OI Pain ManagementEdward Dolomisiewicz, MD

MAJ, MC, USAPM&R and Pain Medicine

Department of Rehabilitation

Disclosures:Financial: None

The views expressed in this presentation are those of the presenter and do not reflect the official policy of the Department of Army, Department of Defense, or United States Government.

Objectives• Emphasize interdisciplinary pain management• Know pain risk factors associated with traumatic amputation• Review some pain management treatment options

Pain DefinedAn unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage—International Association for the Study of Pain

Pain Phenotypes and Risk Factors

• Most military service members report phantom and residual limb pain after amputation

• Risk factors for significant neuropathic pain or neuropathic pain of any severity:• PTSD• Depression• Catastrophizing• Absence of regional analgesia catheter

• Other associations with chronic postoperative pain• Preoperative opioid use especially at higher doses• Preoperative anxiety

Perioperative Pain Management and Mitigation • Gabapentinoids

• Gabapentin• Pregabalin

• NMDA antagonists• Ketamine

• NSAIDs*/acetaminophen• Interventional modalities

• Perineural catheter• Epidural analgesia

• Opioids as needed• Wean as soon as possible

*not recommended for OI patients—bone healing

Sciatic Nerve Block, digital image, NYSORA, 2017, http://bnkclient.com/ultrasound-guided-popliteal-sciatic-block

Diagnosing Pain

Causes• Phantom limb pain• Residual limb pain

• Neuroma• Inflammation/edema• Heterotopic ossification• Bone erosion• Bursa• Infection• Thrombus• Surgical complication

• Complex Regional Pain Syndromea) Lateral radiograph of distal residual limb, b) Neuroma visualized at the distal fibula by ultrasound long Axis View, O'Reilly, Marian AR, et al. "High-resolution ultrasound findings in the symptomatic residual limbs of amputees." Military medicine 178.12 (2013):1291-1297.

Ultrasound Guided Neuroma Injection

Interdisciplinary Pain Team• Acute Pain Physicians• Chronic Pain Physicians• Physiatrists• Behavioral Health Specialists• Primary Care Physicians• Surgical Specialists• Physical Therapists• Occupational Therapists• Prosthetists• Acupuncturists Log PT, Digital Image, photographer unknown,

https://upload.wikimedia.org/wikipedia/commons/d/dd/US_Army_soldiers_in_SFAS_class_0410_participates_in_log_and_rifle_PT_at_Camp_MacKall_on_Wednesday,_January_13,_2010..jpg

Interdisciplinary Chronic Pain Management

• Modalities• TENS, mirror, motor imagery,

virtual feedback, desensitization, laser, alpha stim

• CAM• Acupuncture

• Behavioral health• Sleep management, biofeedback,

mindfulness, CBT

• Pharmaceuticals• Oral: TCAs, SNRIs, gabapentinoids,

opioids, cannabinoids• Topical: compound creams,

capsaicin• Interventional

• Nerve blocks, corticosteroid injections, ablation, neuromodulation

• Surgical• TMR/TSR, HO excision, etc.

Cannabinoids—Endocannabinoid System• Play a role in the inhibitory control of nociception (pain)• Receptors

• CB1• Inhibit nociceptive transmission• Modifies emotional component acting at limbic system

• CB2• Reduces release of pronociceptive agents• Modulates immune responses leading to sensitization

• Endogenous ligands• N-arachidonoylethanolamine (anandamide)• 2-arachidonoylglycerol (2-AG)

Dronabinol (Marinol)Composition: THC from cannabis resin + sesame oilIndication: appetite stimulant and antiemeticOff-label: neuropathic pain, spasticityDosing for pain: 2.5 – 10mg (20?) daily, typically divided BIDMechanism of action: activates CB1 > CB2 receptorsDuration: 4-6hrs (psychoactive) >24hrs (appetite stim)

