In my fever I had a long consistent delirium. I dreamt that I was in Hell, and that Hell is a place full of all those happenings that are improbable but not impossible.
(Quote courtesy of the Bertrand Russell Peace Foundation from The Basic Writings of Bertrand Russell, (2009) Routledge.)
Introduction
In Chapter 14, preventive strategies against postoperative cognitive complications were discussed. The major risk factors for postoperative delirium (POD) were listed, from predisposing patient factors (age, chronic diseases, presurgical functional state and comorbidity), to precipitating factors, such as the type of surgery (emergency, cardiovascular and orthopedic), the choice and management of anesthesia (depth, postsurgical pain) and the environment (isolation, sleep–wake cycle alteration). An official definition of delirium was provided (“an acute and fluctuating alteration of mental status, characterized by reduced awareness and disturbance in attention”), together with a synopsis of its clinical presentation. Common symptoms (short-term inability to focus attention, altered perception, hallucinations and reduced cognition) were described. Different clinical forms according to psychomotor features (hyperactive, hypoactive or mixed) and a typical occurrence between days 1 and 7 postoperatively were also discussed.
This chapter provides indications on how to manage and treat postoperatively patients presenting with signs of cognitive alteration and POD, in accordance with the Guidelines on POD prevention and treatment recently issued by the European Society of Anaesthesiology (ESA 2017).
Approach to POD: Promptness, Effectiveness, High-quality Care
POD is associated with longer hospital stay, increased cost and – mostly when not promptly diagnosed and treated – higher likelihood of cognitive and non-cognitive complications, cognitive deterioration, at times requiring institutionalization, and death. As its etiology is multifactorial and no first-choice treatment is available, prevention remains the best treatment and a proactive approach is advisable.
Clear evidence exists that prompt diagnosis and effective treatment are fundamental measures to reduce POD consequences. Together with prompt and effective treatment, high standards of care are needed; in accordance with the British Geriatric Society, these standards include (NICE 2014):
systematic assessment of patients at risk
tailored preventive intervention
limited prescription of antipsychotic drugs
adequate information given to the patient/family
after discharge, communication to the general practitioner that delirium occurred.
A patient at risk for POD should be “labelled” for this and all the team members should be aware. POD diagnosis is the responsibility of all the team members (ESA 2017). Anesthetists are those in the best position for diagnosing POD during awakening from anesthesia; the time at which nurses have their shift rotation is the most appropriate for systematic postoperative checks.
Diagnosis
When to Start Observation
Checking the patient’s cognitive status should start preoperatively, in order to determine the patient’s mental baseline, to which future assessments will be referred and compared. Demented patients, for example, are commonly agitated before entering the hospital, but do not necessarily develop delirium; ignoring the patient’s baseline could lead to a misdiagnosis of POD instead of recognizing the patient’s chronic mental status.
(Preoperative) delirium and cognitive status should be addressed at least once before surgery and, from the day of surgery on, delirium and other cognitive alterations should be monitored at least once every shift, that is more or less once every 8 hours.
What to Check: Diagnostic Tools
The presence of POD is diagnosed by the use of specific scales. Only validated scales (such as CAM or Nu-DESC) should be used. In order to correctly interpret the patient’s mental status immediately after surgery, when anesthetic drugs still have residual effects, the Richmond Agitation Sedation Scale (RASS) should be used preliminarily (Sessler et al. 2002). Following this scale, a score of 0 corresponds to a patient alert and calm. Positive scores, indicating hyperactivity, are:
+1: restless (anxious, apprehensive, but movements are neither aggressive nor vigorous)
+2: agitated (frequent non-purposeful movements, fights ventilator)
+3: very agitated (pulls at or remove tubes, aggressive)
+4: combative (violent, immediate danger for staff and others).
RASS negative scores indicating hypoactivity are:
−1: drowsy (not fully alert, sustained awakening to voice with eye opening and contact >10 seconds)
−2: lightly sedated (the patient briefly awakens to voice, with contact <10 seconds)
−3: moderately sedated (the patient moves or opens the eyes, but without eye contact)
–4: deeply sedated (the patient does not respond to voice, but reacts to physical stimulation)
−5: cannot be roused (no response to voice or physical stimulation).
The RASS score is fundamental in distinguishing between a patient still under the effects of anesthetic and a patient presenting hypoactive POD.
The second step is checking for POD by the use of dedicated scales; the Confusion Assessment Method (CAM) has been widely validated and is the most used. Its shortened version (CAM-ICU) is very easy and quick to use; although specifically developed for use in ICUs and on patients unable to speak, it has also proved its validity in routine situations.
