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Delirium in Hospitalized Patients


General Information

General InformationGeneral Information


  • delirium is defined as reduced ability to direct, focus, sustain, and shift attention, coupled with change in cognition in the form of memory deficit, disorientation, or perceptual disturbances, that cannot be attributed to preexisting neurocognitive disorder or severely reduced level of arousal1,2,3
  • usually caused by interaction of predisposing factors (such as older age, cognitive impairment, and visual or hearing impairment), and precipitating factors (such as surgery, anesthesia, infection, metabolic abnormality, psychoactive drugs, and polypharmacy)1,2,3

Also called

  • acute organic brain syndrome
  • acute confusional state
  • metabolic encephalopathy
  • toxic encephalopathy
  • septic encephalopathy
  • postoperative psychosis
  • intensive care unit psychosis
  • ICU psychosis
  • ICU syndrome


  • subsyndromic delirium - symptoms of delirium, but not meeting diagnostic criteria for delirium3
  • delirium and mental function change in postoperative period
    • postoperative delirium - delirium developing after surgery, with or without lucid intervals, lasting hours or longer; more common in older adults (> 60 years old)
    • emergence delirium - delirium developing on emergence from postoperative anesthesia (without a lucid interval) lasting about 30 minutes; more frequent in younger adults2
    • postoperative cognitive decline (or dysfunction) - subtle cognitive impairment apparent on neuropsychological tests of memory and attention following surgery2
    • Reference - 21775401BMJ 2011 Jul 20;343:d4331OpenInNew
  • semistructured Barthel Index
  • Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5) criteria for classification of delirium include
    • disturbances in both attention and awareness with acute change from baseline that develops over a short time period and typically fluctuates in severity during a 24-hour period
    • additional disturbance in memory deficit, language, disorientation, visuospatial ability, or perception is also present
    • disturbances are not better explained by another neurocognitive disorder and do not occur in the context of severely reduced level of arousal, for example, coma
    • history, physical exam, or laboratory findings suggest the disturbance is a direct consequence of another medical condition, substance intoxication or withdrawal, exposure to toxin, or is due to multiple etiologies
    • Reference - BMC Med 2014 Oct 8;12():141OpenInNewfull-textOpenInNew


  • psychomotor forms of delirium1,2,3
    • hypoactive delirium characterized by decreased responsiveness, apathy, lethargy, withdrawal, and flat affect
    • hyperactive delirium characterized by agitation, restlessness, attempts to remove invasive treatment or monitoring measures
    • mixed delirium characterized by fluctuations between hypoactive and hyperactive delirium


General references used

  1. Inouye SK, Westendorp RG, Saczynski JS. Delirium in elderly people. Lancet. 2014 Mar 8;383(9920):911-22OpenInNew, commentary can be found in Lancet 2014 Jun 14;383(9934):2044OpenInNew
  2. Hall RJ, Meagher DJ, MacLullich AM. Delirium detection and monitoring outside the ICU. Best Pract Res Clin Anaesthesiol. 2012 Sep;26(3):367-83OpenInNew
  3. Mistraletti G, Pelosi P, Mantovani ES, Berardino M, Gregoretti C. Delirium: clinical approach and prevention. Best Pract Res Clin Anaesthesiol. 2012 Sep;26(3):311-26OpenInNew

