Grand Rounds Recap 8.17.22
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Ultrasound in Cardiac Arrest WITH Dr. Stolz
General Epidemiology
Out of hospital cardiac arrest causes are almost as varied as patients themselves. We must both avoid anchoring to a certain etiology while treating the presumed cause of arrest.
~30% of OHCA will survive to hospital admission
~10 % of OHCA will survive to hospital Discharge
~8% of OHCA will survive with good neurologic function
How can we use Ultrasound as an aid to improve
Goal
Differentiate Organized cardiac rhythm from Asystole, True PEA and PseudoPEA
PEA - Organized electrical activity without palpable pulses
True PEA Organized electrical activity without cardiac motion
PseudoPEA-organized electrical activity without a palpable pulse with organized cardiac motion
Find reversible causes of cardiac arrest
Guide procedures
In observational studies Ultrasound has been shown to improve survival in OHCA and in-ED cardiac arrest (Here)
In patients with a PEA arrest who achieved rosc 43% have been seen to have cardiac activity on US
Cardiac Activity on Ultrasound
Many different definitions and hard to come to a consensus but ventricular wall motion is likely the most agreed upon predictor.
Reversible causes which are identifiable on Ultrasound
Hypovolemia
Tension Pneumothorax
Tamponade
PE
Ultrasound as a Hindrance to resuscitation
Pulse check duration
Multiple studies have shown that pulse checks with ultrasound take longer and longer time without compressions is bad
This is a modifiable behavior which can be changed to create parity between ultrasound and non-ultrasound pulse checks
Interference with needed interventions
Ultrasound is not an IV.
It is not airway support.
It is not chest compressions.
Ultrasound needs to take a backseat to all of these things.
Best done after initial vital interventions are done
ACCESS, MONITOR, AIRWAY iGel, oxygen
LUCAS
Accuracy
There has been seen to be little agreement between interpretation of cardiac stand still on ultrasound by EM physicians, cardiologists,intensivists, faculty, fellows, and residents.
Confounders
Mechanical Ventilation can cause valve flutter
Bradycardia can complicate pulse checks
RV dilation occurs to some extant after cardiac arrest for multiple reasons
Hypoxia, pulmonary vasoconstriction, PA pressure elevation, RV afterload
Best Practices in Cardiac Arrest POCUS
PRO-10
Prepare before the pause
Coordinate so probe is in place prior to pulse check
This makes pulse checks faster
Review after CPR resumes
Take a clip during the Pause in CPR
Review the clip once CPR has resumed
Consider
Cardiac activity
Pericardial effusion
LV size/function
RV size/function
Other provider performs the US
This allows the Resuscitationist to offload this cognitive burden and will allow images to be acquired with less delay
<10s duration pause in CPR
Set clip duration to 10 seconds
Assign a count down person
Ignore the person doing the ultrasound
Not Another Boring Lecture WITH Dr. Santen, Broadstock and Zalesky
Learners retain
5-10% by reading
5-30% by hearing
20-40% with audiovisual
30% demonstration
50% with discussion
70% with saying the information
90% say, hear and do
90% if they have to teach others
Techniques to improve lectures in a lecture hall style room
Muddiest point: have learners write down the most confusing part of the lecture
1 minute paper: take one minute to write down what you have learned
Pretest: test the audience on the information before the teaching. This primes them on what to listen to and identifies knowledge gaps. This is followed by a post test to show knowledge acquisition.
