Deconstructing delirium in the post anaesthesia care unit.

Area of Science:

• Anesthesiology
• Neuroscience
• Geriatric Medicine

Background:

• Neurocognitive recovery post-anesthesia and surgery is complex and not well understood.
• Identifying pathological recovery patterns in the post-anesthesia care unit (PACU) is crucial for patient outcomes.
• Existing delirium assessment tools may vary in efficacy within the PACU setting.

Purpose of the Study:

• To identify distinct patterns of neurocognitive recovery in key domains assessed for delirium in the PACU.
• To compare these recovery patterns with existing literature to detect abnormal recovery trajectories.
• To evaluate the performance of 3D-CAM, CAM-ICU, and NuDESC for delirium detection in the PACU.

Main Methods:

• Secondary analysis of the Alpha Max study data (200 patients, >60 years, elective surgery >2h).
• Assessment of delirium using 3D-CAM, CAM-ICU, and NuDESC at 30 minutes post-PACU arrival in adequately arousable patients (RASS ≥ -2).
• Comparison of temporal recovery patterns across neurocognitive domains and assessment tools.

Main Results:

• The incidence of PACU delirium was 35% (3D-CAM).
• Attention deficits were most common (72%), even in non-sedated patients.
• Vigilance and disorganized thinking deficits were less common, indicating earlier recovery in these domains.

Conclusions:

• Neurocognitive recovery is a stepwise process; vigilance and disorganized thinking are early indicators of returning function.
• Lingering deficits in vigilance or disorganized thinking may signal abnormal recovery.
• The 3D-CAM demonstrated superior performance in detecting PACU delirium compared to CAM-ICU and NuDESC.