Lec 1-2 Anasthesia Flashcards
What does the term ‘anesthesia’ mean?;
The term ‘anesthesia’ is derived from the Greek term ‘anaesthesia meaning ‘insensibility’
How is anesthesia induced?;
Anesthesia is induced by drugs that depress the activity of nervous tissue locally regionally
What are the key components of understanding anesthesia in veterinary practice?;
The key components include understanding the terms that describe the effects of anesthetic drugs in animals the pharmacology of anesthetic drugs and their antagonists
How was patient restraint achieved for anesthesia prior to 1540?; Patients were restrained by physical force as a method of anesthesia before 1540.
What physical trauma methods were used for anesthesia before 1540?; Physical trauma methods included inflicting a blow to the head
strangulation
What types of drugs were used for anesthesia before 1540?; Drugs such as alcohol
hashish
What was one method of anesthesia that involved the carotid artery?; Carotid artery compression was one method used for anesthesia prior to 1540.
What methods were used for anesthesia prior to 1540?; Prior to 1540
anesthesia was accomplished using drugs like alcohol
What physical methods were used to produce analgesia before 1540?; Rudimentary physical methods included packing a limb in ice or using a tourniquet.
How is general anesthesia defined?; General anesthesia is a state of unconsciousness produced by a process of controlled
reversible drug-induced intoxication of the CNS
What does analgesia imply in a conscious subject?; Analgesia implies diminished perception of pain in an otherwise conscious subject.
What are narcotics?; Narcotics are substances that can produce insensibility or stupor from which simple stimuli like noise can produce a temporary partial arousal. All anesthetics are narcotics
but not all narcotics are anesthetics.
What is narcosis?; Narcosis is a sleep-like state (unconsciousness) accompanied by varying degrees of analgesia.
What do hypnotics do?; Hypnotics are drugs that induce sleep from which the subject can easily be awakened by a wide variety of stimuli.
What is surgical anesthesia and what does it entail?; Surgical anesthesia is the loss of consciousness and sensation accompanied by sufficient muscle relaxation and analgesia to allow surgery to be performed without pain or movement by the animal.
What are ataractics and how do they differ from sedatives?; Ataractics are substances that produce sedation without causing drowsiness
and they are also known as tranquillizers.
What are sedatives and their primary effect on animals?; Sedatives are narcotic agents used to calm a nervous
vicious
What are the differences between local
regional
What are the three effects involved in general anesthesia as suggested by balanced anesthesia?; Narcosis
analgesia
What is balanced anesthesia?; Surgical anesthesia produced by a combination of two or more drugs or anesthetic techniques
each contributing its own pharmacologic effects; includes tranquilizers
How can general anesthesia be used in the management of convulsions?; To control convulsions like in epilepsy and tetanus.
What is one humane reason for using general anesthesia in veterinary practice?; For euthanasia.
In what situation might general anesthesia be used to capture animals?; To capture wild and vicious animals.
What dental procedure may necessitate the use of general anesthesia?; For dentistry procedures.
What is the primary physiological effect of general anesthetics on the central nervous system?; General anesthetics produce progressive loss of consciousness and voluntary motor function.
What are the two groups of general anesthetics?; The two groups of general anesthetics are volatile or gaseous agents
such as halothane and nitrous oxide
What are the two distinct types of substances used in anesthesia?; The two distinct types of substances used in anesthesia are local anesthetics
which have selective transient paralytic action on sensory and motor nerves
How are volatile anesthetic agents administered?; Volatile anesthetic agents are administered by inhalation.
How are nonvolatile anesthetic agents typically administered?; Nonvolatile anesthetic agents are usually given by injection.
What are the methods of administering local anesthesia or achieving analgesia?; Local anesthesia or analgesia can be achieved by surface application
intradermal or subdermal infiltration
What are the two types of spinal block injections used in regional analgesia?; The two types of spinal block injections used in regional analgesia are epidural injection and intrathecal injection.
What is regional analgesia and how can it be administered?; Regional analgesia can be administered by perineural injection
spinal block (which includes epidural and intrathecal injections)
What is one method of administering regional analgesia through the veins?; One method of administering regional analgesia through the veins is by intravenous regional anesthesia.
