Delirium in critical care patients

In Brief

Delirium can impact up to 80% of CCU patients and increases their length of stay and cost of hospitalization. Often, delirium may be misdiagnosed as dementia, depression, or other psychiatric disorders.

Figure

Mrs. J, 78, is admitted to the hospital with heart failure and right hip fracture. She has a history of hypertension and osteoporosis and is started on furosemide and enalapril to treat her heart failure. On day 2 of her admission, Mrs. J's respiratory status and heart failure have improved, and she is taken to the OR for repair of her fractured right hip. She returns to the critical care unit (CCU) postoperatively and is prescribed patient-controlled analgesia (PCA) morphine for surgical site pain. Mrs. J remains on supplemental oxygen at 2 L/minute by nasal cannula and her cardiac medications are continued. Her indwelling urinary catheter is draining an adequate amount of clear yellow urine.

On day 3 of her admission, Mrs. J becomes confused, pulling at her I.V. and urinary catheters. The nurse reorients her but Mrs. J forgets the instructions. Mrs. J has very brief periods of sleep during the night and fluctuates between periods of confusion and sleep during the day. Her husband is very concerned and angry about his wife's condition.

Defining delirium

Delirium is an acute state of confusion characterized by rapid onset, usually hours to days, with alterations in consciousness and change in cognition.^1,2 Delirium also can be manifested as a form of agitation in the critical care patient.³ Delirium can impact up to 80% of CCU patients and increases their length of stay and cost of hospitalization.⁴ Often, delirium may be misdiagnosed as dementia, depression, or other psychiatric disorders. Delirium is not a psychiatric disorder but a serious medical disorder that must be addressed promptly to insure patient safety and optimal patient outcomes. The nurse must be able to recognize the differences among delirium, depression, and dementia while caring for these patients.

While delirium is characterized by rapid-onset confusion, depression, as a mood state, can be normal or a symptom of a psychopathologic syndrome or a general medical disorder. Depression is indicated by feelings of sadness, despair, anxiety, emptiness, discouragement, or hopelessness; apathy; or appearing tearful.⁵

Unlike delirium, dementia has an insidious onset and a slowly progressive course that can take months to years to manifest. The patient with dementia may have disturbed sleep patterns, memory problems, and variable mood disturbances.² Depression and dementia are both classified as psychiatric disorders² while delirium is an acute confusional state typically caused by a medical problem that requires immediate interventions.⁵ (See Five features that characterize delirium.)

Assessment

One of the first steps in caring for the adult with delirium is to identify the underlying cause. Delirium may be caused by a variety of factors including infections, fever, metabolic disorders, prescription and nonprescription medications, recent surgery, mechanical ventilation, acute vascular changes, and respiratory disorders.² Patients may be agitated, restless, verbally abusive, and striking out at nonexistent objects. Clinical manifestations may include tachycardia, diaphoresis, a flushed face, dilated pupils, and hypertension that may mimic other medical problems. These patients are often at risk for injury to self or others.² However, not all patients with delirium act agitated or restless. Some may appear lethargic or depressed with cognitive problems such as hallucinations or disorganized thoughts.²

To perform accurate patient assessments, utilize valid evidence-based tools such as the Confusion Assessment Method for the ICU (CAM-ICU; available online at www.icudelirium.org/docs/CAM_ICU_training.pdf) or Intensive Care Delirium Screening Checklist (ICDSC; available online at www.icudelirium.org/docs/2013-Tufts-ICU-Delirium-Screening-Checklist.pdf). The CAM-ICU is a reliable, valid, easy-to-use tool. It addresses four categories:

• acute onset or fluctuating change in mental status
• inattention
• disorganized thinking
• altered level of consciousness.⁷

The CAM-ICU can be easily implemented in a short amount of time. However, the CAM-ICU may be difficult to use for nonverbal patients or endotracheally intubated patients. While the CAM-ICU provides reliable assessment data for early detection of delirium, its feasibility as a tool to monitor the fluctuating features of delirium is unknown.^1,3 The CAM-ICU tool remains one of the most widely studied and validated screening tools in detecting delirium.¹

Another tool for assessing delirium is the ICDSC. The ICDSC is an easy-to-use, eight-item checklist. The checklist consists of the following eight categories:

• altered level of consciousness
• inattention
• disorientation
• hallucinations, delusion, or psychosis
• psychomotor agitation or retardation
• inappropriate speech or mood
• sleep/wake cycle disturbances
• symptom fluctuation.⁸

The ICDSC is implemented once during every 24-hour period, tracking the patient's signs and symptoms. Data pertaining to the ICDSC tool can be collected during routine nursing care. Each item is scored as absent or present (0 or 1) and the total is calculated. Scores range from zero to eight. A patient with scores of 4 or greater is classified as having delirium.⁹

Interventions

After assessing the patient for delirium, provide effective care aimed at treating the underlying etiology and maintaining patient safety. The nursing care strategies involve risk factor reduction, patient safety, and medication management. Addressing all these care strategies may shorten the patient's hospital stay and optimize patient outcomes.

