1

1

Clinical Pain!End it Now !

End it for Good !

Ralph Harvey, DVM, MS, Diplomate ACVA University of Tennessee College of Veterinary Medicine

  Pain management is individualized for each patient

Leader Dogs for the Blind, Rochester, Michigan

Pain is an unpleasant sensory and emotional experience with actual or potential tissue damage. (Merskey 1979)

This definition of pain is also applied to the animal patient.

Clinical Pain:

1.  Acute Pain Operative and Trauma Care

2.  Chronic Pain Arthritic Pain Cancer Pain

3.  Critical Care Analgesia

1. Acute Pain and Perioperative Pain Management:

  Perioperative and Trauma Care

  The first area of marked improvement

2. Chronic Pain, Arthritic Pain, and Cancer Pain

  For our clients, the most obvious improvements in veterinary pain management.

  For example, have you heard of “Rimadyl”? (>8M dogs in US alone)

2

3. Critical Care Analgesia:

  Advantages are well defined.

  Mechanisms are documented.

  Tools are available.

  Application of these too often lags. Same is unfortunately true in human medicine.

8

Benefits of Pain/Stress Management

  Reduced sympathetic stimulation   Better control of cardiovascular function   Reduced neurologic stimluation (maladaptive neuro-endocrine response)

  Improved eating & drinking

  Improved general well being

  Reduced morbidity and mortality

Pre Medication

Post Medication

Pain as a Vital Sign

AAHA PM Standards: “Pain assessment using a standardized scale or scoring

system is recorded in the medical record for every patient evaluation”

  Pain scales…

Pain Evaluation in our Patients

3

Options for Evaluation

1.  Simple Descriptive Scale

2.  Numerical Rating Scale

3.  Composite Scale

4.  Interactive Visual Analog Scale

Measurement of stress: neuroendocrine catecholamines electrical impedance/conductance

Measurement of pain: Intraspinal c-fos

Behavioral signs… Severe Pain

--10

Many Factors Influence Pain Scores

  Temperament

  Vocalization

  Posture

  Locomotion

  Other behavioral changes

  There are species-specific variations in the

reliability of the behaviors or indicators of pain

  Behavioral differences may be observed when

the patient is removed from its normal

environment

  Client / owner input should be considered

  Reassessment after treatment should be made

by the same individual

Species-specific responses to chronic pain:

  Dogs - eating behavior is rarely affected

  Cats - isolation from others in the household, decreased grooming, and cessation of eating

  Horses - inappetance, severe weight loss, dull expression, glazed eyes, and basewide stance

  Ruminants - weight loss and isolation from the herd

  Pigs - reluctance to rise, reduced social interaction, and little appetite change

4

Behaviors as potential indicators of pain in the dog:

  Hunched or prayer position   Glazed facial expression   Attention-seeking and whining   Licking the painful area   Not hiding the painful body part

Behaviors as potential indicators of pain in the cat:

  Poor or lack of grooming   Hissing or aggression if the painful part is

manipulated   Tendency to hide the painful part and

look normal   Dissociation from the environment   Vocalization is rare

Common behaviors associated with chronic pain:

  Temperament - dull, grouchy, and grumpy.

  Posture and locomotion - limited ambulation, altered gait, overt lameness, reluctance to move, difficulty rising, and reduced play behavior.

  Grooming - alteration in or lack of grooming, grooming of specific parts, and licking of painful parts.

  Reduction of activity level.   Reduction of food and water consumption.

  Inappropriate urination and defecation.

  Human sensitivity to vocalization and extreme behaviors.

  Lameness evaluation:

Affected by joint

Severely subject to observer bias

Owner evaluation subject to placebo effect

  Caretaker expectation of perceived pain

Documented Observation Biases:

Sudden Changes in Behavior:

  Non-responsive:

  Hiding, motionless, silent

  Vocalization:

  Crying, barking, hissing

  Aggression:

  Biting, kicking, pawing, scratching, …Caution!

CAUTION   Pain induces neurological activity, which will increase

arterial blood pressure & heart rate

  It also creates stress & its related impact on function

  It causes changes in temperament

5

Pain Posture and Attitude Pain Behavior

Scales for Evaluation of Pain:

1.  Simple Descriptive Scale

2.  Composite Scale

3.  Interactive Visual Analog Scale

4.  Numerical Rating Scale (Interactive, 0-10)

(Repeated evaluations by owners, veterinarians & staff)

Our choice for evaluation of clinical pain.

Other pain scales have been developed and should be considered

Pain Scales: Simple Descriptive Scale   Modified Verbal Rating Scale

  Adapted from Jensen & Karoly, 1992

  Subjective based on simple observations & conclusions

No Pain Mild Pain Discomforting Distressing Intense Excruciating

(Scale as Used in Human Pain Scoring)

The use of pain scores in animals is more

complex than in humans. The use of single

signs of pain such as facial expressions may

lead to erroneous conclusions.

