Pain management Coleman Palliative Care Conference: February 2016 Josh Baru MD Stacie Levine MD
Case #1 61 yo man with history of Stage 3 colon cancer, s/p resection and adjuvant chemotherapy with FOLFOX now in remission. 8 years later, presented with right sided chest pain and weight loss.
Adenocarcinoma
Started on chemotherapy (Carboplatin/Pemetrexed) Developed progressive chest pain, respirophasic upper back pain and dyspnea. Meds uptitrated by Oncologist in consultation with pain service Return to ED 3 months after initiation of chemotherapy with severe, uncontrolled pain despite treatment at home. Repeat CT.
Meds: Fentanyl patch 100mcg/hr q72h Hydromorphone 4mg PO Q3h PRN Gabapentin 600mg PO TID Docusate-senna 1 tab PO BID
He has been taking 2-3 of his hydromorphone tabs every 3 hours for the past 18 hours. Before meds: pain 20/10 After meds: pain 10/10 Spending most of time in bed, irritable, can t sleep, no appetite
Exam T: 99.3, HR 103, BP 125/81 Brow furrowed, uncomfortable appearing Tender to palpation over entire anterior chest wall; no masses Tachypneic, splinting respirations, decreased breath sounds over lower 1/3 of R lung field Rest benign
Acute pain crisis How do you treat this pain crisis? What do you do with his fentanyl? How do you administer the breakthrough meds? Bolus dosing PCA
What is this patient s 24 hour oral morphine equivalent (OME)?
Our patient Opioid usage Fentanyl 100mcg/hr 200mg oral morphine/24hr Hydromorphone 8mg (2 tabs) PO q3h x 6 (18 hours) 48mg PO hydromorphone 192 mg (48*4) oral morphine TOTAL USAGE: 392 mg oral morphine equivalent (OME)
What would you recommend as a starting bolus dose using IV morphine? IV hydromorphone? Dose: 10% of 24 hour usage
Acute pain crisis Opioid bolus algorithm Dose: 10% of 24 hour usage Starting bolus dose: 39.2 mg OME 13mg IV morphine 2mg IV hydromorphone Re-assess every 10-15 mins Rebolus if: Partial control: same dose (50% decrease if SEs) Partial control : decrease in VAS of 2 Uncontrolled (severe): increase by 50-100% Uncontrolled : no improvement in pain score
Our patient 11:00 AM: Given 2mg IV hydromorphone 11:20 AM: Pain 10/10 Given 4mg IV hydromorphone 11:35 AM: Pain 7/10 Given 4mg IV hydromorphone 11:55 AM: Pain 4/10 ( tolerable ); alert, no SEs
Maintenance regimen If you wanted to administer a round-the-clock, hydromoprphone bolus regimen to manage this patient s pain, what dose and frequency would you give? What would your breakthrough dose be?
Acute pain crisis Maintenance regimen: Bolus dosing + breakthrough Mild pain, no SEs (Total amount administered) q 4h + 0.1(Total 24-hour dose) q1h PRN No pain OR Ses 0.5(Total amount administered) q4h + 0.1(Total 24-hour dose) q1h PRN EXAMPLE: 10mg IV hydromorphone administered Order: 10mg IV hydromorphone q4h RTC 6mg IV hydromorphone q1h
Acute pain crisis Maintenance regimen: PCA What drip do you start? Medication? Dose/Rate? If you are going to give a bolus, what dose do you give? What is the demand dose? What is the frequency?
Comparing opioid drips Drug Potency Metabolites Cost* Morphine Active $ Hydromorphone Minimally active $$ Fentanyl Inactive $$ *Note that cost depends on doses used as PCAs are charged per unit
Based on your round-the-clock calculation, if you wanted to give this patient a hydromorphone drip, what dose would you choose?
Calculating drip rate Calculated total daily dose: Hydromorphone 10mg IV Q4h= 60mg/24h 60/24= IV hydromorphone 2.5mg/hr IV Morphine: ~15mg/hr (2.5*6) IV fentanyl: ~ 160mcg/hr (2.5/15)
Acute pain crisis Conversion to PCA If you stop the fentanyl, what drip do you start? Medication? Dose/Rate? What is the demand dose? What is the frequency?
