Exam 1: Lecture 7: Thermoregulation and Postoperative Care Flashcards
What is thermoregulation?
Ability of an oragnism to maintain body temperature within a certain range (+- 0.2C), even when surrounding temperatures vary
What range do we thermoregulate dogs and cats?
100 to 102.5
Homeothermic or Poikilothermic?
Most domestic animals
Homeothermic
Homeothermic or Poikilothermic?
reptiles, amphibians and some fish
Poikilothermic
Core body temperatures are often how much higher than skin temperatures?
2-4 C
Abnormal body temperatures in awake animals can be caused by?
metabolic dysfunction
Abnormal body temperature in anesthestized animals can be caused by?
fluid or drug related
enviornmental
In the brain, where is temperature regulation controlled
Hypothalamus
What type of fibers are caused by Noxious mechanical stimulus
Alpha delta fibers
What type of fibers are caused by noxious head and chemical stimuli
C fibers
Where do spinothalamic (along the spine) tract transmit temperature signals?
CNS: central nervous system
Where do efferent pathways end
- blood vessel tones
- shivering or sweating
Alpha motor neurons
What are the 4 heat loss mechanisms?
- Radiation
- Convection
- Conduction
- Evaporation
What are the two main mechanisms of heat loss?
Radiation and convection
Define Radiation
loss of heat via electromagnetic waves
- standin outside in the sun = warming up
Define Convection
Process of losing heat through the movement of air or water molecules across the skin
- moving through the pool
Define conduction
Loss of heat to objects directly in contact with the body
Define evaporation
Loss of heat through conversion of water to gas (moisture from skin and lungs)
What type of heat loss is illistrated by number 1
Convection
What type of heat loss is illistrated by number 2
Radiation
What type of heat loss is illistrated by number 3
Evaporation
What type of heat loss is illistrated by number 4
Conduction
What type of heat loss is descibed as:
- Body warmed by absorbing rays of subshine and the body loses heat by thermal radiation
Radiation
What type of heat loss is descibed as:
- Wood stove warming a room
Radiation
What type of heat loss is descibed as:
- Microwave uses electromagnetic ________ to transfer heat to food
Radiation
What type of heat loss is descibed as:
- Heat exchange between the body and ambient air or water in which it moves
Convection
What type of heat loss is descibed as:
- Fan blowing on you
Convection
What type of heat loss is descibed as:
- Wind-chill factor
Convection
What type of heat loss is descibed as:
- Swimming in a cold pool or moving body of water
Convection
What type of heat loss is descibed as:
- A seat staying warm after you have sat on it
Conduction
What type of heat loss is descibed as:
- Cold surgery table cooling a patient down
Conduction
What type of heat loss is descibed as:
- Holding water bottle to your head
Conduction
What type of heat loss is descibed as:
- Passively through respiration (air breathed out has moisture)
Evaporation
What type of heat loss is descibed as:
- Active through sweating (body creates a layer of water on the skin to cool down)
Evaporation
What type of heat loss is descibed as:
- transfer of heat via electromagnetic waves through airspace
usually occurs when ambient temperature is below 68 degrees F
Radiation
In radiation heat loss this occurs when ambient temperature is blow ______ degrees F
68
Most of the electromagnetic radiation that comes to the earth from the sun is ________
Invisible
- only a small portion is visible light
- light is made from waves of different frequencies
What are the main 4’s to remeber in regards to anestheisa?
Hypothermia
Hypotension
Hypoventilation
Hypoxia
What extent of hypothermia has the following conditions:
Temperature: 89.6 to 98.6 F
Mild
What extent of hypothermia has the following conditions:
Temperature: 82.4 to 89.6 F
Moderate
What extent of hypothermia has the following conditions:
Temperature: less than 82.4 F
Severe
What extent of hypothermia has the following conditions:
Phsyiological changes
- Increased basal MR and O2 consumption
- vasoconstriction
- SNS activation
Mild
What extent of hypothermia has the following conditions:
Phsyiological changes
- Slowing of HR and Breathing
- Low BP
Moderate
What extent of hypothermia has the following conditions:
Phsyiological changes
- Further slowing of HR
- development of arrythmias prior to stopping
- No PLP
Severe
What extent of hypothermia has the following conditions:
Clinical Changes
- Heat seeking behavior
- Shivering
- Tachycardia
- Tachypnea
- Diuresis
Mild
What extent of hypothermia has the following conditions:
Clinical Changes
- Decreasing conscious state
- No longer shivering
Moderate
What extent of hypothermia has the following conditions:
Clinical Changes
- No longer conscious
- Rigid Muscles
- Pulses and respiration difficult to detect
Severe
What are passive rewarming strategies to warm anesthetized patients?
