What is the recommended sedation depth scale for intubated patients?

Recommended Sedation Depth Scale for Intubated Patients

The Richmond Agitation-Sedation Scale (RASS) is the recommended sedation depth scale for intubated ICU patients, with a target score of -2 to +1 (light sedation) for most mechanically ventilated adults. 1, 2

Primary Sedation Assessment Tool

Use the RASS or Sedation-Agitation Scale (SAS) as your primary sedation monitoring tool, as these demonstrate the highest validity and reliability with excellent inter-rater reliability (r = 0.956 for RASS) across diverse ICU populations. 1, 2 The 2013 and 2018 Critical Care Medicine guidelines both identify RASS and SAS as superior to all other subjective sedation scales based on robust psychometric testing and number of study participants. 1

RASS Scale Structure

• The RASS is a 10-point scale ranging from +4 (combative) to -5 (unarousable), providing clear categorical distinctions for both agitation and sedation levels. 2
• The scale demonstrates moderate to high correlations with objective measures like EEG and bispectral index values. 1

Target Sedation Depth

Target a RASS score of -2 to +1 (or SAS 3-4) for most mechanically ventilated patients, which the 2018 guidelines define as "light sedation." 1, 2 This represents a shift from the 2013 guidelines, which suggested RASS ≥-2 may be too deep. 1

Clinical Benefits of Light Sedation

• Light sedation (RASS -2 to +1) reduces time to extubation by 0.77 days (95% CI: -2.04 to -0.50) compared to deep sedation. 1
• Light sedation reduces tracheostomy rates (RR 0.57; 95% CI: 0.41-0.80). 1
• Light sedation does not increase 90-day mortality (RR 1.01; 95% CI: 0.80-1.27) or self-extubation rates (RR 1.29; 95% CI: 0.58-2.88). 1

Assessment Frequency and Documentation

Assess and document RASS scores at least every 6 hours in all mechanically ventilated patients, or more frequently (hourly) when titrating sedation to target. 1, 3 The 2018 guidelines specifically required that sedation targets be measured systematically over the entire ICU stay, not just at single time points. 1

Treatment Adjustments Based on RASS

For Over-Sedation (RASS < -2)

• Immediately hold all sedative medications until the patient reaches target sedation level. 2
• Restart sedatives at 50% of the previous dose once target is achieved. 2

For Under-Sedation or Agitation (RASS > 0)

• First assess and treat pain using validated pain scales (BPS or CPOT for intubated patients), as pain is frequently the underlying cause of agitation. 2
• Administer sedatives as needed, preferring non-benzodiazepine agents (propofol or dexmedetomidine) unless specifically treating alcohol or benzodiazepine withdrawal. 2

Critical Pitfalls to Avoid

Do not rely on objective brain function monitors (BIS, entropy, PSI) as the primary sedation assessment method in non-paralyzed patients—these are inadequate substitutes for RASS scoring. 2 While BIS correlates with RASS (tau = 0.56, p < 0.0001), it should only supplement, not replace, clinical assessment. 4

Avoid maintaining deep sedation (RASS -3 to -5) without specific clinical indication, as this increases adverse outcomes including prolonged ventilation and ICU stay. 2 Studies show 78% of ICU patients are routinely over-sedated (BIS < 60), highlighting the need for systematic assessment. 5

Do not use benzodiazepines as first-line sedatives unless treating alcohol or benzodiazepine withdrawal, as they increase delirium risk. 2 The correlation between BIS and clinical scales is lost in midazolam-sedated patients at deeper sedation levels (Ramsay = 6), suggesting benzodiazepines produce sedation quality that differs from other agents. 5

Implementation Strategies

Implement nurse-protocolized sedation protocols or daily sedative interruption (DSI) protocols, as both can effectively achieve and maintain light sedation levels. 1 These approaches empower bedside nurses to titrate sedatives to achieve prescribed RASS targets without requiring physician orders for each adjustment. 1

Use visual management tools and reminder cards to improve RASS assessment compliance, which can achieve 83-100% adherence rates. 6 Implementation of RASS-based protocols reduces sedation consumption, mechanical ventilation duration, and ICU length of stay. 3, 6

Special Considerations

In neurocritical care patients, both RASS and SAS provide workable assessment tools, though clinical examination may be confounded by underlying neurological injury. 2 Avoid routine "wake-up tests" in patients with unstable intracranial hypertension. 2

The RASS scale demonstrates excellent inter-rater reliability in pediatric patients aged 1 month to 18 years in PICU settings, though it was originally validated in adults. 2