Sedation in Critical Care Study Notes
LEARNING OBJECTIVES
Why Sedation Matters
Patient Comfort:
Essential in managing discomfort from:
Painful procedures
Invasive tubes
Sleep deprivation
Reduce Agitation:
Addresses fear, anxiety, and physiologic stress in critically ill patients
Avoid Oversedation:
Important to balance patient comfort with mobility and rehabilitation goals
ASSESSMENT TOOLS
Sedation-Agitation Scales
Two validated scales are used to standardize assessments in critically ill adults:
Richmond Agitation-Sedation Scale (RASS)
Ranges from +4 (combative) to -5 (unresponsive)
Target is RASS 0 = alert and calm
Sedation-Agitation Scale (SAS)
Ranges from 1 (unarousable) to 7 (dangerously agitated)
Target is SAS 4 = calm and cooperative
Recommendation: Light sedation is advised for mechanically ventilated patients
RASS SCALE BREAKDOWN
+4 to +1: Agitated States
Characteristics:
Combative, very agitated, restless, anxious movements
0: Alert and Calm
Target sedation level where patient follows commands and maintains sustained eye contact
-1 to -3: Light to Moderate
Symptoms include drowsiness, briefly awakening, and responsiveness to voice
-4 to -5: Deep Sedation
No response to voice and minimal response to physical stimulation
PAIN FIRST
Pain Assessment Priority
Rule out pain first when assessing agitated patients
Verbal Patients:
Use a 0-10 pain scale for direct communication about pain location and intensity
Nonverbal/Intubated Patients:
Use validated behavioral scales such as:
Behavioral Pain Scale (BPS)
Critical-Care Pain Observation Scale (CPOT)
Provide preemptive analgesia before painful procedures to alleviate potential discomfort
LEVELS OF SEDATION
Light Sedation (Minimal)
Characteristics:
Alert, responds to verbal commands
RASS 0 or -1 to +1, SAS 4
Moderate Sedation
Characteristics:
Responds to verbal commands but does not require airway support
RASS -2 to -3, SAS 3-4
Deep Sedation
Characteristics:
Cannot maintain airway, challenging to arouse
RASS -4 to -5, SAS 2
General Anesthesia
Characteristics:
Not arousable, requires airway support
RASS -5, SAS 1
MEDICATIONS
SEDATIVE MEDICATIONS
Current Recommendations for mechanically ventilated adults:
Dexmedetomidine:
A central alpha agonist
Effective sedation without causing respiratory depression
Propofol:
A sedative-hypnotic agent
Features:
Rapid onset and short half-life
Benzodiazepines:
Not recommended due to association with longer ventilation and delirium
PROPOFOL: KEY FACTS
Characteristics:
White milky appearance and comes in a glass container
Rapid onset: 30-60 seconds
Short half-life: 2-4 minutes initially
Ideal for quick awakening trials
Critical Nursing Actions:
Change tubing every 12 hours
Monitor triglycerides after 48 hours of use
Watch for propofol infusion syndrome
Not an analgesic - opiates should be added for pain
COMPLICATIONS
PROPOFOL-RELATED INFUSION SYNDROME
Description: Rare but serious complication with prolonged use >5 mg/kg/hr for >48 hours
Signs & Symptoms:
Metabolic acidosis
Rhabdomyolysis
Acute kidney injury
Cardiac dysrhythmias
Mortality Rate: 50%
Requires immediate recognition and intervention
Monitor serum triglycerides in all patients receiving propofol for >48 hours
DEXMEDETOMIDINE
BENEFITS
Unique Mechanism:
Alpha-2 agonist inhibits the sympathetic nervous system, providing sedation and analgesia
No Respiratory Depression:
Patients can be extubated while on infusion, beneficial during weaning process
Interactive Sedation:
Patients are lightly sedated but can still interact, aligning with current guidelines
BEST PRACTICE
DAILY SEDATION INTERRUPTION
Spontaneous Awakening Trial (SAT):
Prevent dependence and withdrawal through systematic management
Steps:
Stop Sedatives:
Turn off continuous infusions at scheduled times
Monitor Awakening:
Assess consciousness using RASS/SAS and perform neurologic exams
Conduct Breathing Trial:
Evaluate readiness for extubation if appropriate
Restart at Lower Dose:
Resume at 50% of previous dose and titrate to target level