Risk factor reduction: No single cause of delirium exists, and it may result from a variety of factors such as cognitive impairment, advanced age, severe illness such as respiratory or cardiac disorders, polypharmacy, electrolyte imbalances, urinary catheterization, and substance abuse.^10–12 Although not all of these factors are modifiable, interventions can modify some of these risks. Common interventions include obtaining a comprehensive health history, frequent monitoring, including vital signs and lab data, and family involvement in the patient's care. Implementing these interventions may reduce the incidence of delirium. (See Reducing risk factors for delirium.)

Maintain a safe environment: Environmental factors such as isolation, hospital admission, or sensory deprivation contribute to delirium.¹ Some strategies to minimize these effects include noise reduction and appropriate lighting, provision of radio, television, and family photographs to help patients rest and assist in reorienting patients to the new environment. Be welcoming and encouraging of close family members' involvement in the patient's care. Nurses and family members can support the patient with memory cues and reorientation. Support from family members and nursing staff may decrease patient anxiety and fear.

Educate unlicensed assistive personnel (UAP) about delirium prevention and management.⁹ Education strategies should focus on causes, signs and symptoms, and interventions. UAP play an important role in the patient's safety by providing assistance with activities of daily living, sitting with the patient, and implementing fall precautions. Through collaboration with family and support staff, the patient can experience a safe environment and possible improved outcomes.

Medication management: Available evidence does not support the use of medications to prevent delirium in acute care settings.⁶ Drug therapy is reserved for patients who are at risk for harm to themselves or others, for example by pulling out essential medical tubes or catheters. Pharmacotherapy for delirium is an understudied area, with little data available comparing different drugs.¹³ During the search for an underlying medical disorder, symptomatic treatment for delirium may include the use of antipsychotic drugs to control agitation and hallucinations, and to improve cognition, such as improved attention and orientation. Although no medication has been FDA approved for the treatment of delirium, there is a general consensus that select drugs can be administered when nonpharmacologic interventions have failed.¹⁴

The existing treatment guidelines recommend haloperidol as the medication of choice.¹⁵ Advantages of haloperidol include various routes of administration (including the I.V. route for rapid action) and its favorable adverse reaction profile compared with other antipsychotic drugs commonly used. While haloperidol has been studied most often in the symptomatic management of delirium, newer, atypical antipsychotics such as risperidone, olanzapine, and quetiapine are also being studied. The newer atypical antipsychotic agents have less extrapyramidal adverse reactions than the older typical antipsychotic medications, such as chlorpromazine.¹⁵

Adverse reactions of antipsychotics may include:

• extrapyramidal effects such as akathisia (motor restlessness and muscular tension especially in the lower extremities) and dystonia (prolonged involuntary muscle contractions). Antipsychotics may prolong the QT interval.¹³
• neuroleptic malignant syndrome (NMS), a rare but potentially fatal neurologic emergency, is also more common with typical antipsychotics. NMS is characterized by a clinical syndrome of mental status change, rigidity, fever, and dysautonomia, including tachycardia and hypo- or hypertension.¹³
• other adverse reactions during short-term treatment with antipsychotics include sedation, orthostatic hypotension, seizures, weight gain, and disturbed glucose and lipid metabolism. Sedation may, at times, be a desired effect but it can also prolong delirium and increase fall risk.¹³

Short-acting benzodiazepines such as lorazepam and midazolam have been used to manage delirium associated with alcohol and sedative withdrawal. However, a Cochrane Review completed in 2009 concluded that while benzodiazepines are effective in delirium management for the patient experiencing alcohol withdrawal, no adequately controlled trials could be found to support the use of benzodiazepines in the treatment of delirium. The Review also stated that benzodiazepines are risk factors for delirium. Based on the lack of research, this Review recommended that benzodiazepines not be used until further studies are completed.¹⁶

Update on Mrs. J

Using the CAM-ICU tool, the nurse identifies signs of delirium exhibited by Mrs. J. The nurse notifies the HCP of her findings and reviews Mrs. J's plan of care, noting that she is receiving a continuous basal dose of morphine by PCA infusion. The HCP states that the morphine may be responsible for Mrs. J's signs of delirium. The nurse informs the HCP that Mrs. J is not activating the PCA button. The HCP discontinues the PCA and prescribes an around-the-clock nonsteroidal anti-inflammatory drug (NSAID) to treat Mrs. J's postoperative pain.