The CAM-ICU algorithm (see Figure 38.1) assesses variations in the patient’s level of consciousness, inattention, altered level of consciousness and disorganized thinking. Diagnosing delirium requires that at least three positive symptoms out of four are found (the first, the second and the third; or, otherwise, the first, the second and the fourth).
How to Manage Patients After Symptoms Manifest
Emergence Delirium
Emergence delirium (ED), also known as emergence agitation and detected by agitation scales such as RASS, can occur in a wide range of postsurgical populations with an incidence of less than 5%. It appears straight after awakening from anesthesia, can last 30 to 45 min and requires prompt management in the recovery room, sometimes on the operating table. Its occurrence in the elderly is infrequent, as older patients often remain sedated and scarcely responsive after general anesthesia, however so far there have been few investigations.
Treatment should first rule out possible underlying causes such as pain, hypoxia, hypercapnia or external stimuli (catheters, tubes), hypothermia, electrolyte imbalance (especially hyponatremia) or administration of anticholinergic drugs. In cases of extreme agitation (and with the awareness that benzodiazepines should be considered inappropriate in POD), small doses of midazolam (1–2 mg intravenously) can help the patient to relax and reduce blood pressure, if elevated. Until symptoms are resolved and have ceased, the patient should stay in the recovery area (where the intensity of care is higher and the nurse:patient ratio is 1:1–3) and only after repeated cognitive evaluation, investigation and treatment be transferred to the ward. If the patient is still agitated, hypoactive or disorientated, transfer to the ICU should be considered.
What to do When POD Manifests on the Ward
As soon as a team member realizes that a patient is developing POD, the first thing to do, mostly in hyperactive forms, is to avoid the patient hurting him/herself or others. The patient should be calmed down with the help of relatives; with combative patients, a sedative drug can help manage the situation for further investigations. The care team should be fully informed and a prompt resolution of POD should be considered a team goal (see Chapter 9).
The family and caregivers should be promptly informed about what delirium is and what to expect. Staff should maintain, and suggest to caregivers, an empathetic, unembarassed approach. In these situations patients need emotional and psychological reassurance from the presence of their loved ones, to stop aggressive escalation.
Non-pharmacological Treatment
Non-pharmacological treatment is the first choice. The patient’s baseline parameters (temperature, pain, mental status) should be monitored and the pharmacological regimen reassessed in terms of number of drugs, number of administrations and dosages. The further need for any invasive presidium, such as bladder or central venous catheters, should be evaluated and any useless presidium eliminated. The patient should be mobilized and allowed to take physical exercise as soon as possible and occupational therapy is helpful. Nutritional status and intestinal function should be checked.
Of particular importance is the issue of sleep routines. Sleep–wake cycles are commonly altered during hospitalization and sleep deprivation is a strong trigger for delirium. Usual methods to help sleep must be encouraged; night-time sleep protocols must be adopted, such as soft lightening, relaxing music and hot beverages. If needed, a sleep hygiene program should be applied by staff and taught to caregivers, including reduction of daytime naps, respect of the natural sleep–wake cycle, patient exposure to natural sunlight as much as possible, physical exercise and reduction of disturbing stimuli. Noise and light should be adjusted to the patient’s needs (Harari et al. 2007, Björkelund et al. 2010, AGS 2015). Should these measures fail, melatonin can be administered (Hanania and Kitain 2002; see below).
Where available, “delirium rooms” – dedicated areas where delirious patients are admitted with the aim of reducing disturbing sensorial inputs and promoting the physiologic night/day rhythm – represent an optimal allocation for delirious patients (Flaherty and Little 2011). These spaces, which offer insulation from noise, create an artificial environment through multisensory equipment (soft lights and music) and are free of physical restraints, have proven to effectively improve recovery from delirium, reduce hospital stay and improve clinical outcome (see Chapter 46).
Patients should be encouraged to personalize their room, in order to give it a sense of familiarity (photos, personal objects, etc.). Patients should be informed about monitor alarms, hospital procedures and timetables. Constant orientation in space and time and about the staff (i.e. they should introduce themselves with their names and inform the patient about the reason for their visit) should be given. A clock and a calendar should be clearly visible by the patient’s bed.
Restraints: A Problematic Issue
In caring for older people, it is sometimes necessary to carry out actions that limit their freedom of movement. Older people with functional disabilities, decreased activities of daily living independence, reduced mobility, cognitive disturbances or behavioral problems have a higher risk of being physically restrained.
Physical restraint is commonly defined as any device, material or equipment attached or adjacent to an individual’s body that he/she cannot easily remove, thus immobilizing or reducing the ability of the individual to move his/her body parts freely and/or to have normal access to his/her own body (Retsas 1998). Examples of physical restraint include vests, straps/belts, limb ties, wheelchair bars and brakes. In addition to physical restraint, chemical restraint (sedatives, antipsychotics and anxiolytics) are also used.
