Оглавление
Группа авторов. Manual of Equine Anesthesia and Analgesia
Table of Contents
List of Tables
List of Illustrations
Guide
Pages
Manual of Equine Anesthesia and Analgesia
List of Contributors
Preface
Acknowledgments
1 Preoperative Evaluation and Patient Preparation. The Risk of Equine Anesthesia
I Risk of equine anesthesia
II Classification of physical status (see Box 1.1)
Box 1.1 ASA Classification System
III Risk factors. A Age and physical status
B Type of surgery and recovery
C Time of day
D Body position
E Drug choice
F Duration and management of anesthesia
Suggested Reading
Patient Preparation
I Preparation of the horse. A Evaluation
B Laboratory tests
C Physical examination
D History
E Fasting
F Medications
G Jugular catheter
H Flushing the oral cavity
I Removal of shoes
Suggested Reading
2 Serum Chemistry and Hematology
I Complete blood count (CBC) A Erythrocytes
B Leukocytes
Neutrophils
Eosinophils
Lymphocytes
Monocytes and Basophils
C Platelets
Thrombocytosis (platelet count >400 000/μl)
Thrombocytopenia (platelet count <75 000/μl)
II Blood chemistry interpretation
A Creatine kinase (CK)
B Aspartate aminotransferase (AST)
C Gamma glutamyl transferase (GGT)
Urinary GGT
D Alkaline phosphatase(ALP)
E Sorbitol (Iditol) dehydrogenase (SDH)
F Total bilirubin(TBIL)
G Serum bile acids(SBA)
H Blood urea nitrogen(BUN) andcreatinine(Cr)
Pre‐renal azotemia
Renal azotemia
Post‐renal azotemia
III Plasma proteins
A Albumin
Hypoalbuminemia can result from:
B Globulins
Hyperglobulinemia
Hypoglobulinemia
C Fibrinogen
IV Lactate
Suggested Reading
3. The Cardiovascular System: Physiology of the Cardiovascular System
I Anatomy. A Chambers
Atria
Ventricles
Atrio‐ventricular valves
Semilunar valves
B Structural or “skeletal” components of the heart
C Neural input to the heart
II Cardiac contractions. A Initiation
B Components of the specialized electrical conducting system
III Unique features of the equine heart
IV Circulatory systems
A Components of the systemic circulation
B Components of the pulmonary circulation
C Blood
V Cardiovascular physiology
A Events occurring during late diastole
B Events occurring during systole
C Events occurring at the end of the ejection period (late systole/early diastole)
D Events occurring during early diastole
VI Cardiovascular function and clinical applications
A Cardiac output
Factors affecting cardiac output:
B Heart rate
Factors influencing HR:
C Stroke volume (SV)
Preload
Afterload
Contractility (inotropy)
Relaxation (lusitropy)
D Blood Pressure (see Table 3.2)
E Physics of flow
Ohm's law
Poiseuille's law (Hagan‐Poiseuille)
Laplace's law
Starling's law (Frank‐Starling mechanism, see Table 3.1)
F Tissue oxygen delivery
Box 3.1 Effects of Decreases in [Hb] and SaO2 on CaO2
VII Anesthesia. A Effects of anesthetic drugs (see Table 3.3)
B Effects of cardiovascular disease
VIII Cardiovascular disease in horses presented for anesthesia. A Diseases of the conducting system
Atrial fibrillation
B Congenital disease
C Primary myocardial disease
D Secondary cardiovascular compromise
IX Anesthetic plan for horses with cardiovascular disease. A Patient preparation
B Sedation and induction
C Maintenance
D Recovery
Evaluation of the Cardiovascular System
I Cardiovascular evaluation. A Body condition
B Edema
C Mucous membranes
Color:
Moistness:
Exposure:
Capillary refill time(CRT):
D Peripheral arteries (pulses)
Sites for palpation:
Assessment of the pulse:
E Peripheral veins
Jugular vein waveforms
Occluding the jugular vein
F Heart. Cardiac silhouette
Heart rate
Heart rhythm
Auscultation
Left side heart sounds:
Right side heart sounds:
Normal heart sounds (see Figure 3.1)
ECG (see Section III below)
II Heart murmurs
A Location
B Timing in cardiac cycle
C Intensity
Sounds
D Physiologic (non‐pathologic) murmurs
E Pathologic murmurs
III Electrocardiogram. The elements of the ECG (see Figure 3.3)
B Evaluation of the ECG
Is each QRS complex preceded by a P wave?
Is each P wave followed by a QRS complex?
IV Arrhythmias
A Bradycardia
B Tachycardia
C Second‐degree AV blockade (see Figure 3.4)
D Atrial fibrillation (see Figure 3.5)
Treatment of atrial fibrillation
E Atrial flutter
F Premature atrial contractions(PACs)
Treatment
G Premature ventricular complexes(PVCs) (see Figures 3.6 and 3.7)
Treatment of single PVCs
Treatment of multiple PVCs
H Ventricular tachycardia(VT) (see Figure 3.8)
Treatment
Suggested Reading
4 The Respiratory System: Anatomy of the Equine Respiratory System
I Organization of respiratory system
A Conducting components
B Gas exchange components
II Tubular organs
A Tunica mucosa
B Tunica submucosa
C Tunica muscularis
D Tunica adventitia
III Nasal cavity
IV Paranasal sinuses
V Pharynx
Guttural pouch
VI Larynx (see Figure 4.1)
A Cartilages
B Innervation of the larynx
VII Trachea
VIII Lungs and pulmonary circulation
A Blood supply
B Nerve supply
IX Bronchi and bronchioles
X Respiratory epithelium
XI Alveolar region
A Alveoli
B Type I pneumocytes
C Type II pneumocytes
XII Blood–air barrier
XIII Muscles of respiration
Suggested Reading
Physiology of the Respiratory System
I Alveolar ventilation (VA)
A Mechanics of ventilation
B Work of breathing
C Lung and airway resistance
II Lung volumes (see Figure 4.2) A Minute ventilation (VE)
B Tidal volume (VT)
C Dead space
D Measurement of dead space – Bohr equation
Factors that increase dead space include
E Functional residual capacity(FRC)
III Pulmonary compliance
A Distribution of alveolar ventilation
B Factors decreasing pulmonary compliance
IV Alveolar perfusion. A Lung blood flow
B Distribution of blood flow in lung
C Hypoxic pulmonary vasoconstriction
D Ventilation/perfusion (V/Q) ratio (see Figure 4.4)
V Alveolar gas exchange. A Composition of gases
B Movement of gases
C Factors influencing diffusion
D Carbon dioxide
E Oxygen
F Alveolar‐arterial oxygen gradient [P(A-a)O2]
G Arterial/alveolar ratio
H Oxygen carriage
I Oxygen binding to Hb
J Shunting and oxygenation
VI Effects of sedation and anesthesia on respiratory function. A Sedation
B General anesthesia
C Mechanisms for decreased oxygenation
Suggested Reading
Evaluation of the Respiratory System
A Patient history
B Physical examination
Auscultation
Airway Management
I Larynx. A Function
B Innervation
C Recurrent laryngeal nerve neuropathy
D Iatrogenic laryngeal neuropathy
E Hyperkalemic periodic paralysis(HYPP)
II Assessment of airway. A History
B Physical examination
C Situations in which difficulty is to be expected
III Airway equipment
A Mouth gag
B Laryngoscope
C Endotracheal tubes
D Inflatable cuffs
IV Complications of airway intubation. A Tissue damage
B Edema
C Over inflation of the cuff
D Lubrication
V Intubation of trachea. A Difficulty
B Position
C Technique
D Confirmation of tracheal tube placement
E Intubation of the difficult airway
VI Extubation of the trachea
VII Airway obstruction
A Signs of airway obstruction include:
B Laryngospasm
C Obstruction of the upper airway. At induction