Have a protocol ready to restart sedatives if the patient becomes dangerously agitated
MANAGING AGITATION
Hyperactive movements can range from restlessness to physical aggression
Assess Causes:
Pain, hypoxia, full bladder, ventilator dyssynchrony, delirium
Use Validated Scale:
RASS or SAS to identify agitation early
Treat the Cause:
Address underlying issues rather than resorting to overmedication
Avoid Benzodiazepines:
Associated with higher incidence of delirium
DELIRIUM
UNDERSTANDING DELIRIUM
Description: Acute brain dysfunction affects over 50% of critical care patients
Definition: Global impairment of cognitive processes with sudden onset, leading to:
Disorientation
Altered perceptions
Not Always Obvious:
Delirious patients may present as calm rather than agitated
Serious Consequences:
Increased hospital stay and mortality in mechanically ventilated patients
DELIRIUM ASSESSMENT TOOLS
Two validated instruments for mechanically ventilated patients:
CAM-ICU (Confusion Assessment Method for ICU):
Evaluates 4 features:
Acute change in mental status
Inattention
Disorganized thinking
Altered consciousness
ICDSC (Intensive Care Delirium Screening Checklist):
Scores 8 items including:
Altered consciousness
Inattention
Disorientation
Hallucinations
Both tools used in combination with RASS to exclude patients in a coma
PREVENTION
PREVENTING DELIRIUM
Key Points:
No medication prevents delirium; strategies focus on non-pharmacologic interventions
Early Mobility:
Prevents muscle weakness and reduces cognitive complications
Sleep Protocols:
Dim lights, reduce noise, cluster care, provide earplugs/eye masks
Avoid Restraints:
Physical restraints are associated with negative memories
DELIRIUM PREVENTION BUNDLE
Light Sedation:
Use the lightest level tolerable for patient comfort
Daily Awakening:
Implement spontaneous awakening trials
Breathing Trial:
Assess readiness for extubation
Delirium Monitoring:
Conduct daily screenings with validated tools
Early Mobility:
Encourage patients to move as soon as possible
LONG-TERM IMPACT
POST-ICU SYNDROME (PICS)
Description:
Depression and cognitive decline experienced after surviving critical illness
Risk Factors:
Advanced age
Prior cognitive impairment
Delirium
Prolonged critical illness
Prevention Strategy:
Employ same interventions used to reduce delirium
Patient Diaries:
Written by team and family to assist in answering patient questions about unconscious periods
SPECIAL POPULATION
ALCOHOL WITHDRAWAL SYNDROME
Description:
Critically ill alcohol-dependent patients are at risk for severe complications
Prevalence: 50% of these patients experience AWS
Complications:
Less than 5% of alcohol-dependent patients develop severe complications like delirium tremens or seizures
Assessment Tools:
AUDIT: identifies alcohol dependence
CIWA-Ar: assesses withdrawal severity
Treatment Approach:
Long-acting benzodiazepines (e.g., diazepam, lorazepam)
Include phenobarbital and adjunctive medications per protocol
DELIRIUM TREMENS MANAGEMENT
MANAGEMENT TECHNIQUES
Close Monitoring:
Be vigilant for escalating agitation, tremor, anxiety, and sweating
Symptom-Triggered Dosing:
Utilize benzodiazepines guided by CIWA-Ar score >10
Thiamine Prophylaxis:
Administration of multivitamins including vitamin B1 to prevent neurological damage
Prohibition:
Never administer oral or IV alcohol to treat AWS
TEAMWORK
COLLABORATIVE MANAGEMENT
Shared Responsibility: Ensures effective management across the healthcare team, including:
Nursing: Continuous assessment, medication administration, and ensuring safety
Physicians: Setting sedation goals and adjusting medications based on patient response
Pharmacists: Optimizing medication regimens and monitoring for potential interactions
Rehabilitation Staff: Early mobility to prevent complications
Respiratory Therapists: Managing ventilators and conducting breathing trials
Family Members: Providing a familiar presence and participating in care activities