VEM027 Lecture 2.2: Veterinary Anesthesia PDF

Drugs acting on the: Central Nervous System DEAN SIDNEY S. LEYSON, DVM Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved.  Anesthetics Anesth...

Drugs acting on the: Central Nervous System DEAN SIDNEY S. LEYSON, DVM Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved.  Anesthetics Anesthesia A reversible condition achieved through pharmacological or other methods, resulting in the loss of sensation and/or consciousness. Anesthesiology The art and science of administration of anesthesia and managing vital functions before, during, and after surgical and medical procedures. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved.  Anesthetics Objectives To minimize or eliminate pain To relax muscles and facilitate patient restraint during surgical, obstetrical, and other medical, diagnostic, and therapeutic procedures. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved.  Types of Anesthesia General vs Local The patient loses Only a specific body region consciousness with lowered loses sensation and motor sensitivity to stimuli from function, without affecting the environment and consciousness. diminished motor response to such stimuli. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved.  Balanced Anesthesia Using multiple drugs in low doses to enhance desired effects while minimizing the risk of adverse reactions. Ex: Xylazine + Zoletil Xylazine + Ketamine Acepromazine + Fentanyl Midazolam + Hydromorphone Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved.  Balanced Anesthesia Components: 1. Sensory blocking – analgesia Morphine, Ketamine, Fentanyl 2. Motor blocking – muscle relaxation Xylazine, Barbiturates, Guaifenesin 3. Mental blocking – unconsciousness & amnesia Phenothiazines, Neuroleptics, Ketamine 4. Reflex blocking – minimize ANS response Atropine, Barbiturates, Glycopyrrolate Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved.  Anesthesia Stages: 1. Stage I – Stage of Voluntary Excitement 2. Stage 2 – Stage of Involuntary Excitement 3. Stage 3 – Stage of Surgical Anesthesia 4. Stage 4 – Stage of Medullary Paralysis/Overdose Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved.  Anesthesia Stages Conscious Reflexes Muscle Respiration HR Tone I ✓ ↓ ↓ Normal Normal II ✓ ↑ ↑ Irreg ↑ III x ↓/x ↓/x Reg, slow ↓ IV x x x Absent/ ↓/x Irreg Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved.  Anesthesia Stage Characteristics I The patient is awake and may resist, showing fear and anxiety through increased heart rate, breathing, and physical responses like pupil dilation, urination, and defecation. II The patient loses consciousness but may exhibit involuntary movements, vocalization, and irregular breathing. The patient may also struggle violently, regardless of their normal temperament. III Plane I The patient is unconscious with absent reflexes and involuntary eye movements. Breathing is irregular, but muscle movement has stopped. This stage may be suitable for minor surgical procedures. Plane 2 Laryngeal reflex diminishes, eyes fixate, and muscle relaxation begins. Suitable for most surgeries except abdominal procedures. Plane 3 Breathing becomes shallow and irregular with pauses between breaths. Suitable for abdominal procedures. IV The patient's breathing is labored and irregular, with the diaphragm struggling to function. Their pupils are very dilated, indicating a deep level of anesthesia. Riskand/or Any unauthorized reproduction is distribution too great forisany of this document procedures. punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Anesthetics Pre-anesthetics Inhalant Anesthetics Opioids Gases Tranquilizers Alkanes Anticholinergic Agents Ethers Central Muscle Relaxants Injectable Anesthetics Local Anesthetics Barbiturates Esters Cyclohexylamines Amides Propofol Etomidate Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Pre-anesthetics Opioids Tranquilizers Anticholinergic Agents Central Muscle Relaxants Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Pre-anesthetics Purpose: Smooth induction Reduce anxiety Pain relief Inducing amnesia Counteracting side affects Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Pre-anesthetics Opiods Anticholinergics Atropine Glycopyrrolate Central Muscle Tranquilizers Relaxants Guaifenesin Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Anticholinergics MOA: Antagonizes acetylcholine (ACh) at the muscarinic receptors. Indications: Reduce salivary and respiratory secretions caused by anesthetic agents. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Anticholinergics Atropine Unique Characteristics: a competitive and nonselective antagonist of ACh at muscarinic receptors. Tertiary amine that is the prototype for all antimuscarinic drugs. Obtained from deadly nightshade (Atropa belladonna). Goats and rabbits are resistant (Atropinase). Cattle are quite resistant if administered PO. Use parenteral routes instead. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Anticholinergics Atropine Unique Characteristics: Not required in horses unless absolutely necessary (renal & biliary colic w/ opioids). Was used in ophthalmic procedures to induce mydriasis. Tx of organophosphate & carbamate poisoning together with Pralidoxime, and muscarine poisoning. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Anticholinergics Glycopyrrolate Unique Characteristics: “Glyceryl guaiacolate” A synthetic quaternary ammonium. 5x more potent than atropine as anti-sialagogue. Less CNS and cardiovascular effects than atropine. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Pre-anesthetics Opiods Anticholinergics Atropine Glycopyrrolate Central Muscle Tranquilizers Relaxants Guaifenesin Methocarbamol Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. CMRs MOA: Block internuncial neurons which are responsible for polysynaptic reflexes. Pharmacologic Effects: Induce temporary paralysis of skeletal muscle They do not markedly depress the CNS. Sedation & tranquilization w/o loss of consciousness. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. CMRs Guaifenesin Unique Characteristics: Used in humans as an oral expectorant. Used IV with thiobarbiturates and ketamine for induction of anesthesia in horses, cattle, and swine for short procedures. Causes occasional allergic-reaction to horses (urticaria). DO NOT USE with anticholinesterase agents (Neostigmine, Physostigmine, Edrophonium). Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. CMRs Methocarbamol Unique Characteristics: Guaifenesin-analog with similar effects to guaifenesin. Used adjunctively to treat muscle inflammation and spasms, such as in canine intervertebral disc disease (IVDD), equine rhabdomyolysis, and pyrethroid toxicity. Used only PO and IV. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Pre-anesthetics Opiods Anticholinergics Atropine Glycopyrrolate Central Muscle Tranquilizers Relaxants Guaifenesin Methocarbamol Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Pre-anesthetics Opiods Anticholinergics Atropine Glycopyrrolate Central Muscle Tranquilizers Relaxants Guaifenesin Methocarbamol Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Anesthetics Pre-anesthetics Inhalant Anesthetics Opioids Gases Tranquilizers Alkanes Anticholinergic Agents Ethers Central Muscle Relaxants Injectable Anesthetics Local Anesthetics Barbiturates Esters Cyclohexylamines Amides Propofol Etomidate Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Injectable Anesthetics Barbiturates Propofol Thiopental Methohexital Cyclohexylamines Etomidate Ketamine Tiletamine Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Barbiturates Thiopental Unique Characteristics: Ultrashort-acting. DOC in inducing anesthesia on patients with increased intracranial pressure. Administered only IV in all species. Commonly administered with guaifenesin in large animals. Prolonged recovery in greyhounds and other sighthounds. Use always with intubation. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Barbiturates Methohexital Unique Characteristics: Ultrashort-acting, more potent than thiopental. Safe for use in greyhounds and other sighthounds. More likely to cause a period of excitement during induction and recovery than the thiobarbiturates. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Injectable Anesthetics Barbiturates Propofol Thiopental Methohexital Cyclohexylamines Etomidate Ketamine Tiletamine Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Cyclohexylamines Ketamine Tiletamine Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Dissociative Anesthesia characterized by analgesia and superficial sleep. The different levels of CNS seem to become dissociated from one another:  Depressed thalamoneocortical portion.  Enhanced limbic system. Animals are cataleptic – a state characterized by rigidity and partial extension of the limbs w/o loss of consciousness. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Cyclohexylamines Pharmacologic Effects: ↑/maintain heart rate ↑ blood pressure and cardiac output Respiratory depression ↑ cerebral blood flow, intracranial pressure Mydriasis Rapidly crosses the placenta Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Cyclohexylamines Ketamine/Tiletamine MOA: Blocks the action of excitatory neurotransmitters (ACh and glutamate) in the spinal cord and a powerful NMDA receptor antagonist. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Cyclohexylamines Ketamine Unique Characteristics: Schedule III drug, FDA-approved for humans, cats, and primates. Cats – “for restraint or sole anesthetic agent for diagnostic and minor/brief surgical procedures that do not require muscle relaxation.” Primates – “for restraint.” Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Cyclohexylamines Ketamine Unique Characteristics: Has significant analgesic activity and lacks cardiopulmonary depressant effects. Contraindicated in food-producing animals. Induces anesthetic stages I & II, but not stage III. Acidic drug with slow onset of action. Cat’s eyes remain open and should be protected from injury and an ophthalmic lubricant should be applied. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Cyclohexylamines Tiletamine Unique Characteristics: Better analgesic properties than ketamine. Usually prepared with zolazepam. Contraindicated in rabbits due to renal toxicity. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Injectable Anesthetics Barbiturates Propofol Thiopental Methohexital Cyclohexylamines Etomidate Ketamine Tiletamine Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Propofol MOA: Activates GABAA receptors. Unique Characteristics: An alkylphenol derivative unrelated to any other anesthetic drugs currently in use. Formulated in a 1% aqueous emulsion containing 10% soybean oil, 1.2% egg lecithin, and 2.25% glycerol. Ideal for outpatient cases due to rapid recovery. Safe for use in animals with head trauma. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Propofol Unique Characteristics: Short-acting agent with rapid and smooth induction. Repeated use in cats causes Heinz body anemia. Primary a hypnotic agent with poor analgesic properties. Tx/mgt for refractory status epilepticus. It should ideally be used in a single-use fashion as it is a good growth medium (contains no preservative) for bacteria. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Etomidate MOA: GABA-like effects. Depression of the activity and reactivity of the brainstem reticular formation system. Unique Characteristics: Ultrashort-acting, non-barbiturate sedative hypnotic drug. Wide margin of safety. IV injection may cause pain and hemolysis due to hypertonicity. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Etomidate Unique Characteristics: Myoclonus and excitement can occur either on induction or recovery. Negative inotropic drug due to inhibition of Ca2+ influx in the myocardial cells. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Injectable Anesthetics Barbiturates Propofol Thiopental Methohexital Cyclohexylamines Etomidate Ketamine Tiletamine Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Injectable Anesthetics Barbiturates Propofol Thiopental Methohexital Cyclohexylamines Etomidate Ketamine Tiletamine Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Anesthetics Pre-anesthetics Inhalant Anesthetics Opioids Gases Tranquilizers Alkanes Anticholinergic Agents Ethers Central Muscle Relaxants Injectable Anesthetics Local Anesthetics Barbiturates Esters Cyclohexylamines Amides Propofol Etomidate Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved.  Inhalant Anesthetics MOA: UNKNOWN Pharmacokinetics: Passive diffusion  Increasing either the inspired concentration of anesthetic or alveolar ventilation will increase the partial pressure in the alveolus. The drug diffuses from the alveoli into the blood and is circulated to all parts of the body. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved.  Inhalant Anesthetics Pharmacokinetics: Factors affecting diffusion: 1. Solubility of the anesthetic in the blood (blood:gas partition coefficient). 2. Cardiac output 3. Concentration (Dalton’s Law) 4. Difference in partial pressure (Henry’s Law) Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved.  Inhalant Anesthetics Pharmacokinetics: Minimum Alveolar Concentration (MAC):  The minimum alveolar concentration of an inhaled anesthetic that prevents movement in response to a painful stimulus in 50% of patients  Measures potency of inhalant anesthetics.  