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188 Cards in this Set
- Front
- Back
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Atropine |
Anticholinergic
Increases heart rate NOT an anesthetic or analgesic Often the first drug used in cardiac arrest (Faster, more potent and doesn't act as long) Does cross the blood brain barrier, which may prolong CNS effects of other drugs. Short onset, short duration (vs glycopyrrolate) |
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Glycopyrrolate
(Category, Major benefits/uses, Major negative side effects, Where metabolized/excreted, Reversal agent) |
Anticholinergic
Increases heart rate NOT an anesthetic or analgesic NOT used for cardiac arrest b/c it has a longer onset than atropine Does NOT cross blood brain barrier or placenta Recommended over atropine in sight hounds, very lean/sick animals, C-sections, head injury or brain lesions. |
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Anticholinergics
(Drugs, Major benefits/uses, Major negative side effects, Where metabolized/excreted, Reversal agent) |
Atropine, Glycopyrrolate
Increases heart rate NOT an anesthetic or analgesic Decrease gut motility and stomach acidity (fighting is not the time to res or digest). Cause pupilary dilation (to increase vision for flight). Bronchial dilation (to increase oxygenation to skeletal muscle for fighting or fleeing). |
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Tranquilizers
(Drugs, Major benefits/uses, Major negative side effects, Where metabolized/excreted, Reversal agent) |
Phenothiazines, Benzodiazepines, Alpha-2 Agonists
Main Purpose - Calm, Ease anxiety and quiet a patient Also called sedatives or neuroleptics Depresses the CNS Depresses motor activity Decreases the amount of general anesthesia No analgesic effect (alpha-2 agonists are the exception) |
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Phenothiazines
(Drugs, Major benefits/uses, Major negative side effects, Where metabolized/excreted, Reversal agent) |
Acepromzaine
Vasodilate Potent sedatives, very good calming effect, good muscle relaxation Antiarrhythmic Antiemetic No reversal agent and long duration Good for sight hounds |
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Uses of Phenothiazines
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Pre-op or post-op for calming effect, relaxation during maintenance
Not used repeatedly during induction or maintenance b/c they are long acting |
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Alpha-2 Agonists
(Drugs, Major benefits/uses, Major negative side effects, Where metabolized/excreted, Reversal agent) |
Xylazine (Rompun)
Stimulates A2 receptors in the brain causing sedation and analgesia Negative Side Effects - bradycardia and significant reduction in cardiac output. Causes vasoconstriction which causes an initial increase in BP, then pressure drops due to reduction in cardiac output. Has analgesic properties Causes vomiting in cats when used with other drugs Poor mm color Reversal Agent - Yohimbine (A2 Antagonist) |
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Uses of Alpha-2 Agonists
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Short procedures due to rapid onset, short duration and reversibility
Good for aggressive or fractious patients Should only be used in healthy patients Not good for old guys, very good for aggressive dogs. |
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Benzodiazepines
(Drugs, Major benefits/uses, Major negative side effects, Where metabolized/excreted, Reversal agent) |
Diazepam (Valium)
The most safe for sick patients, but the least effective for healthy ones. No analgesia. Good muscle relaxants. Used to add to sedation, but often causes agitation Very effective anticonvulsant Minimal cardiovascular and respiratory effects, safe for debilitated animals. Stimulate appetite Reversal Agt - Flumazenil |
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Xylazine
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Rompun
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Diazepam
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Valium
NOT water-soluble Does not mix well with other drugs (most are water soluble) Is painful on IM injection Not absorbed well IM |
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Uses of Benzodiazepines
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IM as part of a pre-med
IV with other drugs for induction/maintenance of general anesthesia/sedation IV as an anticonculsant |
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Opioids
(Drugs, Major benefits/uses, Major negative side effects, Where metabolized/excreted, Reversal agent) |
Morphine, Methadone, Hydromorphone, Fentanyl
MOST POWERFUL ANALGESICS IN THE WORLD! Main function is to provide pain relief Often causes decrease in heart rate Can cause Respiratory Depression Metabolized by liver Reversal Agt - Opioid antagonists |
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Mu Receptors
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Potent Analgesia
Sedation Decreased Respiration Decreased HR Euphoria/Dysphoria |
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Kappa Receptors
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Moderate analgesia
Sedation Much less respiratory depression Much less dysphoria |
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Uses of Opioids
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Preop for analgesia, sedation and easier restraint
Induction to help allow intubation Maintenance - Pain relief Post op - pain relief In combo w/a tranquilizer, opioids provide sedation for procedures in which general anesthesia is not necessary |
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Morphine
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The first opioid made from opium and is the standard against which new analgesics are compared.
