Exam 3 Flashcards
What are five risk factors for anesthesia emergency?
o Breed o Patient health o Experience skills of the vet team o Case circumstances o Owner idiosyncrasy
Define laryngeal eversion.
edges of larynx are depressed or are everted
What issues arise when surgically correcting an elongated soft palate?
o Surgical correction with complications of swelling and incorrect length
o Too short causes food in the nares
o Too long does not solve the problem
How do you determine the correct ET tube size?
o Palpate to check size - Should not be tight going down
o Septum of the nares
What is one complication of the ET tube being too tight?
scrapes mucosal surface causing a postoperative cough
What is one factor in determining the order of surgical procedures?
most life threatening goes first
What must one evaluate before performing a procedure which requires anesthesia?
must weigh risks and benefits - benefits must outweigh risks
What is the number one reason for anesthetic emergencies?
human error
What are five examples of human mistakes which may lead to an emergency?
o Lack anesthesia and drug familiarity o Wrong drugs administered o Preoccupied or in a hurry o Fatigue o Inattentiveness
What are four symptoms/warning signs that a patient has a diaphragmatic hernia?
o Internal organs displaced into the thorax
o Skinny abdomen
o Muffled heart sounds
o Dyspnea
What are two examples of drugs that come in different dosage strengths?
Xylazine, Butorphanol
What is a potential route of administration drug complication that may occur with aggressive dogs?
aggressive dogs may be dosed IM in emergency situations, but if there is a struggle the vein may be hit
What is the second most common reason for emergencies?
equipment failure
What are six potential anesthesia machine equipment problems?
o CO2 absorber exhausted o Decreased O2 flow o Misassembled o ET tube problems o Vaporizer problems o Pop off valve
How often should the CO2 absorber be changed?
every ten hours
What are five symptoms of CO2 absorber exhaustion in the patient?
o Hypercapnia because of the increased CO2 buildup o Increased HR and RR o Brick red MM o Arrhythmias o No reflexes
What are four possible reasons for decreased O2 flow?
o Tank runs out (change at 500 psi though 2-3 more surgeries could be done)
o Valves are closed
o Flow meter ball is lodged in the flow meter tube
o Obstruction or leak
What is one symptom of decreased O2 flow in the patient?
appears cyanotic when O2 has stopped
What should the tech’s reaction to reduced O2 flow be?
o Disconnect the nonrebreathing circuit because room air has 20% oxygen (better than 0%)
o Leave a rebreathing circuit connected as long as the reservoir bag is full (there is still oxygen in it)
What percentage of O2 is found in room air?
20%
What percentage of 02 is administered by the vaporizer?
100%
What are four potential problems with the endotracheal tube?
o Twisting or kinking
o Material in tubes
o Bad positioning
o Blockage
How do you prevent twisting and kinking of the ET tube?
detach before flipping the animal
What drug increases the risk of material being trapped in the tube?
atropine in cats
What may occur when the ET tube is positioned too far past the bifurcation and the thoracic inlet?
only one bronchus is oxygenated and the other side dies
What does blockage of the ET tubes cause?
respiratory arrest
How does a tech check ET tube placement?
o Bag the patient to check for a rising chest - Abdominal rising means the ET tube is down the esophagus and into the stomach
What should a tech do if there is no rise of the chest or abdomen when bagging the patient to check placement of the ET tube?
disconnect and feel for air coming from the ET tube
What should the tech do when there is no air coming from the disconnected ET tube?
o Remove and replace the tube
o Suction the accumulation if this is the problem
What are six potential issues with the vaporizer?
o Wrong anesthetic o Tipping machine over o Dial is stuck and jammed o 2 vaporizers on o Over filling the vaporizer o Increased room temperatures in non-precision vaporizers
What is one potential problem with the pop-off valve?
it is closed
What happens when the pop-off valve is closed?
o The bag will be tense and tight
o The patient will not exhale
o Decreased venous return decreasing heart rate, deceased cardiac output, rapid decrease blood pressure, and possible rapid death
What should the tech’s reaction be if the reservoir bag is too full?
o Open pop off valve
o Decrease O2 flow
o Disconnect from machine if correction is taking too long
How does a tech change the O2 concentration in the reservoir bag?
dump the bag three times
What are three common patient types that require a special drug protocol?
o C-section
o Brachycephalic
o Geriatric
Define balanced anesthesia.
o Using more than one drug (using a preanesthetic) to decrease the amount of gas needed
What five patient factors need to be considered for geriatric patients?
o Aging (how quickly certain breeds age) o Organ function o Stress response decrease o Increased hypothermia risk o Increased risk of overhydration
What is one example of a dog breed that ages slowly?
Chihuahua
What is one example of a dog breed that ages quickly?
Great Dane
What consideration should be made for the heart when choosing an anesthetic agent?
decreased cardiac function calls for isoflurane (decreased heart effects)
What is the role of the liver in metabolizing anesthetic agents?
metabolizes injectable agents
What is the role of the lungs in metabolizing anesthetic agents?
removes anesthetic gas through blow off
What is the role of the kidneys in metabolizing anesthetic agents?
excretes (does not metabolize!) injectable agents
What is different about the kidney’s metabolism and secretion mechanism in the cat?
kidneys completely remove the agents
Explain anesthetic redistribution.
o Anesthetic goes from the machine to the patient’s lungs where diffusion across capillary walls increases the concentration in the blood stream
o The anesthetic then travels to the highly vascularized tissues such as the brain
o Then the agents are pulled into the fats and muscle of the body which are poorly vascularized
o This decreases the concentration in the brain causing the animal to “wake up” even though there is still adequate anesthetic in the body
o The liver cannot metabolize the agents fast enough to eliminate the drugs completely before redosing
Why do older dogs have a higher hypothermia risk?
lost insulation (low body fat content)
Why do older dogs have a higher risk for overhydration?
impaired heart circulation and decreased kidney function
What anesthetic should be used for a patient with liver problems?
inhalation induction (mask, chamber, or cage)
What is the safest minimum age to begin anesthesia induction?