No Pain Mild Pain Discomforting Distressing Intense Excruciating

( Same Scale as Used in Animal Pain Scoring? ) Additional behavioral information is required

for complete assessment.

  Scale of 0-10 based on 0 is no pain and 10 is worst possible pain

1 2 3 4 5 6 7 8 9 10

Pain Scales: Numerical Rating Scale (NRS)

0

6

Pain Scales: Visual Analog Scale (VAS)

  Use of the VAS to evaluate pain management Scale of no pain to worst pain ever, 0-100 mm

100 0

100 0

Pain Scales: Visual Analog Scale (VAS)

10 20 30 40 50 60 70 80 90

77 Animal with pain requiring treatment

100 0

Pain Scales: Visual Analog Scale (VAS)

10 20 30 40 50 60 70 80 90

16 Evaluation after treatment

100 0

Pain Scales: Visual Analog Scale (VAS)

10 20 30 40 50 60 70 80 90

43 Post-treatment. Pain is returning, TIME TO REDOSE.

  Interactive Scale of 0-10   Based on 0 as no pain and 10 as the worst possible

pain for that condition

1 2 3 4 5 6 7 8 9 10

Pain Scales: Numerical Rating Scale (NRS)

0

Numerical Rating Scale

  Scale of 0-10 “0” as no pain “10” as the worst possible pain for that condition

  Based on behavioral signs   Interactive

Approach, engage, physically contact, elicit responses

  Repeated evaluations by owners, veterinarians & staff   Evaluations before and after analgesic interventions   Individualize interactions and evaluations to patient needs   Pain score recorded for every patient evaluation

7

Application of Pain Scales in our Patient Care: Interactive Numerical Rating Scale

Evaluations are conducted by owners, veterinarians & staff.

All evaluations should be interactive with the patient.

RESUSCITATION CODE: GREEN • YELLOW • RED

Protocol Approved by: Patient ID Verified by: Technician Initials:

DATE TIME SCHED. CAGE/STALL SURGEON ASSISTANT

PRE-OP DIAGNOSIS

PROPOSED OPERATION

BODY WT. TEMP. PULSE RESP. M.M. CRT PRE-OP RADS

FASTED YES NO

P.C.V. TPP BUN CREAT. Hb URINE S/G OTHER

Physical Status: 1 2 3 4 5 E Interactive Pain Score: (0-10) ______

ANESTHESIA RECORD

University of Tennessee, W.W. Armistead Veterinary Teaching Hospital

ANESTHESIA RECORD

Date: __________________________ Anesthetist: ________________________________ Anesthesiologist: ____________________________________________ VMRS-003

Pre-Anesthetic Drugs Anesthetic InductionDrug Cont # mg DOSE (mL) Route Time PRE-MED Result Drug Cont # mg DOSE (mL) Route Time

! None! Slight ! Moderate! Profound! Adverse

BLOOD/PLASMA Donor name Donor, PCV/TPRATE gtt/sec

I.V. SOLN 1RATE CRI rate

I.V. SOLN 2RATE CRI rate

I.V. SOLN 3RATE CRI rate

O2 Flow L/m

AG

EN

TS

Isoflurane

ET Iso ( )

Sevoflurane

ET Sevo ( )

___________

___________

8.0

7.0

6.0

5.0

4.0

3.0

2.5

2.0

1.5

1.0

TIME 0100-2400

340

320

280

START ANES. A 260

240

START OPER. O 220

200

END ANES. A 180

END OPER. X 160

B.P.SYST MEAN DIAS.

V X

140

120

C.V.P. (x10) "100

SpO2 !80

ETCO2 "60

55

PULSE !50

45

RESP. "40

35

SPON:30

o-o S 25

CONT20

o-o C 15

10

5

COMMENTS:

TOTAL FLUIDS

Plasma __________ mls Blood ___________ mls

Fluids 1 _________ mls Fluids 2 _________ mls

MONITORING

Blood Pressure Blood Gases

Esophageal Steth Doppler Temp

ECG CVP SpO2 ETCO2

MAINT OF AIRWAY

Mask ET Tube Size _______________

Armoured Murphy Cuffed

Difficulty _______________________________

BODY POSITION

Lateral L R Sternal Dorsal

Head-Up Head-Down

ANESTHESIA SYSTEM

Semi-Closed Bain Ventilator

REGIONAL ANESTH

Epidural Regional Local

Site ___________________________________

Agent # 1 _______________________________

Cont # ________________ Amount _________

Agent # 2 _______________________________

Cont # ________________ Amount _________

CRI

Agent # 1 _______________________________

Cont # ________________ Amount _________

Agent # 2 _______________________________

Cont # ________________ Amount _________

ADDITIONAL MEDS

Agent # 1 _______________________________

Cont # ________________ Amount _________

Agent # 2 _______________________________

Cont # ________________ Amount _________

Total Anesthesia Time _____________________

Anesthesia Base Charge ___________________

Anesthesia ______________________________

Epidural _______ Doppler _______ CVP ______

Misc. drugs ___________ Bair Hugger ________

Wt. 60# ______________ Blood, Plasma ______

CRI Meds _____________ CRI Base __________

Nerve Block ___________ Ventilator _________

ASA III ________ ASA IV _______ ASA V ______

Jugular Catheter 1 2 3 4 _____________

Arterial Line Monitoring ____________________

TOTAL COST:

V

RESUSCITATION CODE: GREEN • YELLOW • RED

Protocol Approved by: Patient ID Verified by: Technician Initials:

DATE TIME SCHED. CAGE/STALL SURGEON ASSISTANT

PRE-OP DIAGNOSIS

PROPOSED OPERATION

BODY WT. TEMP. PULSE RESP. M.M. CRT PRE-OP RADS

FASTED YES NO

P.C.V. TPP HB CREAT. BUN URINE S/G OTHER

Physical Status: 1 2 3 4 5 E Interactive Pain Score: (0-10) ______

University of Tennessee, W.W. Armistead Veterinary Teaching HospitalRECOVERY ROOM RECORD

Date: __________________________ Anesthetist: ________________________________ Anesthesiologist: _____________________________________________ VMR-055

RECO

VERY

ROO

M

Time of Arrival: Release Status: ! Alive ! Dead ! Euthanatized

Time Released: Release To: ! Ward ! ICU Cage/Stall# _________

Total Time: Signature: ! Owner ! Path

CLINICIAN’S RECOVERY ROOM ORDERS:

SPECIAL OBSERAVTIONS REQUIRED: CONTINGENCY ORDERS: (Anticipated problems & what to do, who to call)

CONTROLLED SUBSTANCES: Agent: Total Agent Drawn: mis. Control No. Total Agent Given: mis.

TIME TEMP. PULSE RESP. B.P. M.M. CRT REFLEX U/BM Pain Score Comments & Medications Initials

ANESTHESIA SUMMARY:

RECOVERY ROOM RECORD

Principles in Pain Management

1.  Preemptive analgesia

2.  Balanced analgesia

3.  Dose to effect

  Thorough Nursing Care   Alter the Environment   Distraction / Relaxation   Opioids   Loco-Regional Anesthesia   Alpha-2 Agonists   Adjunctive Analgesics

  tramadol, gabapentin, amantadine, ketamine, acupuncture, etc.

Balanced or Multi-modal Analgesia:

Make best use of Opioids:

  Morphine   Oxymorphone   Hydromorphone   Fentanyl (Duragesic)   Remifentanil (Ultiva)   Butorphanol

(Torbutrol, Torbugesic, Stadol)

  Buprenorphine (Buprenex, Temgesic)

  Tramadol (Mu agonist plus inhibits reuptake of NE & 5-HT) 42

  Powerful and sustained analgesia

  Effective throughout the body

  Technically easy   Cost effective   Numerous benefits

Epidural Opioids +/- Locals

8

Neuroaxial Analgesia:

  12-24 hours of substantial analgesia

  Decreased “Stress response”

  Epidural Morphine Duramorph (preservative free)

Morphine USP

  Bupivacaine or Lidocaine (with volume expansion)

Fentanyl (Duragesic) Patches

  Consistent (basal) level of strong opioid analgesia (3-5 days)

  Many veterinary applications

  Strictly “off-label”

  Limitations / precautions

  Alternatives: CRI fentanyl, oral SR morphine, oral buprenorphine, oral codeine

45

Success with Local Anesthetics:

  Drugs used:   Lidocaine   Bupivicaine, Ropivicaine   Articaine

  Applications:   Regional, Specific Nerve Blocks, Infiltration   Neuroaxial

Epidural, Spinal

  Intravenous (Lidocaine C.R.I.)

  Locals are very cheap and very effective!

Make best use of NSAID’s:

  Ketoprofen   Carprofen   Etodolac   Deracoxib   Meloxicam   Firocoxib   Other NSAID’s   (Acetaminophen)

Recognition of additional actions…

  Recognize tremendous individual patient variability in efficacy and safety of various NSAID’s, and it changes!

  Skill in application and management   Management of toxicities

  Cox-2 selectivity/specificity   Constituitive Cox-1 and Cox-2   Cytoprotective measures   Dual pathway Cox/Lox

  Several paradigm shifts regarding NSAID toxicities

Which NSAID?

48

Principles in Pain Management

1.  Preemptive analgesia

2.  Balanced analgesia

3.  Dose to effect

plan a “wet lab”…

9

49

Case Studies

  Fan-belt Trauma

Case Studies

  Thermal Burns - dog or cat

Case Studies

  Thoracotomy

Case Studies

  Evisceration – Gored by a “Pet” Boar!

  Massive trauma, sepsis, shock

Case Studies

  Total Ear Canal Ablation

10

55

Case Studies

  Polytrauma   Multiple Fractures, etc.

56 Thank you for participating in these sessions!

Dr. Ralph Harvey

How to Manage Clinical Pain