General Rule:  “The lower the MAC, the more potent the drug.” Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved.  Inhalant Anesthetics Pharmacokinetics: Minimum Alveolar Concentration (MAC):  In order of potency: Halothane > Isoflurane > Sevoflurane > Desflurane > Nitrous Oxide Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved.  Inhalant Anesthetics Pharmacokinetics: Blood:Gas Partition Coefficient (BGPC):  A measure of the solubility of an inhaled anesthetic agent in blood relative to its solubility in alveolar gas.  Measures how fast the onset of action of inhalant anesthetics.  General Rule:  “The higher the BGPC, the slower onset of action of the drug.” Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved.  Inhalant Anesthetics Pharmacokinetics: Blood:Gas Partition Coefficient (BGPC):  In order of onset of action: Desflurane > Nitrous Oxide > Sevoflurane > Isoflurane > Halothane Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved.  Inhalant Anesthetics Pharmacokinetics: Administration:  It is necessary to administer high concentrations to the lungs initially in order to establish the necessary partial pressure in the brain.  Most inhalant anesthetics are liquid at room temperature and requires a vaporizer to form a safe and accurate vapor concentration to be inhaled by the patient. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Inhalant Anesthetics Gases Ethers Nitrous Oxide Isoflurane Sevoflurane Desflurane Alkanes Halothane Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Gases Nitrous Oxide (N2O) Unique Characteristics: The “Laughing Gas” Odorless, non-flammable, inorganic gas at room temperature. Induction and recovery is rapid due to very low solubility. Cannot obtain surgical anesthesia alone. Only 50% potency in horses compared to humans. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Inhalant Anesthetics Nitrous Oxide (N2O) Unique Characteristics: Second Gas Effect Nitrous oxide can worsen hypoxemia in horses and cattle. Causes bloat/diffusion hypoxia when oxygen supply is immediately cut off after surgical procedures. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Alkanes Halothane Unique Characteristics: Colorless, non-flammable, sweet-smelling heavy liquid. First introduced in 1956 and heralded the arrival of the modern inhalation anesthetics. Seldomly used today as it was replaced by newer agents (ethers). Causes malignant hyperthermia (most notable in swine). Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Alkanes Halothane Unique Characteristics: DO NOT USE in patients with compromised hepatic function. DO NOT USE with sympathomimetics due to risk of ventricular arrhythmias. Hypotension may occur and is considered to be dosage related. Potential teratogenic properties. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Ethers Isoflurane Unique Characteristics: Halogenated methyl ethyl ether cleared for use in dogs and horses. A colorless liquid with a characteristic, pungent odor stored in a brown bottle. More preferred due to lessened myocardial depressant and catecholamine sensitizing effects. Safe to use in patients with hepatic or renal disease. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Ethers Isoflurane Unique Characteristics: More expensive than halothane. CONTRAINDICATED in patients with a Hx or predilection to malignant hyperthermia. Dose-dependent hypotension, respiratory depression, and GI effects may occur. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Ethers Sevoflurane Unique Characteristics: Similar to isoflurane, but more rapid induction and recovery. And more expensive. Clinically approved use in dogs. Not recommended use in rabbits (breath holding, struggling). Nephrotoxic in rats, but not in dogs. May react with soda lime in a gas machine that will result to fire and formation of CO. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Ethers Desflurane Unique Characteristics: The newest inhalant anesthetic approved for use in humans but very limited use in veterinary medicine. Effects are very similar to that of isoflurane. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Inhalant Anesthetics Gases Ethers Nitrous Oxide Isoflurane Sevoflurane Desflurane Alkanes Halothane Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Inhalant Anesthetics Gases Ethers Nitrous Oxide Isoflurane Sevoflurane Desflurane Alkanes Halothane Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Anesthetics Pre-anesthetics Inhalant Anesthetics Opioids Gas Tranquilizers Alkanes Anticholinergic Agents Ethers Central Muscle Relaxants Injectable Anesthetics Local Anesthetics Barbiturates Esters Cyclohexylamines Amides Propofol Etomidate Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved.  