The nurse uses the dry-erase board in the patient's room to document the date, time, place, and staff caring for Mrs. J. Because Mrs. J has fluctuating periods of sleep and of confusion, the nurse reduces the environmental stimuli by turning down the lights and turning off the television while Mrs. J is sleeping. The nurse informs the staff that Mrs. J is experiencing delirium and directs them to introduce themselves every time they enter her room. All staff should participate in reorienting Mrs. J with each patient contact. The nurse also assures that Mrs. J wears her glasses when she is awake.

As safety is a priority concern for the patient experiencing delirium, the nurse performs medication reconciliation to determine that there are no drug interactions or adverse reactions. The nurse also obtains an order to remove the indwelling urinary catheter as Mrs. J no longer meets the criteria for the catheter (she is now postop day 3). She continues taking around-the-clock NSAIDs for pain managmeent. Mrs. J becomes less restless and and her husband states that she “seems comfortable.” The nurse keeps the bed locked in a low position with the bed alarm on, and the call bell in reach. Nursing staff performs hourly rounds to monitor for pain, toileting needs, and position changes. The nurse teaches Mr. J about delirium and he is encouraged to remain at his wife's bedside and speak to her in a low soothing voice.

When Mrs. J's post-op pain management is optimized, the nurse notes that her mental status improves. Mr. J continues to spend time at his wife's bedside providing support. The nurse continues this plan of care for the remainder of the Mrs. J's hospitalization.

Keeping patients safe

Because delirium has a fluctuating course, it is imperative that the nurse recognizes its signs and symptoms. By utilizing the appropriate assessment tools such as CAM-ICU or ICDSC, the nurse can identify patients at risk for developing delirium and implement appropriate interventions to prevent and manage it. Interventions include maintaining patient safety, effective communication, family involvement, and medication management. Utilizing all of these strategies, the nurse can achieve successful optimal outcomes for these patients.

Five features that characterize delirium⁶

The American Psychiatric Association's Diagnostic and Statistical Manual, 5th edition (DSM-V), lists five key features that characterize delirium:

1. A disturbance in attention (reduced ability to direct, focus, sustain, and shift attention) and awareness.
2. This disturbance develops over a short period of time, usually hours to days, and represents a change from baseline. It also tends to fluctuate during the day.
3. An additional disturbance in cognition, such as memory deficit, disorientation, language, visuospatial ability, or perception.
4. These disturbances are not better explained by another preexisting, evolving, or established neurocognitive disorder; they do not occur in the context of a severely reduced level of arousal, such as coma.
5. Evidence from the history, physical examination, or lab findings shows that the disturbance is caused by a medical condition, substance intoxication or withdrawal, or medication adverse reaction.

Reducing risk factors for delirium⁶

The following interventions can help mitigate risk factors for patients with delirium.

• Orientation protocols. Providing patients with clocks, calendars, and windows with outside views, as well as verbally reorienting patients, may decrease confusion that often results from disorientation in unfamiliar environments.
• Cognitive stimulation. Patients with cognitive impairment may benefit from regular visits from family and friends, but sensory overstimulation should be avoided, especially in the evening.
• Facilitation of physiologic sleep. Avoiding nursing and medical procedures, including medication administration, during sleeping hours can help, as can reducing night-time noises via the use of earplugs.
• Early mobilization and reduced use of physical restraints for patients with limited mobility. A study in mechanically ventilated, critically ill patients found that early institution of physical and occupational therapy along with consequent interruption in the use of sedatives resulted in a lower rate of hospital days with delirium.
• Visual and hearing aids for patients with sensory impairments. Ensure that sensory aids, such as hearing aids and eyeglasses, are used and working properly.
• Avoiding and/or monitoring the use of certain medications. These include benzodiazepines, which should be avoided in high-risk patients; use caution when prescribing opioids, dihydropyridines, and antihistamines.
• Avoiding and treating medical complications. Medical conditions that are known to cause or aggravate delirium should be managed aggressively and prevented where possible. Hypoxemia and infections are common complications in high-risk settings, and may contribute to delirium; actively monitor for these complications and treat appropriately when identified.
• Managing pain. Pain may be a significant risk factor for delirium, and nonopioid medications should be used where possible because they are less likely to aggravate delirium.