A 75-year-old male is admitted to your ICU for management of severe chest pain from unilateral rib fractures with a flail segment following major blunt chest trauma. He has no other injuries. He is haemodynamically stable with a respiratory rate of 30 breaths/min and oxygen saturation of 99% on room air.  
 
Discuss the available options for analgesia, including their advantages and disadvantages.   

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College answer

First-line measures

Paracetamol

Intravenous opioid PCA

Second-line measures

IV ketamine infusion 4-16 mg/h

Tramadol

These have the advantages of simplicity and familiarity.

Disadvantages include lack of efficacy, and side effects of sedation, impaired cough, respiratory depression, and agitation or delirium.

  Regional anaesthetic techniques

 Thoracic Epidural 

Benefits

Analgesia is better than with PCA

Better MIP (maximum inspiratory pressure) than with PCA 

Avoidance of sedation

Less delirium

Less risk of respiratory depression

 Disadvantages

Insertion requires expertise

Risk of failure

Risk of infection

Risk of epidural haematoma

Hypotension

Bradycardia in case of a high block

Intercostal nerve block

Advantages

Simpler than epidural

May require multiple intercostal levels (risk of local anaesthetic toxicity)

Paravertebral catheter infusion

Less effective than epidural, but lower rate of systemic hypotension. 

Patients can be discharged to home with a paravertebral catheter in place. 

Intrapleural infusion

Relatively contraindicated – NSAIDs, COX-2 inhibitors (risk of renal failure and/or GI bleed)

Although there are no randomized trials comparing the efficacy of these modalities, trauma guidelines recommend epidural analgesia for patients with four or more rib fractures and suggest its use in those with fewer fractures who are older than 65 years or who have significant cardiopulmonary disease or diabetes mellitus.

Other options

Although not a primary analgesic option, invasive or non-invasive mechanical ventilation may reduce analgesic requirements by splinting a large flail segment. Disadvantages of complexity, risks associated with intubation, and IMV, as well as patient discomfort and aspiration risk in NIV

Surgical fixation of the fractures

This has been shown to reduce the chronic pain with non-union and help with the weaning of patients with rib fractures causing flail chest, prevents traumatic thoracoplasty

Disadvantages of invasive procedure with associated risks, may require post-operative ventilation.

Discussion

Anything that asks for you to discuss advantages and disadvantages of a series of therapeutic options would benefit from a tabulated answer.

Advantages and Disadvantages of Analgesia Techniques in Blunt Chest Injury
Technique Advantages Disadvantages
Systemic opiates +paracetamol
  • Equivalent to epidural in terms of ICU length of stay and hospital length of stay.
  • Good analgesia
  • Little hypotension
  • Familiar in any ICU/HDU

Adverse effects from opiates, especially:

  • Constipation
  • Nausea
  • Delirium
  • Drowsiness
  • Cough suppression
NSAIDs
  • Salutary analgesic effect
  • Act in synergy with opiates
  • GI haemorrhage risk
  • Platelet dysfunction
  • Little evidence in support
Gabapentin and pregabalin
  • Orally available
  • Some synergistic effect with opiates
  • Sedation
  • Delirium
  • Little evidence in support
Ketamine
  • Potent analgesic
  • Cheap
  • Little hypotension
  • Potent synergistic effect with opiates
  • Delirium/psychosis
  • Sedation
  • Little evidence in support
Epidural

