VETS 238 Surgical Nursing and Anesthesia Spring 2006
Welcome to Surgical Nursing and Anesthesia <ul><li>Dr. Bret Meckel </li></ul><ul><ul><li>Graduate of Texas A&M College of ...
Class # 1 <ul><li>Introductions </li></ul><ul><ul><li>Who are you? </li></ul></ul><ul><ul><ul><li>Name, where from, intere...
Any Questions?
The Preanesthetic Period <ul><li>Read over notes and corresponding text for next class </li></ul><ul><li>Be prepared! </li...
 
Quick Survey <ul><li>Currently working at a practice? </li></ul><ul><li>LA vs SA? </li></ul><ul><li>Anesthetics? </li></ul...
Preanesthesia  <ul><li>What is it?  What comes to mind? </li></ul>
The Preanesthetic Period <ul><li>When? </li></ul><ul><ul><li>The period preceding induction of anesthesia </li></ul></ul><...
Preanesthesia (cont) <ul><li>Major functions of technician </li></ul><ul><ul><li>1) Obtain information </li></ul></ul><ul>...
Patient Evaluation/ Information Collection <ul><li>  Remember :Patients Vary Greatly </li></ul><ul><li>So need to get stan...
Minimum Data Base <ul><li>Paperwork </li></ul><ul><li>Patient History </li></ul><ul><li>Physical Examination </li></ul><ul...
Paperwork/Information Collection <ul><li>Consent Forms </li></ul><ul><ul><li>Filled out/signed  by owner </li></ul></ul><u...
Patient History <ul><li>Information from questions to owner </li></ul><ul><li>“ Chief Complaint” =  main problem   (accord...
History Taking <ul><li>Not yes/no questions </li></ul><ul><ul><li>People avoid “I don’t know” </li></ul></ul><ul><li>Not l...
Physical Examination <ul><li>Signalment  </li></ul><ul><ul><li>1)Species and breed–Why Important? </li></ul></ul><ul><ul><...
Hands On Exam  (read section in VAA) <ul><li>By body system </li></ul><ul><li>Front to Back </li></ul><ul><li>Back to Fron...
In Record by Body System <ul><li>Temperature, heart rate and respiratory rate (TPR)  </li></ul><ul><li>Auscultate the hear...
Diagnostic Tests <ul><li>No Universal Guidelines </li></ul><ul><ul><li>Will depend on work place </li></ul></ul><ul><li>Cl...
CBC <ul><li>RBC #/ Hbg (O2 carrying capacity) </li></ul><ul><ul><li>Anemia </li></ul></ul><ul><li>PCV </li></ul><ul><ul><l...
Urinalysis (UA) <ul><li>Specific Gravity </li></ul><ul><ul><li>Concentration </li></ul></ul><ul><ul><ul><li>High vs low? <...
Blood Chemistry Panel <ul><li>Checks Organ/ Hormone Function </li></ul><ul><li>Liver  </li></ul><ul><li>Kidney </li></ul><...
Blood Clotting Tests <ul><li>IN HOUSE </li></ul><ul><ul><li>Nail cut </li></ul></ul><ul><ul><li>Buccal Bleeding </li></ul>...
ECG <ul><li>Determines rate and rhythm of cardiac contractions </li></ul>
Radiography <ul><li>Plain/Contrast Films, Ultrasound, CT, MRI </li></ul><ul><li>If warranted: </li></ul><ul><ul><li>HBC </...
Misc. Tests <ul><li>Heartworm Test </li></ul><ul><li>Blood Gases </li></ul>
Procedure to be performed <ul><li>Length of time </li></ul><ul><ul><li>Catheter? </li></ul></ul><ul><ul><li>Antibiotics </...
Classification of Patient Physical Status <ul><li>Used w/ minimum data base to determine appropriate anesthetic protocol <...
Selection of the Anesthetic Protocol <ul><li>Factors that affect selection of the anesthetic protocol: (Other than the pat...
