PATIENT PREPARATION

1. PATIENT PREPARATION CHAPTER 2 Part 1

2. PATIENT PREPARATION • The RVT has numerous responsibilities in the pre-anesthetic period. The pre-anesthetic period is the period immediately preceding the induction of anesthesia. • This period can be from minutes to weeks

3. PRE-ANESTHETIC RESPONSIBILITIES OF AN RVT: • obtaining patient history • reviewing consent form with an owner • making sure the patient is fasted • performing a physical exam • drawing blood and running diagnostic tests • placing an IV catheter • calculating drug doses • administering pre-medications • preparing anesthetic equipment • SEE BOX 2-1 pg. 6 for more info… FEELING OVERWHELMED?

4. MINIMUM DATABASE • ANESTHESIA IS NOT A COOKIE CUTTER PROCEDURE: Age, breed, size, & health status play a role in the selection of anesthetic agents and techniques • Every patient should have a minimum database, which would ideally include: • HISTORY • PHYSICAL EXAM FINDINGS • DIAGNOSTIC TEST RESULTS

5. TAKING THE PATIENT HISTORY • DO’s: • Be thorough • Be effective at framing questions to gain the most information • Schedule an appointment several days before the planned procedure • DON’Ts: • Don’t ask “yes” or “no” questions • For example, how can you reframe this question: “Does your dog drink a lot of water?” • Don’t ask leading questions • For example, how can you reframe this question: “ Your dog doesn’t drink very much water does he?”

6. TAKING THE PATIENT HISTORY • What questions should I ask? • What procedure(s) is/are being performed today? • Confirm the affected limb, confirm tumors to be removed & determine if client want histopathology • How old is your animal? • Is there a history of previous illnesses/problems/treatment and if so, do you have past medical records? • Be sure to ask duration, volume/severity, frequency, character/appearance • Is your pet currently ill? • What medications has your pet been on? • Does your pet have any allergies or a history of drug reactions? • Has your pet had any previous anesthetic problems? • Is your pet current on vaccines? • Is your pet in heat or pregnant?

7. TAKING THE PATIENT HISTORY • SIGNALMENT: includes species, breed, age, sex, and reproductive status • This information influences the anesthetic plan • SPECIES & BREED • Each species has unique responses to anesthetic agents. Drug doses will vary between species. • Examples: • Horses and cats are more sensitive to opioids than dogs and ruminants • Cats can tolerate some drugs given alone, while the same drug may cause seizure-like activity in dogs • Large animals are prone to respiratory depression • Boxers & giant breeds are more sensitive to acepromazine • Sighthounds are sensitive to barbiturates • Brachycephalic breeds are difficult to intubate

8. TAKING THE PATIENT HISTORY • AGE • Very young animals-less than 8 wks of age-are much less capable of metabolizing injectable drugs because necessary liver pathways are not fully developed. • Young animals are also more prone to hypothermia and hypoxia • Geriatric patients-who have reached 75% of the normal lifespan- may have difficulty metabolizing drugs due to liver or renal failure

9. TAKING A PATIENT HISTORY • SEX & REPRODUCTIVE STATUS • Confirming the sex of the animal is especially important in cats

10. TAKING THE PATIENT HISTORY • SEX & REPRODUCTIVE STATUS • For males, confirm the presence of both testicles in the scrotum • For females, ask about the possibility of pregnancy, the last estrous cycle, check for a spay scar or a tattoo

11. TAKING THE PATIENT HISTORY • SEX & REPRODUCTIVE STATUS • For females, ask about the possibility of pregnancy. • Determine the client’s wishes if the animal is found to be pregnant

12. CONSENT FORM • Have the client sign a consent form/estimate. • This should be done in person. By phone is an option, although this is not ideal. Make sure a witness also hears the authorization. • A consent form reviews anesthetic risks, resuscitation options, blood work options, and phone numbers for the owner. • Some forms also state that a drug will be used on their animal in an extra-label manner. * If possible, have the owner read the estimate and consent form before the day of surgery.