Analgesia is better than with PCA

  • Better MIP (maximum inspiratory pressure) than with PCA
  • Overall improved respiratory function
  • More rapid weaning from ventilator
  • Less delirium and sedation
  • Less risk of respiratory depression
  • If local anaesthetic used alone, possible to avoid opiate side effects
  • Lower incidence of DVT
  • No mortality benefit
  • No ICU length of stay reduction, or in hospital stay for that matter (in fact, a trend towards slightly longer hospital stay)
  • Requires skill for placement
  • Not   always   effective   (can   get patchy block)
  • Hypotension 
  • May mask other injuries
  • Risk of epidural haematoma
Regional techniques (paraveretebral, intrapleural)
  • Similar to epidural in positive effect
  • Fewer side-effects as compared to epidural
  • Less hypotension
  • Little evidence in support
  • Larger doses of local anaesthetic promote the risk of LA toxicity
  • Risk of pneumothorax
Ventilation
  • Satisfactory analgesia by simple mechanical effect
  • May prevent some of the risks of rib fractures (eg pneumonia developing due to hypostasis)
  • May require intubation
  • NIV may not be very well tolerated
  • Potentiates air leak in penumothorax
  • Exposes patient to risk of VAP
  • Increases length of ICU stay
Surgical fixation
  • Mechanical stability promotes good analgesia
  • Supported by the most recent evidence (Becks et al, 2018); improves short term outcomes
  • Unclear patient selection criteria (who benefits?)
  • Highly invasive
  • Expensive
  • Requires well-practiced surgical team
  • May prolong duration of ventilation and ICU stay
  • The patient needs to be able to sustain one-lung ventilation for anaesthesia

References

Wu, Christopher L., et al. "Thoracic epidural analgesia versus intravenous patient-controlled analgesia for the treatment of rib fracture pain after motor vehicle crash." Journal of Trauma-Injury, Infection, and Critical Care 47.3 (1999): 564-567.

MACKERSIE, ROBERT C., et al. "Prospective evaluation of epidural and intravenous administration of fentanyl for pain control and restoration of ventilatory function following multiple rib fractures." Journal of Trauma-Injury, Infection, and Critical Care 31.4 (1991): 443-451.

Kieninger, Alicia N., et al. "Epidural versus intravenous pain control in elderly patients with rib fractures." The American journal of surgery 189.3 (2005): 327-330.

Moon, M. Ryan, et al. "Prospective, randomized comparison of epidural versus parenteral opioid analgesia in thoracic trauma." Annals of surgery 229.5 (1999): 684.

Jarvis, Amy M., et al. "Comparison of epidural versus parenteral analgesia for traumatic rib fractures: a meta-analysis." OPUS 12 (2009): 50-57.

Galvagno Jr, Samuel Michael, et al. "Pain management for blunt thoracic trauma: A joint practice management guideline from the Eastern Association for the Surgery of Trauma and Trauma Anesthesiology Society." Journal of Trauma and Acute Care Surgery 81.5 (2016): 936-951.

Curtis, Kate, et al. "ChIP: An early activation protocol for isolated blunt chest injury improves outcomes, a retrospective cohort study." Australasian Emergency Nursing Journal 19.3 (2016): 127-132.

Carrie, Cédric, et al. "Bundle of care for blunt chest trauma patients improves analgesia but increases rates of intensive care unit admission: A retrospective case-control study." Anaesthesia Critical Care & Pain Medicine 37.3 (2018): 211-215.

Galvagno Jr, Samuel Michael, et al. "Pain management for blunt thoracic trauma: a joint practice management guideline from the Eastern Association for the Surgery of Trauma and Trauma Anesthesiology Society." Journal of Trauma and Acute Care Surgery 81.5 (2016): 936-951.

Zaw, Andrea A., et al. "Epidural analgesia after rib fractures." The American Surgeon 81.10 (2015): 950-954.

Peek, Jesse, et al. "Comparison of analgesic interventions for traumatic rib fractures: a systematic review and meta-analysis." European Journal of Trauma and Emergency Surgery (2018): 1-26.

Karmakar, Manoj K., and Anthony M-H. Ho. "Acute pain management of patients with multiple fractured ribs." Journal of Trauma and Acute Care Surgery 54.3 (2003): 615-625.

Beks, Reinier B., et al. "Fixation of flail chest or multiple rib fractures: current evidence and how to proceed. A systematic review and meta-analysis." European Journal of Trauma and Emergency Surgery (2018): 1-14.