Preanesthetic Patient Care <ul><li>1). Withholding food and water before anesthesia </li></ul><ul><li>Why?   Don’t assume!...
Preanesthetic Patient Care <ul><li>2) Correction of pre-existing problems </li></ul><ul><li>correct if possible but weigh ...
About any drug we discuss: <ul><li>You NEED to Know: </li></ul><ul><ul><li>Class and MOA </li></ul></ul><ul><ul><li>Common...
PREANESTHETIC  AGENTS <ul><li>Reasons for use: </li></ul><ul><li>1. to calm or sedate the patient </li></ul><ul><li>2. to ...
ANTICHOLINERGICS  (parasympatholytics ) <ul><li>ATROPINE </li></ul><ul><li>Caution:  </li></ul><ul><ul><li>LA vs SA concen...
Effects of atropine: <ul><li>1. Blocks stimulation of the vagal nerve </li></ul><ul><ul><ul><li>Major parasympathetic inne...
Atropine toxicity: <ul><li>Signs: </li></ul><ul><ul><li>Dilated pupils, tremors, ataxia </li></ul></ul><ul><ul><li>Due to ...
Use of atropine  = controversial! <ul><li>Needed with newer drugs? </li></ul><ul><li>Potential for adverse side effects/to...
GLYCOPYRROLATE <ul><li>effects similar to atropine </li></ul><ul><li>Advantages of glycopyrrolate: </li></ul><ul><ul><li>E...
 
TRANQUILIZERS  AND  SEDATIVES <ul><li>Main reasons for use: </li></ul><ul><ul><li>Calm animal for easier handling and indu...
PHENOTHIAZINES <ul><li>= “-promazines”  ACEPROMAZINE </li></ul><ul><li>Effects of phenothiazines:  </li></ul><ul><li>1.) S...
BENZODIAZEPINES <ul><li>= “-ams”  examples: diazepam (valium),  zolazepam (in telazol) </li></ul><ul><li>MOA: cause releas...
Use of benzodiazepines: <ul><li>Diazepam  ( Valium )  IV  slowly (or IM) </li></ul><ul><li>NOT water soluble  (precipitate...
ALPHA  2  AGONISTS  (receptor in brain)  (engage these receptors) <ul><li>=“thiazine derivatives”  </li></ul><ul><ul><li>e...
Use of alpha 2 agonists: <ul><li>Xylazine  SA solution  2%  LA solution   10%     mgs/mL*  </li></ul><ul><li>used alone or...
Alpha Agonists: ADVERSE EFFECTS <ul><li>=significant, frightening, check your own pulse </li></ul><ul><li>1. BRADYCARDIA  ...
OPIOIDS <ul><li>aka  “narcotics”  or  “opiates” (natural) </li></ul><ul><li>Versatile--  can be used for:  </li></ul><ul><...
OPIOID’s (cont) <ul><li>Effects:  </li></ul><ul><ul><li>1. CNS effects:  may cause CNS depression or excitement </li></ul>...
OPIOIDS: Adverse effects <ul><li>1.  Respiratory depression   >>>> decreases respiratory rate and tidal volume </li></ul><...
 
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Vets 238 Intro Preanesthesia Final Draft

  1. 2. VETS 238 Surgical Nursing and Anesthesia Spring 2006
  2. 3. Welcome to Surgical Nursing and Anesthesia <ul><li>Dr. Bret Meckel </li></ul><ul><ul><li>Graduate of Texas A&M College of Veterinary Medicine </li></ul></ul><ul><ul><li>8 years in private practice in Southern Oregon </li></ul></ul><ul><ul><ul><li>Three different small animal practices </li></ul></ul></ul><ul><ul><ul><li>Primary vet for the Oregon Tiger Sanctuary </li></ul></ul></ul><ul><ul><li>Started teaching at Delhi in Spring ‘06 </li></ul></ul>
  3. 4. Class # 1 <ul><li>Introductions </li></ul><ul><ul><li>Who are you? </li></ul></ul><ul><ul><ul><li>Name, where from, interests in veterinary medicine </li></ul></ul></ul><ul><li>VETS238 Syllabus + Lecture Outlines </li></ul><ul><li>VETS239 Syllabus </li></ul><ul><li>VETS239 Lab Guidelines </li></ul><ul><li>VETS239 Lab Schedule </li></ul><ul><li>Academic Integrity Policy </li></ul><ul><li>Safety Release Form </li></ul>
  4. 5. Any Questions?