Management
Intraoperative obstruction
At extubation
Management
D Obstruction of the nasal passages due to edema
E Obstruction of the nasal passages due to nasal bleeding
Suggested Reading
Tracheostomy
I Terminology
Temporary tracheostomy
Permanent tracheostomy (see Figure 4.11)
II Indications
III Surgical anatomy
IV Tracheostomy tubes (see Figure 4.12)
V Technique
VI Post‐operative care
VII Complications
Suggested Reading
5 The Renal System
I Role of the kidney
II Normal anatomy and physiology
A The nephron
The glomerulus
Proximal convoluted tubule
Loop of Henle
Distal convoluted tubule(DCT)
Collecting duct
Equine urine
B Renal blood flow and GFR. Renal blood flow(RBF)
Renal plasma flow(RPF)
Filtration fraction(FF)
Glomerular filtration rate(GFR)
Autoregulation
Tubuloglomerular feedback(TGF)
C Urine formation
D Urine volume in the horse
Comments:
III Renin‐Angiotensin‐Aldosterone‐System(RAAS) (see Figure 5.2)
Renin
Angiotensin I to Angiotensin II
Effects of Angiotensin II
Angiotensin III and IV
Aldosterone
Angiotensin‐converting enzyme (ACE) inhibitors (e.g. enalapril)
IV Effects of anesthetics on renal function
A Changes in RBF with anesthetics
B Inhalational anesthetics
Methoxyflurane
Sevoflurane
Compound A
C α2 adrenergic agonists
D Other injectable sedatives and anesthetics. Phenothiazines
Benzodiazepines
Opioids
NMDA antagonists
Propofol
E Intermittent positive pressure ventilation
F Stress
V Diuretics
A Osmotic diuretics (e.g. mannitol)
B Carbonic anhydrase inhibitors (e.g. acetazolamide)
Use in potential HYPP episodes: (see HYPP Chapter 38)
C Loop diuretics (e.g. furosemide)
D Thiazide diuretics (e.g. hydrochlorothiazide)
E Potassium sparing diuretics
Aldosterone inhibitors (e.g. spironolactone)
Sodium channel blockers (e.g. amiloride)
VI Nonsteroidal anti‐inflammatory drugs
Suggested Reading
6 Neurophysiology and Neuroanesthesia
I Neurophysiology. Membrane potentials
B Synaptic transmission
C Brain metabolism
D Cerebral blood flow
E Cerebral perfusion pressure(CPP)
F Cerebrospinal fluid(CSF)
II Central nervous system pathophysiology. A Seizures
B Intracranial pressure (ICP) increase
III Neuroanesthesia
A Cerebral metabolic rate
B Cerebral blood flow and perfusion pressure. Anesthetic drugs
Increased PaCO2
Positive pressure ventilation of lungs
Venous return
Head position
C Autoregulation
IV Neuroanesthesia for specific procedures
A CSF withdrawal
B Increased intracranial pressure. Includes head trauma, abscess, and tumor removal
Preparation
Sedation, premedication, and induction
Induction of anesthesia in foals
Sedation of adult horses
Maintenance of anesthesia
C Cerebral edema
Drug‐induced decompression
Ventilation
D Seizures
Anesthesia of horses prone to seizures
Suggested Reading
7 The Autonomic Nervous System
I General organization of the ANS (functional anatomy)
A Central autonomic nervous system
B Peripheral autonomic nervous system
C Afferent input
D Efferent output
II Physiology of the autonomic nervous system. A Neurotransmitters
B Synthesis, duration of action, and degradation of ACh
C Synthesis, duration of action, and removal of NE
D Receptors on the effector organs. Cholinergic receptors are subdivided into muscarinic and nicotinic
Adrenergic receptors are subdivided into alpha (α1 and α2), beta (β1 and β2), and dopaminergic (DA)
Dopaminergic receptors
III Function of the adrenal medulla. A SNS innervation of the adrenals
B Effect of NE release from adrenals
C Effect of EPI release from adrenals
IV Autonomic effects on the cardiovascular system. A The heart
B Systemic blood vessels
C Effects of SNS and PNS stimulation on arterial pressure
D Cardiovascular autonomic reflexes
V Autonomic effects on the pulmonary system
VI Pharmacology of the ANS. A Drugs that act on adrenergic effector organs (sympathomimetic drugs)
B Drugs that cause release of NE from nerve endings
C Drugs that have a PNS potentiating effect (anticholinesterase drugs)
D Drugs that block cholinergic activity at effector organs (antimuscarinic drugs) (see Table 7.5)
VII Clinical use of autonomic drugs
A Hypotension (see Chapter 38)
B Cardiac arrest
C Bradycardia
D Circulatory shock
E Bronchodilation
F Priapism (see Chapter 38)
G Reversal of neuromuscular block (see Chapter 15)
H Spasmolytic effect
Suggested Reading
8 Electrolyte and Fluid Therapy: Electrolytes
I Sodium
A Hyponatremia (<125 mEq/l)
B Hypernatremia (>155 mEq/l)
II Potassium
A Hypokalemia (<3.1 mEq/l)
B Hyperkalemia (>6.0 mEq/l)
III Chloride
A Hypochloremia (<90 mEq/l)
B Hyperchloremia (>110 mEq/l)
IV Calcium
A Hypocalcemia (<5.4 mEq/l)
B Hypercalcemia (>6.7 mEq/l)
Suggested Reading
Fluid Therapy
I Introduction
II Total body water
III Solute distribution
Effective osmoles
Effective osmolality
Osmolality
Osmolarity
Colloid oncotic pressure (COP)
ICF versus ECF
IV Fluid dynamics
Capillary hydrostatic pressure (Pc)
Capillary oncotic pressure (πC)
Interstitial hydrostatic pressure (Pi)
Interstitial oncotic pressure(πi)
A Starling's equation
B Revised Starling equation
V Administration of exogenous fluids
A Crystalloids
B Colloids
Synthetic colloids
Clinical use of colloids:
Adverse effects of colloids:
Suggested Reading
9 Acid‐Base Physiology: Traditional Approach
Acidemia
Acidosis
Alkalemia
Alkalosis
I Traditional approach to acid‐base interpretation. A Henderson‐Hasselbalch equation
Lewis Acid
Values for the Henderson‐Hasselbalch equation
B pH and hydrogen ions (see Box 9.1)
C Buffers
The carbonic acid‐bicarbonate buffer system
Non‐bicarbonate buffer systems
Role of the renal system in buffering
D Base excess
E Total CO2 (TCO2)
F Anion gap
G Primary disturbances in acid‐base (see Table 9.1)
Sodium bicarbonate dose is generally calculated as follows:
Anion gap
Winter's formula for use in metabolic acidosis
Winter's formula for use in metabolic alkalosis
Physicochemical Approach
I Brief review of physicochemistry and definitions
A Strong electrolytes
B Weak electrolytes
C Law of electroneutrality
D Strong ion difference(SID) variables
PaCO2
Strong ion difference
Total weak acid concentration (Atot)
E Strong ion gap and unmeasured anions
II Acid‐base disorders: definitions
III Examples of metabolic abnormalities causing acid‐base derangements
A SID acidosis. Hyperchloremia
B Lactic acidosis
C SID alkalosis. Hypochloremic alkalosis
D Atot acidosis
E Atot alkalosis
IV Examples of the physicochemical approach. Example 1:
Example 2:
Suggested Reading
10 Hemostasis and Hemotherapy: Hemostasis
I Normal physiology
II Primary hemostasis. A Adhesion
B Activation
C Aggregation
D Thrombin
E Platelet plug formation
III Secondary hemostasis. A Enzymatic reactions
B Cascade or waterfall model of coagulation
C The cell‐based model of coagulation
Initiation stage
Amplification
Propagation
D Anticoagulants
IV Fibrinolysis
V Coagulation testing
A Primary hemostasis
B Secondary hemostasis
C Fibrinolysis
D Coagulation profiles
E Viscoelastic coagulation tests
VI Coagulopathy