No international shared guidelines on physical restraint are available. Guidelines are generally nation-based and even institution-based, thus generating high variability in how and with which methods patients’ contention is addressed. Recently, a wide European study examined physical restraint practices across European ICUs and provided evidence of the wide range of restraint practice.
Over the last few years, a consensus has been building about the risks associated with contention in older people, the physical consequences of which are bruises, pressure sores, respiratory complications, urinary incontinence and constipation, increased agitation and increased risk of death (Benbenbishty et al. 2010). In many cases, contention only results in increasing discomfort and anxiety, with higher risk of injury and even death. In addition, studies have shown that contention does not prevent treatment interference like self-extubation, removal of venous lines and non-compliance with life-saving treatment.
The use of physical restraint is accompanied by legal and ethical issues (Gastmans and Milisen 2006), dealing with freedom, dignity and autonomy. Communication with the patient and the family on the issue of contention is paramount. If contention measures are judged to be in the patient’s best interest and no other alternative can be applied, staff must ensure that they satisfy all the legal and ethical issues.
Contention methods should be considered only if an older person’s health, integrity, or living and caring environment would be seriously damaged by not using them. However, considering the evidence briefly discussed here, it is questionable whether exposing a patient to potential harmful effects from physical restraint is in his/her best interest.
Pharmacological Treatment
Typical Antipsychotics
Haloperidol is a dopamine-receptor antagonist; it can be administered orally or intramuscularly; although accepted for the treatment of delirium, its intravenous administration is generally considered off-label. The dosage suggested by the ESA Guidelines is 0.25 mg stepwise, titrated to a maximum of 3.5 mg (Pisani et al. 2015). The onset of action is 30–60 minutes after parenteral administration or longer by the oral route. An immediate response is not expected. In order to avoid relapse of agitation, haloperidol should be continued for a couple of days, based on response (Lonergan et al. 2007).
Side effects include prolonged QT interval, extrapyramidal signs and neuroleptic malignant syndrome. Patients receiving antipsychotics for delirium should have their ECG monitored. A Q-T interval >450 ms, or more than 25% over baseline may warrant cardiologist consultation and dose reduction or drug discontinuation (Trzepacz et al. 1999).
Atypical Antipsychotics
This group includes quetiapine, risperidone, ziprasidone, and olanzapine; they have fewer side effects and in small studies showed similar efficacy to haloperidol (Lonergan et al. 2007).
The starting dose of risperidone is 0.25–1 mg/day; if needed, gradual increase should not exceed 2 mg/day. Doses >1 mg daily are associated with higher rates of extrapyramidal symptoms. Periodic dosage adjustments should be considered to reduce or discontinue therapy, as clinically indicated (Rabins et al. 2007). For quetiapine, oral doses are 50 mg twice daily and total daily dosage should not exceed 400 mg (Devlin et al. 2010).
Antipsychotics are identified in the Beers Criteria as potentially inappropriate in older adults with dementia, due to increased risk of mortality, stroke and further cognitive decline. In addition, antipsychotics should be used with caution in the elderly due to their potential to cause or exacerbate the syndrome of inappropriate antidiuretic hormone secretion (SIADH) with severe hyponatremia (AGS 2015).
Dexmedetomidine
Dexmedetomidine is a highly selective, centrally acting α-2-agonist with anxiolytic, sedative and some analgesic effects, and no respiratory depression. Its effect on delirium remains debated. While some studies and meta-analyses report benefits in preventing and reducing delirium (Mo and Zimmermann 2013), others dispute its advantages compared to other sedatives (Ji et al. 2014, Carrasco et al. 2016).
Depending upon whether vasodilation from activation of central α-2a receptors or vasoconstriction from activation of peripheral α-2b receptors predominates, the initial loading dose may result in transient hypotension or hypertension, and should be carefully titrated. The maintenance dose is 0.2–0.7 mcg/kg/hour, with dose increments only every 30 minutes. No guidelines for modifying the dose in elderly patients exist; the right approach might be to start at the lower dose and slowly titrate, based on the patient’s response.
POD usually lasts up to a week; sometimes it can take longer to resolve. With appropriate treatment, acute symptoms disappear within a few days. Constant evaluation of cognitive status with specific diagnostic tools (CAM, CAM-ICU) is suggested until patient discharge. In non-geriatric institutions, there is only limited and inconsistent access to geriatric psychiatry consultation; referral to these specialists may be useful, however no studies are available evaluating their routine involvement in the treatment of postoperative delirium.
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