Acute Pain Part 2 Flashcards
Opioid Analgesics
Considered when:
● Persistent pain despite a reasonable trial of non-opioid analgesics (+/- adjuvants)
● Moderate to severe pain requiring rapid relief
● Contraindications to other analgesics
● Benefits of opioids outweigh risks based on comprehensive assessment
Percocet = APAP 325 mg / oxycodone 5 mg
Equianalgesic dose of 2 Percocet tabs q6h:
● Total daily dose oxycodone PO = 40 mg
● Convert to morphine = 60
Reduce dose for incomplete cross-tolerance?
pt; Can use non-opioids concurrently
● Acetaminophen 1 g PO q6h
Opioids
● Morphine IR 10 mg PO q4h
● Breakthrough dose options:
○ Morphine IR 5 mg PO q2h PRN (~10% of TDD)
○ Morphine IR 10 mg PO q2h PRN (~15% of TDD
Case Scenario 6
40 year old male patient had surgery for bowel resection
following a Crohnʼs flare up. Post-op he has been using
hydromorphone 2-4 mg IV q4h
● Day 1 total: 16 mg
● Day 2 total: 12 mg
● Day 3 total: 12 mg
His pain is well controlled and he is now able to take oral
medications. Provide a regimen using hydromorphone PO
TDD = hydromorphone 12 mg IV
Convert to hydromorphone PO → 24 mg
Hydromorphone 4 mg PO q4h
Consider a plan for weaning
Other Pharmacologic Options
Adjuvants
● Gabapentinoids
● Skeletal muscle relaxants
○ E.g., baclofen, cyclobenzaprine, methocarbamol
● Cannabinoids??
● Others
Pain in ICUs
Highly prevalent condition in critical care
Should be managed prior to giving sedation
Common cause of delirium
Often multiple sources of pain
● Predisposing factors
● Precipitating factors
Sources of Pain in ICU
Predisposing factors
● Recent acute pain
● History of chronic pain, arthritis,
fibromyalgia
● Traumatic injuries
● Thermal injury
● Post-operative surgical site pain
● Infection or malignancy causing
inflammation
Precipitating factors
● Device placement
● Re-positioning
● Diagnostic procedures
● Dressing changes
● Mobilization, physiotherapy
● Endotracheal tube suctioning
● Prolonged immobility
Often multiple sources of pain
Pain Assessment
Patient self-report
Behavioural and physiological signs (cues)
Validated tools
Critical Care Pain Observation Tool (CPOT)
Richmond Agitation Sedation Scale (RASS)
Separate tools available to assess delirium
Validated ICU Pain Assessment Scales
Implementation of assessment scales shown to:
● Improve pain management
● ↓ use of sedatives
● ↓ length of ventilation and ICU stay
● ↓ mortality
● ↓ use of opioids in non-communicative patients
Approach to Pain Management
● Identify underlying sources of pain
● Utilize a validated pain scale
● Implement non-pharmacologic measures
● Implement patient-specific analgesia
● Perform regular reassessment
○ Prevent complications of uncontrolled pain
○ Minimize adverse effects
● Monitor for drug withdrawal upon discontinuation
Parenteral Opioids Commonly Used in the ICU
Morphine
- IV bolus: 1-5 mg
- IV infusion: 0.1-10 mg/h
- 5-10 minutes
- duration 2–4 h
- Caution in renal dysfunction, histamine release
hydromorphone
- IV bolus: 0.1-1 mg
- IV infusion: 0.1-1 mg/h
- 5-10 minutes
- 2-5 hours
- Safer option in renal dysfunction, less histamine release
Fentanyl
- IV bolus: 25-100 mcg
- IV infusion: 25-100 mcg/h
- < 2 minutes
- 1-2 hours
- Less hemodynamic effects, least histamine release
May also use concomitant therapy (e.g., APAP, NSAIDs, gabapentinoids, etc)
Opioid Use in the ICU
IV route most commonly used
● PO: patients often have GI dysfunction → altered absorption
● Subcut/IM: altered absorption due to regional hypoperfusion (e.g.,
shock, subcutaneous edema)
Give bolus if pain not controlled and increase continuous infusion rate
Often bolus will be given prior to bedside procedures
Fentanyl is highly lipophilic → can accumulate and cause prolonged sedation
Pre-operative Patient Evaluation
● Surgery type
● Expected postoperative pain type (e.g., nociceptive, neuropathic),
severity, duration
● Past medical history and allergies
● The risk-benefit ratio for available techniques
● Patient preference and previous pain experience
○ Consider patient pre-op opioid tolerance
Pre-operative Patient Evaluation
Assess for persistent post-op pain risk factors
Assess for persistent post-op pain risk factors
● Severe pre-op pain
● Repeat surgery
● High risk of nerve damage
● Severe post-op pain
Consider other potential factors
● Patient required to be NPO
● Fluid status changes
● Causes of incidental pain
Manage medications that may precipitate a withdrawal syndrome
Treat pre-op pain and anxiety
Pre-medicate prior to procedure as part of multimodal analgesic plan
Provide patient education
● Role in reporting pain and adverse effects
● Using prescription and non-prescription therapy
Analgesic Techniques
Single modality
● Non-pharmacologic measures
● Systemic pharmacologic therapy
○ Non-opioid analgesics (e.g., APAP, NSAIDs)
○ Opioids (consider PCA)
○ Gabapentinoids
○ IV ketamine (opioid tolerant or complex patients)
○ IV lidocaine
● Local, intra-articular, or topical
● Peripheral regional (e.g., intercostal or plexus blocks)
● Central regional (e.g., spinal, epidural)
Multimodal (preferred)
● Using ≥ 2 drugs or techniques with variable MOA
● Associated with superior pain relief and ↓ opioid use\
Postoperative Analgesic Strategy
● ATC analgesia for 48-72 hours
● Non-pharmacologic measures
● Non-opioid analgesics
○ ATC acetaminophen or NSAIDs
■ Choice dependent on procedure and patient factors
○ Consider use of gabapentinoids
● Opioids
○ Use short-acting, oral opioids
○ If parenteral required for > few hours, consider PCA instead
of PRN intermittent boluses
