Anesthesia Monitoring Equipment
What basic monitors should be used on anesthetized patients?
What are the most common heat loss mechanisms in veterinary patient and explain them.
Radiation: loss of heat via electromagnetic waves
Convection: process of losing heat through the movement of air or water molecules across the skin
Your friend just picked her dog up from a procedure at the vet clinic, but the veterinarian forgot to include discharge instructions. She wants to know what type of things she should look out for since her dog just had surgery. What would you tell her (non specific to the procedure, just guidelines?)
Discharge instructions should include:-
What are sites in small animals and large animals to determine pulse quality?
SA: femoral, dorsal pedal, radial, lingual
LA: facial, transverse facia, metatarsal, digital, auricular, femoral, coccygeal
You are an experienced doctor mentoring a new grad and it is a surgery day at your clinic. No patients have been brought in yet and the new grad doctor is assigning them all ASA physical status based on their medical records. What would you tell her?
While it is good to be looking over their records and thinking ahead about the cases, the ASA PS should be assigned after we do our physical exam and look at the diagnostic tests.
What does an increased and decreased ETCO2 indicate and what could be causing it?
increased: hypoventilation, malignant hyperthermia
decreased: hyperventilation, decreased CO, disconnection, hypothermia, airway obstruction
What are the temperature ranges for mild, moderate, and severe hypothermia?
mild: 89.6-98.6
moderate: 82.4-89.6
severe: <82.4
Hi! I just adopted a 6 year old Doberman and I want to get her ears cropped. I talked to her vet about it and they refuse to do it because they say that her ASA score is a 3 and that is too high for them to be comfortable doing an elective procedure. What the heck does that mean???
ASA 3:
-patient with a severe systemic disease
-fever, dehydration, anemia, cachexia, hypovolemia, uncontrolled DM, COPD, renal failure
Owner:" oh yeah... i forgot to tell you i adopted her because she has hypothyroidism and her old owner didn't want to have to deal with it so never started treatment."
Explain where you would place leads for small and large animals and what they are called.
SA: Lead II; White: right elbow; Grey: Left elbow; Red: left stifle or abdomen
LA: Lead I or base Apex: White: Right Jugular Furrow; Grey: left axilla region; red: any site remote from the heart
Lead I used in large animals because it accentuates the P wave so it is easier to identify changes in morphology
How many mg and mL of Acepromazine (2 mg/mL) for a 25 kg dog that you want to give a dosage rate of 0.05 mg/kg?
1.25 mg
0.63 mL
Explain the MOA of a SpO2 monitor and what value we want.
Spectrophotoelectric device is placed over non-haired skin with a pulsatile blood flow. Red and infrared light are absorbed differently by oxygenated and deoxygenated Hb. This difference is calculated and the %Hb saturation is displayed numerically.
preferred SpO2 reading of greater than or equal to 95%
What is the difference between pyrexia and hyperthermia and how do you approach these cases differently?
pyrexia: causes include infection, inflammation, neoplasia, trauma, necrosis, and immune mediated
-cooling a patient is counterproductive; avoid antibiotics until origin known and/or samples collected; avoid NSAIDs or steroids
hyperthermia: elevation in core body temp due to thermoregulation and failure
-requires active cooling and potential sedation
-dont over cool patient, stop when they reach about 104 deg F
Your friend calls you and says her boston terrier has been outside in the summer in Florida playing for an hour with no water. She feels hot to the touch and is having trouble breathing. She was going to give her water with ice cubes in it but wants to know what else she should do to cool her down. What do you tell her?
Your dog is in heat stroke and needs to see a vet this could be life threatening. Start actively cooling her while you drive to the ER. Do not use any aggressive methods of cooling as it could cause more issues (peripheral vasoconstriction and hypothermia). Try applying tepid water to the skin, putting a fan pointed towards her, and shaving the fur on her belly until you get to a clinic. The clinic will most likely give her O2 and room temp IVF.
What affects does hypothermia and hyperthermia have on the cardiovascular system?
hypothermia: reduced CO, decreased contractility, arrhythmias, vasoconstriction, cardiac drugs less effective
hyperthermia: tachycardia, hypotension, cardiac failure due to high output
You are needing to do a biopsy of a skin lesion on a patient to send off to the lab. What plane of anesthesia is good for your patient?
Stage III Plane 1
Walk me through doing a doppler blood pressure reading and what value you are looking to find.