Round table discussion: make people engage in the conversation
Fishbowl: pulls people up front and others watch them have the conversation. People can tap out and have others fill the role
More Resources found here
Topics covered
TEG resuscitation
Check out this great TTS post https://www.tamingthesru.com/blog/grand-rounds/teg
Rule of 55s
R time Abnormal if > 55 seconds
Angle Abnormal if < 55 degrees
MA abnormal if < 55mm
Ly30 abnormal if >3%
Uveitis
Ddx of red eye:
extra-ocular causes (e.g. orbital cellulitis, cavernous sinus thrombosis, carotid-cavernous fistula, cluster headache)
external eye disease (e.g. eyelid and conjunctival disease)
internal eye disease (e.g. iritis, glaucoma)
If extra-ocular cause is excluded, determine:
Painful:
abnormal cornea
e.g. herpes simplex keratitis, corneal ulcer, marginal keratitis, corneal abrasion, chemical burn
abnormal eyelid
e.g. chalazion/stye, acute blepharitis, herpes zoster ophthalmicus
diffuse conjunctival injection
e.g. viral conjunctivitis, allergic conjunctivitis, bacterial conjunctivitis (including chlamydia), dry eyes, acute glaucoma
ciliary injection/ scleral involvement
e.g. scleritis, episcleritis
anterior chamber involvement
e.g. acute anterior uveitis (iritis) from autoimmune disease, traumatic iritis, hypopyon, hyphema
Other: ocular foreign body, globe rupture, endophthalmitis
Painless:
Diffuse
usually this is an eyelid abnormality as most cases of conjunctivitis are painful: e.g. blepharitis, ectropion, trichiasis, entropion, eyelid lesion (e.g. tumor, stye)
Localized
e.g. pterygium, corneal foreign body, ocular trauma, subconjunctival hemorrhage
Other: leptospirosis, kawasaki disease, adenovirus
Workup:
pupillary examination, visual acuity, slit-lamp exam (cell/flare), fluorescein staining, tonometry
ESR/CRP, RPR, HIV, Toxo
Diagnosis:
ocular syphilis can affect several parts of the eye (briefly cover anterior vs posterior chamber)
This is often panuveitis (anterior and posterior), posterior uveitis (chorioretinitis), or more rarely anterior uveitis (iritis). Among patients with anterior uveitis, they are more likely to be HIV+
Supreme Court Ruling Dobbs v Jackson: Emergency Medicine Implications WITH Dr. Pensak
Review the history of abortion care in the US and the State of Ohio.
81% of people in the US believe that abortion care should be legal (Gallup 2021)
40% of pregnancies conclude with abortion care
1 in 4 people who can get pregnant have abortion care in their lifetime
Abortion care is very safe
Mortality from abortion care is 0.41 per 100,000 (2018)
Mortality from pregnancy & delivery is 17.3 per 100,000 (2017)
The need for abortion care is concentrated in communities with limited access to comprehensive health care, including contraceptive care
These are the communities least able to overcome barriers to care
Safety of Abortion care in the US
“The committee concludes that the quality of abortion care depends on where a woman lives. In many states, regulations have created barriers to safe, effective, patient-centered, timely, efficient, and equitable abortion services. The regulations often prohibit qualified providers from providing services, misinform women of the risks of the procedures they are considering, overrule women’s and clinician’s medical decision making, or require medically unnecessary services and delays in care.”
History of Abortion Care in the US
Early 1800s: Abortion was common and legal before quickening
Late 1800s: Abortion was criminalized in each state, with exceptions for the health/life of the pregnant person
By mid 1900s, illegal abortion became a leading cause of pregnancy-related death
Contraceptive counseling and care was illegal in many states
1960s: 1/10 low-income women had ever attempted illegal abortion
1968, LAC-USC admitted 701 women with septic abortions, one admission for every 14 deliveries.
Early 1960s NYC: double rate of perinatal deaths in Puerto Rican pts vs white pts
1972-1974: the mortality rate due to illegal abortion for nonwhite women was 12 times that for white women.
Prior to Roe v Wade abortion did occur in the US
Estimated 1.2 million illegal abortions per year
Nearly 5000 deaths a year
After Roe v Wade deaths due to septic abortion dropped precipitously
1973 Roe V Wade
June 1969 Norma McCorvey sought abortion but could not access, talked out of seeking illegal abortion
Gave birth June 1970 - put baby up for adoption
June 1970, case brought against state to Fifth Circuit court, Texas law declared unconstitutional
Violates right to privacy (9th amendment)
No injunction against enforcing law
Case originally argued Dec 1971, reargued October 1972
Decided 1973: SCOTUS rules that the 14th amendment protects a women’s right to abortion under the Due Process Clause. Created pregnancy trimesters.
The Number of deaths from abortion has declined dramatically since Roe v. Wade
Planned Parenthood v Casey
Introduced in House (01/03/1991)
Freedom of Choice Act of 1991 - Provides that a State may not restrict the right of a woman to choose to terminate a pregnancy: (1) before fetal viability; or (2) at any time, if such termination is necessary to protect the life or health of the woman. Allows a State to impose requirements medically necessary to protect the life or health of such women.
permitted states to restrict abortion as long as such restrictions do not place an “undue burden” on women seeking abortion.