A Defects in primary hemostasis
B Defects in secondary hemostasis
C Hereditary and acquired causes of hypocoagulation
D Treatment for bleeding patients
E Thrombosis
Therapy
F DIC
Clinical signs
Treatment
Hemotherapy
I Indications for hemotherapy
A Oxygen delivery (DO2)
B Preload
Colloid osmotic pressure (COP)
C Diseases resulting in low [RBC]/[Hb] include
D Transfusion triggers
Acute blood loss
Clinical signs of hypovolemic shock
Chronic anemia
Immunoglobulins
II Types of blood products
Whole blood
Autotransfusion
Plasma products
Fresh plasma
Fresh frozen plasma
Frozen plasma
Platelets
Packed red blood cells (pRBC)
III Collecting blood products
A Donors
B Blood typing of donors
C Recipient
D Crossmatching
E Emergency transfusions
Blood collection
IV Administering blood products
Non‐hemolytic reactions
Hemolytic reactions
Replacement of TP/albumin
Box 10.2 Plasma Volume for Transfusion in Hypoproteinemia
Suggested Reading
11 Thermoregulation
I Introduction
II Physics principles applied to thermoregulation
III Mechanisms of heat transfer
A Conduction
Clinical example
B Convection
Clinical examples
C Evaporation
Clinical example
D Radiation
Clinical example
IV Homeostasis of body temperature
V Control of body temperature
A Afferent mechanism
B Central mechanism
Autonomic control
Behavioral control
C Effector mechanism
Autonomic responses
Behavioral responses
VI General considerations regarding thermoregulation during anesthesia
A Effects of individual drugs on thermoregulation
VII Physiologic consequences of hypothermia. A Central nervous system
B Cardiovascular system
C Respiratory
D Miscellaneous
VIII Classification of hypothermia. A Etiology‐based
B Temperature‐based
IX Hypothermia in the foal
X Hypothermia in the adult horse
XI Prevention and treatment of hypothermia
A Proactive heat management
Methods of preventing hypothermia include:
B Warming Devices. Passive
Active
Other considerations
XII Hyperthermia
A Clinical signs of hyperthermia include
B Treatment of horses with hyperthermia
Suggested Reading
12 Pharmacology of Drugs Used in Equine Anesthesia: Phenothiazines
I Mechanism of action of acepromazine
II Physiologic effects
III Clinical use of acepromazine. A Standing sedation
B Premedication prior to general anesthesia
C Contraindications
Suggested Reading
Butyrophenones
I Mechanism of action
II Physiologic effects
III Clinical use of azaperone
IV Contraindications
Suggested Reading
α2‐Adrenergic Agonists
I α2‐receptor subtypes
A α2A subtype
B α2B‐subtype
C α2C‐subtype
II Mechanism of action
III Physiological effects
IV Clinical use of α2 agonists. A Standing sedation
B Premedication prior to general anesthesia
C Maintenance of anesthesia
D Epidural analgesia
E Individual drugs
V Contraindications
VI Adrenergic antagonists
A Mechanism of action
B Physiologic effects
C Clinical use
D Adverse reactions
E Vatinoxan (MK‐467)
Suggested Reading
Opioids
I Opioid receptor types
A Mu (μ) opioid receptor (MOP, OP3)
B Kappa (κ) opioid receptor(KOP, OP2)
C Delta (δ) opioid receptors(DOP, OP1)
II Mechanism of action
A Full agonists
B Partial agonists
C Mixed agonist/antagonists
D Antagonists
III Physiologic effects of opioids. A Central nervous system
B Cardiovascular system
C Respiratory system
D Gastrointestinal system
E Urinary system
F Miscellaneous
IV Clinical use of opioids. A Standing sedation
B Premedication prior to general anesthesia
C Epidural analgesia
D Opioids and ileus
V Individual drugs
Tramadol
I Mechanism of action
II Physiologic effects
III Clinical use
Suggested Reading
Trazadone
I Mechanism of action
II Physiologic effects
III Clinical use
Suggested Reading
Benzodiazepines
I Mechanism of action
II Physiologic effects
III Clinical use
A Chemical restraint
B Induction of anesthesia
C Maintenance of anesthesia
D Individual benzodiazepine drugs
IV Benzodiazepine antagonists. A Flumazenil
B Mechanism of action
C Physiologic effects
D Clinical use
Suggested Reading
Guaifenesin
I Mechanism of action
II Physiologic effects
III Clinical use
A To improve induction quality
B To maintain anesthesia
IV Contraindications
Suggested Reading
Ketamine
I Mechanism of action
II Physiologic effects
III Clinical use. A Induction of anesthesia
B Maintenance of anesthesia
C MAC reduction
D Epidural analgesia
E Analgesia in the awake horse
F Potentiation of α2‐induced sedation in standing horse
Suggested Reading
Tiletamine and Zolazepam (TZ)
I Mechanism of action
II Physiologic effects
III Clinical use
A Induction of anesthesia
Suggested Reading
Alfaxalone
I Mechanism of action
II Physiologic effects
III Clinical use
A Induction of anesthesia
B Maintenance of anesthesia
Suggested Reading
Propofol
I Mechanism of action
II Physiologic effects
III Clinical use
A Induction of anesthesia
B Propofol as a co‐induction drug with ketamine
C Maintenance of anesthesia
Suggested Reading
Barbiturates
I Receptor activity of barbiturates
A Use for euthanasia
Intravenous lidocaine
I Mode of action
II Clinical use of intravenous lidocaine. A As an adjunct to general anesthetics
B To provide analgesia in the awake horse
III Metabolism
VI Adverse effects
A CNS effects
B Cardiovascular effects
C Methemoglobinemia
Suggested Reading
Horse‐related drug Regulations in Europe
I Regulations
II Anesthesia‐related drugs that are not allowed in food producing animals
13 Inhalational Anesthetics
I Introduction
II Mechanism of action
Immobility
Unconsciousness
III Minimum alveolar concentration (MAC)
A MAC Derivatives
B Factors that decrease MAC
C Factors that increase MAC
IV Pharmacokinetics
A Absorption
The rate of delivery of anesthetic to the alveoli is determined by the following factors. The inspired partial pressure of inhalant (Pi)
Vaporizer setting
Oxygen flow rate
Volume of anesthetic circuit
C Alveolar ventilation and alveolar partial pressure (PA)
D The rate at which the anesthetic is removed from the alveolus
Solubility of the anesthetic in blood (see Table 13.1)
Cardiac output of the patient
Alveolar‐to‐venous partial pressure difference
E Distribution
F Metabolism
Elimination
V Pharmacodynamics. A Cardiovascular effects
B Respiratory effects
C Central nervous system effects
D Renal effects
E Hepatic effects
F Analgesia
VI Nitrous oxide
A Mechanism of action
B Pharmacokinetics
C Pharmacodynamics
D Clinical use of N2O
Suggested Reading
14 Local Anesthetics
I Mechanism of action
II Physicochemical properties. A Chemical structure
B Structure–activity relationships. Molecular weight(MW)
pKa
Lipid solubility
Protein binding
Stereoisomerism
III Pharmacokinetics. A Absorption
Dose
Injection site
Lipid solubility
Vasoconstrictors
B Distribution
Effect of pulmonary uptake
Effect of hypercapnia
C Metabolism and excretion
Aminoesters
Aminoamides
IV Local anesthetic adjuvants and combinations. A Epinephrine
B α2 agonists. Effects on peripheral nerve blocks
Effects on epidural anesthesia
C Bicarbonate
D Hyaluronidase
E Carbon dioxide
F Combinations of local anesthetics
