1. Pre, Peri and Post-Operative Care
ASR Certification Prep

2. Pre Operative Care Pre-Surgical Planning:
Pre-surgery Examination & Blood work
Fasting
Set-up of prep area and operating room
Thermo regulation
Aseptic Preparation
Analgesic Regimen
Anesthesia
Aseptic Transfer to Surgical Field

3. Pre-surgery Examination
Examination should include:
Physical examination and blood work in large animals
Check animal identification
Take and record temperature, HR, CRT, RR, BW
Check cage for signs of loose stool or vomiting
Observe animal in home cage for normal behaviors
Review animal medical record

4. All animals should have free access to water.
Pre-surgical Fasting
Rodents & Rabbits (mice, rats, guinea pigs, hamsters, rabbits): 
High metabolic rate
No fasting prior to surgery
Rodents DO NOT have vomit reflex, no regurgitation
Monogastric animals (e.g. dogs, cats, swine):
Fast 6-24 hours prior to surgery  
Ruminants (e.g. sheep, goats, cattle)
Fast for hours prior to surgery.
Reduces fermentation in the rumen
Placing stomach tube reduces rumenal tympany.
All animals should have free access to water.
Restricting water results in dehydration and more difficult anesthesia.

5. Set-up of Prep Area and OR
Ensure prep area has:
Working heat support on table
Functioning anesthesia machine (if required)
Stethoscope
Appropriate drugs and reversal agents (analgesics and anesthetics)
Functioning monitoring equipment
Prep supplies and clippers
Vacuum
Ensure OR area has:
Functioning anesthesia machine (with ventilator)
Fluid support as needed
Emergency supplies (Ambu bag, and crash cart supplies)

6. OR Set Up

7. (e.g., table tops, equipment)
RECOMMENDED HARD SURFACE DISINFECTANTS
(e.g., table tops, equipment)
Always follow manufacturer's instructions for dilution and expiration periods
AGENT
EXAMPLES*
COMMENTS
Alcohols
70% ethyl alcohol
85% isopropyl alcohol
Contact time required is 15 minutes. Contaminated surfaces take longer to disinfect. Remove gross contamination before using. Inexpensive
Quaternary Ammonium
Sodium hypochlorite
(Clorox ® 10% solution)
Chlorine dioxide
(Clidox®, Alcide®, MB-10®)
Corrosive. Presence of organic matter reduces activity. Chlorine dioxide must be fresh; kills vegetative organisms within 3 minutes of contact.
Glutaraldehydes
(Cidex®, Cetylcide®, Cide Wipes®)
Rapidly disinfects surfaces
Phenolics
Lysol®, TBQ®
Less affected by organic material than other disinfectants
Chlorhexidine
Nolvasan® , Hibiclens®
.Presence of blood does not interfere with activity. Rapidly bactericidal and persistent. Effective against many viruses.
* The use of common brand names as examples does not indicate a product endorsement.

8. Aseptic Technique Preparation of the patient
Bland ophthalmic ointment to eyes
remove hair from the surgery site ( #40 blade, vacuum)
initial or preparative scrub
Povidone-iodinefollowed by alcohol rinse
Chlorhexidine followed by saline rinse
move to surgical room / area
final surgical scrub/paint
Povidone-iodine followed by alcohol rinse
Duraprep®, Chloraprep®
sterile draping of surgical site
establish a sterile field
The surgeon should direct how the animal is positioned on the table.
In OR final surgical scrub should be done after the animal has been positioned and put on monitoring equipment.
Establishing a sterile field: When the animal is properly positioned and antiseptically prepped for surgery, a sterile field should be created.
Generally, a sterile field should be large enough to prevent accidental contamination of the incision site(s), operating team, and sterile instruments and equipment.

9. Alternating disinfectants is more effective than using a single agent.
RECOMMENDED SKIN DISINFECTANTS
Alternating disinfectants is more effective than using a single agent.
AGENT
EXAMPLES*
COMMENTS
Idophors
Betadine®, Prepodyne®,
Wescodyn®
Reduced activity in presence of organic matter. Wide range of micobicidal action Works best in pH 6-7
Cholorhexadine
Nolvasan®, Hibiclens®
Presence of blood does not interfere with activity. Rapidly bactericidal and persistent. Effective against many viruses. Excellent for use on the skin.
* The use of common brand names as examples does not indicate a product endorsement.

10. Peri-Operative Monitoring Allows:
Adequate anesthesia.
Adequate analgesia
Adequate immobilization
Early notice of trends which may develop into life-threatening conditions

11. Checking Anesthetic Depth
Reflexes
Jaw tone
Eye position, pupil size and pupillary light response
Heart and respiratory rates
Response to surgical stimuli

12. Reflexes
Palpebral (blink) - tested by lightly tapping the medial or lateral canthus of the eye
Pedal - Elicited by pinching a digit or footpad
Corneal - Tested by touching the cornea with a sterile object
Laryngeal - Stimulated when the larynx is touched by an object.

