What medications are used to keep a patient sedated after intubation?

Post-Intubation Sedation Medications

For normotensive/hypertensive patients after intubation, use a continuous propofol infusion (25-300 mcg/kg/h) combined with fentanyl (25-300 mcg/h) as the preferred maintenance regimen. 1

First-Line Sedation Strategy

Propofol is the preferred sedative agent over benzodiazepines due to its shorter half-life and significantly lower risk of delirium. 2, 1 Continuous benzodiazepine infusions should be avoided whenever possible. 2, 1

Propofol-Based Regimen (Hemodynamically Stable Patients)

• Propofol infusion at 25-300 mcg/kg/h (or 0.5-5 mcg/kg/h) combined with fentanyl 25-300 mcg/h provides optimal sedation maintenance. 1
• Propofol must only be administered by personnel trained in airway management, with immediate availability of equipment for artificial ventilation, supplemental oxygen, and cardiovascular resuscitation. 3
• Critical warning: Propofol causes dose-dependent decreases in cardiac output and blood pressure, and should be titrated slowly to avoid hypotension and respiratory depression. 4, 3
• For elderly patients (>60 years) or ASA physical status 3 or above, reduce propofol dose to 25 mcg/kg/min to minimize cardiovascular depression. 1

Opioid Analgesia Component

• Fentanyl or remifentanil continuous infusion serves as first-line for analgesia and sedation in intubated patients. 2
• Fentanyl provides potent analgesia with anti-shivering properties and duration of 1-4 hours. 2, 1
• An analgesic-first strategy is advocated for sedation of intubated patients. 2

Alternative Regimens for Hemodynamically Unstable Patients

For hypotensive patients or those with hemodynamic instability, use midazolam boluses (2-5 mg) combined with fentanyl, or ketamine alone, instead of propofol. 1

Midazolam-Based Regimen

• Initial dosing: Midazolam 2 mg IV bolus for sedation-naïve patients, followed by infusion of 1 mg/h. 2
• Midazolam dose should be reduced by at least 20% in elderly patients (>60 years) or ASA physical status 3 or above. 1
• Titration protocol: If patient becomes symptomatic on midazolam infusion, give bolus dose equal to or double the hourly infusion rate every 5 minutes as needed. 2
• If patient receives two bolus doses in one hour, double the infusion rate. 2
• Critical consideration: Midazolam provides amnesia, which is essential for patients requiring neuromuscular blockade. 2

Ketamine Alternative

• Ketamine (0.5-2 mg/kg) provides relative hemodynamic stability through sympathomimetic effects, making it valuable in hypotensive patients. 2, 1
• Historical concerns about ketamine increasing intracranial pressure in head injury patients are of little practical significance. 2
• Important limitation: Ketamine must be combined with a GABA agonist to provide amnesia during neuromuscular blockade. 2

Adjunctive Sedation During Recovery Phase

• Dexmedetomidine (infusion rates 4-16 mcg/kg/min) is useful during the recovery/weaning phase but inadequate as sole agent for deep sedation. 2, 1
• Dexmedetomidine has anxiolytic effects and lower risk of delirium, particularly compared to benzodiazepines. 2
• Dexmedetomidine is more useful in latter stages of care (during and after rewarming while patient is in mechanical ventilation weaning phase). 2

Critical Monitoring Requirements

• Waveform capnography must be used continuously to confirm correct tracheal tube placement, with 100% sensitivity and specificity. 1
• Confirmation should be repeated each time the patient is moved. 2, 1
• Pulse oximetry is mandatory for all sedated patients. 1
• At least one individual capable of establishing a patent airway and providing positive pressure ventilation must be present at all times. 1

Essential Safety Considerations

• Small, frequent doses of sedatives minimize hemodynamic side-effects and should be titrated against physiological variables. 2
• Infusions are preferable for longer durations, though infusion pumps may complicate transfer logistics. 2
• Abrupt discontinuation of propofol should be avoided as this may result in rapid awakening with anxiety, agitation, and resistance to mechanical ventilation. 3
• Propofol infusions should be adjusted to maintain a light level of sedation through the weaning process. 3

Post-Cardiac Arrest Patients: Special Considerations

• Excess sedation can aggravate hemodynamic instability and hinder accurate neuroprognostication in post-cardiac arrest patients. 2
• Delayed awakening after Day 7 is common, and accumulation of sedatives can lead to inaccurate early neuroprognostication and premature withdrawal of life-sustaining therapy. 2
• Sedation and neuromuscular blockade may mask clinical manifestations of seizures, warranting EEG monitoring (either serial or continuous). 2

Common Pitfalls to Avoid

• Never use propofol in patients with egg, soy, or sulfite allergies. 4
• Propofol has no analgesic properties and must be combined with opioids for pain control. 4
• Recognize synergistic respiratory depression when benzodiazepines and opioids are combined, increasing risk of hypoxemia. 4
• Propofol Infusion Syndrome can occur with prolonged high-dose infusions (>5 mg/kg/h for >48 hours), characterized by severe metabolic acidosis, hyperkalemia, rhabdomyolysis, and cardiac failure. 3
• In the setting of increasing propofol dose requirements or onset of metabolic acidosis, consider alternative sedation methods. 3