Electroencephalography and delirium in the postoperative period

Neuromonitoring in the ambulatory anesthesia setting: a pro-con discussion

PURPOSE OF REVIEW

Various neurologically focused monitoring modalities such as processed electroencephalography (pEEG), tissue/brain oxygenation monitors (SbO2), and even somatosensory evoked responses have been suggested as having the potential to improve the well tolerated and effective delivery of care in the setting of outpatient surgery. The present article will discuss the pros and cons of such monitors in this environment.

RECENT FINDINGS

There is a paucity of evidence from rigorous, well designed clinical trials demonstrating that the routine use of any neuromonitoring technique in an ambulatory surgery setting leads to meaningful cost savings or a reduction in morbidity or mortality.

SUMMARY

The use of advanced neuromonitoring techniques (primarily pEEG) may be considered reasonable in two instances: for the prevention of intraoperative awareness during the administration of total intravenous anesthesia coupled with the use of a neuromuscular blocking drug, and for the prevention of relative drug overdose (and possibly postoperative delirium) in the elderly.

An update on postoperative delirium: Clinical features, neuropathogenesis, and perioperative management

PURPOSE OF REVIEW

We present a focused review on postoperative delirium for anesthesiologists, encompassing clinical features, neuropathogenesis, and clinical identification and management strategies based on risk factors and current delirium treatments.

RECENT FINDINGS

The literature on postoperative delirium is dominated by non-experimental studies. We review delirium phenotypes, diagnostic criteria, and present standard nomenclature based on current literature. Disruption of cortical integration of complex information (CICI) may provide a framework to understand the neuropathogenesis of postoperative delirium, as well as risk factors and clinical modifiers in the perioperative period. We further divide risk factors into patient factors, surgical factors, and medical/pharmacological factors, and present specific considerations for each in the preoperative, intraoperative, and postoperative periods.

SUMMARY

Postoperative delirium is prevalent, poorly understood, and often missed with current screening techniques. Proper identification of risk factors is useful for perioperative interventions and can help tailor patient-specific management strategies.