How can sedation be achieved in veterinary practice?; Sedation can be achieved in combination with local anesthetics or in combination with general anesthetics.
What are the methods of administering general anesthesia?; General anesthesia can be administered by inhalation
by injection of nonvolatile
What is acupuncture and what are its claimed benefits?; Acupuncture is an alternative medicine that treats patients by insertion and manipulation of needles in the body
claiming to relieve pain
What does TENS stand for and what is its purpose?; TENS stands for Transcutaneous Electric Nerve Stimulation
which is the use of electric current produced by a device to stimulate the nerves for therapeutic purposes.
What is electronarcosis?; Electronarcosis is unconsciousness induced by passing a weak electric current through the brain or to the body for therapeutic purposes.
What is hypothermia in the context of anesthesia?; Hypothermia refers to a medical condition where the body temperature drops below the normal level
which can affect anesthesia management and patient safety.
What are some factors that affect general anesthesia in veterinary practice?; Factors affecting general anesthesia include age
size and body weight
What is the significance of patient health status in relation to anesthetic risk?; Patient health status is significant because underlying health issues can increase the likelihood of complications during anesthesia
making it crucial to assess and address these issues beforehand.
What is anesthetic risk in veterinary practice?; Anesthetic risk refers to the potential complications and adverse effects that may occur during or after the administration of anesthesia in animals.
What role does age play in anesthetic risk for animals?; Age plays a critical role in anesthetic risk
as very young or old animals may have different physiological responses to anesthesia
What factors contribute to anesthetic risk in animals?; Factors contributing to anesthetic risk include the animal’s age
breed
How can veterinarians minimize anesthetic risk?; Veterinarians can minimize anesthetic risk by conducting thorough preanesthetic examinations
selecting appropriate anesthetic agents
How does the experience level of a surgeon influence the duration and quality of an operation?; An inexperienced surgeon may take much longer to perform an operation using rough techniques
which can produce intense and extensive trauma to the tissue and cause severe metabolic disturbances.
How does the experience of the anesthetist influence the risk to the animal during anesthesia?; The experience
familiarity
What is the impact of available facilities on managing crises during anesthesia?; Crises arising during anesthesia are usually more easily overcome in well-equipped veterinary hospitals than under primitive conditions which may be encountered on farms.
How does acquired heart disease differ from congenital heart disease in terms of its impact on anesthesia?; Acquired heart disease is of more serious concern in anesthesia as it tends to affect both the myocardium and the valves
weakening the heart muscle even in early stages
Why is knowledge of the effective function of the heart more important than the exact nature of the cardiac lesion in anesthesia?; Knowledge of the effective function of the heart is more important because acquired heart disease can significantly weaken the heart muscle
impacting anesthesia safety.
What is a soft moist cough associated with in respiratory disease?; A soft moist cough is associated with the presence of airway secretions
which may lead to respiratory obstruction and lung collapse when the cough reflex is suppressed by anesthesia.
What is hypoproteinemia and how does it affect drug binding in the bloodstream?; Hypoproteinemia refers to a condition where there is a low level of protein in the blood
particularly albumin
How does renal disease impact drug activity in veterinary anesthesia?; Renal disease can affect drug metabolism and excretion
leading to altered drug activity and potential toxicity due to impaired clearance of anesthetic agents.
What factors should be considered when selecting an anesthetic method for surgical operations?; The nature and magnitude of the surgical operation are key factors. For simple operations like the incision of superficial abscesses or excision of small neoplasms
local anesthesia may suffice. However
How does the site of the operation influence the selection of anesthesia type?; The selection of the type of anesthesia depends on the complexity of the structures near the operation site; for example
operations near the eye may be dangerous under local anesthesia due to potential movement by the conscious animal.
What type of anesthesia is typically used for short minor operations?; Short minor operations can be performed after intravenous injection of a small dose of an agent such as thiopentone sodium.
