Sedation and Delirium Management - An Overview

Introduction

Patients in the intensive care unit are treated with sedatives to reduce pain, anxiety, and agitation and to promote comfort and amnesia. Oversedation can increase the duration of ICU stays and mechanical ventilation, and it is associated with an increased risk of delirium and mortality. However, delirium is a reversible condition, and it is managed by following suitable sedation protocols and guidelines during an ICU stay.

What Is Sedation?

Sedation, also known as conscious sedation or twilight sedation, is used for less complex and minor surgeries to help the patients relax and not feel pain during surgical procedures. It is provided through an intravenous route to maintain comfort and reduce the patient's anxiety. The three levels of sedation are minimal, moderate, and deep sedation. Deep sedation is associated with an increased risk of delirium and prolonged mechanical ventilation, and hospital stays.

What Is Delirium?

Delirium results in impaired mental abilities. The delirium shows symptoms within a few hours or a few days. The types of delirium are hyperactive, hypoactive, and mixed delirium.

• Reduced Awareness of Surroundings - Easily distracted, little or no response to surroundings, and difficulty focusing.

• Poor Thinking Skills - Reading, writing, or understanding difficulties, poor memory.

• Behavior and Emotional Changes - Anxiety, depression, anger, lack of interest, frequent mood changes, personality changes, altered sleep patterns, and being quiet and sluggish.

What Are the Causes and Risk Factors of Delirium?

The common causes of delirium in critically ill or hospitalized patients include the following:

• Medication or alcohol withdrawal.

• Adverse drug effects or drug interactions.

• Drug toxicity.

• Infections.

• Pain or discomfort.

• Urinary or bowel retention.

• Electrolyte disturbances in the body (altered sugar, sodium, and calcium levels).

• Disturbed sleep-wake cycle.

• Dehydration.

• Immobility.

• Organ failure.

The risk factors associated with delirium include the following:

• Advanced age.

• Associated comorbidities.

• Cognitive impairment.

• Increased severity of illness.

• Alcohol or drug abuse.

• Sleep disturbances.

• Sepsis.

• Mechanical ventilation.

• Drugs such as steroids, benzodiazepines, anticholinergics, opioids, and sedatives.

• Surgeries.

What Is the Link Between Sedation and Delirium?

Deep sedation is essential for patients under mechanical ventilation in critical care. Increased sedation increases delirium risk and reduces restorative sleep and mobility. In addition, delirium is linked to certain medications and sedation practices in the intensive care unit. For example, benzodiazepine (the most common sedative medication) leads to the development of delirium. Lorazepam causes delirium in critically ill and mechanically ventilated patients.

How to Manage Sedation in Intensive Care Unit?

Sedation in the ICU is managed with the help of sedation guidelines and protocols, using ideal sedation agents, monitoring scales, and some sedation strategies. The most commonly used sedative agents include the following:

• Propofol.

• Ketamine.

• Benzodiazepines (Midazolam).

• Opioids (Morphine, Fentanyl).

• Alpha 2 agonists (dexmedetomidine, clonidine).

• Thiopentene.

• Tranquilizers (Haloperidol).

Maintaining patients at a light level of sedation improves both short and long-term outcomes in mechanically ventilated patients. Minimizing sedative use to keep a fair level of sedation in ICU patients shows reduced post-traumatic stress disorder symptoms, improved memories of ICU stays, and increased patient alertness. In addition, this facilitates patient participation in early physical and occupational therapy leading to less delirium, fewer ventilator days, and improved functional status after hospital discharge.

Sedatives should be carefully titrated using sedation scales. The frequently used sedation scales are

• Ramsay sedation scale.

• Sedation agitation scale (SAS).

• Richmond agitation sedation scale (RASS).

Several strategies use these scales to administer sedatives. They are daily interruptions of sedation (spontaneous awakening trial, spontaneous breathing trial) and protocolized sedation titration algorithms. The goal of both these strategies is to reduce overall patient exposure to excessive sedation.

Sedation guidelines for patients in critical care include the following:

1. To Treat Pain - Simple analgesics and intravenous opioids are used concerning the patient's weight.

2. Sedation and Analgesia for Ventilated Patients - A combination of sedatives and analgesics are used. First-line drugs for sedation are opioids and propofol. All patients should have a daily sedation break.

3. Second and third-line drugs are Midazolam and Morphine.

4. Night Sedation - If patients have sleep troubles at night, drugs such as antipsychotics, Zopiclone, and tricyclic antidepressants are prescribed.

How to Manage Delirium in ICU?

Delirium is a medical consequence that requires treatment to reduce its duration and severity. The patients at risk are evaluated, and risk factors of delirium are avoided to prevent and manage delirium. Once delirium is diagnosed, the treatment includes the medications such as Haloperidol, Olanzapine, Risperidone, Quetiapine, Midazolam, Dexmedetomidine, and Lorazepam.

How to Prevent Delirium in ICU?

Delirium prevention strategies are divided into two categories. They are

1. Non-pharmacological strategies.

2. Pharmacological strategies.

Non-pharmacological Strategies:

Non-pharmacological strategies are carried out before pharmacological interventions.

The most widely used approach is the ABCDEF Bundle. The components of the ABCDEF bundle for mechanically ventilated patients include:

• Assess, prevent, and manage pain.

• Both spontaneous breathing and spontaneous awakening trials.

• Choice of analgesia and sedation.

• Delirium: assess, prevent, and manage.

• Early mobility and exercise.

• Family engagement and empowerment.

• Early Mobility - Patients with delirium may develop complications such as infections, pressure ulcers, thromboembolism, and deconditioning. Early mobilization and rehabilitation prevent complications and reduce the duration of delirium.

• Minimizing External Stimuli - External factors, such as frequent tests and assessments, background noise, and artificial lighting, play an essential role in developing delirium. Keeping the rooms bright with natural light during the day and dark at night helps the patients maintain a proper sleep cycle.

• Reorientation Strategies - It allows patients to be aware of their location and illness. Family members can also help patients with memory stimulation activities.

Pharmacological Strategies:

Effective medications for the pharmacological management of delirium still need to be identified. However, using the following drugs can prevent delirium in hospitalized patients.

• Antipsychotics - Haloperidol, Quetiapine, and Olanzapine are used for a shorter duration.

• Cholinesterase Inhibitors - Acetylcholine is used for delirium.

• Melatonin - It is used to regulate the sleep-wake cycle.

• Alpha 2 Agonists - Dexmedetomidine and Clonidine are used for critical neurological illnesses.

Conclusion

Sedation and delirium management practices are not implemented worldwide because more data are needed to establish the best management strategies. In addition, most intensive care units do not monitor the presence of delirium and sedation levels in patients and do not have sedation guidelines and protocols.