Undue burden: “whether in a large fraction of the cases in which [the restriction] is relevant, it will operate as a substantial obstacle to a woman’s choice to undergo an abortion.”
Explain the current abortion provision landscape in the State of Ohio
HB 153 :Bans public facilities from providing non-therapeutic abortions.
SB 127: Bans abortions after 20 weeks post-fertilization. 22 weeks since a a pregnant person’s last menstrual period.
HB 214: Prohibits performing an abortion if sought wholly or in part due to a prenatal diagnosis of Down syndrome diagnosis.
Describe the implications of abortion legislation changes on Emergency Medicine
Dobbs v Jackson
Case involved a Mississippi law that banned abortions at 15 weeks
June 24, 2022: SCOTUS ruled the US constitution does not confer a right to abortion. No longer protected under the 14th amendment. Abortion regulation returned to the states.
ORC 2919.19-.199: Criminalizes abortion when a fetal heartbeat has been detected, except to prevent the death or serious risk of substantial and irreversible impairment of the pregnant woman.
Passed and enjoined 2019
Injunction lifted shortly following SCOTUS ruling
Heart Beat Laws
Bans abortion after detection of cardiac activity
Exceptions: Prevent the death of the woman or prevent serious risk of substantial and irreversible impairment of a major bodily function. No exceptions for mental illness. No exceptions for rape or incest.
Apply only to “intrauterine pregnancies”
Violation charges to provider NOT patient
Charges include felony, fine and loss of license
Post Dobbs Abortion Care
Planned Parenthood in Cincinnati is OPEN and providing abortions prior to cardiac activity
Transvaginal ultrasound has to be used to assess cardiac activity
Has to be confirmed immediately prior to procedure/MAB
Providing both medication and procedure abortions
Abortion can be done without a confirmed IUP
Referring patients out of state
No laws against counseling or referring out of state—you can give patient’s Planned Parenthood or other abortion services referral information
Closest referral states are IL, MI, PA
Emergency Medicine Implications
Pregnancies, miscarriage, post-abortion, pre-viability demise, high-risk pregnancies
Premature deliveries, medically complex neonates
Confirmation of abortion
Patients with limited access to healthcare
Potential for criminalization
Privacy
Strictly limits information that may be provided regarding a patient
Limits a hospital or health care provider’s disclosure of information to law enforcement regarding an abortion
Preempts any State privacy law that is less restrictive than federal law
“According to major professional societies, including the American Medical Association and American College of Obstetricians and Gynecologists, it would be inconsistent with professional standards of ethical conduct to make such a disclosure of PHI to law enforcement or others regarding an individual’s interest, intent, or prior experience with reproductive healthcare.”
EMTALA
The EMTALA statute requires that all patients receive an appropriate medical screening, stabilizing treatment, and transfer, if necessary, irrespective of any state laws or mandates that apply to specific procedures.
Any state that has a more restrictive definition of emergency medical condition or that has a definition that directly conflicts with any definition above is preempted by the EMTALA statute. Physicians and hospitals have an obligation to follow the EMTALA definitions, even if doing so involves providing medical stabilizing treatment that is not allowed in the state in which the hospital is located. Hospitals and physicians have an affirmative obligation to provide all necessary stabilizing treatment options to an individual with an emergency medical condition.
Self Managed abortions
Self-managed abortion(SMA) refers to any action to end a pregnancy outside of the formal healthcare system.
SMA methods can include
Self sourcing mifepristone and misoprostol or misoprostol alone
Consumption of herbs or botanicals
Ingestion of toxic substances
Use of physical methods
Some people may never interact with the formal healthcare system, during this process but some may interact with clinicians before, during or after their abortion.
It is important for medical professionals to be aware of the expected course of SMA with medications, its rare complications and of other less safe methods.