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Hydromorphone, Methadone (and Morphine)
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Pure
Can give IM or IV Often used as a pre-op Part of IV induction, maintenance and post-op analgesia |
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Fentanyl
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Very short acting
Constant rate IV infusions are used for debilitated patients. Transdermal patch provides analgesia for several days. |
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Naxloxone
(Category, Major benefits/uses, Major negative side effects, Where metabolized/excreted, Reversal agent) |
Opioid Antagonist (Mu & Kappa)
No effects other than reversing opioids Restores resp function, HR, consciousness and pain sensation Can administer repeated doses if needed |
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Butorphanol
(Category, Major benefits/uses, Major negative side effects, Where metabolized/excreted, Reversal agent) |
Opioid Agonist-Antagonist (Kappa agonist & Mu antagonist)
Provides mild pain relief for a short period of time (about 45 mins) Creates less rep/cardio depression vs a pure opioid agonist Can be reversal for opioid agonist w/o reversing analgesia There is a ceiling or max effect that cannot be enhanced as higher doses are given |
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Buprenorphine
(Category, Major benefits/uses, Major negative side effects, Where metabolized/excreted, Reversal agent) |
Partial Agonist (Partial mu agonist)
Provides moderate pain relief Slow onset (1/2 hr given any route) long duration Has a "ceiling effect" |
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Neuroleptanalgesia
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Tranquilizer + Analgesic (Opioid) = the two together will make the other more effective
This is beneficial b/c the negative side effects of each drug are reduced, while the positive effects are maximized. Acepromazine (?) |
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Dissociogenics
(Drugs, Major benefits/uses, Major negative side effects, Where metabolized/excreted, Reversal agent) |
Ketamine
Cause overstimulation of the sense, and thus "separate" the mind from the body. Causes hallucinations Derived from PCP or "angel dust" Overstimulate the CNS Muscles will be rigid if a tranq is not added. Neg - Increase HR and BP Excreted thru kidneys Stormy recoveries Can't reverse |
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Uses of Dissociogenics
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A pre-op for cats, exotic cats, primates and other wild animals since it provides immobilization
An IV induction agent A part of a CRI to add to analgesia during or after a procedure |
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Stages of Anesthesia
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I - when the induction drug is started, as the patient begins to lose consciousness
II - May see delirious behavior, uncontrolled movement, increased HR and respiration III - Surgical anesthesia. May be further broken down into light to deeper planes of anesthesia IV - w/o respiratory and cardiovascular support, will result in death |
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Patient Factors Affecting Uptake & Distribution
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Body Composition
Changes in circulation Liver & kidney function Dose and rate of admin Plasma protein level pH of blood and tissues |
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Thiopental
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Off the market
Ultra-short acting barbiturate Avoided or used with extreme caution in - Heart problems, shock, anemia, hypoproteinemia, acidosis, neonates/geriatrics, very thin animals, sighthounds |
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Vet use of barbiturates
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Sedation
Anticonvulsant therapy Euthanasia |
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Propofol
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White, milky substance
Used all the time for anesthesia No analgesia Causes hyptension and resp depression Titrate slowly to minimize such effects Handle aseptically and discard after using Good for short procedures Vasodilator |
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Etomidate
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Minimal cardiovascular effects
Often causes vomiting/gagging Never use alone Does NOT provide analgesia |
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Local Analgesics
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Lidocaine
All are analogs of cocaine Cause loss of sensation Toxic at high doses Can be administered topically, locally, regionally, epidural or spinal blockade |
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Types of blocks
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dental, ring block, line block, tntra-articular block, brachial plexus block, epidural
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Neuromuscular Blocking Agents
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Pancuronium
Paralyzing agents Used for procedures where you don't want patient breathing on its own. Used more in large animals. |
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Sequence of paralysis
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Face
Tail Limbs Throat Abdomen Intercostals Diaphragm |
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Inhalant Anesthetics
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Drugs (gases or vapors) given via lungs instead of injected.
