An Update on Postoperative Delirium: Clinical Features, Neuropathogenesis, and Perioperative Management

Abstract

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.

Comparison of general anaesthesia and regional anaesthesia in terms of mortality and complications in elderly patients with hip fracture: a nationwide population-based study

“…Fourth, as previously stated, the definition of delirium in our study has limitations. The initial treatment of delirium involves multidisciplinary non-pharmacological strategies such as reorientation, family presence and interaction, minimising disturbances in the sleep–wake cycle and addressing sensory impairment with hearing aids and eyeglasses, noise reduction and mobilisation 28. Delirium not requiring pharmacological intervention may have missed detection in this study.…”

“…It comprises 23 ICD-10 codes, which represent the difficulty of the diagnosis, and the sensitivity for delirium is only approximately 3% 27. In clinical settings, where screening instruments are not used systematically, diagnosis is missed in approximately 60%–80% of cases 28. It has seldom been evaluated with nationwide claims data because of the lack of accuracy in defining delirium in a wide-incidence range 7.…”

Incidence of and risk factors for postoperative delirium in older adult patients undergoing noncardiac surgery: a prospective study

“…Some studies reported that more than 50% of patients with delirium were undiagnosed by medical teams [11][12][13]. Moreover, it is sometimes difficult to differentiate delirium, especially hypoactive delirium, from the residual effects of anesthesia during the early postoperative period [14]. Delirium has multifactorial causes and complex pathophysiological mechanisms.…”

Towards a Comprehensive Understanding of Anesthetic Mechanisms of Action: A Decade of Discovery

“…Postoperative delirium is an important clinical problem, one associated with significant morbidity, mortality, and cost (personal, societal, and economic) [112]. To date, a clear mechanistic link between anesthetic administration and delirium has not been identified; whether delirium results from a delay in establishing the native connectome, residual drug effect, surgical-induced inflammation/neuroinflammation, or a combination thereof, is an open question requiring further investigation.…”