external validation study of data from intensive care patients admitted to four Dutch hospitals between Jan. 1 and Sept. 1, 2009. The pooled data included information from 3,056 patients aged 18 years and older, yielding an area under the receiver operating characteristics curve (AUROC) of 0.85. The patients were divided into four risk groups: low, moderate, high, and very high. The sensitivity and specificity were, respectively, 81% and 75% for the group with low-risk group; 62% and 89% for the moderate-risk group; 46% and 95% for the high-risk group; and 30% and 98% for the group with very high risk.

The researchers compared the predictions of patient delirium made by their model to predictions made by doctors and nurses in the hospital, using a convenience sample of 124 patients.

The AUROC for the PRE-DELIRIC model (0.87) was significantly higher than that of the doctors and nurses (0.59).

No significant differences appeared in the predictions of intensive care nurses compared with student intensive care nurses or among intensivists, fellow-intensivists, and residents, the researchers said.

The PRE-DELIRIC model is being used in daily practice in the hospital where the model was developed, the researchers said. "Intensive care patients with a high risk of delirium (at least a 50% PRE-DELIRIC score), and patients with dementia or alcohol misuse, receive preventive measures. The optimal cut-off point of the PRE-DELIRIC model and the most effective delirium preventive interventions for intensive care patients need to be studied in the near future."

The findings were limited by the static nature of the model, which does not account for changes in health status that might affect the odds of developing delirium, the researchers noted.

The researchers reported having no financial conflicts of interest.