Also eliminated by the lungs to a varying extent (depending on the particular agent). Safe and easily controlled. |
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Uptake and Distribution of Inhalant Anesthetics
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Inhaled anesthetic molecules diffuse from the alveoli to the capillaries.
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Soluble agents...
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will take longer to build up effective blood level due to this redistribution.
Cells The more soluble the gas, the more that is absorbed by the tissues and the long it takes to reach effective brain levels (slower onset). |
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Insoluble agents...
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will have a more rapid onset than soluble agents.
Blood |
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MAC
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Minimum alveolar concentration
The minimum concentration needed for a mildly painful stimulus, a surgical plane of anesthesia requires achieving a higher percent. 1.3 MAC - adequate for light surgical anesthesia 2 MAC - may be necessary for deep surgical anesthesia for very painful procedures. MAC also varies depending on many factors such as individual differences in vigor and amt of injectable agents on board MAC values are different in different species. |
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Inhalant Anesthetic Agents
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Isoflurane & Sevoflurane
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Isoflurane
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Causes vasodilation and resultant hypotension
MAC 1.3% (dog), 1.6% (cat) Not an analgesic Slightly more rapid induction/recovery than halothane, due to lower solubility |
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Sevoflurane
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MAC - approximately 1% higher than isoflurane
Slightly more rapid induction/recovery than isoflurane, due to lower solubility. More pleasant odor to inhale. |
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Major components of the inhalant anesthesia machine
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I - The O2 delivery system
II - The vaporizer III - The breathing circuit IV - The scavenging system |
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O2 Tank
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Contains compressed O2 gas.
Explosive - tanks are under pressure and oxygen supports combustion; handle tanks with care, store in a cool, secure area, in a rack or chained in place Full tank - 2200 psi |
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Flow meters
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The O2 flow is calculated from the animal's body weight.
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Precision Vaporizer
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the operator can dial a specific desired concentration.
Isoflurane vaporizers are marked for 0-5%. A dial setting of 3% means that the gas mixture leaving the vaporizer contains 3% isoflurane and 97% oxygen |
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Inhalation/Exhalation Valves
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Unidirectional valves that control the flow of gases thru the circle, so that exhaled gases are not rebreathed before the CO2 is removed.
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Breathing Hoses
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Corrugated to prevent crimping but allow suppleness for positioning.
There is an inhalation and exhalation hose. |
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"Y" Piece
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Adaptor that connects the E-tube to the breathing hoses.
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Rebreathing bag
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Also called the Reservoir Bag
Serves to provide a volume of air to be available as the animal takes a breath. The bag slightly deflates when the animal inhales and inflates when the animal exhales. It can also be used to manually ventilate for the animal. |
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Pop-off Valve
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Allows excess gas to escape from the circle.
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Soda Lime Canister
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Converts the CO2 from the exhaled gases but allows the O2 and the agent to pass thru.
Will turn blue when saturated. Should be changed at least 1x/month (horses need to be changed everyday) |
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Dilution (semi-closed system)
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Any excess gas that leaves the circuit thru the pop off valve, brings exhaled CO2 with it.
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Chemical conversion by the soda lime (semi-closed system)
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the exhaled gases that do re-circulate back to the patient travel thru the soda lime canister before getting back to the patient.
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Nonrebreathing systems
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Delivered gases go to the patient, are inhaled, exhaled and scavenged out of the system.
There is no rebreathing of exhaled gases. |
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2 Main Reasons to use the nonrebreathing systems on very small animals (less than 3-5 kg)
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No valves are present in this system. Valves may create resistance to breathing for very tiny animals.
There is less dead space (area wher emixing of exhaled and inhaled gases occurs) in this system. |
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Scavenging Systems
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Remove excess or waste gases from immediate environment.
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The Scavenger Hose may take the gases to
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A canister of activated charcoal (F/Air canister).
