1 Acute Pain

Question 1

Most common presenting symptom for patients coming to the ED

Answer 1

Pain

Question 2

whenever possible, this approach is preferred to be used in acute pain management

Answer 2

Mechanistic approach
- using medications that act on specific sites that initiate the pain signal
- example: migraine treatment with serotonin agonist (triptan) or dopamine antagonist (phenothiazine)

instead of symptomatic approach with opioids

Question 3

Opioid receptors

Answer 3

mu1 - supraspinal anagesia
m2 - euphoria, miosis, respiratory depression, depressed GI motility
delta - analgesia, but less that of mu1
kappa - dysphira, dissociation, delirium, diuresis

Question 4

basis for pain assessment and treatment

Answer 4

patient’s subjective reporting
Asking if the patient requires more analgesic may even be simpler and accomplish more than using any standardized pain evaluation tool

Question 5

Mainstay of acute pain management

Answer 5

pharmacologic agents

Question 6

Key to effective pharmacoogic pain management in the ED

Answer 6

Selection of an agent appropriate for the
1. intensity of pain
2. time to onset
3. ease of administration
4. safety
5. efficacy

Question 7

If verbal reassurance combined with an analgesic does not suffice, an _____ may be useful

Answer 7

anxiolytic

Question 8

Remarks on tiered approach

Answer 8

1. starts with an agent of low potency regardless of pain intensity
2. Unnecessarily subjects the patient to more prolonged suffering

Question 9

Pain scale severity

Answer 9

1-3: milde
4-6: moderate
7-10: severe

Question 10

Remarks on renal or biliary colic

Answer 10

a parenteral NSAID may control severe pain, although combination therapy with an opioid is usually superior

Question 11

Cornerstone of pharmacologic management of moderate to severe pain

Answer 11

opioid analgesics

Question 12

Typical initial adult dose of morphine

Answer 12

0.1 mg/kg IV
10 mg IM
0.3 mg/kg PO

Question 13

Typical initial adult dose of hydromorphone

Answer 13

0.015 mg/kg IV
1-2 mg IM

Question 14

Typical initial adult dose of fentanyl

Answer 14

1.0 mcg/kg IV

Question 15

Typical initial adult dose of tramadol

Answer 15

50-100 mg PO

Question 16

Remarks on meperidine

Answer 16

1. often underdosed
2. may precipitate a serotonin syndrome
3. parent drug is metabolized to normeperidine, which has neuroexcitatory properties

Question 17

Remarks on tramadol

Answer 17

1. binds to mu-receptorss and weakly inhibits reuptake of norepinephrine and serotonin
2. can induce serotonin syndrome
3. can produce false-positive result on the urine phencylidine screen

Question 18

Remarks on opioid agonsits-antagonists

Answer 18

1. Major benefit is a ceiling on respiratory depression
2. Extreme caution in patients with opioid addiction as these may precipitate withdrawal symptoms
3. Examples:
   - Buprenorphine
   - Nalbuphine
   - Pentacozine

Question 19

Remarks on opioid-induced hypotension

Answer 19

1. Infrequent
2. Almost always due to histamine release with the first dose
3. Usually of short duration

Question 20

Preferred opioids for patients with renal failure

Answer 20

hydromorphone and fentanyl

Question 21

Opioids in abdominal pain

Answer 21

1. Early administration of IV opioids is safe for the treatment of acute abdominal pain in the ED
2. Does NOT affect the accuracy of the evaluation , diagnosis, and management
3. Analgesia without proper evaluation is as inappropriate as proper evaluation without analgesia

Question 22

Remarks on adjuncts

Answer 22

1. Sometimes used to enhance the analgesic effect
2. and reduce the amount of opioid required and prevent side effects
3. Pretreatment with antiemetics is NOT necessary given the low risk of emesis

Question 23

Examples of adjuncts

Answer 23

Paracetamol 1 g IV q6
(max 4 g/day)
Ibuprofen 400-800 mg IV q6
(max 2400 mg/day)
Ketamine 0.15-0.4 mg/kg over 10 mins;
*can follow by IV infusion 0.1-0.2 mg/kg/hour

Question 24

Remarks on ketamine

Answer 24

1. Advantageous for its minimal respiratory depression
2. Can be used in trauma patients, resulting in lower opioid requirement
3. also effective in controlling acute flare-ups of neuropathic pain
4. Reemergence phenomena (disagreeable dreams or hallucinations upon awakening), especially with induction doses ~1.5 mg/kg IV

Question 25

Remarks on NSAIDs

Answer 25

1. All NSAIDs increase the risk of cardiac death in patients with ischemic heart disease (although COX-2 specific agents appear to carry higher risks)
2. Acute renal failure is more common on
   - elderly patients
   - volume depleted
   - with preexisting renal/cardiac disease
   - taking loop diuretics
3. Should not be given in major trauma due to risks of excessive bleeding, gastric stress ulcers, and acute renal failure in a volume-depleted patient

Question 26

Remarks on ketorolac

Answer 26

30 mg IV/IM q6
or 15 mg IV/IM q6 if >65 y or <50 kg
greater risk of GI bleeding than ibuprofen
use limited to 3 days IV and 5 days PO

Question 27

Can be given for neuropathic pain

Answer 27

Gabapentin 300 mg PO per day
Pregabalin 50 mg PO 3x per day

Question 28

Dependence on opioids

Answer 28

requires regular daily usage for 4-6 weeks in most patients
(whereas addiction may occur after one use of heroin)

Question 29

Nonpharmacologic modalitIes of pain management in the ED

Answer 29

Heat or cold
Immobilization
Elevation

Question 30

Discharge instructions for analgesia

Answer 30

1. Take subsequent doses on a regular basis or when their pain begins to return, RATHER THAN when it approaches its peak
2. prescribe only a few days’ worth of analgesics, because conditions with a longer duration of pain require follow-up with the primary care physician