Approximately 7% of individuals in the US attempt SMA at some point in their life
Rates higher in people who experience higher barriers to abortion care:
People of color
People with lower incomes
People who live in states with restrictive abortion laws
Other reasons: cost, distance, autonomy, convenience, experiencing prior stigma and racism within healthcare system
Legal Risk
Medical risks of SMA are low but LEGAL RISKS for people attempting SMA may be significant
NO laws exist in Ohio that require reporting of SMA or suspected SMA
Utilize a harm reduction framework when interacting with these patients
Consider documentation in EMR carefully. Medical records can be subpoenaed
Resources
Patients
Clinicians
Society of Family Planning: https://societyfp.org/clinical-guidance/
Legal: https://www.ifwhenhow.org/
Wilderness Medicine Workshop WITH Dr. Roche
The Wilderness Medical Kit with Dr. Otten
Before putting together a medical kit for wilderness travel you must ask yourself several important questions:
What am I able and willing to do in the wilderness setting?
level of training and experience
malpractice exposure
responsibility towards others on trip
Where am I going?
geography-ocean, mountain, desert, rain forest, combinations
seasonal climate-hurricanes, tornadoes, floods, monsoon, dry
extremes of climate-altitude, cold, hot, dry, underwater, wet
endemic medical problems-malaria, hepatitis, meningitis, polio
medical support systems-EMS, hospitals, doctors, hyperbaric
transportation within country-ground, air, evacuation
political considerations-wars, riots, unfriendly governments
legal considerations-medical licensure, controlled drugs
hazards-unexploded ordinance, wildfires, animal attacks, insects
Who am I going with?
how many, how old, how conditioned-children, seniors, obese
medical problems of fellow travelers--drug interactions, allergies
psychological problems of fellow travelers-risk taking, interactions
responsibility for their medical care
medical expertise of fellow travelers
How long are we staying?
amount of supplies and drugs
resupply options
communications with outside
How are we getting there?
method of travel-air, ship, train, bus-special medical problems
travel options in country-vehicles, animals, safety
immunization certificates-yellow fever, etc.
who is carrying the medical kit-size, weight, security of contents
Where are we eating and sleeping?
food and water supply
sleeping arrangements-cots, mosquito nets, sleeping bags, tents, etc.
sanitary conditions-washing, toilets, laundry, insect control
The Medical Kit
General Principals
Good quality items, multiple uses for each item, replace as needed or when expired, most items are carried on all trips, add and delete items based on above considerations. Be expedient and adapt what you have to what you need i.e. splints, bandages, airway, etc. Gloves should be carried and used when possible.
Waterproof/ resistant container
protect fragile items
compartmentalized if possible
bright color for easy identification
list items included
Equipment
Swiss Army knife-Swiss champ is best
mosquito forceps
needle holder
thermometer ( low reading)
SAM splint
Supplies
Band-Aids
Hibiclens sponge
adhesive tape 2"
cravat (triangular bandage)
field dressing 4x7
stapler 15 shot
sutures (nylon/ absorbable)
sponges 4x4
safety pins
steri strips
moleskin 6x6
elastic gauze or Co ban
syringe 10cc
needles, 25G, 18G, 12G
plastic bags (sm, med, huge)
foley catheter
vaseline gauze 4x8
super glue
duct tape
knife blades # 11, # 10
Drugs: samples or individual blister packs best
Oral
aspirin 325mg
diphenhydramine 25mg
loperamide 2mg
ciprofloxacin 500mg
acetazolamide 125mg
ibuprofen 400mg
dexamethasone 4mg
amoxicillin-clavulanate 250mg
mefloquine 250mg
options-acetaminophen, doxycycline, cefixime, nifedipine, meclizine
Parenteral: Protect by securing in foam and SAM Splint
epinephrine I : I 000
lidocaine 2%
ketorolac
diphenhydramine
options-morphine, prochlorperazine, ceftriaxone, bupivacaine
Topical
triple antibiotic ointment (Neosporin)-cut, bums, abrasions
fluocinolone cream0.2%--dermatitis
gentamicin ophth ointment-eye infections, corneal abrasions
miconazole cream 2%--fungal infections
aloe vera gel--frostbite
Cavit dental-lost fillings, broken teeth
sunscreen 15-30 SPF
DEET insect repellant
povidine-iodine solution-antiseptic, water purification
oxymetazoline nasal spray-sinus squeeze prevention
This is the basic kit and items should be added or deleted depending on the situation. For example aloe vera gel is useful for frostbite but may also help with sunburn or other dermatitis. Acetic acid solution may be included if diving where marine animals with nematocysts are abundant. Intravenous fluids if traveling in hot areas for long periods or with unacclimated individuals. Personal choices concerning drugs and supplies has precedent. Use what you are familiar with and what works for you.