  5. 6. The Preanesthetic Period <ul><li>Read over notes and corresponding text for next class </li></ul><ul><li>Be prepared! </li></ul>
  6. 8. Quick Survey <ul><li>Currently working at a practice? </li></ul><ul><li>LA vs SA? </li></ul><ul><li>Anesthetics? </li></ul><ul><ul><li>Injectable </li></ul></ul><ul><ul><li>Gas </li></ul></ul>
  7. 9. Preanesthesia <ul><li>What is it? What comes to mind? </li></ul>
  8. 10. The Preanesthetic Period <ul><li>When? </li></ul><ul><ul><li>The period preceding induction of anesthesia </li></ul></ul><ul><ul><ul><li>Preanesthesia, induction, maintenance, recovery </li></ul></ul></ul>
  9. 11. Preanesthesia (cont) <ul><li>Major functions of technician </li></ul><ul><ul><li>1) Obtain information </li></ul></ul><ul><ul><ul><li>Preanesthetic forms, history, PE, Dx tests </li></ul></ul></ul><ul><ul><li>2) Patient Care </li></ul></ul><ul><ul><ul><li>Fasting, iv catheter, walking </li></ul></ul></ul><ul><ul><li>3) Administering drugs </li></ul></ul><ul><ul><ul><li>As directed by veterinarian </li></ul></ul></ul>
  10. 12. Patient Evaluation/ Information Collection <ul><li> Remember :Patients Vary Greatly </li></ul><ul><li>So need to get standardized information </li></ul><ul><li>= minimum data base </li></ul>
  11. 13. Minimum Data Base <ul><li>Paperwork </li></ul><ul><li>Patient History </li></ul><ul><li>Physical Examination </li></ul><ul><li>Diagnostic Tests </li></ul>
  12. 14. Paperwork/Information Collection <ul><li>Consent Forms </li></ul><ul><ul><li>Filled out/signed by owner </li></ul></ul><ul><ul><ul><li>anesthesia consent, DNR, IV/Bloodwork waiver </li></ul></ul></ul><ul><li>Estimates </li></ul><ul><ul><li>No surprises </li></ul></ul>
  13. 15. Patient History <ul><li>Information from questions to owner </li></ul><ul><li>“ Chief Complaint” = main problem (according to O) </li></ul><ul><ul><li>What’s wrong with ______ today? </li></ul></ul><ul><ul><li>How used </li></ul></ul><ul><li>Observations </li></ul><ul><ul><li>Objective : facts and information </li></ul></ul><ul><ul><ul><li>ie – not urinating very much </li></ul></ul></ul><ul><li>Interpretations </li></ul><ul><ul><li>Subjective: adds evaluation to information </li></ul></ul><ul><ul><ul><li>ie – dehydrated vs blocked? </li></ul></ul></ul>
  14. 16. History Taking <ul><li>Not yes/no questions </li></ul><ul><ul><li>People avoid “I don’t know” </li></ul></ul><ul><li>Not leading questions </li></ul><ul><ul><li>ie - drinking too much? </li></ul></ul><ul><li>Persist until adequate answer received </li></ul><ul><ul><li>Ie – one cup of food per day </li></ul></ul><ul><li>Examples = pg 3 VAA </li></ul>
  15. 17. Physical Examination <ul><li>Signalment </li></ul><ul><ul><li>1)Species and breed–Why Important? </li></ul></ul><ul><ul><li>2)Weight (possible complicating factor for anesthesia) </li></ul></ul><ul><ul><li>3)Age </li></ul></ul><ul><ul><ul><li>geriatric? Depends on breed </li></ul></ul></ul><ul><ul><li>4)Sex with reproductive status (M/F S/N) </li></ul></ul><ul><ul><ul><li>ie prostate or pyometra </li></ul></ul></ul><ul><ul><li>5)Disposition and Activity Level </li></ul></ul><ul><ul><ul><li>Helps determine drug choice, suture, e-collar </li></ul></ul></ul>