Recommendation grading systems used

  • American Geriatrics Society (AGS) Beers Criteria grading system for recommendations
    • strength of recommendation
      • Strong - benefits clearly outweigh harms, adverse events, and risks, or harms, adverse events, and risks clearly outweigh benefits
      • Weak - benefits may not outweigh harms, adverse events, and risks
      • Insufficient - evidence inadequate to determine net harms, adverse events, and risks
    • quality of evidence
      • High - evidence includes consistent results from well-designed, well-conducted studies in representative populations that directly assess effects on health outcomes, based on either
        • ≥ 2 consistent, higher-quality randomized controlled trials
        • multiple, consistent observational studies with no significant methodological flaws showing large effects
      • Moderate - evidence sufficient to determine risks of adverse outcomes
        • strength of evidence limited by any of
          • number, quality, size, or consistency of included studies
          • generalizability to routine practice
          • indirect nature of evidence on health outcomes
        • based on any of
          • ≥ 1 higher-quality trial with > 100 participants
          • ≥ 2 higher-quality trials with some inconsistency
          • ≥ 2 consistent, lower-quality trials
          • multiple, consistent observational studies with no significant methodological flaws showing at least moderate effects
      • Low - evidence insufficient to assess harms or risks in health outcomes due to any of
        • limited number or power of studies
        • large and unexplained inconsistency between higher-quality studies
        • important flaws in study design or conduct
        • gaps in chain of evidence
        • lack of information on important health outcomes
    • Reference - AGS 2015 updated Beers Criteria for potentially inappropriate medication use in older adults (26446832J Am Geriatr Soc 2015 Nov;63(11):2227OpenInNew), commentary can be found in 27100608J Am Geriatr Soc 2016 Apr;64(4):920OpenInNew
  • Society of Critical Care Medicine (SCCM) grading system for recommendations
    • levels of evidence
      • Level A - high-quality evidence from a high-quality randomized controlled trial (RCT); confidence in estimate of effect unlikely to change due to further research
      • Level B - moderate-quality evidence from a downgraded RCT (significant limitations) or an upgraded observational study; further research likely to have important impact on confidence in estimate of effect, and estimate may change
      • Level C - low-quality evidence from an observational study; further research very likely to have important impact on confidence in estimate of effect, and estimate likely to change
    • strength of recommendations
      • 1 - strong
      • 2 - weak
    • intervention recommendations
      • + -- for
      • - -- against
      • 0 -- no recommendation
    • SCCM clinical practice guidelines on management of pain, agitation, and delirium in adult patients in intensive care unit (SCCM 2013 Jan PDFPictureAsPdf)

