Can we prevent chronic pain after surgery?

1. Colin J.L. McCartneyColin J.L. McCartney
MBChB PhD FCARCSI FRCA FRCPCMBChB PhD FCARCSI FRCA FRCPC
Professor and Chair of Anesthesiology and Pain MedicineProfessor and Chair of Anesthesiology and Pain Medicine
University of OttawaUniversity of Ottawa
Head of Anesthesiology and Pain MedicineHead of Anesthesiology and Pain Medicine
The Ottawa HospitalThe Ottawa Hospital
Scientist, Ottawa Hospital Research InstituteScientist, Ottawa Hospital Research Institute
Chronic Pain after Surgery:Chronic Pain after Surgery:
Does it matter and can weDoes it matter and can we
prevent it?prevent it?

2. Conflicts of InterestConflicts of Interest

3. Objectives (40 mins)Objectives (40 mins)
 Understand incidence of CPSP (10 mins)Understand incidence of CPSP (10 mins)
 Who are the populations at risk? (10 mins)Who are the populations at risk? (10 mins)
 What new approaches exist for preventingWhat new approaches exist for preventing
CPSP? (15 mins)CPSP? (15 mins)
 What does the future hold? (15 mins)What does the future hold? (15 mins)

4. SummarySummary
 Chronic pain is a $10 billion burden perChronic pain is a $10 billion burden per
year to Canadian Health Careyear to Canadian Health Care
 CPSP defined as pain >2 months afterCPSP defined as pain >2 months after
surgerysurgery
 312 million major surgical procedures per312 million major surgical procedures per
year worldwideyear worldwide
 1 year incidence of CPSP 12-22%1 year incidence of CPSP 12-22%
 20% of adults and 17% children at pain20% of adults and 17% children at pain
clinics have CPSPclinics have CPSP

5. SummarySummary
 CPSP common and varies by type of surgeryCPSP common and varies by type of surgery
 Preoperative pain and psychological factorsPreoperative pain and psychological factors
major predictorsmajor predictors
 Prevention possible with high qualityPrevention possible with high quality
perioperative pain relief including LA techniques,perioperative pain relief including LA techniques,
NMDA antagonists and surgical approachNMDA antagonists and surgical approach
 Future management possibilities include novelFuture management possibilities include novel
therapeutic, psychological andtherapeutic, psychological and
pharmacogenomic approachespharmacogenomic approaches

8. Incidence ofIncidence of
Chronic Post-Surgical PainChronic Post-Surgical Pain
 Pain after surgery of primary concern toPain after surgery of primary concern to
patients (Apfelbaum et al 1999)patients (Apfelbaum et al 1999)
 Acute postoperative pain remainsAcute postoperative pain remains
undertreatedundertreated
 Incidence of severe acute pain a problemIncidence of severe acute pain a problem
 Severe acute pain associated with CPSPSevere acute pain associated with CPSP
 Definition: pain >2 months after surgeryDefinition: pain >2 months after surgery

10. A&A 2003

11.  300 patients300 patients
 2/3 had moderate-severe pain after2/3 had moderate-severe pain after
surgerysurgery
 No change from 10 years earlierNo change from 10 years earlier
Gan TJ et al CMRO 2014

12. Or does it?

13.  5130 patients attending chronic pain5130 patients attending chronic pain
clinicsclinics
 Surgery contributed to pain in 22.5%Surgery contributed to pain in 22.5%
 Research needed into: aetiology andResearch needed into: aetiology and
procedures contributing to highest risk ofprocedures contributing to highest risk of
CPSP.CPSP.
 Preventive strategiesPreventive strategies
Pain 1998

14.  Prevalence of persistent postsurgical painPrevalence of persistent postsurgical pain
 12982 participants/3111 undergone surgery12982 participants/3111 undergone surgery
within 3 yearswithin 3 years
 Persistent pain in 40.4%. Mod-Severe 18.3%Persistent pain in 40.4%. Mod-Severe 18.3%