½ life biphasic: initial 4-5hrs, terminal 25-36hrsControlled: schedule III

Dronabinol Warnings and Contraindications • Known allergy• Caution with driving/machinery• Seizure disorders - possible lowered threshold• Cardiac disorders – BP fluctuations, syncope, tachycardia• Psych – substance abuse or mood disorders• Elderly – may be more sensitive• Pregnancy – Class C, not recommended if nursing

Dronabinol Side Effects

• Euphoria• Asthenia• Palpitations• Tachycardia• Vasodilation• Facial flush• Abdominal pain• Nausea and vomiting

• Anxiety or nervousness• Confusion • Depersonalization • Dizziness • Hallucinations • Paranoid reaction • Somnolence• Abnormal thinking

Capsaicin (Qutenza) 8% Patch

• “Hot” ingredient of chili peppers• Agonist of TRPV1 nocireceptors• Effective for neuropathic pain• Applied for 60min in outpatient

setting• Peak effect reached in 1-2 weeks• May provide pain relief for up to

3mos

Left: Capsaicin patch, Right: patch applied to residual limb. Privitera, Rosario, et al. "Capsaicin 8% patch treatment for amputation stump and phantom limb pain: a clinical and functional MRI study." Journal of pain research 10 (2017): 1623.

Capsaicin 8% Patch

Left: outline of pinprick hypersensitivity (blue) and allodynia (red/green) prior to treatment, Right: outline pinprick hypersensitivity (blue) and allodynia (red/green) after treatment. Privitera, Rosario, et al. "Capsaicin 8% patch treatment for amputation stump and phantom limb pain: a clinical and functional MRI study." Journal of pain research 10 (2017): 1623.

Neuromodulation

• Modulation of nerve activity through electrical or pharmaceutical agents

• Neuraxial vs peripheral lead placement

• Temporary vs permanent• Permanent: trial prior to implantation

• Paresthesia vs paresthesia-free programming

• Safe and effective Left: DRG epidural lead placement, Right: paramedial epidural lead placement. Deer, Timothy R., et al. "Dorsal root ganglion stimulation yielded higher treatment success rate for complex regional pain syndrome and causalgia at 3 and 12 months: a randomized comparative trial." Pain 158.4 (2017): 669.

Summary

• Pain associated with amputation/osseointegration can be complex and may require complex pain management strategies

• Interdisciplinary, multimodal, multimechanistic, and opioid sparing pain management is strongly recommended

• Constant surveillance and communication by the interdisciplinary team is critical in order to expeditiously treat patients and mitigate poor outcomes

Questions?

References• Buchheit, Thomas, et al. "Pain phenotypes and associated clinical risk factors following traumatic

amputation: results from Veterans Integrated Pain Evaluation Research (VIPER)." Pain Medicine 17.1 (2016): 149-161.

• Herrador Colmenero, Laura, et al. "Effectiveness of mirror therapy, motor imagery, and virtual feedback on phantom limb pain following amputation: a systematic review." Prosthetics and orthotics international 42.3 (2018): 288-298.

• Kent, Michael L., et al. "Perioperative pain management strategies for amputation: a topical review." Pain Medicine 18.3 (2017): 504-519.

• Lexi-Comp, INC. (Lexi-Drugs). Lexi-Comp, inc.; Jan 28, 2018• Maldonado, Rafael, Josep Eladi Baños, and David Cabañero. "The endocannabinoid system and neuropathic

pain." Pain157 (2016): S23-S32.• Meng, Howard, et al. "Selective cannabinoids for chronic neuropathic pain: a systematic review and meta-

analysis." (2017): 1638-1652.• Petersen, Bailey A., et al. "Phantom limb pain: peripheral neuromodulatory and neuroprosthetic approaches

to treatment." Muscle & nerve 59.2 (2019): 154-167.• Privitera, Rosario, et al. "Capsaicin 8% patch treatment for amputation stump and phantom limb pain: a

clinical and functional MRI study." Journal of pain research 10 (2017): 1623.