  16. 18. Hands On Exam (read section in VAA) <ul><li>By body system </li></ul><ul><li>Front to Back </li></ul><ul><li>Back to Front </li></ul><ul><li>Top to Bottom </li></ul><ul><li>Key is to do it the SAME every time or you’ll miss things </li></ul>
  17. 19. In Record by Body System <ul><li>Temperature, heart rate and respiratory rate (TPR) </li></ul><ul><li>Auscultate the heart and lung and note any unusual characteristics and if necessary postpone the anesthesia until fully clear the questionable condition. </li></ul><ul><li>Body condition; obesity, cachexia, dehydration </li></ul><ul><li>Cardiopulmonary system: heart rate and rhythm, auscultate the characteristics, CRT, color of mucous membrane, exercise intolerance, coughing, dyspnea </li></ul><ul><li>CNS and special senses: temperament, seizure, coma, stupor, ataxia, vision and hearing impairment </li></ul><ul><li>Gastrointestinal: auscultate the gut sound, parasites, palpatition </li></ul><ul><li>Hepatic: icterus, abnormal bleeding </li></ul><ul><li>Renal: palpate kidneys and bladder, polyuria/polydipsia, oliguria </li></ul><ul><li>Integument: tumors and flea infestation </li></ul><ul><li>Musculoskeletal: fractures, deformity, and lameness </li></ul>
  18. 20. Diagnostic Tests <ul><li>No Universal Guidelines </li></ul><ul><ul><li>Will depend on work place </li></ul></ul><ul><li>Clinic Policy vs Vet Decision </li></ul>
  19. 21. CBC <ul><li>RBC #/ Hbg (O2 carrying capacity) </li></ul><ul><ul><li>Anemia </li></ul></ul><ul><li>PCV </li></ul><ul><ul><li>% RBC </li></ul></ul><ul><ul><ul><li>Low means? </li></ul></ul></ul><ul><li>TPP (TP) = albumin + immunoglobulins </li></ul><ul><ul><li>High vs Low? </li></ul></ul><ul><li>WBC differential </li></ul><ul><ul><li>Infection (bacterial or parasitic) or Leukemia </li></ul></ul>
  20. 22. Urinalysis (UA) <ul><li>Specific Gravity </li></ul><ul><ul><li>Concentration </li></ul></ul><ul><ul><ul><li>High vs low? </li></ul></ul></ul><ul><li>Chemistries </li></ul><ul><ul><li>Protein/Glucose significance? </li></ul></ul><ul><li>Microscopic Exam (sediment) </li></ul><ul><ul><li>Crystals, RBC, WBC, casts </li></ul></ul>
  21. 23. Blood Chemistry Panel <ul><li>Checks Organ/ Hormone Function </li></ul><ul><li>Liver </li></ul><ul><li>Kidney </li></ul><ul><li>Diabetes Screen </li></ul><ul><li>Pancreas </li></ul><ul><li>Electrolytes </li></ul><ul><ul><li>Ca,K,Na,Cl </li></ul></ul>
  22. 24. Blood Clotting Tests <ul><li>IN HOUSE </li></ul><ul><ul><li>Nail cut </li></ul></ul><ul><ul><li>Buccal Bleeding </li></ul></ul><ul><ul><li>ACT (Activated Clotting Time) </li></ul></ul><ul><li>TO LAB </li></ul><ul><ul><li>PT/PTT </li></ul></ul><ul><ul><li>Especially consider in ? </li></ul></ul>
  23. 25. ECG <ul><li>Determines rate and rhythm of cardiac contractions </li></ul>
  24. 26. Radiography <ul><li>Plain/Contrast Films, Ultrasound, CT, MRI </li></ul><ul><li>If warranted: </li></ul><ul><ul><li>HBC </li></ul></ul><ul><ul><li>Possible Malignancy </li></ul></ul><ul><ul><li>Otherwise called for in PE </li></ul></ul>
  25. 27. Misc. Tests <ul><li>Heartworm Test </li></ul><ul><li>Blood Gases </li></ul>
