Lecture 7: Thermoregulation & Post Op Care (Exam 1) Flashcards
Define thermoregulation
Ability of an organism to maintain body temp w/in a certain range (+/- 0.2 degree C) even when surrounding temps vary
What is the norm temp ranges in cats and dogs
100 to 102.5 F
Most domestic mammals are (homeothermic/ poikilothermic)
Homeothermic
What animals are poikilothermic
- Reptiles
- Amphibians
- Some fish
What transmits temperature signals to the CNS (hypothalamus)
Spinothalamic tract
What fibers are important to thermo regulation pathways
A gamma fibers & C fibers
Define radiation
Loss of heat via electromagnetic waves
Define convection
Process of losing heat through the movement of air or water molecules across the skin
Define conduction
Loss of heat to objects directly in contact w/ the body
Define evaporation
Loss of heat through conversion of water to gas (moisture from skin & lungs)
Give examples of radiation
- A body is warmed by absorbing rays of sunshine & the body loses heat by thermal radiation
- Wood stove warming a room
- Microwave uses electromagnetic radiation to transfer heat to food
Give examples of convection
- Fan blowing on you
- Wind-chill factor
- Swimming in a cold pool or moving body of water
Give examples of conduction
- A seat stay warm after you have sat on it
- Cold surgery table cooling a px down
- Holding cold water bottle to your head
Give examples of evaporation
- Passively through respiration (air breathed out has moisture)
- Active through sweating (body creates a layer of water on the skin to cool down
What is radiation
The transfer of heat via electromagnetic waves through airspace
When does radiation occur
When ambient temp is below 68 degrees F
T/F: Most of the electromagnetic radiation that comes to the earth from the sun is invisible
True
What body temp defines hypothermia?
How varied it is from their norm temp
What factors are related to heat loss
- Drugs
- Size of the px
- Not good nutrition/immune sys
- Amount of body fat
Fill out the chart:
What are the passive rewarming techs
- blankets/towels
- Wrap extremeties
What are the active rewarming tech
- Forced - air blankets
- Circulating warm water blankets
- Resistive polymer electric heating
- Humidifiers placed (not really used)
- IVF warmers
- Warm fluids to lavage in abdominal cavity
- Prewarming pxs skin and peripheral tissue
T/F: The use of an electric heating pad/blanket is safe for use in anesthetized or recovering px
False it is not
What body temp defines hyperthermia
When px is experiencing a higher temp than normal for them
When does organ damage occur
Somewhere around 107.6 (108 to 109 is when damage presents)
What is the diff btw/ pyrexia (fever) & hyperthermia
- Fever - causes infection, inflammation, neoplasia, trauma, necrosis, & immune-mediated
- Hyperthermia - In core body temp due to thermoregulation failure
What are the causes of hyperthermia
- Heat stroke
- Respiratory obstruction
- Exercise induced
- Histamine release
- Iatrogenic (caused by doc)
- Prolonged seizure activity
- Malignant hyperthermia (Pathogenic)
How should a fever be approached
- Cooling a px may be counter productive since the body w/ expend energy to get back to the temp it was to fight bacteria, virus, etc
- Avoid ax until origin is known &/or samples collected (sepsis is the exception)
- Acetaminophen can be used in DOGS ONLY
How should hyperthermia be approached
- Requires active cooling & potential sedation
- No ice packs b/c of vasoconstriction & inhibits dissipation of heat from core body
- alcohol on foot pads = not helpful
- Dont over cool px stop when they reach ~104 to avoid rebound hypothermia
What is the first line strategies to actively cool px
- O2
- room temp IVF
- Fan
- Tepid water applied to skin
- Shaving fur on bell
What is the 2nd line of strategies for cool px
Peritoneal dialysis & cool IVF
What should be avoided when cooling a px
- Cold water enema (cool water may be considered but could damage the GI tract)
- Gastric lavage due to potential aspiration
What is commonly associated w/ hyperthermia in cats
Hydromorphone (can be other drugs) - seen in first few hours of recovery & resolved w/ supportive care
How do you convert from C to F
(Celsius temp x 1.8) + 32
What happens when surgery is done (steps)
- Remove drapes, instruments & nonessential monitors from px
- Turn off inhalant (empty reservoir bag in to scavenging system then turn O2 flow rate turned up to double) - administer for O2 for 3 to 5 mins
- Px placed in lateral or sternal recumbency (Disconnect px from circuit prior to turning)
- Cont monitoring until extubated & alert but not necessary to record vitals
- Make sure they can swallow then take out ETT
- Make sure they are breathing when you extubate
What monitors should be left of the px
- Leave ETCO2
- +/- SpO2
- Palpate pulses or use stethoscope
When is px put into sternal recumbency
If they are brachycephalic
How many swallows for cats & dogs before we take out the ETT
- cats = 1 good swallow
- dogs = 2 good swallows
What is done after the px is extubated
- Assess for dysphoria &/or pain
- Monitor rectal temp every 15 to 30 min until 98 F
- Monitor all vital signs (HR, RR, MM, CRT, temp, +/- BP) until the px is alert, able to move, & temp is norm
- Consider removing IV catheter if no further fluid of IV meds are planed (observe pain first)
- +/- E collar when left alone in cage
How to tell if its dysphoria or pain
- Glazed over look = dysphoria
- Painful when touched
What if the px is staying for hospitalization
- IVC should be properly flushed, wrapped & secure
- Tx orders should be approved by clinician in charge
- Tech monitoring in hospital px should be “rounded” on the case
When should the animal be released to the owner
When they can walk to the car
What sort of instructions should you provide the owner/caretaker
- Written discharge instruction
- Verbal instructions
What should be in the discharge instructions
- What behaviors to expect
- Restrict activity &/or limit areas of the house
- Recheck date & if & when sutures need to be removed; any bandages to monitor/change
- When to offer food & water (and how much)
- When to start any meds & should they be offered w/ food
- Sx they should monitor their pet for & when to call if concerned (provide a # for clients to call after-hours)
What should hospitalized px treatment orders to include
- Vitals (usually q hour for the first few hours aft anesthesia the q 4 to 6 H)
- Body weight (q 12 H)
- Serial pain scoring
- Urine & feces output
- Hydration status
- Feeding & water instructions or NPO
- IVF maintenance rate (consider any replacement fluid needs, ongoing & insensible losses)
- Complete instructions for meds including amount & route
- Exercise or PT
- all other nursing care instructions
- Be sure to clinician signs off on orders
Answer the problem
What is a prolonged recovery
- Excessive time from discontinuation of inhalant anesthesia & the px has not been extubated (~ 30 to 45 mins)
- Prolonged time to standing in horses (~ 1 H)
What should be checked if there is a sign of prolonged recovery
- Check vitals
- Actively warm px if needed
- Check electrolytes & BG
- Consider reversal of certain drugs
- IV fluids +/- dextrose &/or Ca