Synthesized Recommendation Grading System for DynaMed

  • DynaMed systematically monitors clinical evidence to continuously provide a synthesis of the most valid relevant evidence to support clinical decision-making (see 7-Step Evidence-Based MethodologyOpenInNew).
  • Guideline recommendations summarized in the body of a DynaMed topic are provided with the recommendation grading system used in the original guideline(s), and allow DynaMed users to quickly see where guidelines agree and where guidelines differ from each other and from the current evidence.
  • In DynaMed (DM), we synthesize the current evidence, current guidelines from leading authorities, and clinical expertise to provide recommendations to support clinical decision-making in the Overview & Recommendations section.
  • We use the Grading of Recommendations Assessment, Development and Evaluation (GRADE)OpenInNew to classify synthesized recommendations as Strong or Weak.
    • Strong recommendations are used when, based on the available evidence, clinicians (without conflicts of interest) consistently have a high degree of confidence that the desirable consequences (health benefits, decreased costs and burdens) outweigh the undesirable consequences (harms, costs, burdens).
    • Weak recommendations are used when, based on the available evidence, clinicians believe that desirable and undesirable consequences are finely balanced, or appreciable uncertainty exists about the magnitude of expected consequences (benefits and harms). Weak recommendations are used when clinicians disagree in judgments of relative benefit and harm, or have limited confidence in their judgments. Weak recommendations are also used when the range of patient values and preferences suggests that informed patients are likely to make different choices.
  • DynaMed (DM) synthesized recommendations (in the Overview & Recommendations section) are determined with a systematic methodology:
    • Recommendations are initially drafted by clinical editors (including ≥ 1 with methodological expertise and ≥ 1 with content domain expertise) aware of the best current evidence for benefits and harms, and the recommendations from guidelines.
    • Recommendations are phrased to match the strength of recommendation. Strong recommendations use "should do" phrasing, or phrasing implying an expectation to perform the recommended action for most patients. Weak recommendations use "consider" or "suggested" phrasing.
    • Recommendations are explicitly labeled as Strong recommendations or Weak recommendations when a qualified group has explicitly deliberated on making such a recommendation. Group deliberation may occur during guideline development. When group deliberation occurs through DynaMed-initiated groups:
      • Clinical questions will be formulated using the PICO (Population, Intervention, Comparison, Outcome) framework for all outcomes of interest specific to the recommendation to be developed.
      • Systematic searches will be conducted for any clinical questions where systematic searches were not already completed through DynaMed content development.
      • Evidence will be summarized for recommendation panel review including for each outcome, the relative importance of the outcome, the estimated effects comparing intervention and comparison, the sample size, and the overall quality rating for the body of evidence.
      • Recommendation panel members will be selected to include at least 3 members that together have sufficient clinical expertise for the subject(s) pertinent to the recommendation, methodological expertise for the evidence being considered, and experience with guideline development.
      • All recommendation panel members must disclose any potential conflicts of interest (professional, intellectual, and financial), and will not be included for the specific panel if a significant conflict exists for the recommendation in question.
      • Panel members will make Strong recommendations if and only if there is consistent agreement in a high confidence in the likelihood that desirable consequences outweigh undesirable consequences across the majority of expected patient values and preferences. Panel members will make Weak recommendations if there is limited confidence (or inconsistent assessment or dissenting opinions) that desirable consequences outweigh undesirable consequences across the majority of expected patient values and preferences. No recommendation will be made if there is insufficient confidence to make a recommendation.
      • All steps in this process (including evidence summaries which were shared with the panel, and identification of panel members) will be transparent and accessible in support of the recommendation.
    • Recommendations are verified by ≥ 1 editor with methodological expertise, not involved in recommendation drafting or development, with explicit confirmation that Strong recommendations are adequately supported.
    • Recommendations are published only after consensus is established with agreement in phrasing and strength of recommendation by all editors.
    • If consensus cannot be reached then the recommendation can be published with a notation of "dissenting commentary" and the dissenting commentary is included in the topic details.
    • If recommendations are questioned during peer review or post publication by a qualified individual, or reevaluation is warranted based on new information detected through systematic literature surveillance, the recommendation is subject to additional internal review.

DynaMed Editorial Process

Special acknowledgements

  • Ashhar S. Ali, DO (Senior Staff, Department of Neurology, Henry Ford Health Systems; Michigan, United States)
  • Dr. Ali declares no relevant financial conflicts of interest.
  • Amir Qaseem, MD, PhD, MHA, FACP (Vice President of Clinical Policy, American College of Physicians; Pennsylvania, United States; President Emeritus, Guidelines International Network (GIN); Germany)
  • Dr. Qaseem declares no relevant financial conflicts of interest.
  • Alexander Rae-Grant, MD, FRCPC, FAAN (Deputy Editor, Neurology DynaMed Plus; Neurologist, Cleveland Clinic; Ohio, United States)
  • Dr. Rae-Grant declares no relevant financial conflicts of interest.
  • The American College of Physicians (Marjorie Lazoff, MD, FACP; ACP Deputy Editor, Clinical Decision Resource) provided review in a collaborative effort to ensure DynaMed provides the most valid and clinically relevant information in internal medicine.
  • Choosing Wisely Canada acknowledges dissemination of their recommendations through DynaMed Plus to reach the point of clinical decision-making.
  • The Canadian Geriatrics Society provides review for the incorporation of Choosing Wisely Canada recommendations.
  • DynaMed topics are written and edited through the collaborative efforts of the above individuals. Deputy Editors, Section Editors, and Topic Editors are active in clinical or academic medical practice. Recommendations Editors are actively involved in development and/or evaluation of guidelines.
  • Editorial Team role definitions
    Topic Editors define the scope and focus of each topic by formulating a set of clinical questions and suggesting important guidelines, clinical trials, and other data to be addressed within each topic. Topic Editors also serve as consultants for the internal DynaMed Editorial Team during the writing and editing process, and review the final topic drafts prior to publication.
    Section Editors have similar responsibilities to Topic Editors but have a broader role that includes the review of multiple topics, oversight of Topic Editors, and systematic surveillance of the medical literature.
    Recommendations Editors provide explicit review of DynaMed Overview and Recommendations sections to ensure that all recommendations are sound, supported, and evidence-based. This process is described in "Synthesized Recommendation Grading."
    Deputy Editors are employees of DynaMed and oversee DynaMed internal publishing groups. Each is responsible for all content published within that group, including supervising topic development at all stages of the writing and editing process, final review of all topics prior to publication, and direction of an internal team.