V Local anesthetic toxicity
A Systemic toxicity. CNS
Cardiovascular system(CVS)
Blood
B Local tissue toxicity. Neurotoxicity
Chondrotoxicity
C Allergic reactions
VI Local anesthetic agents. A Lidocaine (see Table 14.3)
B Mepivacaine
C Bupivacaine
D Ropivacaine
E Proparacaine and Tetracaine
F Procaine
VII Clinical use. A Local and regional techniques
B Intravenous lidocaine
Suggested Reading
15 Neuromuscular Blocking Agents in Horses
I Introduction
II Physiology of the neuromuscular junction
III Neuromuscular blocking agents
A Pharmacology
B Physiology
III Individual NMBAs. A Benzylisoquinolones
Atracurium
Cisatracurium
B Neurosteroids
Vecuronium
Rocuronium
C Residual NMB
IV Pharmacologic reversal of NMB. A Acetylcholinesterase inhibitors
Clinical implications:
B Reversal drugs
C Selective relaxant binding agents
Suggested Reading
16 Non‐steroidal Anti‐Inflammatory Drugs and Corticosteroids. Non‐steroidal Anti‐Inflammatory Drugs
I Arachidonic acid cascade
A Isoenzymes of COX
B Synthesis of prostaglandins
C Role of prostaglandins
II Mechanism of action of NSAIDs
III Clinical uses of NSAIDs. A Musculoskeletal analgesia
B Use in gastrointestinal (GI) disease
C Anti‐endotoxin effects
D Perioperative analgesia
IV Specific NSAIDs used in equine practice. A Flunixin meglumine
B Phenylbutazone
C Diclofenac
D Firocoxib
E Meloxicam
F Grapiprant
V Adverse effects of NSAIDs. A Gastrointestinal tract
Stomach and Duodenum
NSAID‐induced enteropathy
B Renal effects
C Hematologic
D Risk factors for NSAID related adverse effects
Corticosteroids
I Mechanism of action of glucocorticoids
II Clinical uses of glucocorticoids. A Musculoskeletal injuries
B Noninfectious inflammatory airway disease
C Immunosuppression
D Topical administration
E Mating‐induced endometritis
III Specific glucocorticoids used in equine practice. A Dexamethasone
B Prednisone
C Prednisolone
D Betamethasone
E Triamcinolone
F Isoflupredone
IV Inhaled corticosteroids
A Fluticasone
B Beclomethasone
V Adverse effects of glucocorticoids. A Musculoskeletal system
B Gastrointestinal Tract
C Metabolic effects
D Coagulation
E Hepatic
F Suppression of HPAA
G Immunosuppression
H Wound healing
Suggested Reading
17 Anesthetic Machines and Equipment
I Introduction
II High‐pressure system
A Cylinder storage of oxygen
Box 17.1 Oxygen Cylinder Conversion Factors
B Pressure regulators
C Liquid oxygen storage
D Oxygen concentrators
III Intermediate‐pressure system
IV Low‐pressure system
A Flowmeter
B The anesthetic vaporizer
C The common gas outlet
D Breathing circuits
E Components of the circle system. One‐way valves
Breathing circuit
Carbon dioxide (CO2) absorbent
Reaction of CO2 with soda lime
Reservoir bag
Adjustable pressure limiting (APL) valve (“pop‐off valve”)
V Time constant for anesthesia circuit (τ)
VI Scavenging system
Collection mechanism
Connection to interface
Interface
Connection to elimination system
Elimination system
VII Ventilators
A Mallard Large Animal Anesthesia Ventilator System
B Drager/Anesco
C Tafonius
D Bird mark respirator
VIII Endotracheal tubes
A Cleaning endotracheal tubes
IX Demand valves
Suggested Reading
18 Positioning the Anesthetized Horse
I Introduction
II Problems associated with recumbency
III Preventing complications in lateral recumbency. A Padding
B Positioning
IV Preventing complications in dorsal recumbency. A Padding
B Positioning (see Figures 18.2–18.6)
V Dorsal recumbency with head‐down position (Trendelenburg)
A Circulatory changes
B Ventilatory changes
Suggested Reading
19 Monitoring the Anesthetized Horse. Monitoring the Central Nervous System
I Awareness during anesthesia
II Monitoring the depth of anesthesia
III Methods of monitoring the depth of anesthesia. A Evaluation of the eye. Position
Nystagmus
Lacrimation
Palpebral reflex
Corneal reflex
Effects of Ketamine or Tiletamine
B Movement
C Anal tone
D Physiologic parameters
E Concentrations of inhalational anesthetic in expired gases
F Quantitative EEG (See Section IV below) IV EEG
A EEG findings in the horse
EEG recording in the horse
B Auditory evoked potentials (AEP)
C Bispectral index (BIS)
BIS in the Horse
Suggested Reading
Cardiovascular Monitoring
I Direct palpation of arterial pulse
II ECG
III Blood pressure monitoring
A Non‐invasive (indirect) arterial blood pressure measurement
Oscillometric technique
B Invasive (direct) arterial blood pressure measurement
Inaccuracies in measurement
Complications of arterial catheterization
IV Cardiac output monitoring
Indicator‐based methods
A Thermodilution
B Lithium dilution
Technique
Disadvantages:
C Fick method
Disadvantages:
D Imaging methods
Pulse contour analysis
Echocardiography
Transthoracic bioimpedance
Suggested Reading
Respiratory Monitoring
I Monitoring respiratory rate and tidal volume. A Spontaneous ventilation
B Controlled ventilation
Pressure‐volume and flow‐volume loops
II Monitoring carbon dioxide
A Minute ventilation (VE)
B Alveolar ventilation (VA)
III Types of capnographs and capnometers. A Time capnography
B Volume capnography
IV Types of gas CO2analyzers. A Sidestream capnometers
Advantages:
Disadvantages:
B Mainstream capnometers
Advantages:
Disadvantages:
V Normal time capnogram (see Figure 19.10)
A Phase I
B Phase II
C Phase III
D Phase 0
VI Abnormal PECO2 values and waveforms. A Absence of PECO2 waveform
B Cardiogenic oscillations
C Widened α angle
D Widened β angle
E Elevated baseline
F Hypoventilation
G Hyperventilation
H Resisting the ventilator
I Cardiac arrest
VII Monitoring the inspired oxygen concentration
Technology
VIII Pulse oximetry
A Types of pulse oximeters
Transmission probe (see Figure 19.18a)
Reflectance probes (see Figure 19.18b)
Co‐oximetry
B Technology
Transmission pulse oximetry
Reflection pulse oximetry
C Factors that may affect accuracy
D Advantages of pulse oximetry
E Disadvantages
IX Arterial blood gas analysis
A Arterial oxygen partial pressure (PaO2)
B Arterial carbon dioxide partial pressure (PaCO2)
Suggested Reading
Anesthetic Agent Monitoring
I Technology
A Factors that may affect accuracy
Monitoring Temperature
I Thermal compartments. Core compartment
Peripheral compartment
II Monitoring sites. A Core temperature. Pulmonary artery
Aorta
B Near‐Core
Rectum
Esophagus
Nasopharynx
Urinary bladder
C Peripheral. Skin
III Technologies
Thermistor (see Figure 19.19)
Thermocouple
Infra‐Red
IV Hazards of temperature monitoring. Thermal burn
Probe contamination
Incorrect temperature readings
Faulty probe
Suggested Reading
Monitoring Neuromuscular Function
I Peripheral nerve stimulation
A Current
B Duration of stimuli
C Pattern of stimulation
II Repetitive stimulation and fade. A TOF
Advantages of TOF
III Methods to measure the evoked response. A Mechanomyography
B Alternative methods
Visual or tactile:
Acceleromyography (AMG):
Electromyography
IV Peripheral motor nerves used for monitoring neuromuscular blockade
Peroneal:
Radial:
Facial:
Suggested Reading
20 Standing Sedation
