4/3/2018. Management of Acute Pain Crises. Five Mistakes I ve made and why you shouldn t

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Randolf Wilson
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1 Management of Acute Pain Crises Maggie O Connor, M.D. Retired Palliative Care Physician Hope is not the conviction that something will turn out well, but the certainty that something makes sense, regardless of how it turns out. Vaclav Havel Disturbing the Peace Five Mistakes I ve made and why you shouldn t Meperidine (Demerol) Nothing else works for me, doc. Just get comfortable with one (pain) medication so you know it well Narcotic X mg q 4 h prn Narcotic infusion 1-4 mg/hour titrate to comfort Can t give narcotics to an addict 1

2 #1 Meperidine Nothing else works for me, doc. I get nauseated nausea due to narcotics can be treated and is usually transient XYZ doesn t work for me This could be due to inadequate dosing It worked well for me in the past Not unreasonable to take patient preference into consideration but the high incidence of neurotoxicity at therapeutic doses of meperidine is problematic I can t take anything else Get more information Case 1 49 yo single mother Uterine sarcoma Pathological hip fracture In hospital in traction no repair possible Seizure, no history, negative w/u Neurotoxiciy didn t know the signs Equianalgesic dose didn t know the concept #2 Just get comfortable with one narcotic Unique side effects Patient has had a poor past experience with a particular narcotic Flexibility in delivery Neurotoxicity can require rotation of narcotics 2

3 Flexibility in delivery Morphine IV, PO, long and short acting Hydromorphone IV, PO, short acting Oxycodone PO, long and short acting Fentanyl SL, transdermal, less flexible dosing Methadone PO, SL, (IV), only long-acting Equianalgesic dosing Convert to oral morphine Fahrenheit scale Adjust for incomplete cross-tolerance Reduce dose 50-80% if patient has been on a particular narcotic for a time Equianalgesic conversions Not an exact science Do the math don t rely on online calculators Get comfortable with one way of calculating conversions most often, the one your hospital/hospice uses Morphine Hydromorphone Oxycodone Fentanyl patch 3

4 #3 Narcotic X mg q 4 h prn What is the purpose of prn meds? Breakthrough pain Dose finding NOT continuous pain Never start with a long-acting narcotic Fentanyl patches deceptively easy Narcotic X-Y mg q (time to peak) p r n It s all about the pharmacology Range provides flexibility If no relief at peak, no better four hours later i.e. dose is too small Peak levels IV: 5-10 minutes SQ: minutes PO: minutes #4 Narcotic infusion 1-4 mg/hour titrate to comfort Never write this order!?!!???!!!! Why? 4

5 Case 2 Call to Palliative Care Fellow at 11 pm Mr. Patient is in a lot of pain can we increase the basal rate from 1 mg/hour to 2 mg/hr? No Pharmacokinetics of Continuous Infusions # half-lives % Steady State

6 Drug Concentration Drug Concentration Half-life for most common narcotics? # half-lives % Steady State 1 (4 hours) 50 2 (8) 75 3 (12) (16) (20) (28) R R Pharmacokinetics of Continuous Infusion Toxicity Therapeutic Success Therapeutic Failure

7 Response time How soon do you want your heart restarted? How soon do you want relief from 10/10 pain o dyspnea? Even the perfectly dosed infusion takes hours to reach an effective, therapeutic dose Acute Pain Rapid Titration Comfort Code Estimate and give loading dose (iv) If no relief in minutes Double the dose Filling the bucket Once relief obtained Calculate rate for the continuous infusion 7

8 1 mg iv morphine + 2 mg iv morphine + 4 mg iv morphine + 8 mg iv morphine = 15 mg iv morphine = relief of pain How can I tell if I m going to overdose a patient? Pain stimulates respiratory drive What happens to RR when pt in pain? Respiratory rate for sleeping person? 5-10 breaths/minute in normal volunteers 1 mg iv morphine + 2 mg iv morphine + 4 mg iv morphine + 8 mg iv morphine = 15 mg iv morphine = relief of pain 8

9 mg Drug Given Rapid titration in acute pain crisis 8 mg 1 mg 4 mg 2mg 1 mg Hours 15 mg 4 hours (t 1/2) 7.5 mg Half of drug lost in 4 hours. 7.5 mg morphine needs to be replenished over 4 hours 7.5 /4 = mg/hour ~ 2 mg/hour infusion Calculation of continuous infusion Total of doses (TD) mg/2 = X mg Replacement dose mg over 1 half-life X mg/4 hours = infusion rate mg/hour Hourly dose needed to keep the bucket full TD mg /8 = infusion rate mg/hour 9

