EM E1: Analgesia/Anesthesia/Sedation

What is responsible for somatic pain?

Peripheral nervous system

Which type of pain is originates from internal organs and poorly localized?

visceral pain

*dull, achy, diffuse

What are the opioid receptors?

delta, kappa, mu

What is the mainstay of pain assessment & tx based on?

self-report measurement -not physician’s impression or nonverbal signs (tachycardia, pt expression, movements)

What level do you control someone’s pain to?

to the level the pt desires

Which pts are at risk of inadequate pain management?

pts who have difficulty communicating

(extremes of age, psychotic, cognitively impaired, language barrier)

What is the preferred pain assessment tool when there are language difficulties or cross-cultural differences?

Visual analog scale -least affected by these factors

When can you bypass the tiered approach to pain management?

acute pain

*may unnecessarily subject pts to prolonged suffering

T/F: True allergic reactions to opioid agonists are extremely rare

True

When should you withhold opioids?

respiratory depression (<10 breaths/min in an adult)

What drugs should be used w/ extreme caution in pts w/ opioid addiction?

Opioid agonists-antagonists

(buprenorphine, butorphanol, nalbuphine, pentazocine)

What opioid is used more in a surgical setting?

Fentanyl

*rapid CNS uptake

Which opioid is used for severe pain?

Morphine

*slow to penetrate BBB

Which opioid can also serve as a cough suppressant?

Hydrocodone & Codeine

What opioid can also be used for tx of opioid dependence?

Methadone

What is the max dose for APAP?

3g/day for adults

What are adverse effects of NSAIDs?

inc risk of cardiac death in patients with ischemic heart disease, acute renal failure

What is used to tx inflammation?

Corticosteroids

Which non-opioid produces analgesia or dissociative anesthesia w/ minimal resp. depression?

*good for brief, minor procedures; useful in pediatric ED

Ketamine -do NOT use in pts w/ psychosis or schizophrenia

Which non-opioid has a fast onset and provides short-acting analgesic and sedation?

*useful for brief, minor procedures

Nitrous Oxide (NO)

What class of meds is useful in patients with acute onset neuropathic pain?

TCAs & Anticonvulsants- Amitriptyline, Gabapentin, Lyrica

(often resistant to opioids)

T/F: Appropriate use of opioids has not been shown to produce dependence after a short duration of therapy for acute pain

True

What local anesthetic:

Shorter duration of action, lower toxicity profile

Lidocaine

What local anesthetic:

Short onset, longer duration of action

Mepivacaine

What local anesthetic:

Used in topical anesthetic preparations (eyes)

Tetracaine

What local anesthetic:

Oral procedures, GI

Cetacaine spray

What is local anesthetic toxicity related to?

potency and duration

What is the fastest route of absorption of local anesthetics?

Intercostal/Intratracheal

What is the slowest route of absorption of local anesthetics?

subcutaneous

What local anesthetic:

Highest incidence of CV toxicity

Bupivacaine

What local anesthetic:

can cause methemoglobinemia resulting in visible cyanosis

Prilocaine & Benzocaine

What is the most common usage of local anesthetics in the ED?

local infiltration into wound margins or in a "diamond-shaped wheal (auricular block)"

What local anesthetic:

Drug of choice for brief procedures

Lidocaine

What local anesthetic:

used for longer procedures

Bupivacaine or Mepivacaine

What can be added to nerve blocks to enhance the duration and safety?

Epinephrine

What should you always do before the administration of a peripheral nerve block?

document neurovascular status

What nerve is anesthetized by inserting a 27 gauge needle perpendicular to the skin between the tendons of the palmaris longus and flexor carpi radialis muscles?

Median

What nerve is anesthetized by passing a 27-gauge needle between the ulnar artery and the flexor carpi ulnaris at the level of the proximal volar skin crease?

Ulnar

What nerve can be blocked beginning at the level of the tendon of the extensor carpi radialis and extending around the dorsum of the wrist to the styloid process?

Radial

What is a CI to a digital nerve block?

any compromise to the digit's blood supply

What agent is avoided in a toe block due to irreversible ischemia?

Epinephrine

What type of nerve block is done for the hallux (great toe)?

Modified collar (ring) block

What type of block that is effective for isolated closed fracture reduction when an IV regional (Bier's) block is CI?

hematoma block

What is an IV regional block (Bier's block)?

IV infusion of local anesthetic distal to an inflated pneumatic tourniquet

What are CI to IV regional block (Bier's block)?