I Indications for standing sedation
II Advantages of standing sedation over general anesthesia
III Disadvantages of standing sedation
IV Patient evaluation and preparation
V Drug administration
A Premedication with IM administered drugs
Examples of IM Premedication Protocols
B Bolus injections
Examples of IV Bolus Doses of alpha2 Agonists ± an Opioid
C Continuous rate infusions (CRI)
Examples of α2‐agonist CRIs
D Opioids as part of the CRI. Examples of Opioid Doses (IV) When used in Conjunction with an α2 Agonist
E Ketamine use in standing sedation
F Intravenous lidocaine use in standing sedation
G Reversal of sedation
21 General Anesthesia Techniques
I Sedation
A Reasons to sedate prior to anesthesia induction
B Drugs used for sedation prior to induction
II Induction of anesthesia
A Drugs used for induction of anesthesia (see Table 21.2)
III Maintenance of anesthesia
Inhalational Anesthesia
I Clinical use of inhalational anesthetics
II Potential advantages of inhalational anesthesia
III Potential disadvantages of inhalational anesthetics
IV Recovery quality
Total Intravenous Anesthesia (TIVA) I Potential advantages of TIVA over inhalational anesthesia
II Potential disadvantages of TIVA
III Methods of drug delivery
A Intermittent injection of drugs
B Drip technique
C Infusion pump
D Syringe pump
E Computerized syringe pump
IV Choice of injectable drugs
V Drug combinations used for TIVA
A α2 agonists + Ketamine
B α2 agonist + Ketamine + Guaifenesin
C Propofol
D Alfaxalone
Partial Intravenous Anesthesia (PIVA)
I Potential advantages of PIVA
II Potential disadvantages of PIVA
III Choice of IV drugs for PIVA
IV Drugs and drug regimens used in PIVA
A Lidocaine
B α2 agonists
Medetomidine/Dexmedetomidine/Xylazine
Dexmedetomidine
Xylazine
Detomidine/Romifidine
C Ketamine
D Ketamine and α2 agonists
E Lidocaine + Ketamine
Suggested Reading
22. Anesthesia of the Head and Neck. Anesthesia of the Head
A Infraorbital nerve block
Location
Technique (within the infraorbital canal)
B Maxillary nerve block
Location
Technique
C Mandibular alveolar (or inferior alveolar) nerve block
Location
Extra‐oral approach
Intra‐oral approach
D Mental nerve block
Location
Technique (within the mandibular canal)
E Ethmoidal nerve block
Location
Technique
Suggested Reading
Maxillary Nerve Block in Donkeys
I Indications
II General principles. A Local anesthetic drug selection and doses
B Ultrasound‐guided maxillary blockade allows for:
C Equipment
III Patient preparation. A Physical restraint
B Chemical restraint
C Preparation of injection site
IV General technique
Needle insertion. Blind technique
Ultrasound guided approach
V Checking for desensitization
VI Complications
VII Specific techniques for maxillary block. A Blind maxillary nerve block
Angled approach (see Figure 22.6)
Perpendicular approach (see Figure 22.7)
B Ultrasound‐guided maxillary nerve block (see Figure 22.8)
Cervical Plexus Block
I Introduction
II Indications for the block
III Contraindications
IV Clinical anatomy (see Figure 22.10)
V Expected distribution of anesthesia
A Local anesthetic
B Patient preparation and positioning
VI Step‐by‐step performance of the block. A Surface anatomy and landmarks (see Figure 22.12)
B Ultrasound anatomy (see Figure 22.13)
C Needle insertion technique (see Figure 22.14)
VII Complications
Suggested Reading
23 Anesthesia of the Eye
I Restraint. A Intravenous sedation
II Topical local anesthesia. A Topical anesthesia
B Proparacaine and tetracaine
C Adverse effects of topical anesthetics
III Subconjunctival anesthetic injection. A Technique
B Indication
IV Subcutaneous injectable local anesthesia. A Technique
B Local anesthetic drugs
C Adjunctive agents
Hyaluronidase
Epinephrine
Bicarbonate
α2agonists
D Methods of using injectable local anesthetics
V Motor nerve blocks. A Auriculopalpebral nerve (see Figure 23.1 and 23.2)
Location
VI Sensory nerve blocks (see Figures 23.1–23.3) A Supraorbital nerve
Location
Technique
B Lacrimal nerve
C Infratrochlear nerve
D Zygomatic nerve
VII Deep orbital nerve blocks. A Nerves blocked
Oculomotor nerve
Trochlear nerve
Trigeminal nerve
Abducens nerve
B Techniques. Four‐point block
Peterson‐type block
Supraorbital fossa block (see Figure 23.5)
C Potential complications of deep orbital blocks
VIII Field block anesthesia of the eye. A Line blocks
B Infiltration anesthesia of the eye
Suggested Reading
24 Anesthesia of the Limbs
I Indications
II General principles. A Selection of the local anesthetic drug and dose
B Deposition of local anesthetic
C Equipment
III Patient preparation. A Physical restraint
B Chemical restraint
C Preparation of the injection site
IV General technique
A Needle insertion
B Localization of lameness
V Checking for desensitization
VI Complications
VII Forelimb: distal aspect. A Palmar digital nerve block at the level of the cartilages of the foot
B Midpastern semi‐ring block
C PDN block at the level of the base of the proximal sesamoid bones (abaxial sesamoid, or basisesamoid, nerve block)
D Low four‐point nerve block (i.e. Low palmar nerve block)
E High four‐point block (i.e. High palmar nerve block)
F Lateral palmar nerve block
Site 1
Site 2
VIII Forelimb: proximal aspect
A Median nerve
B Ulnar nerve
C Medial cutaneous antebrachial nerve
IX Hind limb. A Plantar digital nerve block at the level of the cartilages of the foot
B Mid‐pastern ring block
C Plantar digital nerve block at the level of the base of the proximal sesamoid bones (abaxial sesamoid or basisesamoid nerve block)
D Low six‐point nerve block (i.e. low plantar nerve block)
E High six‐point nerve block (i.e. high plantar nerve block)
F Tibial and peroneal (Fibular) nerve blocks. Tibial Nerve
G Deep and superficial peroneal nerves
Suggested Reading
25. Anesthesia of the Perineum and Testicle. Pudendal Nerve Block – Electrostimulation Technique
I Target nerves and region anesthetized
II Location (see Figure 25.3)
III Technique. Desensitizing superficial planes
Desensitizing the pudendal plexus
IV Choice and volume of anesthetic
V Caution
Pudendal Nerve Block – Blind Approach
A Location
B Technique
C Choice of anesthetic
Local Anesthesia for Castration
I Introduction
II Nerve supply
III Uptake and distribution of IT administered drugs
IV Volume of IT local anesthetic
Suggested Reading
26 Anesthesia of the Abdominal Wall. Thoracolumbar Paravertebral Block (TPVB) – Electrostimulation Technique
A Location
B Technique
Desensitizing superficial planes
Desensitizing the thoracolumbar nerves
Paravertebral Nerve Block – Blind Technique
I Indications
A Equipment
II Patient preparation. A Physical restraint
B Chemical restraint
C Preparation of injection site
III General technique
A Needle insertion
Transversus Abdominis Plane Block
I Indications
II Anatomy
III TAP block
A Flank approach
Technique
Results
B Intercostal ventral approach (see – Küls et al., Suggested reading)
Technique
Results
C Subcostal approach (see Suggested reading – Freitag et al.)
