Pain Management of Dental Patient

Lecture 15

What is the goal in regards to acute pain identification and management for the dentistry patient?

move rapidly to period of healing and return to function

In order to treat pain effectively, we need to understand what?

where it comes from

Pain receptor acitivty is proportional to the stimulus in the normal state, but pain does what?

generates an intense stimulus and then triggers a proportional response in CNS

The relationship between pain and CNS response changes with repeated stimulation. What can result from this?

increased sensitivity (lower pain threshold)

budding of new receptive terminals

receptive field expansion

recruitment of previously quiescent nociceptors (quiet nociceptors)

List the order for signal transmission of pain.

stimulus —> transduction —> transmission —> modulation —> projection —> perception

Spinal cord changes as a result of repeated and amplified stimulation associated with chronic pain can result in what phenomenon?

windup pain (NMDA receptors play big role)

Repeated and amplified stimulation associated with chronic pain can affect what in the brain stem, thalamus, and cortex?

central sensitization

Conscious perception of chronic pain can be inhibited by what?

general anesthesia

opioids

alpha 2 agonists

Spinal cord sensitization of chronic pain can be inhibited by what?

opioids

NSAIDs NMDA antagonists

alpha 2 agonists

local anesthetics

Nociceptor stimulation of chronic pain can be inhibited by what?

local anesthetics

opioids

NSAIDs

Transmission of chronic pain along peripheral nerves can be inhibited by what?

local anesthetics

alpha 2 agonists

What are key factors for treating chronic/maladaptive pain?

how quickly/effectively initial pain is treated

degree of nerve injury/CNS injury

secondary healing problems from initial injury

degree of anxiety/depression/feear

What is the purpose of analgesic interventions for the dental patient?

minimize magnitude and duration of pain signal generated

modulate neuroplasticity away from reactive/maladaptive and toward healing/adaptive

The first key to treating pain in dental patients should be geared towards how to implement what?

gentle handling

appropriate positioning

decrease in stress

What is the first line of pain treatment in dental patients since they work centrally and peripherally to decrease the magnitude of the acute pain signal?

opioids

Which drugs are extremely effective analgesics with anti-inflammatory properties that can work synergistically with opioids to allow for opioid dose reduction, but require patient stabilization first and should not be used in patients that are hypothermic, hypotensive or have poor perfusion as a result of GI toxicity or renal compromise?

NSAIDs

List indications for oral nerve blocks.

regional analgesia for oral surgery, including tooth extractions

reduce amount of inhalant anesthetic needed as part of multimodal approach

continued post op analgesia by limiting CNS sensitization

What are the four most often used nerve blocks for oral analgesia?

rostral maxillary (infraorbital) block

caudal maxillary block

rostral mandibular (mental) block

caudal mandibular (inferior alveolar) block

Which nerve block covers the bone, teeth, and intraoral soft tissue from the maxillary third premolar rostral to the midline?

rostral maxillary (infraorbital) block

Which nerve block covers the bone, teeth, and intraoral soft tissue from the mandibular second to third premolar rostral to the midline?

rostral mandibular (mental) block

Which nerve block covers the bone, teeth, and intraoral soft tissue from the last molar rostal to the midline, including the ipsilateral soft and hard palatal mucosa and bone?

caudal maxillary block

Which nerve block covers the bone, teeth, and intraoral soft tissue from the mandibular third molar rostral to the midline?

caudal mandibular (inferior alveolar) block

Which block is indicated by A?*image

rostral maxillary block in infraorbital foramen

Which block is indicated by B?*image

caudal maxillary block

Which block is indicated by C?*image

caudal maxillary block

Which block is indicated by D? *image

rostral mandibular block in mental foramen

Which block is indicated by E? *image

caudal mandibular block in inferior alveolar via extraoral approach

What is the maximum total dose you can use in a cat or dog for oral nerve blocks using bupivacaine/ropivacaine?

2mg/kg (FOR ALL SITES COMBINED)

What drug(s) is preferred for oral nerve blocks?

0.5% bupivacaine or ropivacaine

What volume can be injected per site in cats and small dogs (<15kg) for oral blocks?

0.2-0.3mL

What volume can be injected per site in medium dogs (15-25kg) for oral blocks?

0.3-0.6mL

What volume can be injected per site in large dogs (26-40kg) for oral blocks?

0.8-1.2mL

What volume can be injected per site in giant dogs (>40kg) for oral blocks?

1.4-1.6mL

What gauge and length of needle should be used for oral blocks in patients </=15kg?

25 gauge

5/8”

What gauge and length of needle should be used for oral blocks in patients >15kg?

22 gauge

1/2”

What product can be used instead of regular bupivacaine for oral nerve blocks but is expensive?

Nocita

Why do small to medium size brachycephalic patients not require a caudal maxillary block?

their infraorabital canals are very short and allow the agent to be placed via the rostral maxillary block to reach nerves before entry into the infraorbital foramen and maxillary bone

What is the purpose of adding adjuvant or supportive analgesics with opioids?

avoid opioid side effects by lowering opioid dose needed

drugs work at different receptors to provide additive or synergistic effect

What are common adjuvant/supportive analgesics that attenuate excitatory neurotransmitters in the brain and spinal cord to help prevent and treat CNS sensitization and to prevent and reverse opioid tolerance/hyperalgesia?

ketamine

amantadine

memantine

Adding an NMDA antognist, such as ketamine or amantadine, or an anti-hyperalgesic, such as gabapentin, to an analgesic plan with opioids can help decrease what phenomenon?

wind up pain

What drug has activity at the alpha 2 delta subunit of voltage gated calcium channels in order to decrease CNS excitation and transmission of nociceptive impulses; acting as a mild sedative and anxiolytic for short term use; anti-hyperalgesic NOT analgesic?

gabapentin

pregabalin