How to cite

National Library of Medicine, or "Vancouver style" (International Committee of Medical Journal Editors):

  • DynaMed [Internet]. Ipswich (MA): EBSCO Information Services. 1995 - . Record No. T116623, Delirium in Hospitalized Patients; [updated 2018 Nov 30, cited place cited date here]. Available from Registration and login required.
  • KeyboardArrowRight

    Overview and Recommendations

    • Background

    • Evaluation

    • Prevention and Management

  • Related Summaries

  • KeyboardArrowRight

    General Information

    • Description

    • Also called

    • Definitions

    • Types

  • KeyboardArrowRight


    • Who is most affected

    • Incidence/Prevalence

  • KeyboardArrowRight

    Etiology and Pathogenesis

    • Cause

    • Pathogenesis

  • KeyboardArrowRight

    Risk Assessment

    • Risk factors

    • Screening

  • KeyboardArrowRight

    Clinical Assessment

    • Clinical presentation

    • History

    • Physical exam

    • Cognitive testing

    • KeyboardArrowRight

      Tools for diagnosing delirium

      • Tools for diagnosing delirium in hospitalized patients

      • Tools for diagnosing delirium in intensive care or stroke unit patients

      • Tools for diagnosing delirium in emergency department

      • Comparative efficacy

      • Tools for diagnosing delirium in pediatric intensive care patients

    • Laboratory testing and imaging

    • Differential diagnosis

  • KeyboardArrowRight


    • Management overview

    • KeyboardArrowRight


      • Nonpharmacologic prevention strategies

      • Pharmacologic prevention strategies

    • KeyboardArrowRight


      • Nonpharmacologic treatment strategies

      • Pharmacologic treatment strategies

  • Prognosis

  • KeyboardArrowRight

    Quality Improvement

    • Choosing Wisely

    • Choosing Wisely Canada

    • Choosing Wisely Australia

  • KeyboardArrowRight

    Guidelines and Resources

    • KeyboardArrowRight


      • United States guidelines

      • United Kingdom guidelines

      • Canadian guidelines

      • European guidelines

      • Australian and New Zealand guidelines

    • Review articles

    • MEDLINE search

  • Patient Information

  • KeyboardArrowRight

    ICD Codes

    • ICD-10 codes

  • KeyboardArrowRight


    • General references used

    • Recommendation grading systems used

    • Synthesized Recommendation Grading System for DynaMed

    • DynaMed Editorial Process

    • Special acknowledgements

    • How to cite

Topic Editor
Ashhar S. Ali DO

Senior Staff, Department of Neurology, Henry Ford Health Systems; Michigan, United States

Conflicts of Interest

Dr. Ali declares no relevant financial conflicts of interest.

Recommendations Editor
Amir Qaseem MD, PhD, MHA, FACP

Vice President of Clinical Policy, American College of Physicians; Pennsylvania, United States; President Emeritus, Guidelines International Network; Germany

Conflicts of Interest

Dr. Qaseem declares no relevant financial conflicts of interest.

Deputy Editor
Alexander Rae-Grant MD, FRCPC, FAAN

Deputy Editor Neurology, DynaMed Plus; Massachusetts, United States; Neurologist, Cleveland Clinic; Ohio, United States

Conflicts of Interest

Dr. Rae-Grant declares no relevant financial conflicts of interest.

Produced in collaboration with American College of Physicians
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