To Tell the Tooth
To Tell the Tooth
Anesthesia and Pain Management in the Dentistry Patient
Tasha McNerney BS, CVT, CVPP, VTS (Anes.)p.1
VETERINARY ANESTHESIA NERDS
WHO SAYS VET MEDICINE IS STRESSFUL?
I'M 29 AND I FEEL GREAT!p.2
"There are no safe anesthetic drugs or procedures; only safe anesthetists."- Dr. Bob Smithp.3
"What makes an anesthetic procedure "successful"?
-Simply having the patient awake after anesthesia is no longer good enough.
-We need to incorporate adequate pain control as well as a level of anesthesia that allows the surgeon to accomplish the patient suffering adverse effects."p.4
The Dentistry Patient
Often loder patients---is this important?
Often have concurrent disease---is this important?
No one size fits all protocol for dentistry patients.p.5
-Often state of the art monitors are used for surgical patients.
-What do we often find for the dentistry patients?p.6
-Often less monitoring equipment
-Often one technician monitoring anesthesia and preforming cleaning/charting and radiographs.p.7
Choosing the right pre-medication
-What is the desired effect?
-Can the drug produce it?
-What are the side effects?
-Can this patient handle these side effects?
-ASA I patient vs.ASA III-IVp.8
-Opioids are the most frequently used pre-anesthetic analgesic agents. Why? They Work well and most are very cost effective.$$$
-Although it is thought that opioids cause respiratory depression this is more of a human dose dependent issue.
-Opioids are not contraindicated simply because the patient is brachycephalic, senior, or well...anything!p.9
-Drugs that stimulate are called agonists and those that block are called antagonists
Normal cellular activity
Enhanced cellular activity
Blocked cellular activityp.10
Mu Opioid Agonists
Hydromorphone HCI Injection, USP
Partial Agonist Opioids
-Buprenorphine is considered a partial agonist at the mu receptors. It is considered an antagonist at kappa receptors.
-Because it is only a partial agonist, it may not provide adequate analgesia for more painful procedures, such as orthopedic procedures.
Slower onset of action than other opioids with peak effect noted 45-60 minutes after IV administration.
10 Carpuject TM
Sterile Cartridge Units with Luer Look
Tamper Detection Package
Buprenorphine HYdrochloride Injection
For Intramuscular or Intravenous Use
contains 10mg butorphanol base per mL as butorphanol tartrate, USP
CAUTION: Federal law restricts this drug to use by or on the order of a licensed veterinarian.
NADA 135-780, Approved by FDA
-Butorphanol Bind to more than one type of receptor, causing an effect at one but no effect, or a less pronounced effect at another.
-Kappa agonist/mu antagonist
-Kappa receptor is responsible for sedation and some analgesia
-Mu receptors are responsible for supraspinal analgesia, euphoria, bradycardia, and some respiratory depression.p.14
-Diazepam, Midazolam, and zolazepam(a component of Telazol)
-Anti-anxiety and calming effects.
-Enhances the sedation and analgesia of other agents.
-Have no analgesic effects
-Few effects on the cardiovascular&respiratory systems.p.15
-Effective IM, IV, SQ, intranasal, and transmucosally.
-Induces a dose dependent CNS depression that leads to a dissociative state(profound amnesia and analgesia with maintained reflexes)
-Stimulates the cardiovascular system resulting in increases in heart rate, blood pressure, and cardiac output
Ketamine HCI Injection, USP
Caution: Federal law restricts this drug to use by or on the order of a licensed veterinarian.
-Induction should be rapid in order to gain control over the airway.
-Injectable medications are preferred over mask induction.
-When possible use the following order of events:
-Pre-oxygenate while placing IV catheter
-Induction medication IV(still administering O2)
-Intubation when patient adequately anesthetized.p.17
Agents that are rapidly metabolized are preferred in brachycephalic, diabetic, and liver disease patients.
-propofol-a short acting hypnotic agent. It should be administered
s-l-o-w-l-y(over 90 seconds to reduce side effects such as apnea)
-Etomidate-a short acting intravenous sedative hypnotic anesthetic agent
-Alfaxalone-an ultra short acting neuroactive steroid molecule with the properties of a general anestheticp.18
-Unlike ketamine, alfaxalone is not associated with adverse cerebral outcomes or cardiac stress.
-Unlike propofol, alfaxalone is not associated with respiratory depression or hypotension at normal induction dosesp.19
-By combining lidocaine with bupivacaine, you can get a fast onset because of the Lidocaine, and a long duration because of the Bupivicaine.
Bupivacaine HCI injection
NOT FOR SPINAL ANESTHESIA
Lidocaine 2% Injectable
FOR ANIMAL USE ONLY
KEEP OUT OF REACH OF CHILDREN
Lidocaine HCI Injection, USP,2%
20mg per mlp.20
J Am Podiatr Med Assoc.1996 Oct;86(10):487-91.
Local anesthetics. Is there an advantage to mixing solutions?
Ribotsky BM1, Berkowitz KD, Montague JR.
no significant difference between the duration of anesthesia of plan lidocaine and the 50/50 mixture.
The results of this study suggest that there is no clinical advantage, with respect to onset and duration of local blockade, to using a 50/50 mixture of plain lidocaine and plain bupivacaine in place of their independent use."p.21
Useful LOcal Blocks
-Local(regional)anesthesia plays an important part in the pain control of oral surgical patients.
-Local anesthesia allows a decreased plane of general anesthesia required to complete a procedure.