Technique
Results
Caudal Intercostal Block for Abdominal Surgery (CIBAS)
I Anatomy
Technique
Drugs administered
II Disadvantages of the CIBAS technique
Suggested Reading
27 Epidural Analgesia and Anesthesia
I Anatomy and technique for caudal epidural. A Location
B Technique
C Verification of needle or catheter placement
II Indications for epidural drug administration
III Contraindications
IV Effects. A Analgesia
B Anesthesia
C Other spinal effects
D Systemic effects
V Complications
VI Drugs. A Local anesthetics
Lidocaine (2%) or mepivacaine (2%)
Ropivacaine (0.5%)
B Opioids
Morphine (0.1–0.2 mg/kg)
Methadone (0.1 mg/kg)
C α2 agonists
Xylazine (0.17–0.22 mg/kg)
Detomidine (0.01–0.06 mg/kg)
D Ketamine
E Combinations. Opioids and α2agonists
Suggested Reading
28 Pathophysiology of Pain
I Introduction. A Acute vs. chronic pain
B Five general steps in the pain pathway
Transmission
Transduction
Modulation
Projection
Perception
II Ascending nociceptive pathways
III Types of nociceptors
Transient receptor potentialion channels (TRPs)
Neuronal sodium channels (NaV)
Acid‐sensing ion channels (ASICs)
Glutamate receptors
Neurokinin 1 receptors (NK‐1)
Lamellated corpuscles
IV Descending modulatory pathways
V Development of chronic pain states. A Peripheral sensitization
B Central sensitization
NMDA receptor
C Neuropathic pain
VI Physiologic consequences of pain
Suggested Reading
29 Pain Recognition in Horses
I Introduction
II Steps necessary to implement pain scoring in the hospital routine
A Select a practical and applicable pain scale
B Select a key person responsible for the procedures of clinical pain‐scoring
Develop local routines for pain scoring
D Assessment
E Conduct training sessions for all caregiving personnel
III How pain scoring is performed – key points
A Use a structured score sheet (e.g. Table 29.2)
B View the horse, as discretely as possibly, during a quiet time in the stall
C Timing
D Recommended intervals for assessing pain
Recommendations
IV Video assistance. Key points
V Factors that influence pain scoring. Key points
A Baseline measures or input from owner should be considered
B Fear and stress
C Medication
D Owner contact and other social intervention
VI Interpretation of pain scores. Key points
VII Guide on how to use the Equine Pain Scale (EPS) (see Table 29.2) Key points
A Detailed description of the EPS
B Pain Face, present or not
C Gross pain behavior
D Activity
Location in the stall
F Posture/weightbearing
G Head position
H Attention toward the painful area
I Interactive behavior
J Response to food
VIII Interpretation and actions due to EPS Pain Scores
A Key points – Action for score “4”
Suggested Reading
30 Management of Pain:The Pharmacologic Approach to Pain Management
I Drug classes commonly utilized for management of pain in horses. A Non‐steroidal anti‐inflammatory drugs(NSAIDs)
B Opioids
Mu opioid receptors
C α2‐adrenergic agonists
D N‐methyl‐D‐aspartate receptor antagonists
E Local anesthetics
F Gabapentin
II Pain management
III Examples of case management using balanced analgesia
Premedication:
Induction:
Premedication:
Induction
Local anesthesia:
Suggested Reading
Rehabilitation Modalities for Acute and Chronic Pain in Horses
I Introduction
II Pain assessment
A Lameness assessment
B Articular pain
C Pressure algometry
III Rehabilitation modalities used to treat acute and chronic musculoskeletal pain. A Therapeutic laser (Light amplification by stimulated emission of radiation.) (see Figure 30.3)
Analgesic effects of laser therapy
B Acupuncture
C Cryotherapy
D Thermotherapy
E Electrical stimulation (Transcutaneous electrical nerve stimulation [TENS]) (see Figure 30.4)
F Extracorporeal shockwave therapy (see Figure 30.5)
Suggested Reading
Equine Acupuncture
I Introduction
II Mechanism of acupuncture‐induced analgesia
III Patient evaluation and treatment
A Acupuncture techniques
Acupressure
Dry needle
Hemoacupuncture
Aquapuncture
Electroacupuncture (EA)
Moxibustion
Lasers and infrared light sources
Implanted materials
B Choice of technique
C Number of treatments required
IV Evaluation of the musculoskeletal system
V Environment
VI Patient tolerance
VII Needle placement
VIII Treatment of musculoskeletal pain
A Foot pain. Non‐laminitic foot pain
Laminitic foot pain
B Joint pain
C Tendon and ligament injuries
D Cervical pain
Case report:
E Thoracolumbar pain
F Pelvic region pain (see Figure 30.10)
G Gastrointestinal pain
Summary
Suggested Reading
31 Anesthesia of Foals
I Transition to adult life. A Transition to adult circulation
B Reopening of shunts
II Respiratory system of the neonatal foal
A Breathing pattern
B Control of breathing
C Arterial blood gas values in neonatal foals
III Cardiovascular system of the foal (see Table 31.1)
IV Thermoregulation
A Heat production
B Heat loss is exacerbated by:
C Neutral thermal environment
D Effects of anesthesia on heat balance
E Effects of hypothermia on anesthesia
V Drug metabolism and excretion
A Injectable drugs. Neonatal foals
Older foals
B Inhalational anesthetics
VI Sedation and general anesthesia. A Preoperative evaluation
B Fasting
C Sedation. Neonates
Older foals
Benzodiazepines
Opioids
α2agonists
α2antagonists
D Induction of anesthesia with intravenous drug(s)
Ketamine (2–3 mg/kg, IV)
Propofol (2–4 mg/kg, IV) or alfaxalone (1–3 mg/kg, IV)
Example induction protocols for neonatal foal
Propofol (1–3 mg/kg, IV) administered slowly to effect
Induction protocol for older, healthy foal. Example 1
Induction protocol for older foal. Example 2 (Combining drugs)
E Induction of anesthesia with an inhalational anesthetic
Reasons for rapid uptake of volatile anesthetics in neonate
F Maintenance of anesthesia
Volatile anesthetics
Partial intravenous anesthesia (PIVA)
Neonatal foal – Example PIVA protocol
Older foal ‐ Example of PIVA protocol
Total intravenous anesthesia (TIVA)
VII Monitoring and patient care. A Positioning and padding
B Monitoring (see Chapter 19)
Depth of anesthesia
Cardiovascular system
Respiratory system
Body temperature
Blood glucose
VIII Recoveries
IX Managing the mare at induction and recovery
Examples of sedation regimens for the mare
Induction phase
Recovery phase
X Analgesia for the neonatal foal
Examples of balanced anesthesia
NSAIDs
Flunixin meglumine
Phenylbutazone
Meloxicam
Opioids
XI Anesthesia for foals with uroabdomen
A Clinical presentation
Clinical signs
B Metabolic changes
Hyponatremia([Na+] < 125 mEq/l)
Hyperkalemia([K+] > 5.5 mEq/l)
C Preoperative treatment
Plasma volume expansion
Reduce plasma [K+]
Reverse membrane effects of hyperkalemia
D Anesthesia (see sections E and F)
Sedation
Induction
Maintenance
E Monitoring
F Analgesia
Suggested Reading
32 Anesthesia of Horses with Intestinal Emergencies (Colic)
I Preoperative evaluation
II Preparation for anesthesia
A Fluid therapy
Isotonic fluids (e.g. lactated Ringer's)
Hypertonic saline
Synthetic colloids
Acid‐base correction
B Sedation and analgesia
α2 agonists
