Pre, Peri and Post-Operative Care

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
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 12-36 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
• Working heat support on table
• Functioning anesthesia machine (with ventilator)
• Functioning monitoring equipment
• Fluid support as needed
• Emergency supplies (Ambu bag, and crash cart
  supplies)

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OR Set Up
7

• 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 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.
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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
• Chlorhexidine followed by saline rinse
• Duraprep, Chloraprep
• sterile draping of surgical site
• establish a sterile field

9

• 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

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Checking Anesthetic Depth

• Reflexes
• Jaw tone
• Eye position, pupil size and pupillary light
  response
• Heart and respiratory rates
• Response to surgical stimuli

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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.

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Parameters to Monitor(every 10-15minutes)

• ECG (EKG)
• Peripheral Perfusion
• Pulmonary Monitoring
• Temperature
• Blood Pressure

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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.

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ECG (EKG)

• Cardiac dysrhythmias
• Tachycardia excessive rapidity of the heart
• Bradycardia slowing of the heart
• Ventricular fibrillations total disorganization
  of the ventricular activity

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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

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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

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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
• drug effects

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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

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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.)

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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 95-100 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
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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.

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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 30-40 mm Hg will
  usually breathe on their own
• Low ETCO2

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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 10-20 mL/kg/respiration
• Normal respiratory sounds are almost inaudible

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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

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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 (lt8-10 bpm) is
  cause for concern. Apneic animals may need to be
  manually ventilated throughout the procedure at a
  rate of 8-12 bpm.

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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
• (lt20 Cm H20 Intra-alveolar Pressure)
• slow Respiratory Rate
• Hypoxemia
• Diagnosis EtCO2 gt 45 mm Hg

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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 lt 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

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 lt 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 gt180 mm Hg and
• Diastolic gt110mm Hg
• Inadequate anesthesia, partially or fully
  occluded airway
• Controlling Blood Pressure
• anesthetic level
• IV fluids
• Body temperature

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Blood Pressure

• Noninvasive/Indirect- accurately reflects trends
• Oscillometric method Ultrasonic Doppler

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Blood Pressure

• Invasive/ Direct accurate quantitative value
• Arterial catheter connected to pressure
  transducer

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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 24-48 hours
  post-surgery
• Provide analgesics as directed by veterinarian.

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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.
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Post-Operative Care

• Administration of drugs
• 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

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References

• NIH website http//oacu.od.nih.gov/ARAC/surgui
  de.pdf
• Duke University Animal Care and Use Program
  http//vetmed.duhs.duke.edu/guidelines_for_general
  _surgery_in_animals.htm
• Doctors Foster and Smith Website
  http//www.peteducation.com/article.cfm?c013021
  478aid977
• http//www.ruralareavet.org/PDF/Anesthesia-patient
  _Monitoring.pdf