Delirium

Abbott, T. E. F., et al.  Depth of Anesthesia and Postoperative Delirium. Jama, (2019).
https://pubmed.ncbi.nlm.nih.gov/30721279/

Brown, C. H., et al. Effect of Targeting Mean Arterial Pressure During Cardiopulmonary Bypass by Monitoring Cerebral Autoregulation on Postsurgical Delirium Among Older Patients. (2019)
https://pubmed.ncbi.nlm.nih.gov/31116358/

Brown C, et al. Shaping anesthetic techniques to reduce post-operative delirium (SHARP) study: a protocol for a prospective pragmatic randomized controlled trial to evaluate spinal anesthesia with targeted sedation compared with general anesthesia in older adults undergoing lumbar spine fusion surgery. (2019)
https://bmcanesthesiol.biomedcentral.com/articles/10.1186/s12871-019-0867-7

Evered L, et al. ​​Anaesthetic depth and delirium after major surgery: a randomised clinical trial. (2021)
https://www.sciencedirect.com/science/article/pii/S0007091221004931?via%3Dihub

Evered L, et al. Acute peri-operative neurocognitive disorders: a narrative review. (2022)
https://associationofanaesthetists-publications.onlinelibrary.wiley.com/doi/10.1111/anae.15613

Herman J, et al. Which interventions can reduce post-operative delirium in the elderly? Synthesis of multidisciplinary and pharmacological intervention data. (2022)
https://www.sciencedirect.com/science/article/pii/S0952818020322121?via%3Dihub

Mahanna-Gabrielli, E., et al. (2019). State of the clinical science of perioperative brain health: report from the American Society of Anesthesiologists Brain Health Initiative Summit 2018. British Journal of Anaesthesia, 123(4), 464–478. doi: 10.1016/j.bja.2019.07.004
https://pubmed.ncbi.nlm.nih.gov/31116358/

Partridge, JSL. et al. Measuring the distress related to delirium in older surgical patients and their relatives. (2019)
https://pubmed.ncbi.nlm.nih.gov/30945343/

Patel, V., et al. Effect of regional versus general anaesthesia on postoperative delirium in elderly patients undergoing surgery for hip fracture: a systematic review. (2018).
https://pubmed.ncbi.nlm.nih.gov/30518580/

Pun, B. T., et al. Caring for Critically Ill Patients with the ABCDEF Bundle. (2019)
https://pubmed.ncbi.nlm.nih.gov/30339549/

Ross J, et al. Neurophysiologic predictors of individual risk for post-operative delirium after elective surgery. (2023)
https://agsjournals.onlinelibrary.wiley.com/doi/10.1111/jgs.18072

White, S., et al.  Guidelines for the peri-operative care of people with dementia. Anaesthesia
https://pubmed.ncbi.nlm.nih.gov/30633822/

Wiredu K, et al. Intraoperative plasma proteomic changes in cardiac surgery: In search of biomarkers of post-operative delirium. (2023)
https://onlinelibrary.wiley.com/doi/10.1002/prca.202200066

Wahba N, et al. Genome-wide DNA methylation analysis of post-operative delirium with brain, blood, saliva, and buccal samples from neurosurgery patients. (2022)
https://www.sciencedirect.com/science/article/pii/S0022395622005660?via%3Dihub

We encourage frontline staff to carefully review the detailed steps provided below to gain a deeper understanding of delirium detection and prevention.

 Explain why delirium prevention strategies are important. A member of the healthcare team should elaborate on the need for post-operative delirium strategies and should provide a basic overview of post-operative family engagement strategies. Include the patient’s family and/or support persons (friends and other support) in a patient’s care planning preoperatively and while in the hospital to provide complete care for the patient and provide an opportunity to implement delirium prevention strategies.

Indicate what to watch out for. Family members can serve as an extra pair of eyes and ears and can alert medical staff if something might be wrong. Family members should have an understanding of what to look for that may indicate postoperative delirium, such as restlessness or agitation. In order to adequately welcome patients and family members into the care team, it is not enough to explain “what” patients and family members should look for or “what” is going to happen in their care. The “what” must always be followed with a “why” to aid in genuine understanding.