The outside environment. |
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Tidal Volume
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What you breath
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Depth of Anesthesia
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Level of conscousness
Pain sensation Muscle tone Reflexes |
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Metabolic Status
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Cardiovascular function
Respiratory function Other Systems (Kidney, brain) |
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Patient Evaluation should include
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History
Current PE Current BW EKG, radiographs and other relevant diagnostics Past anesthesia records Handling the patient yourself: palpate pulses, judge temperament. |
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The anesthetist should be familiar with
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Age, breed, sex
Physical condition - hydration, nutrition, respiratory and cardiovascular status Disposition Areas of pain and degree of pain Previous illnesses, existing diseases Exposure to drugs, medication Allergies to drugs Blood type Recent feedings |
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The anesthetist should be prepared with
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Calculations for drugs that may be needed: ER drugs, reversal agents
Equipment should be checked for proper functioning and readily accessible. Thinking ahead and preparing for problems that could arise with a particular patient. |
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Large Dog HR
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60 - 120 bpm
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Small dogs HR
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80 - 140 bpm
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Cats HR
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120 - 200 bpm
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Systolic BP
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85 - 160 mmHg
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Diastolic BP
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40 - 90 mmHg
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Mean BP
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60 - 120 mmHg
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Normal Blood Volume
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60 ml/kg (cat) - 90 ml/kg (dog)
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Tidal volume
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10 - 15 mls/kg
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Eye position
Light plane Moderate Surgical plane Too deep |
Looking forward, brisk blink
rotated ventromedially, no blink Rotated halfway up again; no blink Central again but no blink |
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Process of intubation
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Injectable
Inhalation Mask Chamber |
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What are the 4 components (or goals) of Anesthesia?
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Loss of consciousness
Decreased sensitivity to pain Muscle relaxation Reduced reflexes |
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What does analgesia mean?
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Relief from pain
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What does balanced anesthesia mean?
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Using multi drugs in smaller quantities thereby maximizing desired effects & minimizing adverse effects.
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Describe 3 distinct purposes for a pre-med.
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Ease Anxiety
Provide restraint Provide pain relief |
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What occurs during the induction phase of anesthesia?
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Change the state of the patient from awake to anesthetized.
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What are 4 things to consider when choosing an anesthetic protocol?
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Type of procedure
Length of time Patient temperament Patient status - age, health |
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What are the 2 major types of side effects of anesthesia?
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Cardiovascular depression
Respiratory Depression |
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What type of drug is used to decrease vagal tone and therefore increase heart rate?
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Anticholinergics
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Name two types of anticholinergics.
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Atropine
Glycopyrrolate |
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Anticholinergics work by blocking the ____ Nervous System, which is part of the involuntary nervous system.
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parasympathetic
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Name a category of tranquilizers.
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Phenothiazines
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What is an example of a phenothiazine?
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Acepromazine
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Which tranquilizer is more likely to cause hypotension: acepromazine or valium?
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Acepromazine
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Which drug provides more analgesia: acepromazine or hydromorphone?
valium or morphine? |
Hydromorphone
Morphine |
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Name an alpha 2 agonist used for sedation in vet patients?
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Xylazine
Dex-Medetomidine |
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Which category of drugs used in anesthesia act at the body's natural endorphin receptors and are therefore potent analgesics?
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Opioids
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Describe effects of drugs in this category that are usually considered negative side effects.
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Behavioral effects are unpredictable
Can cause respiratory depression Can cause a decrease in HR |
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Name 2 drugs that are opioids.
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Morphine
Fentanyl |
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Name a pure antagonist for opioid.
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Naloxone
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Name an agonist-antagonist in opioids.
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Butorphanol
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Ketamine causes ____ of the CNS.
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Stimulation
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T/F
Ketamine is a tranquilizer |
False
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T/F
Ketamine provides muscle relaxation. |
False
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Ketamine aids in restraint.
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True
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What type of category of drug is ketamine?
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Dissociogenics
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Name 3 examples of patients in which ketamine should be avoided.
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Head trauma
Hyperthyroidism Renal disease |
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Which drug causes extensor rigidity, ketamine or acepromazine?
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Ketamine
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How can this extensor rigidity be counteracted?
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???
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The speed at which a drug is absorbed into the brain depends largely on what characteristic of the drug?