Non‐steroidal anti‐inflammatory drugs (NSAIDs)
Opioids
Phenothiazines
C Anti‐endotoxin therapy
Polymyxin B
NSAIDs
D Antimicrobial therapy
III Sedation and induction
IV Intubation and oxygenation
V Maintenance of anesthesia
VI Intraoperative support. A Fluid therapy. Isotonic fluids
Colloids
B Cardiovascular support (see Chapter 38)
Preload
Inotropic support
Calcium infusions
C Respiratory support (see Chapter 38)
VII Recovery
VIII Intraoperative use of phenylephrine
Suggested Reading
33 Anesthesia of the Geriatric Horse
I Definition of geriatric
II Mechanisms of aging
III The impact of aging on body systems
IV Pharmacologic considerations in geriatric horses
V Anesthetic considerations in geriatric horses
Suggested Reading
34 Anesthesia and Pregnancy
I Physiology of pregnancy (see Table 34.1)
A Cardiovascular
B Respiratory
C Renal
D Uterus
II Factors affecting drug disposition during pregnancy. A Maternal
B Placental
C Fetal
III Anesthesia concerns in the pregnant mare. A Compression of the vena cava
B Hypoventilation, hypoxemia, and impaired gas exchange
C Myopathy
D Recovery
IV Anesthetic management in pregnancy
A Sedation and premedication. Acepromazine
α2 agonists
Opioids
Flunixin meglumine
B Induction. Ketamine
Diazepam
Midazolam
Guaifenesin
C Maintenance
D Specific monitoring. Direct blood pressure
Arterial blood gas analysis
Electrocardiography
FHR
E Cardiovascular supportive measures
F Recovery
G Pain management
V Managing anesthesia in the pregnant mare
A Non‐obstetric procedures. Abdominal surgery for intestinal emergency
Trauma
B Obstetric procedures. Uterine torsion
Dystocia/Cesarean section (see Table 34.2)
Live foal at presentation (see Figures 34.1 and 34.2)
Dead foal at presentation
Suggested Reading
35 Anesthesia for Equine Imaging
Magnetic resonance imaging. I Introduction
A Specific challenges
II MRI safety
III MRI scanning room equipment
A MRI‐safe equipment
B MRI‐compatible equipment
C Use of non‐ferrous anesthetic equipment
D Use of ferromagnetic equipment
IV Patient preparation
V Patient positioning
Box 35.1 Avoid Excessive Traction on Limbs
VI Anesthesia and monitoring. A Anesthesia (see Chapter 21)
B Monitoring
Blood pressure
Urine collection
Assessing anesthetic depth
ECG
Pulse oximetry
Temperature
VII MRI contrast media
Low‐field standing MRI. I Introduction
A Advantages of low‐field MRI
B Disadvantages of low‐field MRI
II MRI safety
III Patient preparation
Patient limitations
IV Standing sedation for image acquisition
A Concerns in standing sedation
V Monitoring
Computed tomography
I Introduction
II Radiation safety
III Equipment and facilities. A Conventional recumbent CT under general anesthesia
B Standing CT
Performing a head CT in a modified, adapted standard CT scanner:
IV Patient preparation for CT
A Conventional recumbent CT
B Standing head CT in a modified scanner
V Anesthesia, sedation, and image acquisition. A Conventional recumbent CT under general anesthesia
B Standing CT of the head
VI Monitoring
VII CT contrast media
A Adverse effects
Radiographic myelography
I Introduction
II Radiation safety
III Patient and procedure preparation
IV Anesthesia, monitoring, and procedure. A Anesthesia
B Monitoring
C Procedure
V Myelographic contrast media
VI Recovery
Suggested Reading
36 Anesthesia of Donkeys and Mules:Anatomic, Physiologic, and Behavioral Differences
I Anatomical differences
A Upper airway
B Endotracheal intubation (see Airway management Chapter 4)
C Nasogastric intubation
D Jugular catheterization
E Epidural anesthesia
F Miscellaneous anatomic differences. Distal colon
Nasolacrimal duct
Dentition
Vertebral formula
II Physiologic differences
A Evolution in a desert environment
III General behavioral characteristics
IV Preoperative evaluation
A Blood and chemistry differences
Suggested Reading
Sedation and Anesthesia of Donkeys and Mules
I Differences in drug dosages compared to horses
II Sedation of donkeys and mules
III Induction of anesthesia
Ketamine (2.5–3 mg/kg)
Ketamine (2.5–3 mg/kg) + benzodiazepine (e.g. diazepam/midazolam 0.05–0.1 mg/kg)
Ketamine (2.5 mg/kg) + Propofol (0.5–1.0 mg/kg)
Propofol (2.0 mg/kg)
Alfaxalone (2.0 mg/kg)
Thiopental (5–8 mg/kg)
Tiletamine + zolazepam (1–2 mg/kg)
IV Maintenance of anesthesia. A Inhalational anesthetics
B Total intravenous anesthesia (TIVA)
Example of TIVA: donkey (150–200 kg)
C Partial intravenous anesthetic (PIVA)
V Recovery from anesthesia
VI Analgesia
A Non‐steroidal anti‐inflammatory drugs (NSAIDS)
Phenylbutazone
Flunixin meglumine
Meloxicam
Carprofen
B Opioids
Butorphanol
Morphine
Hydromorphone
Buprenorphine
Suggested Reading
Donkey Pain Assessment Scales
I Natural pain responses in donkeys
II Pain assessment scales for acute pain in equids. A Current types of pain assessment scales
Composite Pain Scales(CPS) consisting of:
Facial expression‐based Pain Scales (FAP) consisting of:
B Basic set‐up of pain assessment scales
C Primary use and advantages of using pain scales
III Donkey pain assessment scales for acute pain
A Donkey composite pain scale (Donkey CPS)
B Donkey facial expression‐based pain scale
C Which scale to use
D How to carry out a COMPASS and/or FAP for acute pain manually. Preparation (See Table 36.1)
E How to carry out a COMPASS and/or FAP for acute pain by means of EPWA(the Equine Pain and Welfare App)
IV Donkey pain assessment scales for chronic pain. A The Donkey Chronic pain scale (See Table 36.4)
B THE DCP CPS for chronic pain assessment to perform manually. Preparation
V Donkey grimace scale (DGS)
VI Pain assessment in mules and hinnies
Suggested Reading
37 Remote Capture of Equids
I General considerations. A The decision to use remote delivery
B Trauma reduction
C Environment
II Equipment. A Choice of delivery equipment. Distance
Trauma
Familiarity
B Equipment options. Pole syringe
Blow pipe
Pistol
Rifles (see Figure 37.1)
III Pharmacology. A Choice of drugs
B α2 agonists and antagonists
Xylazine
Detomidine
Romifidine
Medetomidine
Yohimbine (0.1–0.2 mg/kg, IM) or tolazoline (2–4 mg/kg, IM)
Atipamezole
C Phenothiazines and butyrophenones
D Opioids and opiates. Morphine
Butorphanol
Thiafentanil
Etorphine
E Dissociative anesthetics. Ketamine
Telazol (Zoletil®)
IV Monitoring and supportive care. A Field anesthesia
B Monitoring
C Oxygenation
D Position and padding
V Sedation of fractious horses. A The decision to use IM sedation
B Sedative protocol
VI Sedation and anesthesia of captive feral horses. A Technique
VII Remote capture of free‐ranging feral horses. A Techniques
B Telazol - α2 mixtures
VIII Wild equids. A Techniques
B Zebra
Adult Grevy's zebra
Common zebra
C Przewalski's horse
Suggested Reading
38 Complications:Intraoperative Hypotension
I Common causes of hypotension. A Inhalational anesthetics
B Hypovolemia
Static measures of preload
Dynamic measures of preload
PPV
C Bradycardia
Treatment
II Treatment of hypotension
A Positive inotropic agents
Dobutamine
Ephedrine
Dopamine
Epinephrine
Calcium salts