How is anesthesia maintained during longer operations?; For longer operations
a longer acting agent supplemented by local anesthesia is used
What is the purpose of using preanesthetic medications in veterinary anesthesia?; Preanesthetic medications are used to prevent undesirable effects of certain anesthetics
reduce the amount of general anesthetic required
How does the size of an animal affect the difficulty and dangers associated with general anesthesia?; In general
the larger an animal is
Why might methods used for dogs and cats be unsuitable for larger animals like horses and oxen?; Methods that are safe and satisfactory for dogs and cats may be quite unsuitable for horses and oxen due to their larger size and different physiological responses.
What can be used to induce a transient period of unconsciousness in horses during operations?; Recent introduced drugs can be used to induce a transient period of unconsciousness in horses during operations.
Why is adequate restraint necessary during operations on horses?; Adequate restraint is necessary for the safety of both the surgeon and the animal
even for simple operations that require the horse to be recumbent.
What is an important consideration when administering general anesthesia to horses in the standing position?; Induction must be unassociated with excitement
and excitement should also be avoided during the recovery period.
What is the purpose of blocking peripheral sensory nerves in anesthesia?; Blocking peripheral sensory nerves provides anesthesia for a part of the body
allowing operations to be performed without the use of general anesthesia.
Why are ruminants considered unsuitable subjects for inhalation anesthesia?; Ruminants are unsuitable subjects for inhalation anesthesia unless endotracheal intubation is used.
What method of anesthesia is recommended for fieldwork with ruminants?; General anesthesia by intravenous injection without abolition of the swallowing and belching reflexes is recommended
especially if combined with local anesthesia.
What is perineural block suitable for?; Dehorning.
What type of anesthesia is widely used for major abdominal operations in certain animals?; Paravertebral or lumbar epidural injection.
What type of anesthesia is used for digit surgery?; Intravenous regional anesthesia.
What specific care is required when using agents that cause slow recovery from anesthesia in brachycephalic dogs?; Particular care is required to monitor and manage their airway due to the risk of obstruction from jaw muscle relaxation.
Why are brachycephalic breeds of dogs considered bad subjects for general anesthesia without endotracheal intubation?; Brachycephalic breeds have a skull structure that can lead to jaw muscle relaxation causing airway obstruction
necessitating careful management during anesthesia.
What challenges are commonly faced when anesthetizing cats?; Cats are often a difficult subject to anesthetize quietly and smoothly
and restraining them may provoke violent struggling and sometimes frenzy.
What is one method to achieve a quiet onset of unconsciousness in cats during anesthesia?; There are agents which can be given by intramuscular injection to produce a quiet
trouble-free onset of unconsciousness.
Why should food and water be withheld from an animal on the day of an elective operation under general anesthesia?; Food and water should be withheld to prevent a distended stomach
which may interfere with diaphragm movement and hinder breathing
Why is fasting life threatening for birds and many small animals?; Fasting of birds and many small animals is actually life threatening.
What risk does a full stomach pose in horses during general anesthesia?; A full stomach in horses may rupture when the animal is forcibly cast or falls to the ground as unconsciousness is induced.
How does a few hours of starvation affect fermentation in ruminants under general anesthesia?; A few hours of starvation will reduce the rate of fermentation and delay the development of tympany when eructation is suppressed by general anesthesia in ruminants.
What is the treatment for fluid deficit in veterinary practice?; Treatment involves intravenous infusion with isotonic saline
Hartmann’s solution
What should be done when a delay in surgery is inadvisable and hemoglobin levels are low?; The transfusion of red blood cells is indicated.
What is the recommended action for raising hemoglobin levels when surgery can be delayed for 2 or more weeks?; The oral or parenteral administration of iron may raise the hemoglobin to a satisfactory concentration.
Why is it important to use short-acting insulin before elective surgery in diabetic animals?; Using short-acting insulin ensures that there is no active long-acting insulin preparation left on the day of operation
making it easier to control blood sugar during the perioperative period.
What is the recommended insulin treatment for diabetic animals prior to elective surgery?; It is advisable to treat diabetic animals with purely short-acting insulin a few days prior to elective surgery.