  26. 28. Procedure to be performed <ul><li>Length of time </li></ul><ul><ul><li>Catheter? </li></ul></ul><ul><ul><li>Antibiotics </li></ul></ul><ul><li>Open GI Tract, Urinary Tract, Orthopedic </li></ul><ul><ul><li>Antibiotics! </li></ul></ul>
  27. 29. Classification of Patient Physical Status <ul><li>Used w/ minimum data base to determine appropriate anesthetic protocol </li></ul><ul><li>Classes I-V (see page 15 in VAA) </li></ul><ul><li>Example: </li></ul><ul><ul><li>1 yr old hyper young lab class I </li></ul></ul><ul><ul><ul><li>Injectables w/ heavy sedation </li></ul></ul></ul><ul><ul><li>10 yr old intact male blocked cat class V </li></ul></ul><ul><ul><ul><li>Mask down </li></ul></ul></ul>
  28. 30. Selection of the Anesthetic Protocol <ul><li>Factors that affect selection of the anesthetic protocol: (Other than the patient’s physical status) </li></ul><ul><li>1. Availability of equipment and facilities </li></ul><ul><ul><li>Anesthetic machine? </li></ul></ul><ul><li>2. Familiarity with the agent and the anesthetic protocol </li></ul><ul><ul><li>Safest drug is the one you’re used to </li></ul></ul><ul><li>3. Nature of the procedure </li></ul><ul><ul><li>Painful? Long? Local? </li></ul></ul><ul><li>4. Special patient circumstances </li></ul><ul><ul><li>Pregnant animal/ C-section </li></ul></ul><ul><li>5. Cost of anesthetic agents </li></ul><ul><ul><li>Important but remember #2 </li></ul></ul><ul><li>6. Speed of induction and recovery </li></ul><ul><ul><li>Emergency? End of day? </li></ul></ul>
  29. 31. Preanesthetic Patient Care <ul><li>1). Withholding food and water before anesthesia </li></ul><ul><li>Why? Don’t assume!* </li></ul><ul><li>Duration: food: 8 hr water: 2hr? </li></ul><ul><li>With GI procedures: </li></ul><ul><ul><ul><li>food: 24 hours if possible water: 8hrs? </li></ul></ul></ul><ul><li>Risks: </li></ul><ul><ul><li>Dehydration – anesthesia risk factor </li></ul></ul><ul><ul><li>Hypogycemia – esp. puppies/kittens </li></ul></ul><ul><ul><li>anorexia – delays healing/recovery </li></ul></ul>
  30. 32. Preanesthetic Patient Care <ul><li>2) Correction of pre-existing problems </li></ul><ul><li>correct if possible but weigh the risks </li></ul><ul><li>ie UTI in blocked cat </li></ul><ul><li>3) Intravenous Catheter and Fluid Therapy </li></ul><ul><li>nice to have started couple hours before surgery if possible </li></ul><ul><li>4) Other Care </li></ul><ul><li>walking, antibiotics, other meds? </li></ul>
  31. 33. About any drug we discuss: <ul><li>You NEED to Know: </li></ul><ul><ul><li>Class and MOA </li></ul></ul><ul><ul><li>Common and Trade Name </li></ul></ul><ul><ul><li>Common route(s) </li></ul></ul><ul><ul><li>Indications (why we use) </li></ul></ul><ul><ul><ul><li>What effects it has (good and bad) </li></ul></ul></ul><ul><ul><li>Contraindications (when not to use) </li></ul></ul><ul><ul><li>Reversal agent if applicable </li></ul></ul>
  32. 34. PREANESTHETIC AGENTS <ul><li>Reasons for use: </li></ul><ul><li>1. to calm or sedate the patient </li></ul><ul><li>2. to reduce or eliminate possible adverse side effects </li></ul><ul><li>3. to reduce the amount of general anesthetic required </li></ul><ul><li>4. to decrease pain and discomfort </li></ul><ul><li>BUT remember: </li></ul><ul><ul><li>NO preanesthetic agent is entirely free of side effects </li></ul></ul><ul><ul><li>NO single preanesthetic agent is safe for every animal </li></ul></ul><ul><ul><li>ALL preanesthetic agents (except glycopyrrolate) cross the placenta </li></ul></ul>
