Sedation Strategies

Selecting the optimal sedation strategy is crucial for managing patient comfort and safety while avoiding adverse outcomes like prolonged mechanical ventilation. This chapter reviews evidence-based approaches for titrating and minimizing sedative medications in critically ill patients.

Light vs Deep Sedation

Historically, deeply sedating critically ill patients was common practice to ensure ventilator synchrony and patient compliance. However, clinical trials over the past two decades demonstrate improved outcomes with lighter sedation targeted to the minimum level that maintains patient comfort and ventilator synchrony.

Potential benefits of light sedation:

• Shorter duration of mechanical ventilation – Multiple RCTs show lighter sedation shortens time on mechanical ventilation versus deep sedation. Meta-analyses suggest a reduction in ventilation duration of up to 2.5 days with lighter sedation protocols.
• Reduced ICU and hospital length of stay – Lighter sedation is associated with 2-4 day reductions in ICU and hospital length of stay compared to deep sedation.
• Lower risk of delirium – Lightly sedated patients have a 12-39% lower relative risk of developing delirium compared to deeply sedated patients. Delirium is associated with prolonged ventilation and higher mortality.
• Improved ability to detect neurological changes – Deeper sedation can mask seizures or other neurologic changes. Lighter sedation facilitates more frequent neurologic assessment.
• Earlier mobilization and rehabilitation – Lightly sedated patients can participate in physical/occupational therapy sooner, improving functional recovery.

There are certain situations where deeper sedation remains appropriate, including:

• Severe respiratory failure requiring high ventilator support
• Use of neuromuscular blockade
• Traumatic brain injury
• Status epilepticus
• Alcohol or benzodiazepine withdrawal

Overall, RCTs and meta-analyses provide strong evidence that maintaining light sedation improves outcomes compared to deep sedation for most ventilated patients. Regular sedation assessment with scales like the RASS allows careful titration to optimal levels.

Analgesia-First Sedation

Sedation guidelines endorse an analgesia-first approach, where opioids are used to control pain before adding sedatives for agitation or anxiety. This prevents under-treatment of pain while reducing sedative exposure.

Observational studies show most ICU patients experience significant pain, but can become calm and cooperative with analgesia alone. Pretreating with opioids before painful procedures also blunts sympathetic responses.

An analgesia-first strategy results in lower cumulative doses of sedatives, shorter duration of mechanical ventilation, and less delirium compared to sedative-first approaches. Focusing analgesia on pain rather than sedation delivers patient-centered care while improving outcomes.

SAT and SBT Protocols

Spontaneous awakening trials (SATs) and spontaneous breathing trials (SBTs) are coordinated, protocolized approaches to lighten sedation and evaluate extubation readiness in ventilated patients.

SAT involves daily interruption of sedatives and analgesics to allow patients to awaken and demonstrate neurological function and respiratory capability. SBT is a structured trial of unassisted breathing to assess extubation readiness.

Combined SAT and SBT protocols result in:

• Shorter duration of mechanical ventilation – SAT/SBT reduced ventilation by 2-4 days versus usual care in RCTs.
• Reduced ICU and hospital length of stay – SAT/SBT reduced ICU stay by 2-6 days and hospital stay by 3-4 days compared to usual care.
• Lower delirium risk – SAT/SBT reduced delirium by 20% versus usual care sedation in one RCT.
• Improved mortality – A meta-analysis found SAT/SBT protocols reduced 28-day mortality by 22% compared to usual care.

SATs are often incorporated into lighter sedation protocols, while SBTs objectively evaluate ability to be liberated from mechanical ventilation. These coordinated trials promote patient-centered extubation as soon as clinically feasible.

This chapter has reviewed evidence supporting lighter sedation strategies, analgesia-first approaches, and protocolized awakening/breathing trials for improving outcomes in ventilated patients. Carefully tailoring sedation to patient needs while minimizing exposure is key to optimizing recovery.