16. Poulakka PA et al EJA 2010

18. Differentiating CPSPDifferentiating CPSP

19.  Systematic review. 281 studies assessedSystematic review. 281 studies assessed
investigating PSPS in 11 surgical typesinvestigating PSPS in 11 surgical types
 Prevalence of NeuP determined using NeuPPrevalence of NeuP determined using NeuP
grading systemgrading system
 Prevalence of NeuP high after thoracic andPrevalence of NeuP high after thoracic and
breast surgery (66/68%). 31% after groin herniabreast surgery (66/68%). 31% after groin hernia
repair and 6% after THA and TKArepair and 6% after THA and TKA
 Prevalence of PneuP varies by type of surgeryPrevalence of PneuP varies by type of surgery
and probability of nerve injuryand probability of nerve injury

20.  >200 patients with MSK trauma>200 patients with MSK trauma
 Testing at baseline and 4 months after injuryTesting at baseline and 4 months after injury
 Injury severity, pain, anxiety, depression andInjury severity, pain, anxiety, depression and
PTSDPTSD
 21% moderate to severe pain at baseline and21% moderate to severe pain at baseline and
11% at 4 months11% at 4 months
 High prevalence of neuropathic painHigh prevalence of neuropathic pain
 Neuropathic pain poorly managed in-hospitalNeuropathic pain poorly managed in-hospital

21. Chronic Pain after SurgeryChronic Pain after Surgery

22. Risk Factors for CPSP?Risk Factors for CPSP?
 Preoperative: Pain, Repeat surgery,Preoperative: Pain, Repeat surgery,
Psychological factors, Female gender andPsychological factors, Female gender and
younger age, Genetic predispositionyounger age, Genetic predisposition
 Intraoperative: Surgical approach andIntraoperative: Surgical approach and
risks of nerve injuryrisks of nerve injury
 Postoperative: Acute Pain, Radiation Rx,Postoperative: Acute Pain, Radiation Rx,
Neurotoxic chemotherapy, Anxiety andNeurotoxic chemotherapy, Anxiety and
Depression, NeuroticismDepression, Neuroticism
McIntyre et al 2010

23. What can we do about theWhat can we do about the
problem?problem?
 Regional anesthesia techniquesRegional anesthesia techniques
 Systemic drug interventionsSystemic drug interventions
 Modified surgical techniquesModified surgical techniques
 Focus on postoperative pain controlFocus on postoperative pain control

24.  Case: Patient with two TKA proceduresCase: Patient with two TKA procedures

25. Regional anesthesia techniquesRegional anesthesia techniques

26.  23 RCTs in total23 RCTs in total
 Pooled 3 studies for epidural afterPooled 3 studies for epidural after
thoracotomy and 2 for PVB after breastthoracotomy and 2 for PVB after breast
surgerysurgery
 Unable to pool data from other studies dueUnable to pool data from other studies due
to marked heterogeneityto marked heterogeneity

27. Andreae MH et al BJA 2013

28.  Case: Call from home 3 days post-surgeryCase: Call from home 3 days post-surgery

29. Perioperative pharmacotherapyPerioperative pharmacotherapy
 KetamineKetamine
 LidocaineLidocaine
 GabapentinoidsGabapentinoids
 NSAIDSNSAIDS

30. KetamineKetamine

31. 2013 Cochrane Collaboration

33.  No long term benefit for:No long term benefit for:
– GabapentinGabapentin
– PregabalinPregabalin
– NSAIDSNSAIDS
– CorticosteroidsCorticosteroids
– MexilitineMexilitine
2013 Cochrane Collaboration

34. Other techniquesOther techniques
 IV LidocaineIV Lidocaine
 DexmedetomidineDexmedetomidine

39.  Case: Chronic pain post-hernia repairCase: Chronic pain post-hernia repair

40. Modified Surgical TechniquesModified Surgical Techniques

43. Future PossibilitiesFuture Possibilities
 Impact of psychological factorsImpact of psychological factors
 Pharmacogenomics and personalizedPharmacogenomics and personalized
medicinemedicine
 Novel ‘analgesic’ agentsNovel ‘analgesic’ agents

44. Psychological FactorsPsychological Factors

45.  Preoperative painPreoperative pain
 Pain catastrophizingPain catastrophizing
 Mental healthMental health
 Pain at other sitesPain at other sites