What has changed in the clarity of anesthetic stages due to modern anesthetic drugs?; Nowadays
due to rapid induction anesthetic drugs
What are the stages of anesthesia that an animal passes through during general anesthesia?; The animal passes through a series of anesthetic stages and planes correlated with changes in anesthetic depth.
How do anesthetic drugs like diethyl ether affect the clarity of anesthetic stages during induction?; Diethyl ether causes slow induction
making the stages of anesthesia very evident.
How does fear affect an animal in Stage I of anesthesia?; Fear may cause increased respiratory and pulse rates
or it may remain normal
What is the muscle tone like in Stage I of anesthesia?; Muscle tone is good in Stage I of anesthesia.
What can be observed about pupil size in Stage I of anesthesia?; Pupil size may be normal or dilated due to fear in Stage I of anesthesia.
What is the status of reflexes in Stage I of anesthesia?; All reflexes are present during Stage I of anesthesia.
What characterizes Stage I of anesthesia in animals?; In Stage I
the animal is conscious and may show forceful efforts to avoid being anesthetized
What occurs during Stage II of anesthesia in animals?; During Stage II
the animal loses consciousness abruptly
What are the characteristics of respiration during Stage II of anesthesia?; Respiration is very irregular with breath holding due to struggling.
When does Stage II of anesthesia end?; Stage II ends when the animal shows signs of relaxation
slower respiration
Why is Stage II of anesthesia considered unpleasant for the animal?; Stage II is unpleasant for the animal and potentially hazardous to the anesthetist due to the risk of epinephrine release and the possibility of cardiac arrhythmias or arrest.
How does the pupil respond to light during anesthesia?; The pupil is dilated but will constrict in response to intense light.
What characterizes Plain 1 of Stage III surgical anesthesia?; In Plain 1
respiration becomes regular
What type of surgical procedures can be performed during Plain 1 of Stage III anesthesia?; Minor operations can be done.
What happens to the pupil’s size and response to light during certain stages of anesthesia?; The pupil becomes constricted and normal in size
with diminished response to intense light.
How does an animal appear during anesthesia
and what is its tolerance for surgical procedures in Plain 1 of Stage III?; The animal appears unconscious but will not tolerate surgical procedures.
What reflex disappears
allowing for successful endotracheal intubation during anesthesia?; The swallowing reflex.
What physiological responses occur in an animal’s respiratory and heart rate when exposed to painful stimuli during anesthesia?; Both respiratory and heart rate will increase in response to painful stimuli.
What reflex is observed in dogs and cats when the web between the digits is pinched during anesthesia?; The pedal reflex
where the animal pulls away the limb.
What effects does Plain 2 anesthesia have on heart rate and blood pressure?; Plain 2 anesthesia causes a mild decrease in heart rate and blood pressure.
What response may surgical stimulation evoke in a patient under Plain 2 anesthesia?; Surgical stimulation may evoke a mild response such as increased heart and respiratory rate
but the patient remains immobile and unconscious.
What is the suitability of Plain 2 anesthesia for surgical procedures?; Plain 2 anesthesia is suitable for most surgical procedures except intra-abdominal surgeries.
How does respiration change under Plain 2 anesthesia?; Under Plain 2 anesthesia
respiration is regular but shallow with little changes in character.
What changes occur in skeletal muscle tone and reflexes during anesthesia?; Skeletal muscle tone becomes more relaxed
many reflexes like laryngeal
What happens to the position of the eyeball during anesthesia in dogs and cats?; In dogs and cats
the eyeball becomes fixed and central in position
What does a sluggish pupillary light response indicate in an anesthetized animal?; A sluggish pupillary light response may indicate a deeper level of anesthesia or potential neurological issues.
What are the characteristics of deep anesthesia in veterinary practice?; In deep anesthesia
automatic breathing is still present but the respiratory rate increases while the respiratory depth decreases
What are the signs indicating Stage IV of anesthesia
which is characterized by overdose?; 1 - The thoracic components of the inspiratory act gradually disappear. 2 - The pulse becomes rapid and weak. 3 - The pupil becomes dilated. 4 - The eyeball presents a fish eye appearance due to cessation of lacrimal secretion. 5 - Cyanosis appears and is replaced by an ashen-grey color