Materials: inflatable cuff with width 30-40% the circumference of the limb or tail, sphygmomanometer, ultrasonic doppler flow detector with piezoelectric crystal probe, ultrasound gel
Place cuff on arm and doppler distal to the cuff. Squeeze the sphygmomanometer until it does not increase anymore, and mark what number it indicates when you can hear blood flow on the doppler.
This gives you the systolic arterial pressure and we want it to be greater than 90 mmHg to make sure the patient isnt hypotensive.
Explain the general trend of what being hypothermic and hyperthermic does to the body systems and give some examples.
hypothermia generally causes decreased function of body systems. Ex: decreased RR, decreased renal tubular function, decreased immune function and delayed wound healing
hyperthermia generally increases body systems into overdrive. Ex. tachycardia, cardiac failure due to high output, DIC, inflammatory response, severe hypoglycemia, depletion of glycogen stores
Your friend who is into businesses is funding opening a vet clinic, but knows nothing about vet med. The lead doctor he hired wants an extra budget to get safety mechanisms for the anesthesia machine that are not already included in the price. Explain to him what the safety pieces do and why they are important.
key fill adapters: to make the filling of the anesthetic gasses easier and safer, assure no input of the wrong gas into the wrong vaporizer, and limit the chance of spills and workers inhaling it
Pop-Off Occlusion Valve: The occlusion valve allows assisted ventilation without the worry of leaving the pop-off valve closed. Just press the button, “sigh” your patient and release.
Pressure Relief Valve: If the pop off valve is left closed it can cause a build up of pressure in the patient's lungs and ultimately kill them. This tool monitors the pressure of the system and slowly releases air when needed to ensure the pressure does not get too high.
What does each part of an ECG represent?
P wave: atrial depolarization
PR interval: AV depolarization
QRS Complex: ventricular depolarization
ST segment: time between ventricular depolarization and repolarization
T wave: ventricle repolarization
One of the clients on their way to an appointment with you comes in with a patient that is not their pet and they just found outside during the snowpocalypse. You put the patient in an exam room and hook it up to monitoring and notice a slow HR, RR, and a low BP. You think he might be cold, but he is not shivering and just looks to be sleeping. What is you diagnosis?
Moderate hypothermia: slowing of HR, breathing, and low BP; decreasing conscious state and no longer shivering
range: 82.4-89.6 deg F
Name the normal limits under GA for dog, cats, horses, and ruminants.
Dogs: T: 98-102.5, HR: 50-160, RR: 10-20, BP: MAP> 60 SAP>80 mmHg, SpO2: 95-100, ETCO2 35-45 mmHg
Cats: T: 98-102.5, HR: 100-200, RR: 10-20, BP: MAP>60 SAP>80, SpO2: 95-100 ETCO2: 35-45
Horses: T: 98-102.5, HR: 28-50 foal: up to 80, RR: 10-20, BP: MAP>70 SAP>80, SpO2: 95-100 ETCO2: 35-45
Ruminant: T: 98-102.5, HR: cow: 48-90 sheep or goat: 60-150, RR: 10-20, BP: MAP>60 SAP>80, SpO2: 95-100 ETCO2: 35-45
Run through the basic steps of recovering a patient from anesthesia.
Your old friend from high school got married and now has a farm with dogs, cats, horses, cattle, etc. She takes pretty good care of them and takes them to the vet frequently. She recently rescued a small bird that has health issues and needs surgery. She wants to know why the vet told her not to fast her bird as in the past when her pets have gotten surgery (dogs, horses, cows), they have all needed to be fasted. What is the difference?
The purpose of fasting is to
As this is helpful and necessary for the larger animals, it is not necessary for neonates, small birds, and small mammals because they are prone to hypoglycemia within the first few hours of starvation and they have an increased metabolic rate.
What are clinical uses of an ECG besides HR and rhythm?
-morphology of wave to locate disease
-cardiac oxygenation and adequate perfusion
-electrolyte abnormalities
How many drops per second will a 4 kg patient receive if a fluid rate of 5 ml/kg/hr is desired and a 60 drops/mL IV drip set is selected? What size reservoir bag would you select and what would be the oxygen flow rate on a non-rebreathing system?
0.33 drops per second
about 1 drop every 3 seconds
4 kg x 10 mL/kg x 5 = 200 mL so 0.5 L bag
250 mL/kg/min= 1000 mL/min