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Lipid Solubility
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The effect of one bolus of an ultrashort-acting drug such as propofol diminishes rapidly due to ____ of the drug into non-nervous tissue. What does this mean?
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Redistribution
The drug stays in the less vessel rich areas but animal wakes up due to lowered concentration in the vessel rich brain. |
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With regard to many anesthetic drugs, the amount of proteins that are contained in the plasma may affect dose needed, and depth of anesthesia produced. Explain.
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Anesthetic drugs will bind w/blood protein & are unable to affect brain & considered inactive. The amount of proteins therefore will affect the amount of unbound & active drug.
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What hypnotic is most sparing on the cardiovascular system?
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Etomidate
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Name an undesirable side effect of Etomidate.
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Respiratory depression
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What injectable anesthetic drug looks like milk, grows bacteria readily and can be injected IV to induce sleep?
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Propofol
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Name a beneficial property of propofol.
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Good for short procedures.
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Name 2 undesirable side effects of propofol.
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Repiratory Depression
Myocardial Depression |
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Artificial ventilation is always necessary in a patient given:
a neuromuscular blocking agent a local anesthetic an epidural block a neuroleptanalgesic a large order of fries |
A neuromuscular blocking agent
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Lidocaine is:
a local analgesic a barbiturate a neuroleptic an opioid a delicious soft drink |
a local analgesic
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How do local anesthetics alter the anesthetic protocol with regard to other drugs?
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Reduce systemic drug to reduce the effect of other drugs.
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A neuromuscular blocking agent:
may also be called a paralyzing agent may also be called a local anesthetic may also be called a muscle relaxant is a potent analgesic is a respiratory depressant |
may also be called a paralyzing agent
may also be called a muscle relaxant is a respiratory depressant |
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Four major components of general anesthesia are pain relief, reflex reduction, muscle relaxation and _____
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Loss of consciousness
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What are 3 groups of tranqs? Give an example of each one and name its reversal agent.
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Phenothiazines
Acepromazine None Benzodinzepines Diazepam Flumazenil Alpha-2 Agonists Xylazine Yohimbine |
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Name 3 drugs that are pure opioid agonists.
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Morphine
Hydromorphone Fentanyl |
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The primary use for opioids is:
muscle relaxation analgesia dissociation of mind from body a calming effect neurolepsis |
analgesia
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What is the pure antagonist reversal agent for opioids?
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Naloxone
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What is the group of drugs that are used to counteract stimulation of the parasympathetic NS, and therefore prevent bradycardia? Ex?
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Anticholinergics
Atropine |
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Propofol is used in many IM pre-meds in both dogs & cats.
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False
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Propofol is a growth medium for bacteria.
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True
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Plasma proteins influence the effect of propofol.
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True
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Rapid induction with propofol is due largely to its solubility in fat.
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True
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The major cardiovascular side effect of Propofol is vasoconstriction.
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False.
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Lidocaine is:
a dissociogenic a local anesthetic a neuroleptic an opioid |
a local anesthetic
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Name a drug that has all of the following characteristics:
used to aid in restraint increases CNS stimulation Can cause hallucinations and stormy recoveries |
Ketamine
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A neuromuscular blocking agent may cause severe respiratory depression.
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True
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A neuromuscular blocking agent will provide analgesia.
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False
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A local anesthetic may be used to provide regional analgesia.
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True
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Describe at least 3 benefits of using intubation and inhalant anesthesia as compared with injectable drugs?
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Rapid induction & recovery, easy to control the level of anesthesia, easy to control drug eliminations.
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Diffusion of gases occurs across the thin membrane between ____ and pulmonary capillaries into the blood. Diffusion occurs from areas of ____ concentration to areas of _____ concentration. Once inhalant molecules are in the blood they travel to _____ and cause loss of consciousness.
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alveoli
greater lesser brain |
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Describe the mechanism of recovery from inhalant anesthesia.
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Shut off inhalant, drug will leave brain & tissue, ret into circulation & exhale thru the lungs.
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The degree to which inhalants are stored in the tissues is dependent upon what characteristic of the inhalant?
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Solubility
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What are the percents of each gas in the atmosphere?