Additionally, family members should know exactly when to call for help, where to go for help, and with whom they should speak. It is essential that patients and family members understand that they should not be ashamed to ask any of their questions and that many patients in similar situations often have similar questions.

Instead of employing a directive conversation style, an active, engaging conversation should take place, leaving capacity for questions and repeat-back strategies. When patients and family members understand the signs and symptoms that could be indicative of a problem, they are able to serve as an extra set of eyes in order to elevate this concern as early as possible.

For patients identified at risk in the preoperative period, provide education to the patient and support persons on postoperative delirium, potential risks and preventative measures. Informed consent should include risks of postoperative delirium based on pre-operative screening

Describe what can be anticipated. In addition to explaining when to call for help in the case of a potential emergency, healthcare providers should also thoroughly explain the typical treatment that can be expected before, during, and after the operation. Additionally, it is important to discuss potential postoperative delirium complications.

Clinicians should provide a high-level overview of the processes in place at their organization to ensure usage of screening for the risk of developing delirium before the operation. This demonstrates competence of the organization, will likely bolster patient and family comfort, and will provide the patient and family members with information for which to reference if they may be suspicious of a problem post-operation.

By engaging in these conversations before a problem arises, family members can be prepared in the circumstance of necessary treatment and will have an understanding of where to go to find out more information about their loved one’s condition.

Explain what is expected of them during their care. By giving patients and family members a “job” while they are in the hospital, they can be immersed fully in the routine care, can hold other team members accountable, can feel more confident voicing their concerns or opinions, and can serve as an extra set of informed and vigilant eyes to optimize delirium prevention and treatment. This team involvement can also reduce their anxiety by transforming concern into proactive action.

Risk reduction strategies include inviting a carer or family member to be with the patient at risk of delirium throughout as much of the perioperative period as possible. This includes accompanying the patient to the OR holding/preparation area and being present in the post-anaesthesia care unit (recovery room) as they emerge from anaesthesia. The benefits of orientation at these times with a familiar person present may be significant:

1. Describe the organization’s postoperative delirium precaution standards that were
   1. If any of the protocols changed due to this specific patient’s circumstance, articulate that to the patient and family members.
2. Have a discussion with the patient and family around end of life care and advanced
   1. Make an attempt to thoroughly understand the religious or cultural nuances in any of the patient’s or family members’ decisions or questions.
3. Ensure thorough explanation of necessary post-discharge appointments, therapies, medications, and potential complications.
   1. Assess for patient preference in time and location of follow-up appointments, if possible.
4. Provide patients and family members resources, including direct contact phone numbers, to the hospital for post-discharge questions.
   1. Make sure the resources are in their own
5. Provide thorough instructions to the patient and family members in the days leading up to discharge regarding procedures if the patient were to become delirious after operation and recovery after discharge.
   1. If delirium care is required after discharge, set aside time with the patient and family member more than once to ensure their understanding and confidence.

Tools for Screening and Assessment.
Predictive Tools in the General Hospital Surgical Population:

 A number of tools with published performance data have been reviewed (Lindroth et al., 2018). Not all are designed for postoperative risk. Common features included are pre-existing cognitive impairment, age, and general health status. Factors to consider when selecting a tool for routine use in any healthcare environment include use of variables and assessments that are readily available in clinical practice and are feasible to administer without extensive training or interpretation (Lindroth et al., 2018). Examples include:

1. AWOL (Douglas et , 2013; Brown et al., 2017)
   1. The AWOL prediction rule was derived by assigning 1 point to each of 4 items assessed upon admission that were independently associated with the development of delirium:
   2. A: Age ≥ 80 years
   3. W: Unable to spell “World” backward,
   4. O: Disorientation to place
   5. L: Higher illness severity
   6. Higher scores were associated with higher rates of delirium with a score of 2 or higher indicating a 5% or higher risk of delirium (ROC AUC 69 in the validation cohort).
   7. The AWOL-S variant takes surgical complexity into account (Whitelock et , 2020).
2. NSQIP-derived predictive risk in hip fracture patients (Kim et , 2019).
   1. This is a 9-feature, 20 point maximum risk index for delirium following surgery for fractured neck of femur (ROC AUC 77):
   2. preoperative delirium (8 points);
   3. preoperative dementia (3 points);
   4. age (0–3 points);
   5. medical co-management (1 point);
   6. American Society of Anesthesiologists (ASA) physical status III–V (1 point);
   7. functional dependence (1 point);
   8. smoking (1 point);
   9. systemic inflammatory response syndrome/ sepsis/septic shock (1 point);
   10. and preoperative use of mobility aid (1 point);
3. Screening for Cognitive Impairment
   1. Cognitive impairment is a well-validated risk factor for developing postoperative delirium. A number of tools and resources are available. Commonly used tests such as the Mini-Mental State Examination are able to detect possible dementia but are less sensitive to milder forms of cognitive impairment. Simple tests include the Montreal Cognitive Assessment (MoCA) (Ciesielska et al., 2016), MiniCog (Quitoriano et al., 2017), IQCODE-16, and TICS (Cook et al., 2009) which are more sensitive to subtle impairment.
4. Tests for the Presence of Delirium
   1. Opinions vary widely on the most appropriate screening tool for delirium in hospitalized patients, noting that patients may manifest hypoactive or hyperactive psychomotor forms. It should be noted that a screening tool is not diagnostic and needs to be sensitive rather than specific. Any tool should also be easy and quick to administer, have a high inter-rater reliability and ideally need minimal training. A patient who screens positive for delirium should have an escalated care plan including appropriate support and treatment strategies, have the managing medical team notified, and be considered for geriatric, neuropsychiatric or psychological referral.
   2. There are many screening tools available of varying ease of use, and sensitivity and specificity (Scottish Intercollegiate Guidelines Network, 2019). Screening tools aid risk assessment and can guide ‘next steps’ including clinical intervention and support and/or referral. Simple one or two questions tests such as the Single Question to Identify Delirium (SQID) are usually based on orientation to time and place (Hendry et al., 2016) and have only moderate sensitivity and specificity.
   3. When applying tests for delirium, especially in the perioperative/ICU setting, an assessment of the state of alertness of the patient should be part of this and made using a tool such as the Richmond Agitation and Sedation Scale (RASS) (Aldecoa et al., 2017). This is because delirium can present in different psychomotor forms (ie hyperactive versus hypocative (and mixed). Some specific tests for delirium can then be applied and include:
      1. 4AT
         1. The 4AT is a screening instrument designed for rapid (< 2 mins) initial assessment of delirium and cognitive impairment using 4 test domains. A total score of 4 or more (maximum 12) suggests delirium but is not diagnostic. Sensitivity is 86-100%; specificity is 65-82%. Any score >0 suggests possible cognitive impairment (www. the4at.com).
      2. 3D-CAM
         1. The 3D-CAM is a derivative of the Confusion Assessment Method CAM, taking less time (under 5 mins) and requiring less operator training. Sensitivity is 66-100%; specificity is 90-99% (Marcantonio et al., 2014).
      3.  Nu-DESC
         1. The Nursing Delirium Screening Scale (Nu-DESC) is designed to be completed quickly with minimal training using nurse administration. It comprises an observational five-item scale. Sensitivity is 32-96%; specificity is 69-92%.
   4. The gold standard for diagnosis of POD is by an appropriately qualified physician according to the DSM-5 criteria. For suitably trained experts (or research), tools that may be used include the CAM, Comprehensive Geriatric Assessment or DRS-R-98 (Delirium Rating Scale- Revised). For non-experts options include (with appropriate training): 3D-CAM; CAM-ICU (only validated in ICU).

 Prediction of Delirium in ICU

There are several assessment tools that can, with variable precision, predict the development of delirium in ICU patients (including postoperative patients) from various weighted clinical features. All models have been found to have moderate to good predictive abilities. While the features in Pre-DELIRIC (recalibrated) were most accurate, the early predictive model (Table 1, center column although slightly less sensitive had the benefit that it could be applied early in the ICU admission and may allow for timely preventive measures (Green et al., 2019).