Symptom Control in Chronic Illness WITH Dr. Kiser
Describe the evaluation of acute pain in the context of chronic illness
Prevalence of pain in the ED is between 50-70%
Pain is the primary complaint of cancer patients for 10-40% of encounters
Pain Pathways
Peripheral Sensitization
Damage in the periphery leads to inflammatory response in the dorsal horn and exaggerated pain response
Segmental central sensitization
Damage at a peripheral site leads to neuroplastic changes at the dorsal horn leading to chronic firing
Suprasegmental sensitization
Physical damage or No damage leads to neuroplastic changes in the thalamus and cortex causing a continuous pain response in the presence of little or no stimuli.
Pain is multifaceted
Biological, social and psychological factors
Barriers to Pain treatment in the ED
Delays to seeign providers
Delays in medication ordering
Delays in medication administration
Delays in re-assessment
Delays in re-dosing
Failure to consider chronic opioid use
Opioid Pain medication
Act pre-synaptically to block calcium channels on nociceptive afferent nerves to inhibit the release of neurotransmitters such as substance P and glutamate
Post-synaptically they open potassium channels, hyperpolarizing cell membranes and increasing the required action potential to generate nociceptive transmission
Mu, kappa and delta opioid receptors mediate analgesia both spinally and supraspinally
Some opioids can affect serotonin kinetics in presence of other serotonergic agents (tramadol, oxycodone, fentanyl, methadone, dextromethorphan, meperidine, codeine, buprenorphine)
Can lead to serotonin syndrome
Some opioids have activity at NMDA receptor (methadone)
Can cause respiratory depression, hypotension, dysphoria, euphoria, sedation, constipation, nausea, vomiting, pruritis
Opioid induced hyperalgesia can occur
Dose Finding 1
Opioid naïve
Not receiving chronic opioid therapy dail
Opioid tolerate
Morphine 60mg/day
Oxycodone 30mg/day
Dilaudid 8mg/day
Fentanyl 25mcg/hr
Hydrocodone 60mg/day
Step 2
Dose finding
Opiate Niave - use conventional doses
Opiate tolerant
Administer IV opioid dose equivalent to 10-20% of the total opioid dose taken in the last 24 hours
Opioid Equivalents
Morphine IV 10mg and PO 25mg
Fentanyl 0.15
Hydrocodone IV NA and 25mg
Hydromorphone 2mg IV and 5mg PO
Oxycodone 10mg IV and 20mg PO
Start at the low end
Keep in mind the weight based dosing is usually more than most Physicians give
Communicate with nurses if using very high doses.
Step 3 Reassess pain and relief
Every 15-20 minutes for IV
Every 60 mins for PO
If pain is worse then increase dose by 50% 100%
If pain is better but still severe then repeat the same dose
If pain is better and tolerable continue current dose as a PRN
Other Considerations
CKD/CRI/AKI
Avoid morphine and dilaudid or reduce dose by 50-75%
Safest are fentanyl and oxycodone
Alternate routes of administration
American College of Hematology (Brandow et al., 2020) recommends SQ/IN if no IV available
Can give many medications subcutaneously, there are special SQ devices for infusions or frequent boluses but can give via butterfly needle (<2mL)
Macy catheter
Intranasal fentanyl
Consider PCA for patients requiring frequent dosing
Consider PRN orders
Consider writing PRN dosing
When using low starting doses
When not actively titrating
Once you’ve found effective dose
Must inform nursing of PRN order
Allows nurses to give meds without having to find or interrupt you for orders
Consider for anti-emetics as well
Opioid Adjuncts
Acetaminophen
Mechanism of action unknown
Peaks in 30-60 minutes
Equivalent to aspirin for antipyretic and analgesic effects
Does not inhibit platelet function
Hepatic metabolism – caution in liver disease and alcohol abuse
Ofirmev is IV formulation, works well but very expensive
675-1000mg PO Q8H (PRN)
675mg PR Q8H (PRN)
Max dose 4000mg (3000mg OTC)
NSAID’s
COX-1 and COX-2 inhibitors
COX1 important in regulation of blood flow to kidneys and GI tract via prostaglandins.
