Reference — Critical Care
ICU Sedation & Analgesia Agents
The drugs that sedate and relieve pain in the ventilated ICU patient, grouped by class — propofol, dexmedetomidine, the benzodiazepines, ketamine, and the opioids — with the features and the bedside monitoring notes that change how an RT watches the patient.
Written by Apex Respiratory Editorial Team
Educational use only. This material supports respiratory therapy education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional protocols, or physician orders. Always follow facility policies and current provider orders, and verify calculations independently before clinical use.
Overview
Sedation and analgesia in the ICU come down to a short list of agents, each with a distinct profile. Knowing whether a drug is a pure sedative or also an analgesic, whether it suppresses the respiratory drive, and what its signature toxicity is tells you what to expect and what to monitor. The table groups the common ICU sedatives and analgesics by class with the RT-relevant notes.
Agents by Class
| Agent | Class | Key Features | RT / Monitoring Notes |
|---|---|---|---|
| Propofol | Sedative-hypnotic (GABA) | Rapid on/off, allows quick neuro checks; causes hypotension and respiratory depression; risk of propofol-related infusion syndrome (PRIS); lipid emulsion adds calories | Not an analgesic; monitor BP and triglycerides |
| Dexmedetomidine | Central α2 agonist | Light, “cooperative” sedation with mild analgesia; minimal respiratory depression; less delirium | Does not suppress respiratory drive — useful during weaning; watch for bradycardia and hypotension |
| Midazolam | Benzodiazepine (GABA) | Amnestic; associated with delirium and prolonged ventilation; active metabolite accumulates in renal failure | Reserve for specific indications; minimize use |
| Lorazepam | Benzodiazepine | Longer-acting; prolonged infusions risk propylene glycol toxicity | Avoid prolonged infusion |
| Ketamine | NMDA antagonist (dissociative) | Analgesia plus sedation; bronchodilation; preserves respiratory drive and blood pressure; emergence reactions | Useful in bronchospasm or hemodynamic instability |
| Fentanyl | Opioid analgesic | Fast onset, short acting; first-line ICU analgesic; chest-wall rigidity with rapid IV push | Supports the analgesia-first approach; monitor for respiratory depression |
| Morphine / Hydromorphone | Opioid analgesics | Morphine causes histamine release and has an active metabolite that accumulates in renal failure | Monitor respiratory rate and sedation level |
Clinical Notes
- Analgesia first. Treat pain before adding a sedative — an opioid such as fentanyl often reduces the agitation that would otherwise prompt more sedation.
- Prefer propofol or dexmedetomidine over benzodiazepines. The non-benzodiazepine agents are associated with less delirium and shorter ventilation; reserve midazolam and lorazepam for specific indications.
- Titrate to the lightest effective sedation. Aim for a RASS of 0 to −2 in most patients rather than the deepest level the drug can reach.
- Monitor hemodynamics and respiratory drive. Propofol drops blood pressure and depresses ventilation, dexmedetomidine causes bradycardia and hypotension — watch both the numbers and the patient’s breathing.
- Dexmedetomidine is favored during weaning. Because it spares the respiratory drive, dexmedetomidine lets a patient stay comfortable while still breathing — an advantage when liberating from the ventilator.
Related Resources
Sources
- Devlin JW, Skrobik Y, Gélinas C, et al. Clinical practice guidelines for the prevention and management of pain, agitation/sedation, delirium, immobility, and sleep disruption in adult patients in the ICU (PADIS). Crit Care Med. 2018;46(9):e825-e873.
- Gardenhire DS. Rau's Respiratory Care Pharmacology. 10th ed. Elsevier; 2019.
- Kacmarek RM, Stoller JK, Heuer AJ. Egan's Fundamentals of Respiratory Care. 12th ed. Elsevier; 2021.