10 Setting up infusions with PCA Continuous infusion: 2 mg/hour PCA at ¼ hourly dose: 0.5 mg q 15 min Patient able to double hourly rate Case 3 83 yo woman with severe dementia (bedbound, nonverbal), wt 80# Decubitus ulcers on sacrum, both heels, R hip Cries out and stiffens up with any attempts at cares. Screamed when transferred from the ambulance gurney into bed 10

11 Dare we do a Comfort Code?? Think LOW DOSE e.g. hydromorphone 0.2 mg iv or sq 0.2 mg mg mg = 1.4 mg Pain relief in 45 minutes Continuous infusion at??? 1.4 mg /2 = 0.7 mg /4 hr = 0.17 mg/hr ~0.2 mg/hour How long before pain relief if simply started infusion at 0.2 mg/hour? Comfort Code Model works best for cancer pain crisis Constant acute pain (Or severe dyspnea with underlying disease already optimally managed) Not post-op pain Not chronic pain syndrome Moving target Acute pain management Post-op or post-injury pain Pain is stimulus to respiratory drive PRN dosing most appropriate 11

12 Pain Constant infusion Risk of toxicity Chronic Pain Syndrome Complex pain situation Ongoing pain without active tissue damage Comfort code must be applied with care because opioids may not be the best medication for management Oversedation + c/o 10/10 pain Your body doesn t tolerate narcotics # 5 You can t give narcotics to an addict He s got his own anesthetic going She s scamming for drugs You ll just get burned 12

13 Case 4 56 yo woman history of chronic alcoholism presents to ED with severe chest pain suicidal, admitted to psych OD d on acetaminophen CXR - extensive lung cancer, into chest wall Long-acting morphine, Fentanyl, prn MS iv q 1 hour Pain 10+/10 every time she is asked Nurses suggest Palliative Care Consult Case 4 Sleeping 2-3 hours/night Anorexic Exam: Unable to get out of bed 2/2 pain Localized chest wall pain MS intact Affect flat Case 4 Long-acting morphine 60 bid (~40 mg MS iv/24 h) Fentanyl patch 50 mcg (~30 mg MS iv/24 h) MS iv prn 140 mg over past 24 h Total ~170 mg MS iv over past 24 hours or ~ 7 mg/hour, PCA 2 mg q 15 min 13

14 Next Day Feels some relief for first time Total of 330 mg iv morphine/24 hours (continuous infusion + PCA) = ~1000 mg oral morphine Addiction vs. Pseudoaddiction What does somebody in pain do? On the call light Asking for meds early Preoccupied with getting meds What does an addict do? On the call light... Addiction vs. Pseudoaddition Is the person functioning better? OR Lost meds, missed appointments, deteriorating relationships Call from county SW 14

15 Case 4 6 months later Rotated to methadone in hospital Living in nursing home because unable to manage meds at home Regularly visiting with friends/family Still receiving chemorx Gradually increasing med needs because of extension of tumor Opioid Side Effects and Fears Sedation inability to wake up/ foggy thinking rapid tolerance over 2-3 days Exhaustion due to sleep deprivation sleeps a lot but able to wake fully between sleeps resolves over 1-2 weeks as person catches up on sleep Side Effects and Fears Rapid tolerance to: high respiratory depression sedation Minimal or no tolerance to: constipation pain control (assuming pain stable) 15

16 Side Effects and Fears Respiratory depression Rare unless opioid naïve or Sudden decrease in pain (e.g. response to treatment of disease) Neurotoxicity Accumulation of toxic metabolites Renal insufficiency increases risk Side Effects and Fears Neurotoxicity Myoclonus earliest and most frequent symptom Ask family if notice any twitching Hyperalgesia (Agitated) delirium Seizures Side Effects and Fears Neurotoxicity treatment Lorazepam (benzo s) Opioid Rotation Gentle iv hydration High risk 3rd spacing fluids Cachetic, bedbound cancer patient ~500 cc/24 hours (21 cc/hour) Dermoclysis SQ rehydration 16

Take home points Pain is an emergency especially if it is your own A rapid bedside titration of narcotics can safely bring most acute pain under control

17 Take home points Pain is an emergency especially if it is your own A rapid bedside titration of narcotics can safely bring most acute pain under control within hours Don t forget to assess the patient again and again "Life is not holding a good hand. Life is playing a poor hand well."---danish proverb. 17

Equianalgesic Dosing: Making Opioid Interchange Easier. Joseph Bubalo PharmD, BCPS, BCOP Oncology Clinical Pharmacist Assistant Professor Of Medicine

Equianalgesic Dosing: Making Opioid Interchange Easier Joseph Bubalo PharmD, BCPS, BCOP Oncology Clinical Pharmacist Assistant Professor Of Medicine 1 Why Change Opioids? Side Effects Insufficient Pain