Critical Care · Year 4 · from Critical Care
Case 2: Delirium and Sedation Management
Clinical Image
Source: Wikimedia Commons - Intensive Care Unit - CC BY-SA 4.0
Case Presentation
A 72-year-old man with COPD is intubated for hypercapnic respiratory failure. He is initially sedated with midazolam infusion at 4 mg/hour and fentanyl at 100 mcg/hour, maintaining RASS of -4 (deep sedation). On day 3, the team attempts to lighten sedation for a spontaneous awakening trial (SAT), but the patient becomes severely agitated (RASS +3), pulling at lines and attempting to self-extubate. Midazolam is restarted at 6 mg/hour. On day 5, despite adequate analgesia, he remains deeply sedated even 6 hours after holding midazolam, and when he does awaken, he is confused with fluctuating attention. CAM-ICU is positive for delirium. The team transitions sedation from midazolam to dexmedetomidine 0.5 mcg/kg/hour, which is titrated to achieve target RASS of -1 to 0. They implement delirium prevention measures: minimizing benzodiazepines, promoting sleep with nighttime light reduction and clustered care, mobilizing the patient to sit at the edge of bed, providing reorientation and hearing aids. Haloperidol 1 mg IV is given for episodes of severe agitation. By day 8, delirium resolves, and he successfully completes a spontaneous breathing trial. He is extubated and transferred to the floor on day 10.
Key Learning Points
- The RASS scale ranges from +4 (combative) to -5 (unarousable), with targets typically -2 to 0 for light sedation that allows assessment and participation
- Benzodiazepines (particularly midazolam) accumulate in critically ill patients and are associated with higher delirium incidence compared to propofol or dexmedetomidine
- The CAM-ICU detects delirium by assessing: acute onset/fluctuating course, inattention, altered level of consciousness, and disorganized thinking
- The ABCDEF bundle integrates Assess/manage pain, Both SAT and SBT, Choice of sedation, Delirium monitoring, Early mobility, and Family engagement