1. Rationale for Supportive Care

Delirium is a manifestation of acute brain dysfunction that can perpetuate secondary organ injury, prolong the duration of mechanical ventilation, and increase the length of stay in the intensive care unit (ICU). An integrated approach to supportive care, encompassing ventilator management, sedation protocols, and prophylactic bundles, is crucial to mitigate the physiologic stressors that trigger or exacerbate delirium.

Delirium is associated with systemic inflammation and profound neurotransmitter imbalances. This state is often worsened by deep sedation and immobilization, which further impair cognitive function. The implementation of evidence-based bundles, such as the ABCDEF or PADIS bundles, unifies the management of pain, agitation, delirium, mobility, and sleep. This comprehensive strategy has been shown to shorten the duration of delirium and improve overall patient outcomes.

2. Mechanical Ventilation Strategies

Optimizing ventilator settings and implementing structured weaning protocols are fundamental to minimizing sedative exposure and ventilator-associated stress, thereby reducing the risk and severity of delirium.

2.1 Lung-Protective Ventilation

Adherence to lung-protective ventilation principles is key. This involves:

• Low Tidal Volume: Targeting 6 mL/kg of predicted body weight.
• Plateau Pressure Control: Maintaining a plateau pressure of ≤ 30 cm H₂O.

This approach attenuates biotrauma, reduces systemic cytokine release, and helps preserve the integrity of the blood–brain barrier, all of which are implicated in the pathophysiology of delirium.

2.2 Spontaneous Breathing Trials (SBT)

Daily spontaneous breathing trials are essential to assess a patient’s readiness for extubation. Key criteria for a successful trial include a respiratory rate < 35 breaths/min, SpO₂ ≥ 90%, and stable hemodynamics. Performing daily SBTs reduces total ventilator days and, consequently, the cumulative dose of sedatives required.

2.3 Sedation Targets

The goal is to maintain a light level of sedation, corresponding to a Richmond Agitation-Sedation Scale (RASS) score of −2 to 0. This level of sedation permits neurologic assessment, facilitates patient interaction, and enables early mobilization. Deep sedation (RASS ≤ −3) should be avoided as it is a major risk factor for delirium, particularly when benzodiazepines are used.

3. Sedation Interruption and Protocolized Sedation

Systematic approaches like daily sedation interruption (DSI) and nurse-driven protocols help standardize sedation to the minimum effective dose. These strategies have been proven to shorten ventilation duration and lower delirium rates.

3.1 Daily Sedation Interruption (DSI)

Also known as a spontaneous awakening trial (SAT), DSI involves pausing continuous sedative infusions each morning while the patient is closely monitored. This “sedation vacation” allows clinicians to assess the patient’s underlying level of consciousness, evaluate pain control, and determine readiness for extubation.

3.2 Nurse-Driven Sedation Protocols

These protocols empower bedside nursing staff to titrate sedative agents like propofol or dexmedetomidine to a specified RASS target (typically −2 to 0) using a validated algorithm. This facilitates real-time adjustments based on patient needs, preventing over-sedation.

4. Prevention of ICU-Acquired Complications

Prophylactic measures targeting common ICU complications are essential, as each additional physiologic insult can contribute to or worsen delirium.

4.1 Venous Thromboembolism (VTE) Prophylaxis

• Pharmacologic: Low-molecular-weight heparin (e.g., enoxaparin 40 mg SC daily) or unfractionated heparin (5,000 units SC q8–12h) is standard unless a high risk of active bleeding exists.
• Mechanical: Intermittent pneumatic compression devices are used when anticoagulation is contraindicated.

4.2 Stress Ulcer Prophylaxis (SUP)

• Indications: Generally reserved for patients with high-risk features, such as mechanical ventilation for >48 hours or coagulopathy.
• Agents: Proton pump inhibitors (e.g., pantoprazole 40 mg IV daily) or H₂-receptor antagonists are commonly used. The choice should balance efficacy against risks like Clostridioides difficile infection and drug interactions.

4.3 Infection Control Bundles

• CLABSI Prevention: Adherence to maximal barrier precautions during insertion, chlorhexidine skin antisepsis, and daily review of line necessity are critical.
• VAP Prevention: Key measures include elevating the head of the bed to 30–45 degrees, regular oral care with chlorhexidine, and using endotracheal tubes with subglottic suctioning capabilities.

5. Management of Iatrogenic Drug Toxicities

Pharmacologic agents used to manage agitation or sedation can precipitate significant adverse events. Proactive monitoring and prompt management are essential to ensure patient safety.

6. Multidisciplinary Goals of Care Conversations

Persistent delirium, especially in the context of ongoing invasive support, necessitates clear communication and shared decision-making that aligns with the patient’s values and prognosis.

6.1 Decision Points for Invasive Therapies

When delirium persists for more than 7 days, it serves as a critical trigger to reassess the goals of care. This includes re-evaluating the appropriateness of continued mechanical ventilation, renal replacement therapy, and vasopressor support, weighing the burdens of treatment against the likelihood of a meaningful recovery.

6.2 Family Engagement

Engaging families is paramount. Structured communication tools and proactive palliative care consultations can facilitate these difficult conversations. The VALUE mnemonic is a useful guide for clinicians:

6.3 Ethical and Prognostic Considerations

The principle of proportionality should guide decisions. Interventions may be ethically withdrawn or limited when their burden outweighs the potential benefit, or when the likelihood of the patient achieving a quality of life they would find acceptable is low.

7. Documentation and Handoff Integration

Consistent and clear documentation of delirium status, sedation targets, and supportive care measures is vital for ensuring patient safety, continuity of care, and adherence to protocols across shifts.

• Delirium Screening: Document the CAM-ICU or ICDSC score every nursing shift to track trends.
• Sedation Management: Record the target RASS, outcomes of sedation holds (SATs), and any adjustments to sedative infusions.
• Structured Handoff: Use a standardized tool like SBAR for transitions of care:
  • Situation: Current delirium status (e.g., “CAM-ICU positive, hyperactive”).
  • Background: Key medications, active protocols, recent events.
  • Assessment: Current sedation depth, recent ECG results, mobility status.
  • Recommendations: Plan for the next shift (e.g., “Continue RASS target -1 to 0, attempt SAT in AM”).
• Pharmacist Role: Clinical pharmacists can create and maintain templates that highlight a patient’s delirium risk factors, current prophylaxis regimen, and any pending goals-of-care discussions.