13. Parameters to Monitor (every 10-15minutes)
ECG (EKG)
Peripheral Perfusion
Pulmonary Monitoring
Temperature
Blood Pressure

14. ECG (EKG)
An EKG measures the electric currents generated by the heart.
Monitors heart function
Continuous monitoring with an EKG allows early recognition of electrical changes associated with disorders of conduction in the heart and arrhythmias that may need to be treated.

15. ECG (EKG) Cardiac dysrhythmias:
Tachycardia: excessive rapidity of the heart
Bradycardia: slowing of the heart
Ventricular fibrillations: total disorganization of the ventricular activity

16. ECG (EKG) Premature ventricular contractions (PVCs): early contraction
Heart Block: loss of or non-P-wave associated QRS complexes
Indicate lack of electrical transmission in the heart

17. Heart Rate Monitored by : Palpation of heart beat through chest wall
Palpation of peripheral pulse for strength and quality
Auscultation of heart beat with stethoscope
Electrocardiogram (EKG, ECG) with continuous display

18. Heart Rate
Know the acceptable HR for the species you are monitoring. Bradycardia: excessive anesthetic depth, “too deep” vagal stimulation hypertension hypothermia drug effects elevated cranial pressure Tachycardia: inadequate anesthetic level, “too light” pain/surgical stimulation hypotension hypoxemia hypercarbia

19. Peripheral Perfusion Capillary refill time (CRT)
Measures the time taken for refilling blanched mucus membranes
Observe the color of mucus membranes
CRT should be 1-2 seconds and gums (when not pigmented) should be pink
Other sites for color are tongue, buccal mucous membrane, conjunctiva of the lower eyelid, and the mucous membranes about the prepuce or vulva
Pale membranes indicate poor perfusion, blood loss, or anemia
Purple/blue membranes indicate cyanosis

20. Pulse Oximetry
Measures the percentage of oxygenated hemoglobin and heart rate
Is broadly accurate for SaO2
sensory probe needs to be placed on nonpigmented area (tongue, tail, ear ,etc.)

21. Pulse Oximetry
Sensor beams infrared light through tissue and records the absorption either of light passing through the tissue to a receiver on the other side (transmission) or reflected back to the sensor (reflectance) Reflector sensor Transmission sensor

22. Pulse Oximetry
Normally SaO2 is 80-90% in spontaneously breathing animals and % in ventilated animals
Numbers reflect animal on 100% oxygen
SaO2 readings are susceptible to lowering by positional factors (slipping away from tissue, thick tissue, pigment), vasoconstriction, drying of contact surface, and confusion with respiratory artifact
Without pulse oximetry, early hypoxia can be difficult to assess as cyanosis only becomes apparent if values fall below 85% saturation.

23. Pulse Oximetry Monitors

24. End-tidal CO2 (ETCO2)
Capnography measures ETCO2 concentration, at the end of an exhalation
Usually somewhat lower than PaCO2
A PaCO2 measurement requires blood gas analyzer and arterial blood samples.

25. End-tidal CO2 (ETCO2)
Accuracy is subject to mechanical factors with the breathing circuit such as volume, dead pockets, tubing diameter, gas flow, etc.
Animals with ETCO2 over mm Hg will usually breathe on their own
Low ETCO2
Surgical support for cleaning and autoclaving

26. End-tidal CO2 (ETCO2)
When displayed as a capnographic waveform much useful information may be derived such as:
“Spiky” topped waves may indicate a waking animal taking short, sharp breaths
Plateau with a drop to the right may indicate a leak in the circuit as the pressure of inspiration is not held

27. Respiration Monitored by : Observation of chest wall movement
Observation of breathing bag movement
Auscultation of breath sounds
Audible respiratory monitor
Respiratory volume may be estimated visually, by reservoir bag inflation, or by using a ventilator or ventilometer
Normal tidal volume is mL/kg/respiration
Normal respiratory sounds are almost inaudible

28. Respiration Normal respiratory rates can vary widely
Should be evaluated along with tidal volume and respiratory trends
May indicate an underlying physiologic change
Arrhythmic breathing patterns are usually the effect of a medullary respiratory control problem
However, some abnormal patterns may be normal in certain species
A Cheyne- stokes pattern is normal for horse but could be sign of heart failure or brain damage.
Apneustic breathing (inspiratory hold) seen in healthy cats, dogs, and animals anesthetized with ketamine

29. Respiration
Tachypnea: inadequate anesthetic level, “too light”, pain, hypoxemia, hypercarbia, hyperthermia,
CSF acidosis, drug effects
Hypoventilation : Inadequate or reduced alveolar ventilation leads to
Atelectasis : partial collapse of the lung
Periodic 'bagging/sighing' (every 5 minutes) throughout the procedure can prevent this.
Apnea: excessive anesthetic depth, “too deep”, hypothermia, recent hyperventilation, musculoskeletal paralysis, drug effects

30. Respiration
Harsh noises, whistles or squeaks may indicate narrow or obstructed airways or the presence of fluid in the airways.
Difficult or labored breathing may indicate the presence of an airway obstruction.
An abnormally low respiratory rate (<8-10 bpm) is cause for concern. Apneic animals may need to be manually ventilated throughout the procedure at a rate of 8-12 bpm.