Small Animal Regional Anesthesia and Analgesiap.22
Rostral Mandibular Block
Use the index finger of your opposite hand to fee for the foramen and assess whether the tip of the needle is in the correct position.p.23
Infraorbital Nerve block
-By blocking the infraorbital nerve, the continuation of the maxillary nerve, as it exits the infraorbital foramen anesthetizes the upper lip, premolars, nose roof of the nasal cavity, and skin as far caudal as the infraorbital foramen. The maxillary incisors are inconsistently blocked with this technique, particularly in dogs.p.24
Maxillary Nerve Block
-Maxillary nerve block. This blocks the entire maxillary quadrant on the buccal and palatal sides of the teethp.25
Middle Mental Nerve block
-The middle mental nerve exits the middle mental foramen, which in the dog is located on the lateral aspect of the mandible, below the mesial(cranial)root the lower second premolar.p.26
Constant Rate Infusions:
-CRI's have several advantages:
1.Less break through pain
2.A lower drug dosage is used resulting in a lower incidence of dose related side effects
3.Greater control over drug administration
4.Decreased cost(when compared to technician time and repeated costs of multiple needles and syringes)p.27
Other useful CRI's
-MLK CRI is easiest one to master and provides the most multimodel pain control with the lowest cost.
-Morphine-can interchange any other opioid.
-Lidocaine-underused wonder drug!
Ketamine-prevents wind up
-Extremely useful in major abdominal surgery, dentistry with multiple extractions, and orthopedics
Maropitant citrate mimics the structure of substance P and binds the NK-1 receptors so that they cannot bind substance P, thus making stimulation of the vomit center extremely difficult
Substance P is involved in numerous inflammatory conditions, so it has led to further investigation of maropitant citrate uses far beyond nausea control.p.29
Join the "Block the Box" movement!p.30
Monitoring the Dentistry Patient
-Many monitors available
-You are the most important monitor/
-Think of procedure
-Anticipated Pain Level?
-ASA Status of Patient?p.31
-Cardiac Output is essential to ensure oxygen delivery to tissues
-Cardiac output is aflow measurement
-This will only occur if there is adequate driving pressure.
Mean Arterial Pressure
Total Peripheral Resistance
Sympathetic: norepinephrine epinephrinep.33
-Mean arterial pressure
-<60 mmHg poor renal perfusion
-<50 mmHg cerebral oxygen delivery is compromised
-<30mmHg brain ischemiap.34
-A palpable pulse pressure is the difference between the diastolic and the systolic pressures.
-A difference of at least 30mmHg is needed to palpate a strong pulse.
-This means you could have a systolic of 70mmHg and a diastolic of 30mmHg with a pulse pressure of 40mmHg and still feel a good pulse.p.35
-Detects arterial wall motion and RBC movement
-Movement is then converted into an audible sound.p.36
-Limitations to accuracy with the doppler
-Pressure reading on the sphygmomanometer gives a pressure reading somewhere between mean and the systolic pressure.
Treatment for hypotension
-Treatment depends on the cause.
-Most animals under anesthesia experience hypotension due to vasodilation(due to drugs such as inhalant anesthetics)and bradycardia(due to drugs such as dexmedetomidine and an increase in patient depth of anesthesia)p.38
If your patient is hypotensive
Reduce the inhalant anesthetic dose, if hypotension is due to patient being too deep, lighten them up!
Increase the fluid administration. Consider colloids: keeps your crystalloids in the vasculature longer.
Warm water circulating blankets
-By circulating water through a leak-proof pad, conductive temperature therapy effectively treats a variety of localized conditions including muscle and joint pain, arthritis, and edema. It also helps prevent body heat loss and hypothermia during veterinary surgery and recoveryp.40
Hot Dog Warming System
-The flexible blankets feature electrically conductive fabric for even heat distribution
-Three heat settings
-No blowing air on the surgical site, won't dry out EKG leads,
No noise pollutionp.41
Warmed IV Fluids
-Warmed IV fluids or irrigation fluids must be used with caution.
-If fluids are warmed in the microwave, temperatures can become damaging to tissuesp.42
-As the patient looses heat, it is "trapped" in the air bubbles of the bubble wrap. This means the bubble wrap can help prevent heat loss!p.43
-Can cut to fit any patient size.
-No risk of overheating or thermal burns.
-Wrap around extremities.p.44
Dentistry technique - Which way prevents more heat loss?p.45
Pain management is so importantp.46
Moe 13yr M/N DSH HCM
cranky pants, spicy pepper
Avoid stress in these patientsp.47
-A. Purrito restraint and administer IV propofol to facilitate intubation.
-B. Pre-med with opioid + other agent and allow to sit in a quiet area while drugs take effect.
-C. Be extremely cautious and avoid opioids, use tank or chamber induction.p.48
low dose dexmedetomidine
-No ISO BOX!
NO MASK INDUCTION!p.49
-Needs both lower canines removed
-Mental nerve block
-In cats, foramen is usually hard to palpate due to redundant tissue
-Landmark in cats, usually under premolarp.50
Case Report - HCM
- Need pre-load... fluids ok but don't overload
- 5ml/kg bolus of crystalloid
- Can repeat up to 3x
- If not working... move on to phenylephrine
- Cost effective
- Short half lifep.51
-Vasoconstriction and increases afterload
-Dopamine is an inotrope and increases contractility
-This may worsen obstruction
I NEED TO SEE A DENTIST
ONE OF MY CANINES IS GETTING LOOSE
-Provide adequate analgesics for pain anticipated
-Monitor senior/debilitated patient appropriately
-Use appropriate local blocks
-Change plan as needed based on specific patient needs.p.53
Questions & Discussion
Ma, the Meatloaf!p.54