- Blankets
- towels
- wrap extremities
What are active rewarming stratigies to warm anesthetized patients?
- Forced air blankets
- circulating warm water blankets
- Resistive polymer eletric heating
- Humidifiers
- IVF warmers
- Warm fluids to lavage in abdominal cavity
T/F: The use of eletric heating pads/blankets are safe and effective for use in anesthetized of recovery patients
False! they are NOT safe
When does organ damage occur during hyperthermia?
around 106 to 107 F
Define pyrexia
Fever
- a cause for the problem
What is defined as a regulation probelm in animals
hyperthermia
What is defined as causes (Ex: pyrogens) included infection, inflammation, neoplasia, trama, necrosis, and immune mediated
Pyrexia
What is defined as elevation in core body temperature due to thermoregulation failure
hyperthermia
Give some causes of hyperthermia
- Heat stroke
- respiratory obstruction
- Exercise induced
- Histamine release
- Iatrogenic (doctor causes the problem)
- Prolonged seizure activity
- Malignant hypethermia
From a clinical standpoint, how is fever treated / managed?
Cooling a patient may be counter productive since the body wall will expend energy to get back to the temperature it was at to fight bacteria, virus, etc.
dont fan a fever
Avoid antibiotics until origin of known and/or samples collected. Sepsis is the exception
Avoid NSAIDS and steroids if possible (use opiods or gabapentin if painful)
use acetaminophen in dogs
T/F: Acetaminophen can ONLY be given to cats
BIG FALSE!!!!!!!
ONLY given to dogs
- if you give to cats = DeAtH
From a clinical standpoint, how is hyperthemia treated / managed?
Requires active cooling and potential sedation
- no ice packs because it causes vasoconstriction and inhibits dissipation of heat from core body
- Alochol on foot pads not considered helpful
Dont over cool patient
When a patient reached a temp of ______ stop cooling the patient to avoid rebound hypothermia
104F
If you do not use caution with agressive methods of cooling what may happen to the patient?
- think blood flow
Vasoconstriction may cause hypothermia
What is the 1st line strategy to cool a patient
- O2
- room temperature
- IVF
- Fan
- tepid water applied to skin
- Shaving fur on the belly
What is the 2nd line strategy for cooling a patient
- Peritoneal dialysis
- Cool IVF
What strategy do you want to avoid when cooling a patient
cold water enema (cool water may be considered, but could damage the GI tract) and gastric lavage due to potential aspiration
What drug in cats is hyperthermia commonly assoicated with
Hydromophone
- other drugs may also cause hyperthermia
During recovery of anesthesia in cats when do signs of hyperthermia occur
first 5 hours
What body system may cause hypothermia in the following clinical signs
- Decreased function (chemotaxis, phagocytosis, antibody production, etc.)
