Should sedation be stopped during a spontaneous breathing trial (SBT) or can it continue?

Should Sedation Be Stopped During Spontaneous Breathing Trials?

Sedation should be minimized but does not need to be completely stopped during spontaneous breathing trials (SBTs), with protocols that pair daily sedation interruption (spontaneous awakening trials) with SBTs showing superior outcomes compared to standard sedation management. 1

Evidence-Based Approach to Sedation During SBTs

Primary Recommendation: Paired SAT-SBT Protocol

The American College of Chest Physicians/American Thoracic Society guidelines suggest using protocols that minimize sedation for patients ventilated more than 24 hours (conditional recommendation, low-quality evidence). 1 This does not mandate complete cessation, but rather systematic reduction.

The most effective approach pairs spontaneous awakening trials (SATs) with spontaneous breathing trials (SBTs):

• Patients managed with daily SAT followed by SBT spent 3.1 more days breathing without assistance (14.7 vs 11.6 days, p=0.02) compared to usual sedation care. 2
• This paired protocol reduced ICU length of stay (9.1 vs 12.9 days, p=0.01) and hospital stay (14.9 vs 19.2 days, p=0.04). 2
• One-year mortality was significantly lower with the SAT-SBT protocol (HR 0.68,95% CI 0.50-0.92, p=0.01), with a number needed to treat of 7.4 to save one life. 2
• The intervention reduced mechanical ventilation and sedation time by nearly 50%. 3

Practical Implementation Algorithm

Step 1: Daily Assessment for SAT Eligibility

• Neurological status is a critical factor physicians consider before performing SBTs, with patients who undergo same-day SBTs having significantly better mental status (GCS-Cook 13±3 vs 9±3 points, p<0.001). 4

Step 2: Conduct Spontaneous Awakening Trial

• Continuous-infusion analgesia does NOT need to be withheld during the SAT - this is a common misconception. 5
• Propofol infusions should be adjusted to maintain a light level of sedation throughout the weaning process, not abruptly discontinued. 6

Step 3: If SAT Successful, Proceed to SBT

• The SBT should be conducted with inspiratory pressure augmentation (5-8 cm H₂O) rather than T-piece alone. 1
• Maintain light sedation during the SBT itself - the goal is optimization, not elimination. 6

Step 4: Timing of Complete Sedation Discontinuation

• Propofol should be continued at light sedation levels until 10-15 minutes prior to extubation, then discontinued. 6
• Abrupt discontinuation before this point results in rapid awakening with anxiety, agitation, and resistance to mechanical ventilation, making weaning difficult. 6

Critical Safety Considerations

Physiological Monitoring During Sedation Adjustment

When conducting SATs paired with SBTs, expect and monitor for:

• Significant increases in heart rate, respiratory rate, and systolic blood pressure during the SAT (p<0.05 for all), though mean increases typically remain below 20%. 5
• SAT failure criteria include: RASS scores of +1 to +2 (70% of failures), tachycardia (15%), or ventilator asynchrony (15%). 5

Common Pitfalls to Avoid

Pitfall #1: Complete sedation cessation too early

• Abrupt discontinuation prior to weaning causes rapid awakening with anxiety and agitation, compromising the weaning process. 6
• Instead, titrate to light sedation and maintain this level throughout weaning. 6

Pitfall #2: Ignoring neurological status

• Physicians appropriately delay SBTs when mental status is inadequate, even when other criteria are met. 4
• Delaying SBTs for poor neurological status results in longer intubation times and ICU stays (p<0.001). 4

Pitfall #3: Withholding analgesia during SAT

• This is unnecessary and potentially harmful - continuous-infusion analgesia can be safely maintained during SATs. 5

Self-Extubation Risk vs Benefit Analysis

The paired SAT-SBT protocol does increase self-extubation rates:

• More self-extubations occur with the intervention (16 vs 6 patients, 6.0% difference, p=0.03). 2
• However, reintubation rates after self-extubation are similar (5 vs 3 patients, p=0.47), as are total reintubation rates (13.8% vs 12.5%, p=0.73). 2
• The mortality benefit far outweighs this risk. 2

Specific Drug Considerations for Propofol

For patients on propofol specifically:

• Propofol should be adjusted to light sedation levels, not discontinued, during the weaning process. 6
• Opioids and paralytic agents should be discontinued and respiratory function optimized prior to weaning. 6
• Failure to reduce propofol infusion rates in extended ICU sedation may result in excessively high drug concentrations. 6
• The rapid clearance of propofol makes abrupt discontinuation particularly problematic for weaning success. 6