Table 1. Variables included in selected predictive models of ICU delirium (Green et al., 2019)

We encourage unit managers to carefully review the detailed steps provided below to gain a deeper understanding of delirium detection and prevention.

 Anesthesia Strategies

1. Type of anesthesia. There is a lack of evidence to support that type of anesthesia (regional versus general) has a substantial impact on the incidence of POD. This is likely due to many factors involved including the presence of multiple risk factors and the use of sedatives to decrease psychological stress for patients. There is no consistent evidence to suggest a difference exists regarding delirium outcomes to guide choice regarding the administration of total intravenous anesthesia (TIVA) versus volatile agents.
2. Depth of anesthesia (dose of anesthetic). Avoiding excessively deep anesthesia by titrating anesthetic agents can be achieved clinically, or supported by processed frontal EEG-based (pEEG) neuromonitoring or age-adjusted minimum alveolar concentration for volatile agents. This has been recommended in a number of guidelines. The use of pEEG guided anesthesia results in lower doses of anesthetic agents being administered and decreased burst-suppression activity on the EEG, and a meta-analysis suggested a benefit in its use in reducing incident delirium. Subsequently, a large randomized controlled trial failed to confirm a benefit in this outcome – noting that the intervention was confined to volatile agents, and burst- suppression still occurred frequently in both groups. Similarly, a study in patients having hip fracture repair did not find a difference in incident delirium in patients undergoing deep or light sedation (with BIS pEEG monitoring in both groups). Possible benefit in POD reduction with the use of intraoperative EEG monitoring awaits clarification by further studies comparing the specific targeting of pEEG and/or burst-suppression levels in appropriately controlled and randomized groups.
3. Cerebral perfusion. Cerebral perfusion monitoring and support has a plausible physiological basis, and hypotension has been associated with increased incidence of. A 2018 best practices statement published by the American Society of Anesthesiologists Brain Health Initiative also suggested that optimizing intraoperative cerebral perfusion may improve outcomes. Limited trial data suggests that avoidance of significant blood pressure excursions (either hyper- or hypo-tension) may be important. Near infrared spectroscopy-based (NIRS) regional cerebral perfusion monitoring may be used to provide an indirect indicator of frontal cortex perfusion. To date there are limited studies of sufficient size or quality to confirm a strong beneficial impact of NIRS on delirium or neurocognitive outcomes either during surgery or in the ICU.
4. Specific Drugs. Dexmedetomidine is a potent alpha-2 adrenoceptor agonist with sedative and analgesic properties. Dexmedetomidine given postoperatively, predominantly in the ICU, has been shown to reduce the incidence of postoperative delirium in cardiac and non-cardiac surgery patients (Duan et al., 2018). It is still uncertain that intraoperative administration on its own is of benefit, and further trials are awaited There is growing evidence that perioperative administration of an alpha-2 agonist (dexmedetomidine) may have efficacy in the prevention and treatment of post-operative delirium in ICU patients. A meta-analysis and a large RCT failed to demonstrate any benefit in delirium reduction in major surgery with the use of single- low dose ketamine.

Technology Plan

Technology is an enabler of good clinical care. In some cases, technology is the only practical means by which some objectives can be achieved (eg EMR medication alerts or audit; online tools). In many cases recommendations for the use of technology are based on ‘best practice’ recommendations, awaiting further evidence (eg pEEG monitoring) and in others, possible applications of technology are listed as they are ‘emerging’ (eg motion tracking or regional cerebral oximetry).

