Surgery Pharm

Question 1

What are the adverse outcomes of undertx perioperative pain?

Answer 1

• thromboembolic complications
• pulmonary complications
• increase length of hospitalization
• hospital readmission for further pain management
• needless suffering
• impairment of quality of life
• development of chronic pain

Question 2

Adverse outcomes of perioperative pain management?

Answer 2

• respiratory depression
• brain injury
• neuro injury
• sedation
• circulatory depression
• N/V
• pruritius
• urinary retention
• impairment of bowel fxn
• sleep disruption

Question 3

What must you always document regarding pt and pain throughout operation?

Answer 3

• pain intensity
• effects of pain therapy
• SEs caused by therapy

Question 4

What are factors to consider when deciding pain management for pt?

Answer 4

• type of surgery
• expected severity of postop pain
• underlying medical conditions: CVD, pulm, allergies, renal or liver failure
• risk-benefit ratio for available techniques
• pt’s preference
• pt’s previous experience w/ pain

Question 5

Preop prep of pt?

Answer 5

• H and P

- post op pain control plan

Question 6

What should you do preop w/ pt?

Answer 6

• adjust or continue meds that may provoke a withrawal syndrome
• tx to reduce preexisting pain and anxiety: consider initiaion of post op pain management
• premeds b/f surgery
• pt and family education:
  addiction
  adverse effects of meds
  optimal use of pt-controlled analgesia

Question 7

Periop techniques for pain management?

Answer 7

• central regional opioid analgesia
• pt controlled analgesia w/ systemic opioids
• peripheral regional analgesia:
  intercostal blocks
  plexus blocks
  local anesthetic infiltration of incisions

Question 8

What is central regional opioid analgesia? Benefits and risks?

Answer 8

• epidural or intrathecal admin of analgesia - epidural: injection outside of the dura
  intrathecal: aka spinal anesthesia - injection through dura directly into CSF
• benefits: improved pain relief when preincisional epidural or intrathecal morphine is admin compared w/ po, IV, or IM morphine
• risks: increased pruritus and urinary retention in post op epidural anesthesia compared to IM morphine

Question 9

Amt of intrathetcal opioids admin?

Answer 9

• intrathecal morphine (0.1-0.2 mg) or fentanyl (10-20 mcg)
• a single dose of intrathecal opioid (morphine) can provide pain relief for up to 18-24 hrs post op: onset of action: 45 min
• fentanyl provides pain relief for 1-2 hrs: onset of action 5-10 min

Question 10

What is pt controlled analgesia? Benefits?

Answer 10

• for moderate to severe post op pain
• benefits: decreased delay in pt access to pain med, decreased likelihood of overdose
• pump usually d/c when able to take oral meds
• morphine, hydromorphone and fentanyl can be given via PCA
• fentanyl is less desirable due to short DOA: may be useful if morphine allergy, easier to use in hepatic or renal insufficiency than others
• improved pain scores comparing IV PCA morphine to intramuscular morphine
• studies show that having IV PCA pump w/ a background infusion of morphine vs PCA pump w/o background infusion:
  more analgesic used, findings equivocal regarding pain relief, nausea, and vomiting, pruritus, sedation

Question 11

What are multimodal techniques for pain management?

Answer 11

• using 2 or more drugs that act by different mechanisms for providing analgesia
• systemic meds: opioids+NSAIDs
• central and regional meds: epidural and local anesthetics (ex: fentanyl _ bupivocaine admin via epidural): better pain control but more muscle weakness and pruritus noted

Question 12

Benefits of systemic analgesics?

Answer 12

• improved pain scores and reduced analgesic use when given IV morphine + ketorolac compared to IV morphine alone
• ketorolac along w/ PCA opioid admin is more effective at decreasing pain vs COX-2 or nonselective NSAIDs
• lower pain scores when adding gabapentin or pregabalin to IV opioids
• unless CI pts should receive schedules regimen of NSAIDs, COXIBs or acetaminophen

Question 13

What are peripheral regional techniques of pain management?

Answer 13

• peripheral nerve blocks, intraarticular blocks, and infiltration of incisions
• preop nerve blocks are effective at reducing postop pain and decrease the need for opioid use (post blocks aren’t helpful)
• preop infiltration of the incision w/ local anesthetic (ex. Bupivicaine) decreases postop pain scores

Question 14

What pts are at risk for inadequate pain control?

Answer 14

• peds
• geriatrics
• critically ill
• cognitively impaired
• others who may have difficulty communicating

Question 15

What is the role of the PA in the management of the post surgical pt?

Answer 15

• know the pt’s hx
• procedure performed and any complications
• type of anesthesia used for the case
• duration of case and if that is normal for procedure mentioned
• what has pt received so far, did it work, any adverse rxns and what other modalities are in play? (epidural pain management, nerve block)
• adjustment of opioid dose and/or initiation of acetaminophen, NSAIDs or gababpentin may be needed

Question 16

Diff types of opioids?

Answer 16

• *morphine,
• *hydromorphone (dilaudid)
• *fentanyl
• meperidine
• 3 most commonly used for post op IV pain management

Question 17

Diff routes of opioid admin?

Answer 17

• most widely used med for tx of postop pain
• bolus injections are often used: given this way they fail to provide steady state of drug
• continuous infusions: may be dangerous due to potential for drug build up and cause respiratory depression, must be given in a highly supervised enviro
• pt controlled analgesia

Question 18

Metabolism of opioids?

Answer 18

• all opioids are hepatically metabolized to active and inactive metabolites which are eliminated in urine
• pts w/ severe liver disease will need dosage adjustments

Question 19

Morphine:
type, onset? 
Elimination half life?
Duration of action? 
Admin?
Excretion?
CI?