Local Anesthesia Local Anesthesia A state of reversible loss of pain sensation in a specific body area without loss of consciousness. Types: Surface/Topical Anesthesia Infiltration Anesthesia Peripheral Nerve Block Epidural/Intrathecal Anesthesia Neurolytic Anesthesia Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Local Anesthesia Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved.  Local Anesthetics substances that block nerve impulses in axons and dendrites. Chemical Structure: 1. An aromatic ring. 2. An intermediate chain (Ester/Amide) 3. Amino group Characteristics: Weak bases, usually insoluble in water, and unstable. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved.  Local Anesthetics MOA: Blocks the propagation of an action potential by inhibiting the influx of Na+ through voltage- gated Na+ channels. Therapeutic Uses: Local/Regional anesthesia Control of arrhythmias Facilitation of general anesthesia Treating intestinal hypomotility Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Local Anesthetics Esters Proparacaine Chloroprocaine Tetracaine Amides Lidocaine Mepivacaine Bupivacaine Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Esters Proparacaine Unique Characteristics: Used for desensitization of the cornea for ophthalmic procedures Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Esters Chloroprocaine Unique Characteristics: Indicated for intrathecal injection in adults for the production of subarachnoid block, spinal anesthesia, or ocular surface anesthesia. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Esters Tetracaine Unique Characteristics: Used to reduce pain and pruritus on skin and ears. Currently available in combination with lidocaine as a cream and patch. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Local Anesthetics Esters Proparacaine Chloroprocaine Tetracaine Amides Lidocaine Mepivacaine Bupivacaine Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Amides Lidocaine Unique Characteristics: The most used local anesthetic. Also known as Lignocaine HCl. Used to desensitize the larynx of cats prior to ET intubation. Used in combination with prilocaine to penetrate intact skin. Used to control premature ventricular contractions. Tx/Mgt for post-operative ileus in horses. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Amides Lidocaine Unique Characteristics: DO NOT USE in cats as antiarrhythmic due to sensitivity. DO NOT GIVE IV WITH EPINEPHRINE!! Not effective orally due to high first-pass effect. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Amides Mepivacaine Unique Characteristics: Slower onset of action but longer duration of action without vasoconstrictor compared to lidocaine. Lower potential for cardiovascular toxicity than lidocaine. More painful on injection than lidocaine. Not effective topically. More expensive than lidocaine. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Amides Bupivacaine Unique Characteristics: Long-acting local anesthetic, less potent than lidocaine. Chemically related to mepivacaine. Narrow therapeutic index. More toxic than lidocaine at lower concentrations. DO NOT GIVE IV Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Local Anesthetics Esters Proparacaine Chloroprocaine Tetracaine Amides Lidocaine Mepivacaine Bupivacaine Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Local Anesthetics Esters Proparacaine Chloroprocaine Tetracaine Amides Lidocaine Mepivacaine Bupivacaine Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Anesthetics Pre-anesthetics Inhalant Anesthetics Opioids Gases Tranquilizers Alkanes Anticholinergic Agents Ethers Central Muscle Relaxants Injectable Anesthetics Local Anesthetics Barbiturates Esters Cyclohexylamines Amides Propofol Etomidate Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Anesthetics Pre-anesthetics Inhalant Anesthetics Opioids Gases Tranquilizers Alkanes Anticholinergic Agents Ethers Central Muscle Relaxants Injectable Anesthetics Local Anesthetics Barbiturates Esters Cyclohexylamines Amides Propofol Etomidate Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved. Prepare for a 20-item quiz next meeting. Any unauthorized reproduction and/or distribution of this document is punishable by law. Ⓒ 2024 D.S. Leyson. All Rights Reserved.