COX1 causes platelet aggregation via thromboxane A2 pathway
COX2 has minimal antiplatelet effects, is gastroprotective
Rapid GI absorption, can be delayed by food
Primarily metabolized by kidneys
Have been linked with acute kidney injury, gastritis/gastrointestinal ulcers, serious cardiac events, worsening of underlying CHF
Cancer patients at higher risk for GI and renal injury – use with caution, if at all
Agents
Toradol 15mg IV Q6H (PRN)
Ibuprofen 600-800mg PO Q6-8H (PRN)
Naproxen 250-500mg PO Q12H (PRN)
Meloxicam 5-10mg PO daily (PRN)
Consider adding PPI in higher risk patients
Multiple drug-drug interactions, can potentiate adverse effects
Carbamazepine, Gabapentin, Pregabalin
Indicated for neuropathic pain, takes 1-4 weeks to reach full effect
Significant adverse effects can limit use
Carbamazepine
Limited evidence of efficacy, mostly in trigeminal neuralgia
Mechanism of action unknown
Adverse effects limit use (somnolence, rash)
Start 100mg PO BID of either IR or ER forms
Can increase by 200mg/day
Maximum 1200mg/day
Requires renal dose adjustment
Gabapentin
Best evidence in post-herpetic neuralgia, diabetic peripheral neuropathy
Limited support for use in other neuropathic conditions
Blocks voltage dependent calcium channels modulating excitatory neurotransmitter release
Adverse effects limit use (somnolence, dizziness, leg edema, gait disturbance)
Will lessen over 10 days or so
Start 300mg PO QD x 1 day then 600mg PO BID x 1 day then 300mg PO TID
Maximum dose 3600mg/day
Must taper if stopping
Must adjust dose in renal disease or avoid altogether
Pregabalin
Binds alpha2 and delta subunit of calcium channels reducing neurotransmitter release
Reasonable evidence for use in postherpetic neuralgia, painful diabetic neuralgia, mixed or peripheral post-traumatic neuralgia
No evidence for benefit in HIV neuropathy
Minimal evidence to support use in central neuropathy
Adverse effects include dizziness, somnolence, constipation, peripheral edema
Start 50mg PO TID, can increase to 100mg PO TID after 1 week
Maximum dose 600mg/day
Must wean off, abrupt withdrawal can cause seizures
Must adjust dose in renal disease, or avoid altogether
Steroids
Anti-inflammatory, but exact mechanism in pain control unknown
Weak evidence to show benefit but is standard of care in several oncology indications (Cochrane Review, Haywood, 2015)
Brain, bone, liver lesions
Dexamethasone most commonly used, lowest mineralocorticoid effect and long half life
Maximum benefit within 5-7 days
Need long, slow wean if decreasing or stopping
Both short term and long term adverse effects
Short: thrush, edema, dyspepsia, PUD, insomnia, delirium, anxiety, glucose intolerance
Long: adrenal suppression, moon facies/fat redistribution, infection, osteoporosis, skin fragility and impaired wound healing
Discuss with oncology before starting*, may disqualify from clinical trials
Dexamethasone 16mg PO daily
Can give 10mg IVP in ED
Can divide PO doses to avoid stomach upset but watch timing of 2nd dose
Methylprednisolone 16mg PO BID
Prednisone 20-30mg PO BID-TID
Ketamine
NMDA receptor antagonist
Can use to avoid opioids or augment them
Evidence supports use with or without opioids in acute pain (Schwenck, 2018)
No great studies in cancer specific pain (Cochrane Review, Bell, 2017)
Adverse effects: nausea, vomiting, emergence delirium at higher doses, HTN, tachycardia
0.1-0.3mg/kg IV, 0.5-1mg/kg IN, avoid with hepatic impairment
PO is being used in outpatient PC
Muscle relaxants
Spasticity
Increased tone caused by increased excitability of muscle stretch
Stiff, hyperreflexic
Central disorder of upper motor neurons
MS, TBI, CP, CVA, motor neuron disease
Spasm
Involuntary muscle contractions, often painful and sometimes palpable
A peripheral process but can have systemic or peripheral cause
Multiple causes: muscle injury, peripheral nerve inflammation, stress, electrolyte disturbance, dehydration
Baclofen
First line therapy in spasticity