31. Respiratory Acidosis Inadequate Elimination Of C02
Production Of C02 Exceeds Elimination
Causes: Reduced Effective Alveolar Ventilation
from:
Pulmonary Edema
Pneumonia
Airway Obstruction
Interstitial Fibrosis
Inadequate Ventilation
(<20 Cm H20 Intra-alveolar Pressure)
slow Respiratory Rate
Hypoxemia
Diagnosis: EtCO2 > 45 mm Hg

32. Respiratory Alkalosis
Enhanced Elimination Of C02
Elimination Of C02 Exceeds Production
Causes: Increased Effective Alveolar Ventilation
From:
High Intra-alveolar pressure
Hyperoxemia
Hypotension
Pulmonary edema
Interstitial fibrosis
Endogenous catecholamines (from stress)
Mechanical ventilation
Diagnosis: EtCO2 < 35 mm Hg

33. Ventilation
Pressure is introduced into the trachea which inflates the lungs.
Causes a significant loss in lung compliance
Necessary in all procedures in the thoracic cavity.
Ventilation can be severely compromised by pneumothorax, hemothorax, hydrothorax or a diaphragmatic hernia.
Routine manual “bagging/sighing” of the
patient can prevent atelectis.

34. Body Temperature Anesthetized animal lose the ability to
thermoregulate normally.
Will lose heat via loss of hair to shaving, the evaporation of prep solutions, evaporation at and chilling of tissues within surgical incisions, and vasodilatation caused by anesthetic agents/adjuncts
Hypothermia will prolong anesthesia recovery
Should be countered with warmed fluids, heating blankets, and towels/wraps
Hyperthermia is also possible and dangerous
May be due to overheating with heating pads and tables or due to anesthesia reactions such as malignant hyperthermia in swine Anesthetized animals lose the ability to thermoregulate normally
Surgical support for cleaning and autoclaving

35. Body Temperature Monitor Temperature throughout surgery
Ways to prevent Hypothermia
Keep animal warm during induction
Warm IV Fluids and irrigating solutions
Circulating warm water/air blankets
Pad between animal and metal table
Hot water bags/bottles wrapped in towel
Covering feet, hands, paws, & head
Heat lamps

36. Blood Pressure
BP = hydrostatic force that blood exerts on wall of vessels Systolic Pressure= pressure of blood when ventricles at maximum contraction Normal range 100 to 160mmHG Diastolic Pressure= pressure of blood when ventricles relax Normal range 60 to 100mmHg MAP= (2 x DP) + SP divided by 3 Normal range 80 to 120mmHg Pulse Pressure= systolic – diastolic Normal ~ 40mmHg

37. Blood Pressure MAP < 60 mmHg is hypotension
Decreased perfusion due to low BP can cause tissue ischemia
Susceptibility of tissue to ischemia depends on metabolic rate of the tissue
Hypertension: Systolic >180 mm Hg and
Diastolic >110mm Hg
Inadequate anesthesia, partially or fully occluded airway
Controlling Blood Pressure:
anesthetic level
IV fluids
Body temperature

38. Blood Pressure Noninvasive/Indirect- accurately reflects trends
Oscillometric method Ultrasonic Doppler

39. Blood Pressure Invasive/ Direct – accurate quantitative value
Arterial catheter connected to pressure transducer

40. Immediate Post-operative Care
Move the animal to a warm, dry area and monitor vital signs every 15 minutes until the animal is sternal.
Turn side to side frequently to prevent pooling of fluid in recumbent side.
Remove endotracheal tube when swallowing/chewing this prevents regurgitation and vomiting.
Do not return to home cage until able to maintain body temperature and hold itself in sternal position.

41. Post-Operative Care
A ”stormy “ recovery could be related to surgical pain.
All animals subject to major surgery must have analgesic agents (i.e. painkillers) available to them for at least the initial hours post-surgery
Provide analgesics as directed by veterinarian.

42. Post-Operative Care Daily evaluation parameters: appearance attitude
appetite
Hydration
TPR
Signs of pain
Surgical Incision - for clinical signs of infection, seroma, hematoma, suture breakdown, wound dehiscence.

43. Post-Operative Care Administration of drugs Suture/Staple Removal
SID or QD once daily
BID twice daily
TID three times daily
QID four times daily
Suture/Staple Removal
The goal of the staples / sutures are to keep the skin margins closed.
Evaluate incision healing prior to removal
Normal removal time is 10 to 14 days

44. References NIH website http://oacu.od.nih.gov/ARAC/surguide.pdf
Duke University Animal Care and Use Program
Doctors Foster and Smith Website