8 weeks
Why are pediatric patients at higher anesthetic risk?
o Decreased liver function pathway o Increased hypothermia and overhydration risk o Difficulty intubating o Fasting avoidance o Catheterization problems
What is the safest way to induce a pediatric patient?
isoflurane mask
Why are pediatric patients not fasted?
hypoglycemia, dehydration risk
When is hypoglycemia most likely to occur in a pediatric patients, and what patients are at greatest risk?
patients less then 6 months old (especially toy breeds) fasted longer then 8 hours
Besides hydration, what must be checked in pediatric patients before surgery?
blood sugar
What is the most common problem in pediatric patients?
hypoglycemia
What is the most common problem in brachycephalic dogs?
tendency for airway obstruction
What causes airway obstruction in brachycephalic dogs?
o Stenotic nares
o Elongated soft palate
o Everted laryngeal ventricles
o Small, short trachea
When should stenotic nares be examined?
at the patient’s first exam
What may cause bradycardia in a brachycephalic dog?
increased vagal tone which causes increased vagal response inducing bradycardia
How is vagal tone decreased?
o Use anticholinergics for preanesthetics which prevent bradycardia and secretions
o Proxygenate before drugs
o Induce rapidly
Why should brachycephalic dogs be induced rapidly?
to avoid stage 2 (excitatory stage)
What special instructions are suggested for brachycephalic patients?
leave the ET tube in as long as possible - until they chew or pick up the head
What is the anesthetic drug of choice for sighthounds?
propofol
Why is propofol the drug of choice for sighthounds?
o Sight hounds lack body fat so drugs will have a larger effect on them
o Propofol is eliminated quickly through liver metabolism
o Because there is less fat and muscle to absorb the drug from the blood stream, rapidly metabolized drugs are a good thing for sight hounds (little to no redistribution)
What drug is not given to sighthounds?
barbiturates because there is no redistribution to decrease concentration of the agents in the brain and blood
How are obese patients dosed?
for ideal body weight, not current body weight
What are three anesthetic complications associated with obesity?
o Difficult for accurate dosing (guessing the dose by weight)
o Poor distribution of anesthetics
o Respiratory difficulty
Why is respiration compromised in obese patients?
fat takes up space where the lungs and diaphragm normally would expand
How should obese patients be treated before surgery?
o Preoxygenate
o Induce rapidly (injectable and inhaled)
How is respiration supplemented in obese patients?
o Assisted PPV when needed
o Delay extubation (maintain airway until completely recovered to breathe on own)
How should all patients be placed in the cage during recovery from anesthesia?
o Face towards the cage door
o Propped so that the nose is not obstructed by the cage wall or bedding
What four complications are c-section patients at increased risk for?
o Heart workload increases
o Compromised respiration
o Vomiting and regurgitation
o Hemorrhage
Why is workload to the heart increased in c-section patients?
there are puppies inside that require blood flow so the heart works overtime to compensate
Why is respiration compromised in c-section patients?
uterus takes up abdominal space restricting diaphragm space for contraction
Why is there an increased hemorrhage risk for c-section patients?
uterus is highly vascularized
What are five special considerations in the care of c-section patients?
o IV fluids o Clip prior to induction with patient on the left side o Preoxygenate o Give lowest effective dose of drugs o Avoid certain drugs
Why are c-section patients given IV fluids?
a lot of fluid is lost and blood pressure must be maintained
Why are c-section patients clipped while laying on their left side and prior to induction?
o if placed on their back the additional weight on the caudal vena cava would compromise blood flow to dam and puppies
o decreases the amount of anesthetic to the puppies
What five drugs are avoided in c-section patients?
o Pentobarbitol o Ketamine o Diazepam o Ace o Xylazine
How are c-section patients induced?
o Mask
o Propofol
What are three common breeds of c-section patient?
English bulldogs, pug, French bulldog
Why are c-sections common in these breeds?
puppies have large heads when compared to the birth canal
What problems may occur with c-section puppies?
agents can cross the placenta which reduces respiratory and CDVS function
What are five ways reduced respiratory and CDVS function can be prevented in c-section puppies?
o Use reversal agents o Use doxopram o Administer oxygen with face mask o Administer atropine for bradycardia o Keep warm
When should the puppies be allowed to nurse?
ASAP once the mother has recovered enough to put the puppies out of danger
What calls for the use of doxopram in c-section cases?
the use of narcotics
When does doxipram work?
only when there was an initial respiratory effect
What are two ways that the bladder may be emptied in the c-section patient?
o Normal outside urination
o Intraoperatively
o NOT MANUAL EXPRESSION
What three things should be done before trauma patients are induced if they are stable enough to have them done?
o Radiographs
o Examinations
o ECG
How is respiration examined in trauma patients?
o Auscultation
o Observation
What can be done if there is a complete oxygen exchange loss from blood or fluid filled lungs?
nothing