  33. 35. ANTICHOLINERGICS (parasympatholytics ) <ul><li>ATROPINE </li></ul><ul><li>Caution: </li></ul><ul><ul><li>LA vs SA concentrations </li></ul></ul><ul><ul><li>Not in tachycardia or GI obstruction/constipation </li></ul></ul><ul><li>Mode of action: </li></ul><ul><ul><li>Acts in parasympathetic component of autonomic nervous system: </li></ul></ul><ul><ul><li>Blocks receptors for the neurotransmitter: acetylcholine at muscarinic receptors (heart, GI, bronchi, salivary glands, iris) </li></ul></ul><ul><ul><li>Inhibits parasympathetic effects parasympatholytic </li></ul></ul>
  34. 36. Effects of atropine: <ul><li>1. Blocks stimulation of the vagal nerve </li></ul><ul><ul><ul><li>Major parasympathetic innervation to heart </li></ul></ul></ul><ul><ul><ul><li>Therefore increases HR </li></ul></ul></ul><ul><li>2. Reduces production of saliva </li></ul><ul><li>3. Reduces GI activity </li></ul><ul><li>4. Causes dilation of pupils </li></ul><ul><li>5. Reduces tear production </li></ul><ul><li>6. Promotes bronchodilation </li></ul><ul><li>7. May produce thick mucus within the airways </li></ul>
  35. 37. Atropine toxicity: <ul><li>Signs: </li></ul><ul><ul><li>Dilated pupils, tremors, ataxia </li></ul></ul><ul><ul><li>Due to excessive supression of parasympathetic response </li></ul></ul><ul><li>Tx: Physostigmine </li></ul><ul><li>Real problem? </li></ul>
  36. 38. Use of atropine = controversial! <ul><li>Needed with newer drugs? </li></ul><ul><li>Potential for adverse side effects/toxicity </li></ul><ul><li>Onset of action: </li></ul><ul><ul><li>15 min SQ/IM </li></ul></ul><ul><ul><li>Within 1 min IV </li></ul></ul><ul><li>Duration of action: </li></ul><ul><ul><li>60-90 min = practical? </li></ul></ul><ul><li>I like it in dogs but not in cats </li></ul>
  37. 39. GLYCOPYRROLATE <ul><li>effects similar to atropine </li></ul><ul><li>Advantages of glycopyrrolate: </li></ul><ul><ul><li>Effects last 2-3X as long as atropine </li></ul></ul><ul><ul><li>Less tachycardia </li></ul></ul><ul><ul><li>More effective at supressing salivation </li></ul></ul><ul><ul><li>Doesn’t cross placental barrier </li></ul></ul><ul><li>BUT: Atropine superior in bradycardic situation </li></ul>
  38. 41. TRANQUILIZERS AND SEDATIVES <ul><li>Main reasons for use: </li></ul><ul><ul><li>Calm animal for easier handling and induction </li></ul></ul><ul><ul><li>Easier recovery for animal (ie ferals) </li></ul></ul><ul><li>Four classes of Tranquilizers/Sedatives: </li></ul><ul><ul><li>Phenothiazines </li></ul></ul><ul><ul><li>Benzodiazepines </li></ul></ul><ul><ul><li>Alpha 2 Agonists </li></ul></ul><ul><ul><li>Opioids </li></ul></ul>
