Anesthesia Flashcards
Why do you want to restraint a rabbit and at the same time be careful?
Bite, scratch, kick
Be careful because thy can have spinal fractures (T-L lower) or tibial fractures
How would you restraint a rabbit? How about a rodent?
Rabbit: grasp at nape, support rump (others: transport cage, cat bags, squeeze cages, and towel over eyes)
Rodents: Pick up in the palm, support under rump, grasp at nape, traps
Why is stress a bad thing?
It can cause physical damage but also release catecholamines (will sensitize myocardium and can cause arrhythmias)
What is the most important factor when it comes to physiological/anatomical with pocket pets vs other pets?
Their small size
Why would the small size of pocket pets is a problem? (5 things)
Difficult vascular access
Mechanical obstruction of airway due to positioning
Compression of thoracic cavity during handling
Challenges with equipment and intraoperative monitoring
Drug dosing
Pocket pets have a (high/low) metabolic rate and therefore will cause (hypoglycemia/hyperglycemia) with prolonged fasting.
High
Hypoglycemia
Pocket pets have (high/low) surface area:volume ratio which means they will go into (hypothermia/hyperthermia) faster.
High
Hypothermia
(T/F) Pocket pets have high oxygen consumption rates which means they have low tolerance to hypoxemia, slow inhalant anesthetic uptake and elimination, and irreversible CNS injury
False - everything true except: they have rapid inhalant anesthetic uptake and elimination
Why do we not want to fast a pocket pet?
Can cause GI ileus and tympany - abdomen will distend and it becomes hard to breathe because they are putting pressure into the diaphragm
Why do we want to intubate pocket pets even though it is really hard?
They can become hypoxemic, hypercapnic, and go into respiratory arrest
Why do we not really need to fast the pocket pets?
Because they do not vomit or regurgitate
What are the three ways we can provide fluids/drugs to pocket pets?
IV, IO, SQ
How much blood volume do pocket pets have and how many can be lost?
Blood volume = 10% BW
Blood loss = 10% of the blood volume
What is the minimum protective equipment we should use to protect ourselves from zoonotic diseases?
Gloves and masks
What are the 4 zoonotic diseases rabbits can transmit?
Pasteurellosis, Ringworm, Crypto, Mycobacterium
What part of the body of rabbits, ferrets, and rodents do we want to make sure we check thoroughly in the physical exam and why?
Respiratory system (upper airway - Nares, nasopharynx, cheek pouches)
They are primary/obligate nasal breathers
What would happen to rabbits that fast before going under anesthesia?
Hepatic lipidosis
What would happen to guinea pigs that fast before going under anesthesia?
Pregnancy toxemia
What are the areas that Dr. Paranjape recommends for vascular access?
Jugular, cephalic, saphenous, marginal ear vein
Rats - lateral coccygeal vein
Where did Dr. P recommended for IO catheritization?
Proximal femur, tibia, humerus
Injury to what artery will cause thrombosis and ischemic necrosis in rabbits?
Auricular artery
How can you cause local vasodilation of the tail in rodents?
Warming of the tail by immersion in a water bath
What can happen with excessive IM volumes?
Muscle necrosis, volume overload
(T/F) You want to preoxygenate always and use different size face masks if not there will be a lot of dead space.
True
(T/F) We should always use sedatives (pre-meds) and then induce with an inhalant.
True
What are the pros and cons of an induction chamber?
Pro:
Minimal physical restraint
Reduces injury to animal/handler
Secure chamber top - prevent animal from escaping
Cons:
Environment contamination/difficult monitoring
How do we fill up an induction chamber effectively to sedate a pocket pet?
Vaporizers set at maximum concentration and oxygen flow rate (2-4L/min)
How do you know when to take out a pocket pet from an induction chamber?
Once animal loses its righting reflex (point at which an animal no longer responds to their innate instinct to avoid the vulnerability of dorsal recumbency)
What is the ET tube size range we should use with rabbits?
2-4.5 mm ID
To intubate a rabbit align larynx and _____ with _____ and displace the epiglottis.
Trachea
Oropharynx
Why do you want to give a lidocaine splash in rabbits, rats, hamsters and ferrets?
Laryngospasms
What are the three equipments to use for direct visualization to intubate a rabbit?
Laryngoscope, otoscope, rigid endoscope
If an endoscope is 2.7 mm OD then the ET tube must be how big?
> 3mm
What is the confirmatory way to check ET tube placement?
Capnograph - detection of exhaled carbon dioxide
What pocket pet species do we not intubate and why?
Guinea pigs because the entry to the glottis is through the palatal ostium (hard to do)
What do we use with rats and hamsters to intubate instead of an ET tube?
14-16 G over the needle catheter without a stylet
Why do we have to make sure the ferrets have to be in deep plane anesthesia?
They have sharp teeth so they could lacerate the ET tube
Why do you not want to use a larger face mask on pocket pets?
There is extra space which will trap exhaled gases high in CO2 (they will rebreathe the CO2)
What type and number of laryngoscope with pediatric straight blade should you use in pocket pets?
Miller # 0 or 1
What two gasses can be used as carrier gasses?
Oxygen alone and oxygen with nitrous oxide
What happens with waste anesthetic gas?
Ducted out of the room or is absorbed using activated charcoal
What kind of anesthetic system should be used for pocket pets?
Brain - non rebreathing system low resistance
What should be the gas flow rate to remove CO2 with pocket pets?
200mL/kg/min
What are the three things we should be looking at to check for light plane of anesthesia?
Reflex (palpebral, corneal), muscle tone, movements
What should we use to check bradycardia/tachycardia in pocket pet anesthesia?
EKG
- Can also use pulse rate, cardiac ausculatation
What should we use to check for hypotension/hypertension in pocket pet anesthesia?
Indirect BP measurement
- Can use direct BP measurement but would need arterial monitors
What should we use to check for hypoxemia in pocket pet anesthesia?
Pulse oximetry (SPO2)
- Can also use arterial blood gas sampling or mucous membranes
What should we use to check for hypoventilation in pocket pet anesthesia?
Capnography (EtCO2)
- Can also use blood gas sampling
What are the tree reflexes that can be used to check anesthetic depth?
Pedal withdrawal (toe/tail pinch), pinna reflex. corneal and palpebral reflex
Fixed (constricted/dilated) pupil + (responsive/unresponsive) to light + (present/absent) corneal reflex = Deep anesthesia (too much)
Dilated
Unresponsive
Absent
What physiologic parameters will you see if there is a light plane of anesthesia?
Increased: heart rate, blood pressure, respiratory rate/depth
Where would you take indirect blood pressure measurements?
Legs, forearms, tail, ear
Where can you place the doppler flow probe?
Tail base, carotid/femoral/auricular arteries, directly over the heart
Where can you place the pulse oximetry measurement?
Digits, paws, tongue, proximal tail, ear, rectum
What type of fluids do we use for pocket pets during anesthesia?
LRS (isotonic fluids)
What is the fluid rate for pocket pets during procedures?
Short procedures = 10mL/kg/hr
Longer = 5-8mL/kg/hr
What routes can be used to provide fluids to rabbits or rodents?
Rabbits - IV, SQ
Small rodents - IP, SQ
What 5 things should we monitor post op?
- Ileus (treat with prokinetic)
- Vomiting/regurg
- Hypoglycemia
- Hypothermia
- Dehydration
What should be do specifically with guinea pigs post op and why?
Anorexia and inappetant we need to supplement with Vitamin C
How do we assess pain because it gets harder to find out the smaller the patient is?
Touch incision site and check for pain