46. Pain 2013

47. Predictive Factors Post-Predictive Factors Post-
MastectomyMastectomy
Schreiber et al Pain 2013

50. Pain GeneticsPain Genetics

51. PharmacogenomicsPharmacogenomics

52. Genetics of PainGenetics of Pain
 3 variants (haplotypes) of gene encoding3 variants (haplotypes) of gene encoding
COMT predicting low, moderate and highCOMT predicting low, moderate and high
sensitivity to painsensitivity to pain
 Encompass 96% of humansEncompass 96% of humans
 Low COMT levels predict high painLow COMT levels predict high pain
sensitivity and risk of developing TMDsensitivity and risk of developing TMD
 Inhibition of COMT in rat model increasesInhibition of COMT in rat model increases
pain sensitivitypain sensitivity
Diatchenko L et al 2005

53.  CPSP is likely 50% influenced by geneticCPSP is likely 50% influenced by genetic
determinantsdeterminants
 Identifying genetic basis of CPSP couldIdentifying genetic basis of CPSP could
lead to significant improvement inlead to significant improvement in
treatmenttreatment
 Prediction of CPSP, PharmacogenomicsPrediction of CPSP, Pharmacogenomics
 Improved treatmentsImproved treatments
CJA 2015

54. Novel neuroactive agentsNovel neuroactive agents
 Not analgesic per seNot analgesic per se
 Prevent mechanism of transition to chronicPrevent mechanism of transition to chronic
painpain
 rhBDNF, neuroprotective agents (e.g.rhBDNF, neuroprotective agents (e.g.
acetyl l-carnitine) and anti-oxidantsacetyl l-carnitine) and anti-oxidants
 Early promising resultsEarly promising results
Bordet T et al Neurotherapeutics 2009

55. SummarySummary
 CPSP common and varies by type of surgeryCPSP common and varies by type of surgery
 Preoperative pain and psychological factorsPreoperative pain and psychological factors
major predictorsmajor predictors
 Prevention possible with high qualityPrevention possible with high quality
perioperative pain relief including LA techniquesperioperative pain relief including LA techniques
and NMDA antagonists and surgical approachand NMDA antagonists and surgical approach
 Future management possibilities include novelFuture management possibilities include novel
therapeutic, psychological andtherapeutic, psychological and
pharmacogenomic approachespharmacogenomic approaches

56. Good Acute Pain Control MajorGood Acute Pain Control Major
Concern for PatientsConcern for Patients
Apfelbaum et al A&A 2003

57. Acute pain controlAcute pain control
 Use regional anesthesia where possibleUse regional anesthesia where possible
 Use NSAIDS, paracetamol in multimodalUse NSAIDS, paracetamol in multimodal
regimenregimen
 For higher risk cases use ketamine and/orFor higher risk cases use ketamine and/or
lidocaine infusion during surgerylidocaine infusion during surgery
 Gabapentin/Pregabalin useful for acuteGabapentin/Pregabalin useful for acute
pain control and reduction of opioidpain control and reduction of opioid
consumptionconsumption

59. Pain Management 2016

60. Transitional Pain ServiceTransitional Pain Service
 Pre-operative review, acute postoperativePre-operative review, acute postoperative
and long-term follow upand long-term follow up
 Patients identified early and referredPatients identified early and referred
 Co-ordinated care by pain physicians,Co-ordinated care by pain physicians,
psychologists, physiotherapists andpsychologists, physiotherapists and
advanced practice nursesadvanced practice nurses
 Bypasses long wait times for chronic painBypasses long wait times for chronic pain
clinicclinic

61. Risk of Developing PersistentRisk of Developing Persistent
Opioid Use after Major SurgeryOpioid Use after Major Surgery
Soneji N et al JAMA Surg 2016

62.  Epidemiology better understoodEpidemiology better understood
 Literature still hampered by varying definitionsLiterature still hampered by varying definitions
and types of painand types of pain
 Shift in attitude occurring: transitional painShift in attitude occurring: transitional pain
programprogram
 Better research developing from centres ofBetter research developing from centres of
excellenceexcellence

63. cmccartney@toh.ca