Invited Commentary <\/p>\n\n\n\n
Surgery<\/p>\n\n\n\n
In adults older than 60 years, surgery is a well-known precipitant of delirium, an acute neuropsychiatric condition characterized by an altered consciousness and fluctuating episodes of confusion and inattention.1<\/a><\/sup> A recent systematic review2<\/a><\/sup> reported a pooled incidence of delirium after cardiac surgery of 24% (95% CI, 21%-27%) among 26\u202f472 patients; in 47 studies, the reported incidence ranged from 4% to 46%. Lander et al3<\/a><\/sup> describe a large, retrospective cohort study reporting the incidence of postoperative delirium among 5\u202f530\u202f054 patients undergoing noncardiac surgery at 3169 hospitals and the association of delirium diagnosis with postoperative morbidity and mortality, including nonhome discharge. Consistent with previous studies, they found that patients who had experienced delirium had significantly increased odds of death and serious complications. In contrast with previous literature, they identified a delirium incidence of only 3.6%, which is much lower than most contemporary estimates.3<\/a><\/sup> Across hospitals, the incidence ranged widely, with a 2.8-fold difference in the odds of delirium across centers.3<\/a><\/sup> While many may assume this variation is due to differences in care across institutions, more likely it reflects the absence of robust and objective means of delirium detection.<\/p>\n\n\n\n There are many potential explanations for this variation, beyond the limitations of evaluating delirium using administrative data, which are well-described.4<\/a><\/sup> As suggested by Lander et al,3<\/a><\/sup> differences in postoperative delirium rates across centers may relate to differences in quality of care. However, while delirium prevention and treatment should be a priority, our understanding of how this can be done remains very limited. Despite the global impact of delirium, its pathophysiology is poorly understood, and treatment options are few. Numerous pharmacological approaches to delirium prevention and treatment have been studied; none have been found to be effective.5<\/a><\/sup> As such, current practice guidelines reflect the consensus that drugs should not be used as a treatment for delirium and do not favor any anesthetic approaches.5<\/a><\/sup> The only effective therapeutic strategy consistently shown to prevent or treat delirium is the use of nonpharmacologic care bundles.5<\/a><\/sup> Given the paucity of evidence-based delirium prevention and management strategies, it is challenging for clinicians to move the needle on this important outcome, making it a poor choice of quality metric.<\/a><\/p>\n\n\n\n Delirium incidence within an institution is likely multifactorial and related to the comorbidity of the patient population, complexity of procedures performed, and other unknown confounders. Delirium researchers believe that patients with an underlying predisposition\u2014a vulnerable brain\u2014develop delirium when exposed to an acute stressor or precipitating factor. Predisposing or nonmodifiable risk factors for delirium include age, preexisting dementia or cognitive impairment, frailty, hearing or visual impairment, and comorbidity. Precipitating factors include acute illness or intervention, such as infection, surgery (especially major surgery), metabolic derangement, and environmental stressors (eg, lack of sleep, lack of daylight, or abnormal noise and surroundings) that are common in the hospital setting. While Lander et al3<\/a><\/sup> adjusted for a large number of potential variables, many risk factors for delirium (ie, frailty) are not easily captured from retrospective databases, and because the underlying pathophysiology of delirium is unknown, residual confounding is likely.<\/a><\/p>\n\n\n\n A plausible explanation for the observed variation in delirium rates across centers is differences in delirium detection. The accepted standard for diagnosis is a neuropsychological assessment, based on the observation of clinical signs and symptoms as defined in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition<\/em> (DSM-5<\/em>) without laboratory or neuroimaging tests. In routine clinical practice, delirium is diagnosed using screening tools, such as the confusion assessment method. However, because such tools rely on subjective bedside assessments, delirium is underdiagnosed, with fewer than one-half of the patients in hospital with delirium accurately diagnosed as having delirium.6<\/a><\/sup> This underdiagnosis likely relates to the challenges faced by frontline health care practitioners in conducting subjective assessments with limited time, skills, and training. The importance of formal diagnosis is reflected by evidence suggesting that nonpharmacologic interventions targeting delirium may delay the onset or progression of dementia.7<\/a><\/sup> Furthermore, in order to study delirium prevention and treatment interventions, it is of the utmost importance to improve delirium diagnosis tools. As such, professional bodies like the National Institute for Health and Care Excellence and the Network for Investigation of Delirium: Unifying Scientists have called for research to develop more robust means of diagnosing delirium in routine clinical care.<\/a><\/p>\n\n\n\n In the postoperative period, delirium can be mistaken for fatigue, depression, or dementia. The development of an objective laboratory test for delirium, similar to the use of troponin for the diagnosis of myocardial infarction, could allow for more accurate delirium diagnosis because test results would be independent of clinicians\u2019 preconceived ideas and time. Beyond more accurate diagnosis, a delirium biomarker would allow for application of proven nonpharmacologic therapies and provide insights into potential causal pathways, such that targeted interventions could be developed. Furthermore, given the association of delirium with adverse neurocognitive and functional outcomes, a delirium biomarker could be used to risk stratify and identify patients at high risk who may benefit from interventions such as closer follow-up, risk factor management, and formal cognitive and dementia screening. Some proteins have shown promise as biomarkers of delirium,8<\/a><\/sup> but these require more extensive investigation and validation. As such, clinicians should acknowledge the uncertainty in evidence, advocate for more accurate means of identifying patients with delirium, and support research addressing this important health care challenge that will likely become more common as our population ages. Scientific advances in delirium are predicated on a future where delirium can be easily and objectively diagnosed. Addressing this knowledge gap is the next step toward optimizing the management of patients with and at risk for postoperative delirium.<\/p>\n","protected":false},"excerpt":{"rendered":" Invited Commentary Surgery Variability in Deliriu […]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[24,23],"tags":[],"_links":{"self":[{"href":"https:\/\/csccm.org.cn\/index.php?rest_route=\/wp\/v2\/posts\/28762"}],"collection":[{"href":"https:\/\/csccm.org.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/csccm.org.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/csccm.org.cn\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/csccm.org.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=28762"}],"version-history":[{"count":1,"href":"https:\/\/csccm.org.cn\/index.php?rest_route=\/wp\/v2\/posts\/28762\/revisions"}],"predecessor-version":[{"id":28763,"href":"https:\/\/csccm.org.cn\/index.php?rest_route=\/wp\/v2\/posts\/28762\/revisions\/28763"}],"wp:attachment":[{"href":"https:\/\/csccm.org.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=28762"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/csccm.org.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=28762"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/csccm.org.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=28762"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}