  39. 42. PHENOTHIAZINES <ul><li>= “-promazines” ACEPROMAZINE </li></ul><ul><li>Effects of phenothiazines: </li></ul><ul><li>1.) Sedation – up to 24 hours </li></ul><ul><li>2.) Anti-emetic -- decreases nausea </li></ul><ul><li>3.) Anti-arrhythmic – helpful with some anesthetics (halothane) </li></ul><ul><li>4.) Anti-histamine – not in allergy testing </li></ul><ul><li>5.) Peripheral vasodilation – not ideal in low blood pressure/shock </li></ul><ul><li>6.) Effects on personality – can cause excitement </li></ul><ul><li>Disadvantages of phenothiazines: </li></ul><ul><li>NO ANALGESIA </li></ul><ul><li>NO REVERSING AGENTS </li></ul><ul><li>LOWER SEIZURE THRESHOLDS </li></ul><ul><li>MANUFACTURERS’ RECOMMENDED DOSES EXCESSIVE </li></ul><ul><ul><ul><li>Decrease by 50% or risk hypotension </li></ul></ul></ul>
  40. 43. BENZODIAZEPINES <ul><li>= “-ams” examples: diazepam (valium), zolazepam (in telazol) </li></ul><ul><li>MOA: cause release of nuerotransmitter GABA in brain </li></ul><ul><li>Effects of benzodiazepines: </li></ul><ul><li>1. Reduces anxiety (little sedation) </li></ul><ul><li>2. Skeletal muscle relaxant (counter acts ketamine) </li></ul><ul><li>3. ANTICONVULSANT increases seizure threshold </li></ul><ul><li>4. Minimal adverse effects </li></ul><ul><li>except in liver disease and neonates?? (poor metabolism ) </li></ul><ul><li>5. appetite stimulant/cats 0.05 cc IV valium = magic </li></ul><ul><li>6. modify behavior (inappropriate urination) </li></ul><ul><li>BUT: NO ANALGESIA ADDICTIVE(paperwork) </li></ul>
  41. 44. Use of benzodiazepines: <ul><li>Diazepam ( Valium ) IV slowly (or IM) </li></ul><ul><li>NOT water soluble (precipitates w other drugs) </li></ul><ul><li>Soluble in plastics </li></ul><ul><li>light-sensitive </li></ul><ul><li>controlled substance </li></ul><ul><li>Commonly used in combination with drugs that induce anesthesia </li></ul><ul><li>2. Midazolam ( Versed ) </li></ul><ul><li>Advantages: </li></ul><ul><ul><ul><li>water soluble </li></ul></ul></ul><ul><ul><ul><li>less irritating </li></ul></ul></ul>
  42. 45. ALPHA 2 AGONISTS (receptor in brain) (engage these receptors) <ul><li>=“thiazine derivatives” </li></ul><ul><ul><li>examples: xylazine (rompun, anased), medetomidine (Domitor) </li></ul></ul><ul><li>widely used in SA and LA potent sedatives not controlled substances </li></ul><ul><li>fast onset predictable results reversible ANALGESIA </li></ul><ul><li>yohimbine (antisedan) </li></ul><ul><li>Mode of action: bind to receptors on sympathetic nerves in brain and spinal cord </li></ul><ul><ul><li>stimulate these “alpha 2 adrenoreceptors” (result is decrease in norepinephrine) </li></ul></ul><ul><li>yielding muscle relaxation sedation analgesia (short 20min) </li></ul><ul><li>metabolized in the liver, metabolites excreted in the urine </li></ul><ul><li>BUT: similar receptors in the heart and blood vessels >>>> side effects </li></ul><ul><li>decrease HR, decrease BP </li></ul>
  43. 46. Use of alpha 2 agonists: <ul><li>Xylazine SA solution 2% LA solution 10% mgs/mL* </li></ul><ul><li>used alone or in combination IM or IV </li></ul><ul><li>2. Medetomidine ( Domitor ) 1mg/mL approved for use in dogs only </li></ul><ul><li>commonly used in combinations: medetomidine(10ug/kg) + butorphanol(0.2mg/kg) mixed and given IM </li></ul>