13. PATIENT DISPOSITION & LEVEL OF CONSCIOUSNESS • Anxious or aggressive animals may require a combination of drugs for sedation • Fearful or aggressive animals may require a different route of medication administration (oral, induction chamber)

14. PATIENT DISPOSITION & LEVELS OF CONSCIOUSNESS • Level of consciousness refers to the patient’s responsiveness to stimuli or how easily it can be aroused. • BAR, QAR • Lethargy – mild decrease in LOC & can be aroused with minimal difficulty • Obtunded – more depressed patients that cannot be fully aroused • Stuporous – sleeplike state; can only be aroused with painful stimuli • Comatose – cannot be aroused and is unresponsive to all stimuli including pain.

15. PHYSICAL EXAM • HYDRATION STATUS • Dehydration increases the risk for hypotension, poor tissue perfusion, & kidney damage

16. PHYSICAL EXAM • HYDRATION STATUS • Ideally, dehydration should be corrected prior to surgery: • (Wt in kg)(1000 mL/kg)(% dehydration) • EXAMPLE: A 33 lb dog that is 9% dehydrated, needs _______mL 33 lb /2.2 = 15 kg (15 kg)(1000 mL/kg) = 15,000 mL (15,000 mL)(0.09) = 1350 mL

17. PHYSICAL EXAM • EXAMINE STRUCTURES OF THE HEAD • ORAL CAVITY: • Check mucous membrane color, CRT: If gums are pigmented check the conjunctiva, inner vulva, prepuce

18. PHYSICAL EXAM • EYES & EARS • Look for signs of dehydration, check pupillary light reflexes • Check the ears for signs of infection, or growths

19. PHYSICAL EXAM • AUSCULTATION: listen to the rate, rhythm, and sounds of the heart and lungs • Normal resting heart rate: • Dogs: 60-180 • Cats: 110-220 • Normal respiratory rate: • Dogs: 10-30 • Cats: 25-40 • Rhythm: listen for normal sinus rhythm vs. arrhythmias • Abnormal sounds: crackles, wheezes, evidence of respiratory distress (flared nostrils, open-mouth breathing, respiratory stridor) • Listen to all 4 quadrants of the chest

20. PHYSICAL EXAM • PULSE: assess the strength and the rate • The femoral artery is the easiest location to palpate a pulse • Other locations: metatarsal, metacarpal arteries • A strong or weak pulse loosely correlates with blood pressure • Pulse deficits may indicate heart disease

21. PHYSICAL EXAM • WEIGHT: assign a body condition score (either use 5 scale or 9 scale) • Drug doses and IV fluid rates are based on weight in addition to species. DON’T ESTIMATE. Weigh accurately. • Use a pediatric scale (if available) if <5 kg; use gram scale if <1 kg • Compare current weight to previous weights.

22. PHYSICAL EXAM • WEIGHT • OBESE ANIMALS can experience dyspnea, they can be difficult to draw blood from, harder to assess hydration status, and difficult to auscultate. • Obese animals do NOT need a higher dose of anesthetics. Although the body mass is larger, the central nervous system is not. • THIN ANIMALS can be at risk for hypothermia and may have an underlying condition causing the weight loss.

23. PHYSICAL EXAM • OTHER SYSTEMS: • Body Temperature: 100.0°-102.5° for dogs & cats • MS: signs of lameness, pain • Lymph: evaluate size of lymph nodes • Abdomen: evaluate for tense or painful abdomen, evaluate organ size, presence of fluid or gas • Repro: evaluate testicles, mammary glands, vulva, prepuce • Integument: check for bruising, petechiae, pyoderma

24. FASTING • Fasting usually begins the night before surgery • Adult dog or cat: Withhold food for 8-12 hours before surgery. Water is withheld anywhere from 2-4 hours before surgery, depending on the veterinarian’s preference. • Neonate and pediatric patients (<8 wks): Much shorter fasting period (depending on species, could be 4-6 hrs, or no fasting) to avoid dehydration or hypoglycemia. • GI surgery: Withhold food for 24 hours, water for 8-12 hours. • Why fast? • Fasting is done to avoid vomiting/regurgitation during surgery or recovery which can cause esophagitis, respiratory obstruction, or aspiration pneumonia.

