Special Populations

Critically ill patients represent a heterogeneous population with diverse needs for sedation management. This chapter examines key special populations requiring modified approaches to post-intubation sedation.

Elderly Patients

The elderly are at higher risk of adverse effects from sedative medications due to age-related pharmacokinetic and pharmacodynamic changes. Reduced renal clearance and increased sensitivity to drugs like benzodiazepines and opioids place them at risk of oversedation.

Strategies for the elderly include:

• Lower medication doses due to enhanced drug sensitivity
• Avoid benzodiazepines due to risks of delirium and confusion
• Short-acting sedatives like propofol preferred over long-acting agents
• Lighter targeted sedation given risks of oversedation
• Frequent reassessment for adequate analgesia and minimal effective sedation

Renal/Hepatic Impairment

Renal or hepatic dysfunction alter medication pharmacokinetics, requiring dose adjustments to prevent toxicity.

Strategies for organ impairment:

• Avoid renally cleared agents (e.g. lorazepam) with kidney injury
• Avoid prolonged infusions (e.g. benzodiazepines) risking drug accumulation
• Reduce doses for hepatic impairment
• Choose short-acting sedatives metabolized by multiple pathways
• Frequent medication and sedation assessment

Alcohol/Substance Withdrawal

Alcohol and substance withdrawal often precipitate agitation, autonomic instability, and delirium. Heavy users require higher sedative doses to prevent withdrawal.

Management principles include:

• Generous benzodiazepine dosing to control CNS and autonomic symptoms
• Considering phenobarbital or anticonvulsants for resistant cases
• Dexmedetomidine helps reduce benzodiazepine needs
• High vigilance for breakthrough withdrawal symptoms
• LT sedation to avoid withdrawal once stabilized

Traumatic Brain Injury

Traumatic brain injury patients require optimized sedation for ventilator synchrony and cerebral perfusion. Deeper sedation may be indicated.

Evidence-based strategies include:

• Monitoring ICP and avoiding exacerbating medications
• Maintaining euvolemia and cerebral perfusion pressure
• Shorter-acting sedatives like propofol due to stability
• Avoiding benzodiazepines due to extended half-lives
• Anticonvulsant use for seizure prophylaxis or control

This chapter has highlighted some unique considerations for sedation management in special ICU populations. Tailoring regimens to individual patient factors improves safety and outcomes.