- Delayed wound healing
Immune
What body system may cause hypothermia in the following clinical signs
- Hemoconcentration and increased viscosity
- Left shift of Oxy-Hb curve
- Decreased RBC deformability
- Coagulation
- Abnormalitlies
- DIC
Hematopoietic
What body system may cause hypothermia in the following clinical signs
- Reduced CO
- decreased contracility
- arrythmias
- vasoconstriction
- cardiac drugs less effective
CV
What body system may cause hypothermia in the following clinical signs
- Falsely increased PaO2
- decreased RR
Respiratory
What body system may cause hypothermia in the following clinical signs
- Decreased renal tubular function
Renal
What body system may cause hypothermia in the following clinical signs
- Elevated serum amylase
GI
What body system may cause hypothermia in the following clinical signs
- reduced hepatic function (altered enzyme activity( can prolong duration and effects of drugs
Hepatic
What body system may cause hypothermia in the following clinical signs
- Falsely decreased pH
- Decreased adrenal activity
- Hyperkalemia
- delayed wound healing
Metabolic
What body system may cause hypothermia in the following clinical signs
- Stupor progressing to coma
- absent motor and reflex function
Neurological
What body system may cause hyperthermia in the following clinical signs
- Inflammatory response
- vascular statis
- extravasation
- edema
Immune
What body system may cause hyperthermia in the following clinical signs
- DIC
- Hemorrhage
Hematpietic
What body system may cause hyperthermia in the following clinical signs
- Tachycardia
- hypotension
- Cardiac failure due to high CO
CV
What body system may cause hyperthermia in the following clinical signs
- Increased ventilation
respiratory
What body system may cause hyperthermia in the following clinical signs
- Acute tubular necrosis
- low urine output
Renal
What body system may cause hyperthermia in the following clinical signs
- Intestinal ischemia infarction
- translocation of bacterial
GI
What body system may cause hyperthermia in the following clinical signs
- Production of PGE2
- Failure of function
Hepatic
What body system may cause hyperthermia in the following clinical signs
- severe hypoglycemia
- depletion of glycogen stores
Metabolic
What body system may cause hyperthermia in the following clinical signs
- Neurologic dysfunction
- delirium, coma, or seizures
Neurological
How do you convert from celsius to Fahrenheit
Celsius temp x 1.8 + 32 = X
An animal has a temp of 36.5 C. What is this temperaure in F
(36.5 x 1.8) + 32 =97.7F
When the patient is done with surgery, drapes are removed, instruments and nonessential monitors from patient, what is left on the animal?
Leave ETCO2 +/- SpO2
palpate pulses or use stethoscope
After surgery when inhalent is turned off, empty the reservior bag into the scaveging system. What do you turn the O2 flow rate up to?
Rule of thumb: double of what is was during surgery
Normally it is turned up to 50-100 ml/kg/min
In simple terms how do you define dysphoria?
Lights are on but no one is home
In simple terms how do you define pain
Lights are on and someone is home
Now the patient is extubated, how long should you monitor the temp of the animal and what temp should be try and reach?
15-30 min until 98F
When should you assess pain for a patient?
While they are awake and conscious. NEVER while they are stil asleep/ under anesthesia
When should the animal be released to the owner?
When the animal is able to walk out on their own
What sort of instruction should you provide the owner/caretaker?
- Written discharge instruction
- Verbal Instructions
(Try to do this before you bring the patient in the room as the client will get easily distracted)
What should be on the Discharge Instruction
- what behaviors to expect
- Restrict activity and/or limit areas of house
- Recheck date and if and when sutures need to be removed; any badges to monitor/change
- When to offer food and water and how much
- When to start any meds and should they be offered with food
- Signs they should monitor their pet for and when to call if concered
What treatment orders are included in post operative care for hospitilized patients?
- vitals
- serial pain scoring
- Body weight
- Urine and feces output
- Hydration status
- Feeding and water instruction or NPO
- IV fluids
- Exercise and other physical activity
- all other nursing care instructions
What is the IVF (IV fluids) maintenance rate for treatment
40-60 ml/kg/day
You need to set up a 20kg dog on a maintenance IVF rate of normasol-M (Maintenance) after surgery. What would you set the fluid pump at (in mL/hr) to meet this patients maintenacne needs? Assume no dehydration, ongoing, or insensible looses are occuring
20 kg x 50 = 1000
1000 or 1 L / day
1000 / 24 =41.66 mL/hr
for normal pt / nurse records say 40 mL/hr to make it easier
What is prolonged recovery?
Ecexssive time from discontinuation of inhalant anesthesia and the patient has not been extubated (30-45 min)
- prolonged time to standing horses (around 1 hour)
- check vitals
- actively warm pt if needed
- Check electrolytes and BG
- Consider reversal of certain drugs
- IV fluids +- dextrose and/or Ca2+