25. FASTING • In addition to not fasting long enough, it is not safe to have animals fasted for too long. • This usually refers to animals refusing to eat for various reasons - usually when the surgery is not elective: serious GI obstructions/perforations, or in the situation where 2 surgeries are performed several days apart and the animal does not want to eat between the surgeries. • Prolonged fasting leads to a longer recovery period, delays healing, and puts the animal at risk for other medical problems ( ex: hepatic lipidosis). • Options include hand/syringe feeding, inserting feeding tubes, or total parenteral nutrition.

26. PATIENT PREPARATION • Be sure the animal is properly identified • Use a cage card or ID collar or BOTH

27. DIAGNOSTIC TESTS COMPLETE BLOOD COUNT ECG CLOTTING TIMES RADIOGRAPHS URINALYSIS CHEMISTRY PANEL

28. DIAGNOSTIC TESTS • The extent of the diagnostic testing will depend on the clinic, the owner, and what is ideal for the patient • It is important to provide the most complete and affordable testing available

29. DIAGNOSTIC TESTS • COMPLETE BLOOD COUNT: • PCV and RBC • used to determine the blood’s ability to deliver oxygen to tissues. Increases usually indicates dehydration (which leads to increased viscosity of the blood, poor perfusion and decreased cardiac output). Decreased levels usually indicates anemia. • PCV less than 25% in a dog or less than 20% in a cat should be reported immediately • TOTAL PLASMA PROTEIN • usually indicates dehydration if increased. Decreased values may indicate decreased production by the liver or a loss through the renal, hepatic or GI systems. Decreased levels can lead to increased drug potency. • Values of less than 4.0 should be reported immediately • BLOOD SMEAR • used to evaluate red blood cell & white blood cell morphology and platelet estimation. • Report all decreases in platelet count or abnormal coagulation test results

30. DIAGNOSTIC TESTS • URINALYSIS: • SPECIFIC GRAVITY • used to detect evidence of dehydration or renal insufficiency • GLUCOSE and KETONES • used to detect diabetes • WBCs and RBCs • can be seen with urinary tract infections and crystalluria (can also be normal in small amounts) • USE THESE RESULTS IN CONJUNCTION WITH OTHER TESTS

31. DIAGNOSTIC TESTS • CHEMISTRY PANEL: • MOST COMMONLY EVALUATED PARAMETERS PRE-OPERATIVELY ARE: • ALT: liver • ALP (or ALKP): liver, possibly bone, possibly GI tract • BUN: kidneys • Creatinine: kidneys • Glucose: diabetes screen • Electrolytes: Na, K, Ca The more parameters that are evaluated, the better picture we have of the patient.

32. DIAGNOSTIC TESTS • CLOTTING TIMES: • Not commonly performed for routine procedures unless coagulopathies are suspected such as in breeds that are commonly affected by hereditary coagulation disorders. • PT, (A)PTT • In-clinic testing is performed by either performing a Buccal Mucosal Bleeding Time (BMBT), a short nail trim to the quick, or placing whole blood in a plain red top. Blood should clot within 4 minutes.

33. DIAGNOSTIC TESTS • ECG Evaluates electrical activity of the heart, pattern, rhythm Perform if heart disease is suspected, there is a history of trauma, electrolyte abnormalities, or if the animal is geriatric

34. DIAGNOSTIC TESTS • RADIOGRAPHS • not routinely done in private practice, but are indicated with dyspnea, abnormal heart/lung sounds, or history of recent trauma. • HEARTWORM TEST – it is important to know heartworm status before undergoing anesthesia

35. DETERMINATION OF (ASA) PHYSICAL STATUS CLASSIFICATION • Classification based on history, physical exam, and diagnostics performed • Classification is objective and can change with animal’s status • Correct problems before surgery if possible

37. 2yr old, mixed breed intact male weighing 12lbs; BCS: 2/5, T-103.5, HR-160, RR-40; 8% dehydrated Bloodwork: PCV: 35%, TP: 7.6 g/dl What anesthetic status would you give this dog?

38. Preanesthetic Pic of the Day This is Oscar

40. This is Oscar's foot

41. Based on the picture, what anesthetic category would you place Oscar in?