If you wanted to convert this regimen to a hydromorphone PCA with a continuous infusion, what would your drip dose be? What would your demand dose be?
Acute pain crisis Opioid bolus Calculating the bolus dose 10% of 24 hour rate/hour 50-150% of basal rate EXAMPLE: IV hydromorphone 60mg/24hr Breakthrough=6mg/hr (1.5mg q15mins OR 1mg q10mins)
Case # 2 50 yo female, former heroin abuse admitted to hospital with increasing abdominal pain and early satiety Home medications: Methadone 60 mg po daily, Tylenol up to 8 grams/day, Aleve prn Pain history: vague, aching, located in mid epigastrum, radiates into her back, 10/10, wakes her up at night, some nausea when severe On exam, ill-appearing and cachetic, stable VS, abdominal is distended and painful to touch, non-tender spine, no fluid wave Labs: LFTs:AST/ALT 300/356, Cr 1.9 (unclear baseline)
CT: Metastatic pancreas cancer
Questions What options do you have to address her pain? Explain why or why not you would choose certain options. What do we do with the Methadone?
Acute pain management for patients on Opioid Agonist Therapy (OAT) for addiction Methadone Buprenorphine
Common misconceptions The OAT provides analgesia Use of opioids in these patients may result in addiction relapse Additive effects of opioid analgesics and OAT may cause respiratory and CNS depression The pain complaint may be drug-seeking
The truth OAT at once daily dosing to prevent withdrawal (24-48 hrs) not consistent with duration of action for analgesia (4-8 hrs) Opioid tolerance is real patients have less effect and for shorter duration when adding another opioid Opioid-hyperalgesia can occur - latent, due to neuro-plastic changes from long-term exposure Stress from uncontrolled pain more likely to cause relapse than treating the pain with an opioid Tolerance to side effects is high for patients on OAT OAT treatment blocks euphoric effect of other opioids
Recommendations - Methadone Continue usual dose of po methadone, but must verify dose with the program If patient cannot take po, give 50% in IV form and divide q 6 or q 8 (example: 60 mg po reduce to 30 mg IV, give 10 mg IV q 8) Add an opioid co-analgesic, higher doses and shorter interval of immediate release with continuous or scheduled dosing Long-acting opioids may cause less euphoric effects Notify methadone program upon discharge of new plan
Our patient Methadone and other home meds continued Celiac plexus block on admission: initially brought pain from 10/10 to 3/10, then increased two days later to 10/10 Steroids added decadron 8 mg po qam, plus PPI Started hydromorphone 1 mg IV q 2 which escalated to 2, then 3 mg IV q 2, switched to IV gtt at 2 mg/hr, with increasing pain, despite multiple boluses q 2 and increase in drip rate Question what could be going on?
Opioid induced hyperalgesia (OIH) Neuroplastic changes in the peripheral and CNS, sensitization of pronociceptive pathways Central glutaminergic system, NMDA Must be differentiated from tolerance which gets better with increase in opioid Exam often find diffuse, ill-defined pain outside of level of original pain source, allodynia Can mimic opioid withdrawal
Our patient Severe abdominal and back pain, 20/10, unable to obtain a comfortable position Renal function declined to 2.5 Non-contrast CT abd/pelvis and Xray no changes OIH leading diagnosis
OIH - Treatment Reduce dose of current opioid Opioid rotation (methadone most common) Hydration Select other medications with pain properties (SNRI) Ketamine -uncompetitive antagonist of the phencyclidine binding site of NMDA receptor -usually given in hospital via infusion -dissociative side effects
Our patient Reduced hydromorphone Hydration Interventional pain performed second block Once pain and renal function improved she was discharged on LA morphine and back to methadone program
Acute pain crisis Opioid side effects Nausea Haldol Sedation Methylphenidate?? Respiratory depression Diluted naloxone Urinary retention Pruritis Myoclonus Opioid induced hyperalgesia