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Nitrogen - 79%
Oxygen - 21% CO2 - 1% |
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How does the solubility (in blood or tissues) of an inhalant anesthetic affect the speed of induction and recovery?
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The more soluble the gas, the more that is absorbed by the tissues and the longer it takes to reach effective brain levels (slower onset).
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What is the major negative cardiovascular side effect of both isoflurane and sevoflurane?
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Vasodilation
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What is meant by the term MAC and why do we need to know that?
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Minimum alveolar concentration - comparing doses of various agents to determine the effective dose for a particular anesthetic.
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What is the MAC value for the following:
Isoflurane in dogs Sevoflurane in dogs Isoflurane in cats Sevoflurane in cats |
1.3%
2.3% 1.6% 2.6% |
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The amount of inhalant a patient needs depends on which of the following?
Cardiovascular status Body condition (fat vs. thin) amount of pre-medication given species eye color |
Cardiovascular status
body condition (fat vs thin) amount of pre-medication given |
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What is used to dial in O2 flow?
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Oxygen flow meter
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What allows excess gases to escape from the breathing circle?
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Pop-off valve
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What controls one-way flow of circle system?
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Inhalation & exhalation valve
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What converts CO2?
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Soda-lime cannister
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What holds the liquid anesthetic?
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Vaporizer
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What holds a reservoir of air for large inspirations and can be used to deliver positive pressure ventilation?
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Rebreathing bag
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In a circle system with the vaporizer "out-of-the-circuit" when the vaporizer setting is kept at the same number, changing the oxygen flows will change the concentration of inhalant the patient actually inspires. Why is this?
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Increase flow O2 will quickly take fresh gases to the patient and will be closer to the % of anesthetic dialed in.
Low O2 flow takes longer to reach the patient and will be mixed with gases that prev occupied the circuit. |
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What are 2 reasons for using a non-rebreathing circuit?
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No valves are present in this system.
There is less dead space in this system. |
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What oxygen flows must be used on a non-rebreathing system and why?
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No soda lime, so system relies on O2 pushing CO2 away from patient.
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What are 2 disadvantages to the patient, of having to use these flows?
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Economy
Cool gas |
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Describe 3 different ways to check to be sure your endotracheal tube is correctly placed? (in the trachea, not the esophagus)
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Condensation in the tube. Check mucous membranes. Look at the air bag to make sure it fills up with air completely & completely releases air.
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What problem can occur if an endotracheal tube is inserted too far down into the airway?
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Too long ET tube will inflate only 1 side and the other side would not receive any oxygen.
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What is the problem with an endotracheal tube that is excessively long at the machine end of the tube?
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Dead space is too great.
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What is a problem with an overinflated cuff on an endotracheal tube?
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Tracheal tearing
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What is a problem with an underinflated cuff?
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Doesn't keep things out of lungs.
Exhaled air goes into the environment. |
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Describe the flow of Oxygen in the anesthesia machine.
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Starts at tank, goes thru vaporizer, into inspiratory side, to patient, out of patient to expiratory side, out pop off to scavenger and passes thru F/Air canister into environment.
Also goes out of patient to expiratory side and then thru soda lime canister and back to inspiratory side. |
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Describe the flow of Inhalant in the anesthesia machine.
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Starts as vaporizer, goes into inspiratory side to patient, out of patient to expiratory side, out pop off to scavenger and stays in F/Air canister
Also goes from expiratory hose and then thru soda lime canister and back to inspiratory side. |
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Describe the flow of Carbon Dioxide in the anesthesia machine.
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Starts from patient, goes expiratory side, out pop off to scavenger and passes thru F/Air canister into environment
Also goes from expiratory hose and then to soda lime canister and does not pass thru to inspiratory side. |
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If the vaporizer setting is at 2%, which oxygen flow would deliver the most inhalant into the circuit?
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2 liters/minute
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Describe 2 ways of getting rid of CO2 from the patient breathing circuit.
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Chemical conversion in soda lime
High O2 flows pushing it out pop-off to scavenger |
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Describe 2 methods by which waste gases may be scavenged from a gas anesthetic machine.
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Absorbed by F/Air can
Taken to outside environment thru active suction or passively routed. |
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In a circle system attached to a patient, if you see the rebreathing bag expanding such that there is positive pressure in the bag, what should you do?