Answer 19

• prototypical opioid
• onset of analgesia is rapid
• peak in 1-2 hrs
• elim half life: 2-3 hrs
• analgesic duration of action: 4-5 hrs
• IV 1-3 mg q 5min until pain relief or adverse effects like sedation, hypotension, respiratory depression, and hypoxemia
• active metabolites eliminated renally
• in renal insufficiency active metabolites may accumulate and cause neurotoxicities: myoclonus, confusion, coma and death
• relatively CI in severe renal disease
• erratic absorption from GI tract

Question 20

Hydromorphone (dilaudid):

Onset, half life?

Answer 20

• more rapid onset of analgesia reaching peak w/in 30 min
• half life: 2.4 hrs
• approx 4-6x more potent than morphine
• 0.2-1 mg q 2-3 hrs

Question 21

What is fentanyl?
How powerful?
When is it preferred?

Answer 21

• synthetic derivative of morphine
• approx 100x more potent than morphine
  more lipid soluble than morphine:
  more rapid onset of action, improved penetration of blood brain barrier, shorter half life, eliminaton half life is 2-4 hrs
• doesn’t release histamine and may be preferred in presence of hemodynamic instability or bronchospasm

Question 22

Fentanyl:

amt admin depending on pain?

Answer 22

• moderate pain: 25-50 mcg IV q 5 min up to max dose
• moderate to severe pain: 50-100 mcg q 2-5 min until pain relief
• IV infusion for pain control in mechanically ventilated pts:
  0. 7-10 mcg/kg/hr, admin over 5 days may lead to deposition of drug in adipose tissue and prolonged sedation

Question 23

Meperidine:
Indication
CI
SEs

Answer 23

• indicated for short term management of acute pain
• CI in pts on MAOIs
• lower seizure threshold
• has dysphoric effect
• not as effective as other drugs
• slower rate of metabolism in elderly or if liver or renal failure
• not usef for PCA pumps b/c of risk for accumulation of active metabolite

Question 24

SEs of opioids?

Answer 24

• somnolence
• depression of brainstem control of respiratory drive
• hypotension
• urinary retention
• N/V
• slowing of GI transit: constipation, ileus
• histamine release: MC after morphine - flushing, tachycardia, hypotension, pruritus, bronchospasm

Question 25

How can you transition from IV to oral opioids?

Answer 25

- switch from IV to oral once pt can tolerate PO - calculate 24 hr opioid consumption to determine coverage needed: consult equianalgesic charts - PO - analgesic effects take 30-60 min - switch to one of the following: oxycodone, hydrocodone, hydromorphone, morphine: ex 40 mg of IV morphine given in 24 hrs would reqr 20 mg oxycodone q 4 hrs or 5 mg of hydromorpone q 4 hrs

Question 26

What are the oral opioids used?

Answer 26

oxycodone (oxycontin) (roxicodone) - - oxycodone/acetaminophen (percocet)* - oxycodone/ibuprofen (combunox) - schedule II hydrocodone (hysingla ER) (Zohydro ER): - hydrocodone/acetaminophen (lortab) (Vicodin) (norco)* - hydrocodone/ibuprofen (vicoprofen) - schedule III hydromorphone (diluadid): schedule II morphine (Avinza) (duramorph) (kadian) (MS contin): schedule II * MC used po pain meds post surgery

Question 27

Duration of action of diff opioids?

Answer 27

- short acting: fentanyl - moderate acting: DOA 4-6 hrs morphine, codeine, hydromorphone, oxycodone - long acting: methadone, long acting morphine preparations

Question 28

What opioids are safe in pts w/ impaired renal fxn?

Answer 28

- hydromorphone and oxycodone have inactive metabolites: safer than morphine for use in renal impairment - fentanyl: safer than morphine for use in renal impairment

Question 29

Opioid reversal agent?

Answer 29

- naloxone (narcan) - reversal of respiratory depression w/ therapeutic opioid doses: IV, IM, Subq, endotracheally: initial 0.04-0.4 mg: may repeat until desired response achieved. If desired response isn't observed after 0.8 mg total, consider other causes of respiratory depression

Question 30

What are non-opioid adjunctive meds used?

Answer 30

- NSAIDs - ketamine - lidocaine - magnesium - IV acetaminophen

Question 31

Use of NSAIDs?

Answer 31

- can reduce dose of opioid reqd - caution w/ kidney impairment nonselective: -IV formulations: ketorolac and ibuprofen -ketorolac reduces opioid constipation by 25-45% -ketorolac dose 15-30 mg IV over 15 sec - then dose q 6 hrs x 3-5 days selective: no IV formulation available, sometimes just a single dose might suffice

Question 32

Dosing of oral NSAIDs?-

Answer 32

- nonselective PO or PR: ibuprofen 400mg q 4-6 hrs diclofenac 50 mg q8hrs ketoprofen 50 mg qid -selective: celecoxib (celebrex): 400 mg po x 1 then 12 hrs later start 200 mg po BID

Question 33

What is ketamine? Use?

Answer 33

- NMDA receptor inhibitor - use limited due to hallucinations - reduces hyperalgesia and opioid tolerance

Question 34

Use of acetaminophen? CI?

Answer 34

- oral or rectal 1st line then can give IV: 325 mg-1000 mg PO or PR q 4-6 hrs/max dose 4 g - may be given in addition to NSAIDs - CI in hepatic failure

Question 35

use of lidocaine?

Answer 35

- class I antiarrhythmic - IV infusion intra-op or post-op for control of pain - 1.5-2 mg/kg bolus then 1.5-3mg/kg/hr - most effective for analgesia following major abdominal surgery

Question 36

Use of Mg sulfate?

Answer 36

- can reduce opioid requirements - NMDA receptor antagonist - bolus or infusion - not routinely used at this time despite many studies to show its effectiveness