GABA agonist at the spinal cord level
Limited crossing of blood brain barrier so higher doses often needed
Start 5mg PO TID, can increase by 15mg/day to maximum 80mg/day
Adverse effects: somnolence, dizziness, constipation, insomnia
Abrupt cessation can cause withdrawal
Consider decreasing dose in renal disease
Tizanidine
Alpha2 agonist, increases presynaptic inhibition of neurons
Sometimes used for additive effects with baclofen
2mg PO TID, can increase 2-4mg/dose to maximum 36mg/day
Adverse effects: somnolence, dry mouth
Abrupt cessation can cause withdrawal
Decrease dose in both liver and renal disease
Diazepam
Works postsynaptically on GABA receptors causing CNS depression
2-10mg PO TID-QID, 5-10mg IVP Q3-4H PRN
Adverse effects: somnolence, dizziness, respiratory depression, confusion
Abrupt cessation can cause withdrawal
Consider decreased dosing with liver disease
Methocarbamol
Unknown mechanism of action
Centrally acting but works better for spasm
500-750mg PO QID, maximum 6000mg/day
1000mg IVP Q8H, maximum 3000mg/day
Contraindicated in renal failure (polyethylene glycol)
Requires renal dosing adjustments
Adverse effects: sedation, dizziness, headache, confusion, falls
Case reports of seizures after IV administration in patients with seizure d/o or polysubstance intoxication
Cyclobenzaprine
Centrally acting, structurally related to TCA’s but exact mechanism unknown
Indicated for muscle spasm
5-10mg PO TID, maximum dose 30mg/day
Adverse effects: somnolence, dizziness, confusion, anticholinergic effects
Topicals
Lidocaine Patch
Blocks voltage gated sodium channels to prevent nerve from firing
No great evidence to support use in neuropathic pain, but individual studies and clinical experience support use (Cochrane Review, Derry, 2014)
4% OTC, 5% Rx
12 hours on, 12 hours off
Can cause rash and local erythema
Capsasin
Reduces substance P from nerve endings reducing pain
Found in chili peppers
High concentration (8% patch, Qutenza) more effective than lower dose creams (Cochrane Review, Derry, 2017)
FDA approved in US but difficult to find
Low concentration (0.025, 0.075% cream) similar to placebo (Cochrane Review, Derry, 2012)
Indications for postherpetic neuralgia, HIV neuropathy, peripheral neuropathy
Can cause local irritation
TCA’s
Inhibit presynaptic reuptake of serotonin and norepinephrine, also likely NMDA blockade
Amitriptyline
Best studied
Limited quality evidence but long history of successful use (Cochrane Review, Moore, 2015)
Effective at lower doses than antidepressant dosing (25-75mg QHS)
Indications in peripheral neuralgia
Both anticholinergic and antihistamine adverse effects
Can lower seizure threshold at higher doses and prolong QTc
Life threatening in overdose
Nortriptyline, imipramine, desipramine are all effective as well
Takes 6-8 weeks to achieve maximum affect
Probably best left to physicians with ongoing relationship to start
SNRI’s
Good evidence to support use in diabetic peripheral neuropathy, less so in fibromyalgia (Cochrane Review, Lunn, 2014)
Potent and selective inhibitor of serotonin and norepinephrine reuptake inhibitor
Start 60mg daily, will need to be increased to 120 mg daily in 2 weeks
Adverse effects: headaches, drowsiness, fatigue, serotonin syndrome
Contraindicated with current or recent MAOI use
Consider lower dose in renal insufficiency, avoid in chronic liver disease
Systemic Lidocaine
Attenuates peripheral nociceptors sensitization and central hyperexcitability through its sodium channel blocking action
Has pain relief and anti-inflammatory effects in central and peripheral neuropathic pain, less evidence for cancer related pain (Kandil, 2017; Golzari, 2014)
1-2 mg/kg as a bolus over 10 minutes, we have done continuous drips in PC
Adverse effects: Perioral numbness, dizziness, dysarthria, tachycardia, tremor
Avoid in chronic liver disease
Not a destination therapy but can be useful in terminal patients or to break a pain cycle