B Vasopressors. Norepinephrine(NE)
Phenylephrine
Vasopressin
Suggested Reading
Intraoperative Hypertension
I Characterization
II Causes of hypertension in anesthetized horses. A Inadequate plane of anesthesia
B Medications. α2 agonists
Sympathomimetic drugs
C Nociception
Somatic
Visceral
Sympathetic
D Miscellaneous causes
Suggested Reading
Hypoxia and Hypoxemia
I Introduction
II Hypoxia
A Causes of hypoxia
III Hypoxemia
A Causes of hypoxemia
Ventilation‐Perfusion (V/Q) mismatch
Shunt (Low V/Q mismatch)
Hypoventilation
Diffusion impairment
Low‐inspired oxygen
B Other factors likely to exacerbate hypoxemia
C Clinical signs of hypoxemia
IV Problems with oxygen delivery
A Central supply
B Anesthetic machine
C Anesthesia circuit
D Endotracheal tube
E Ventilator
V Improving arterial oxygen partial pressure (PaO2 ) A Correct mechanical failures
B Institute intermittent positive pressure ventilation
C Optimize the inspiratory: expiratory ratio
D Increase the FIO2
E Positive end‐expiratory pressure (PEEP)
F Alveolar recruitment maneuvers ( ARM s)
G Aerosolized albuterol
VI Postoperative hypoxemia. A Causes
Pulmonary shunting may result from:
Airway obstruction
B Supplemental oxygen
Suggested Reading
Hypercarbia
I Causes of hypercarbia. A Decreased CO2 elimination
Inadequate ventilation
Decreased lung compliance
B Increased CO2 production
C Increased CO2 delivery to lungs
II Effects of hypercarbia on the cardiovascular system
A Mild increase in PaCO2 (55–65 mmHg) was associated with:
B Moderate increase in PaCO2 (75–85 mmHg) was associated with:
C Severe increase in PaCO2 (>90 mmHg) was associated with:
III Other effects of hypercarbia
IV Management of hypercarbia
Suggested Reading
Pulmonary Edema as a Consequence of Airway Obstruction
I Clinical signs
II Proposed pathogenesis
III Treatment
Suggested Reading
Endotoxemia
I Treatment of endotoxemic horses
II Drugs used in the treatment of endotoxemic horses. A Non‐steroidal anti‐inflammatory drugs (NSAIDs)
B Polymyxin B (PB)
C Lidocaine
D Dimethyl sulfoxide (DMSO)
Suggested Reading
Postanesthetic Myopathy
I Localized myopathy
A Contributing factors
B Pathogenesis. Decreased perfusion
Ischemic injury
Reperfusion of ischemic muscle
C Clinical signs
Laboratory data
Non‐dependent limb myopathy
II Generalized myopathy
A Clinical signs
B Pathogenesis
III Reducing the incidence of postanesthetic myopathy
Dantrolene
IV Sequelae
V Treatment
Suggested Reading
Neuropathy
I Factors contributing to peripheral nerve damage
II Radial nerve injury. A Clinical signs
B Sequelae
C Outcome
III Femoral nerve injury
A Clinical signs
B Sequelae
IV Peroneal nerve injury
A Clinical signs
B Sequelae
V Facial nerve injury (see Figure 38.4)
A Clinical signs
B Sequelae
VI Spinal cord myelomalacia
A Clinical signs
B Sequelae
VII Myelogram associated neuropathy
VIII Cerebral cortical necrosis
A Clinical signs
B Sequelae
IX Treatment of peripheral neuropathies
Suggested Reading
Hyperkalemic Periodic Paralysis (HYPP)
I Introduction
A Triggers for HYPP
II Pathogenesis
III Clinical signs. A Awake horses
B Anesthetized horses
IV Laboratory findings
Diagnosis
V Perioperative preparation and anesthesia. A Owner education
B Diuretic therapy prior to anesthesia
C Patient evaluation
D Pre‐anesthetic sedation
E Anesthesia
VI Intraoperative monitoring
VII Managing an episode of HYPP during anesthesia
A Hyperkalemia (for a more complete description see Chapter 31)
Calcium borogluconate
Dextrose
Insulin
Dobutamine
Hypertonic saline
β2agonists
Sodium bicarbonate
B Hyperthermia
C Decrease PaCO2
VIII Recovery
Suggested Reading
Malignant Hyperthermia
I Introduction
II Clinical signs and immediate diagnostic findings
III Diagnosis
IV Treatment
V Prevention
Suggested Reading
Delayed Awakening and Recovery
I Delayed awakening
A Patient factors. Age
Hypothermia
Genetic factors
Body condition score
Comorbidities
B Drugs
C Anesthesia‐associated pathological changes
II Surgically‐induced pathological changes
III Management of delayed awakening
Suggested Reading
Paraphimosis and Priaprism
I Definitions. A Paraphimosis
B Priapism
II Causes of Paraphimosis and Priapism
III Signs of paraphimosis
IV Signs of priapism
V Treatment for paraphimosis
VI Treatment for priapism
A Sequelae to priapism
Suggested Reading
Anaphylactic and Anaphylactoid Reactions
Anaphylactic reactions
Incidence
Causes
II Anaphylactoid reactions
Incidence
Causes:
III Clinical manifestations
IV Diagnosis
V Treatment
Intra‐carotid and Perivascular Injections
I Factors contributing to intracarotid injection
II Verification of jugular puncture
III Sequelae of failed jugular injection. A Hematoma formation
B Recurrent laryngeal nerve damage
C Horner's syndrome
D Esophageal injury
E Tissue slough or abscess
IV Signs and sequelae of intracarotid injection
A Responses to intracarotid injection
B Treatment
C Prognosis
Equine Cardiopulmonary Resuscitation
I Introduction
II Causes of cardiopulmonary arrest in horses
Foals
III Components of CPR
A Preparedness and prevention. Personnel training:
Equipment:
Foals:
B Basic life support
Chest compressions:
D Post‐arrest care and monitoring
IV Conclusion
Suggested Reading
39 Recovery from Anesthesia
I Risk of morbidity and mortality during recovery
II Predisposing risk factors
III Unassisted vs. assisted recovery
IV Recovery stalls. A Structural features designed to optimize conditions for recovery
B Useful design features for various methods of assisted recovery
V Pre‐recovery preparation
VI Recovery phase. A Positioning and padding
B Sedation and analgesia
C Ensure a patent airway and administer oxygen (see “Airway Management” Chapter 3)
D Other
VII Methods of recovery
A Unassisted recovery
B Personnel within recovery stall assisting horse manually
Technique
C Head and tail rope recovery (see Figure 39.4)
Requirements
Technique
D Deflating air pillow (see Figure 39.2)
Technique
E Large animal vertical lift (LAL) or alternatively the Becker Sling (see Figure 39.7)
F Sling recovery
Technique
Available sling systems
G Pool Recovery
Available pool systems
Suggested Reading
40 Euthanasia
I Important considerations. A Location
B Insurance
C Permission
D Secondary veterinary opinion
E Welfare issues
F Written consent
G Verbal consent
H Written records
I Postmortem examination
J Disposal of the body
K Grief and owner considerations
II The ideal euthanasia solution
III Techniques
A Hypoxia‐inducing agents
B Central nervous system (CNS) depressant drugs
C Adjunctive injectable methods of euthanasia
Potassium chloride (KCl)
Box 40.1 Potassium Chloride (Preparation for Euthanasia)
Magnesium sulfate (MgSO4)
Box 40.2 Magnesium Sulfate (Preparation for Euthanasia)
Intrathecal lidocaine hydrochloride
D Physical method of euthanasia that result in brain damage. Free Bullet
Captive bolt (see Figure 40.3)
IV Confirmation of death
Suggested Reading
Index. a
b
c
d
e
f
g
h
i
j
k
l
m
n
o
p
q
r
s
t
u
v
w
x
y
z
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