PVD/Raynaud's, sickle cell, cardiac conduction abnormalities, HTN, cellulitis, < 5 y/o

What needs to be done prior to a Bier’s block?

assess neurovascular status in the involved limb to prevent masking a primary traumatic neurovascular injury

What is anxiolysis?

reduction of apprehension w/o alterations in LOC

What is neurolepsis?

quiescence, indifference to surroundings, reduced motor activity

What is dissociation?

amnesia, analgesia, sedation, maintenance of muscle tone

What is sedation?

controlled reduction of environmental awareness

What level of sedation/analgesia:

- Individuals respond normally to verbal commands

- Cognitive function & coordination may be impaired

- Ventilatory and cardiovascular functions are unaffected

Minimal sedation (Anxiolysis)

What level of sedation/analgesia:

- Depression of consciousness, individuals respond purposefully to verbal commands alone or accompanied by light tactile stimulation

- No interventions are required to maintain a patent airway

- Spontaneous ventilation is adequate and CV function is usually maintained

Moderate sedation & analgesia (Conscious sedation)

What level of sedation/analgesia:

- Depression of consciousness

- Individual NOT easily aroused, respond after repeated or painful stimulation

- Ability to maintain ventilatory function may be impaired

- CV function is usually maintained

Deep sedation & analgesia

What level of sedation/analgesia:

- Loss of consciousness

- Ventilatory function is often impaired

- CV function may be impaired

Anesthesia

What opioid that is a poor choice for ED analgesia & has fatal reaction when coadministered with MAOIs?

Meperidine (Demerol)

What is the prototypical anxiolytic in common use for PSA in ED?

Benzodiazepines

*Midazolam (Versed) commonly used in ED

What is the MC analgesics in PSA?

Opioids

What anesthetic agent:

- Possesses antiemetic properties

- Sudden resp. depression & apnea, Hypotension

Propofol

What anesthetic agent:

- Sedative & hypnotic properties, NOT analgesic

- Little alteration in hemodynamics, cerebral blood flow, resp. function, or CV function

- SEs: N/V, myoclonus, adrenal suppression

Etomidate

What antidotal agent is used for the reversal of opioid administration?

Naloxone (Narcan)

What antidotal agent is used for the reversal of benzodiazepine administration?

Flumazenil

What constitutes chronic pain?

painful condition lasting > 3 months

What is the goal of therapy of chronic pain?

pain reduction & return to functional status

What type of chronic pain:

Ongoing tissue damage, usually respond well to centrally acting analgesics

(cancer pain, chronic pancreatitis)

Nociceptive

What type of chronic pain:

Nervous system dysfunction in the absence of ongoing tissue damage, caused by disease of the CNS or PNS, respond poorly to common analgesics including opioids

Neuropathic

What type of chronic pain:

No identifiable cause, diagnosis of exclusion

Psychogenic

What is a myofascial headache?

variant of tension headache (trigger points on the scalp)

What is a transformed migraine?

classic migraine headaches change into a chronic pain syndrome, caused by frequent treatment with opioids

What is Fibromyalgia?

widespread muscular pain involving > 6 body areas out of 19 total regions

*dx of exclusion

What is chronic myofascial chest pain?

dull, constant pain with trigger points on the chest wall, mimics MI type chest pain, not provoked by exercise nor completely relieved by rest

What type of chronic back pain:

Constant dull, occasional shooting pain, does not follow a nerve distribution, trigger points at the site of pain

Myofascial or Muscular

What type of chronic back pain:

Constant or sharp pain, exacerbated by movement, with local muscle spasm

Articular

What type of chronic back pain:

Constant or intermittent, burning, shooting or aching, Leg pain > back pain, may follow a dermatome

Neurogenic

What is "Reflex sympathetic dystrophy" (RSD)?

Complex regional pain type I

*associated with prolonged immobilization or disuse (CVA)

What is "Causalgia"?

Complex regional pain type II

*associated with peripheral nerve injury (GSW or fracture)

What are sx of Complex Regional Pain?

presents after acute injury -allodynia, persistent burning or shooting pain

early: edema, warmth, localized sweating

late: edema/warmth alternate w/ cold/pale cyanotic skin → eventual atrophic changes

What may reduce ongoing symptoms of complex regional pain syndrome?

early steroid tx

7 D's of chronic pain:

Drugs, Doctors, Dysfunction, Disability, Dependence, Dramatization, Depression

4 D's describing physicians who contribute to Rx abuse:

Disabled doctor, Dishonest doctor, Duped doctor, Dated doctor

T/F: drug-seeking pts are very persistent and successful

True