  44. 47. Alpha Agonists: ADVERSE EFFECTS <ul><li>=significant, frightening, check your own pulse </li></ul><ul><li>1. BRADYCARDIA decreases cardiac output second degree heart block </li></ul><ul><li>sensitizes the heart to epinephrine >>>> cardiac arrhythmias </li></ul><ul><li>Prevention: Anticholenergics* Treatment: Yohimbine/ Atipamazole(5X dose) </li></ul><ul><li>2. Respiratory effects vary among animals: respiratory depression to no ill effects?? </li></ul><ul><li>BLUE! d/t low bloodflow not hypoxia?? </li></ul><ul><li>3. Vomiting ~50% dogs ~90% cats (less w/ metotomidine) </li></ul><ul><li>4. Depress GI activity >>>> GI stasis Beware of “bloat” (giant breeds) </li></ul><ul><li>5. Temporary behavior and personality changes </li></ul><ul><li>6. Reduce secretion of insulin>>>>>transient hyperglycemia>>>>urination </li></ul><ul><li>Use of Reversing Agents : (have drawn up) </li></ul><ul><li>yohimbine for xylazine (IV) atipamezole ( Antisedan ) for medetomidine (IM) </li></ul><ul><li> *may need to give an analgesic if reversed* </li></ul>
  45. 48. OPIOIDS <ul><li>aka “narcotics” or “opiates” (natural) </li></ul><ul><li>Versatile-- can be used for: </li></ul><ul><li>preanesthesia, induction, analgesia (excellent) </li></ul><ul><li>Very safe Wide safety margins </li></ul><ul><li>Mode of action: four types of opioid receptors throughout body </li></ul><ul><li>Opioid agents differ in their action at each of these types of receptors: </li></ul><ul><li>agonist antagonist mixed </li></ul><ul><li>“ pure agonists” “pure antagonists” “agonist/antagonist” </li></ul><ul><li>Morphine naloxone butorphanol </li></ul><ul><li>fentanyl reversal agent </li></ul><ul><li>oxymorphine </li></ul>
  46. 49. OPIOID’s (cont) <ul><li>Effects: </li></ul><ul><ul><li>1. CNS effects: may cause CNS depression or excitement </li></ul></ul><ul><li>dogs: usually depression, high doses >>>> narcosis </li></ul><ul><li>cats: may show bizarre responses; i.e., excitement, anxiety </li></ul><ul><ul><li>2. Analgesia the most effective analgesics, especially pure agonists (morphine) </li></ul></ul><ul><li>Method of use: Opioid agents </li></ul><ul><li>Common components of preanesthetic protocols (butorphanol) </li></ul><ul><li>mixed with a tranquilizer and/or an anticholinergic </li></ul><ul><li>Used to prevent and treat postoperative pain </li></ul><ul><li>“ Neuroleptanalgesia” = profound sedation and analgesia, for minor surgery </li></ul><ul><li>produced by doses of opioid (at a high dose) plus a tranquilizer </li></ul>
  47. 50. OPIOIDS: Adverse effects <ul><li>1. Respiratory depression >>>> decreases respiratory rate and tidal volume </li></ul><ul><li>2. GI function: initially, increased peristalsis then, GI stasis >>> constipation </li></ul><ul><li>3. Addiction physical dependence (controlled drugs =PAPERWORK) </li></ul><ul><li>4. Drug interactions in patients on selegiline = FATAL </li></ul><ul><li>Reversibility : can reverse the effects, esp. of pure agonists w/ “antagonists” </li></ul><ul><li>Naloxone is preferred reversal agent, causes least respiratory depression </li></ul><ul><li>Molecules of reversing agents bind to the opioid receptor sites: </li></ul><ul><li>act as blocking agents or displace molecules of pure agonists </li></ul><ul><li>but , reversal of analgesia also occurs </li></ul><ul><li>Disadvantage : =$$$, not routinely necessary except in emergencies?? </li></ul>

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