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Open pop-off valve
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What are two reasons to use the non-rebreathing circuit?
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It minimizes the amount of area in which exhaled air can mix with the air to be inspired
Easy to breathe against b/c there are no valves. |
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Why must VERY high oxygen flows be used in this system?
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There is no soda lime in this system. The only way that CO2 is removed from the air that the patient will breathe is b/c of the high flow of new gases (O2 w/inhalant) coming in. So the oxygen flows must be high enough to push the gases up the hose, away from the patient.
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Describe the meaning and importance of "tissue perfusion"
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How well blood is getting to the tissues. Blood brings O2 and nutrients, and takes away CO2 and waste products. Adequate perfusion is necessary for tissue (and patient survival) and must be maintained during anesthesia.
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What are 2 simple tests that can be done to assess tissue perfusion?
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CRT
MM moistness |
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A mean BP of less than ___ will compromise blood flow to the kidneys.
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60 mmHg
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A diastolic BP of less than ____ will compromise perfusion of the cardiac muscle.
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40 mmHg
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All of the following can be used to assess BP, with the exception of:
Doppler EKG Dinamap Arterial line Pulse palpation |
EKG
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What are the main factors that make BP what it is?
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Heart: rate and contractility
Vascular tone (constriction/dilation) Blood volume |
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What are 3 causes of hypotension (low BP) during anesthesia?
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Myocardial depression (decreases rathe and/or contractility)
Vasodilation Hypovolemia |
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What are the first 3 steps in anesthetist should do to correct hypotension in an anesthetized patient?
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Turn down inhalant
Ventilate with lower concentration (or pure O2) to force elimination of inhalant anesthetic Give fluid bolus. |
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What effect does vagal stimulation have on the heart?
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Decreases rate
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Describe 3 different stimuli which may cause a vagal response?
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Manipulation of eye
Manipulation of viscera Intubation |
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It is the level of ___ in the blood that is the main stimulus for respiration. Normally, as this level rises above ____ mmHg, a breath is taken, and the level drops back down.
How does this change under anesthesia? |
CO2
45 The threshold is reset to a higher level before breathing is initiated. |
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What piece of equipment is used to indicate arterial carbon dioxide blood levels?
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End tidal CO2 monitor (Capnograph)
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What does "tidal volume" mean?
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Volume of air in one breath
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What is the tidal volume (range) of a 20 kg dog?
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200 - 400 mls
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What is the tidal volume (range) of a 5 kg cat?
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50 - 100 mls
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An occasional "sigh" should be given to patients under anesthesia, even when they are breathing at a regular rate. Why?
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There is no sigh reflex under anesthesia, and lungs will become atalectatic (areas not expanded). Large breaths will help to open alveoli and improve gas exchange.
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Pulse ox and blood gas analysis are both used to measure oxygenation. How are they different in what they measure?
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Pulse ox measures the amount of arterial hemoglobin that is saturated w/O2.
Blood gas analysis measures the dissolved oxygen content in the blood. |
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What are approx normal values (dog or cat) for pulse ox and blood gas?
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Pulse ox - 95 - 100%
Blood gas - Oxygen PaO2: 85 - 100 mmHg |
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Why do we measure End Tidal CO2?
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To assess effectiveness of ventilation
To indicate arterial CO2. |
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A dog at a good surgical plane of isoflurane anesthesia will have:
Relaxed jaw, slow eye blink, slight ear reflex Moderate jaw tone, no eye blink, a strong swallow reflex Eyes central, brisk blink, little jaw tone Relaxed jaw, no blink, eyes rotated The dog will wink at you and lick your hand |
Relaxed jaw, no blink, eyes rotated
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Name 3 ways of alleviating post-op excitement
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Wrap up patient securely in blankets (swaddle)
Reversal agents Sedatives and/or pain medication |
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Discuss "multi-modal" anesthesia.
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Using several different methods of prevention or treatment of pain, to interrupt the pain pathway from more than one approach.
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Discuss "pre-emptive" analgesia.
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Administering pain medication before the onset of pain, such as before surgery, or before the patient is aware of intense pain post-op.
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