Technology can support

1. EMR – linkages / alerts
2. On-line tools (home assessment / tablet)
3. clinical assessment of cognitive impairment
4. bedside diagnosis of POD
5. risk minimization strategies, including:
   1. Preoperative risk assessment and postoperative diagnosis checklists
   2. Electronic medication management (with warnings)

Appendices
Appendix A

1. Leaders should establish hospital resources including protocols and guidelines for delirium prevention and The following may be appropriate and should be tailored to organizational need, context, and resources:
2. Screening tools administered by suitably trained personnel prior to or on admission and during the postoperative period for cognitive decline and delirium
3. Checklists for risk identification (Predisposing factors)
   1. Conduct discussions with patients and caregivers about the possibility of postoperative delirium, the risks associated with delirium and the importance of its prevention.
4. Checklists for trigger factor minimization (Precipitating Factors)
   1. emphasizing multicomponent / multidisciplinary interventions in high-risk patients [4]; including surgery, geriatrics, anesthesiology, nursing, allied health practitioners and carers/family members
5. Intraoperative and perioperative guidelines which use best practice and evidence-based strategies to minimize the risk of postoperative delirium
6. Assessment tools for ICU and ward use for bedside (point of care) delirium screening; include awareness of hyperactive, hypoactive and mixed presentations
7. Management guidelines for delirium once diagnosed, based on the diagnosis and treatment of contributing factors; including minimization of restraints or antipsychotic medications unless the patient or staff are at risk of harm.
8. Discharge protocols to communicate to patients and caregivers relevant issues relating to perioperative
9. Discharge protocols for primary caregivers and other
10. Referral pathways for psychogeriatric consultation or memory clinics if concerns are identified as appropriate

1. All Phases
   1. Hospital / health system leadership
      1. Support, time, funding
   2. Patient and family and/or carers
2. Prior to Admission
   1. Anesthesia preoperative clinic
      1. Screening for frailty, cognitive dysfunction, nutritional status, etc; delirium prevention education
   2. Surgical clinics
      1. Screening for frailty, cognitive dysfunction, nutritional status, etc; delirium prevention education
   3. Pharmacy review of medications
   4. Social workers, case workers
      1. Discharge planning
   5. Dieticians, Physiotherapy, Occupational Therapy
      1. Preoperative optimization
   6. Geriatricians, palliative care providers
      1. Medical optimization, surgical decision-making and goals of care support
   7. Perioperative
      1. Perioperative nursing
         1. Screening or identification of high-risk patients, keeping sensory aids accessible to patient, patient/family education
      2. Anesthesia providers
         1. Choice of anesthetic technique, use of appropriate monitoring, best-practice intraoperative care
      3. Recovery room nursing
         1. Delirium screening, appropriate medication administration, non-pharmacologic delirium prevention measures, communicating delirium risk to ward or ICU nurse, patient/family education

3. Postoperative
   1. Surgical teams, ICU teams/ Acute Care teams
      1. Ordering of diagnostic / prevention measures, appropriate medication prescribing, appropriate consultation and hand-over
      2. Assess for metabolic disturbances and infection
      3. Ensure adequate hydration
   2. Ward and ICU nursing
      1. Delirium screening, non-pharmacologic delirium prevention/treatment measures, patient/family education
   3. Physiotherapy / Occupational Therapy staff
      1. Early mobilization, discharge planning
   4.  Pharmacists
      1. Medication Review
   5.  Dieticians
      1. Nutrition advice
   6. Case workers/social workers
      1. Discharge planning
   7. Geriatricians, palliative care providers
      1. Medical consultation, assistance with goals of care and symptom management
   8. Caregivers and family members of the patient
      1. Monitor and report changes in mental status, actively support early mobilization and other non- pharmacological prevention measures

 Precipitating Factors for Postoperative Delirium

There are many factors which may precipitate delirium, especially in patients already at risk. Many are preventable, so a delirium care-plan needs to identify and manage as many of these as possible

1. Pain
   1. Poorly controlled pain
   2. Sedating analgesics, especially opioids
2. Disorientation
   1. An unfamiliar environment
   2. Unfamiliar people and little/no family support
   3. Lack of sensory aids, for example, glasses or hearing aids
   4. Loss of sense of time and place
3. Sleep disturbance
4. Sedating drugs
   1. Especially benzodiazepines
   2. Care with tramadol and gabapentinoids
5. Polypharmacy
   1. Especially drugs with anticholinergic side effects
6. Drug withdrawal
   1. g benzodiazepines, opioids, gabapentinoids
7. Dehydration and metabolic disturbances
8. Local Infections and Sepsis
9. Indwelling catheters
   1. especially urinary catheters
10. Physical restraints