Test 5 Thermoregulation Flashcards
Thermoregulation
Mammals ability to self-regulate their body temperature irrespective of the environmental factors
Hyperthermia
Above normal temperature
Normothermia
Normal temperature
Hypothermia
Lower than normal temperature
Thermoregulation goal during surgery is?
Maintain normal body temperature
What are the risks for deviation from normothermia in surgery?
Anesthesia
OR environment
Open body cavities
Ways to measure surgery pt temperature..
Foley catheter
Rectal probe
Describe hypothermia in more detail
Body temp below 35 degrees C
Potentially dangerous/ costly
60% experience some hypothermia
Goal is to be proactive
Hard to reverse once cold
Maintaining normothermia..
Core temp 35C/ 98.6F
Hypothalamus controls
Shouldn’t vary more then 0.5C
Varies with environment
Maintaining normothermia naturally
Cold responses
Thermogenesis- shivering
Vasoconstriction
Cold response
Constricts peripheral vessels to conserve heat in the core
Thermogenesis- shivering
Most common
-Increase in o2
-Stress on respiratory and cardiovascular system
-uncomfortable for most
Post op shivering is common
Thermogenesis- non shivering
Unique to infants
Burning of “brown fat”
- more heat then adipose tissue
- lost as people age
Heat loss- radiation
Loss to OR environment
Ex cold room
Heat loss- convection
Lost to air currents
Ex fans
Heat loss- conduction
Heat loss to cooler surface
Ex OR table
Heat loss- evaporation
Loss due to perspiration or respiration
Heat loss- perioperative
Anesthesia- decrease metabolism and inhibits cold responses
Hypothermia complication-
wound infection
Impairs ability to resist infection
Vasoconstriction > decreased blood pressure> tissue hypoxia> increased wound infection
Hypothermia complication-
Cardiac dysfunction
Cardiac arrest
Unstable angina or ischemia (first 24 hours)
Hypothermia complications-
Coagulopathy
Impairs platelet aggregation= increase bleeding time
Hypothermia complications-
Altered drug effect
Affects neuromuscular blocking agents, local anesthesia, and CV drugs
Hypothermia complications-
Increased mortality
Increase fluids, transfusion, and vasopressors= increase organ dysfunction and death
Hypothermia complications-
Prolonged recovery time
Longer PACU stays to meet temperature discharge requirements
Inducing hypothermia
Intentional
Rewarmed at conclusion
Manipulated by cardiopulmonary bypass machine
What are ways to prevent Hypothermia
Easier to prevent then to treat
Raise OR temp
Limit skin exposure
Cover the head
Warm cotton blankets
-Passive method- don’t provide heat to core body
- insulators which reduce heat loss by 30%
Thermal drapes
Aluminum
Reflects heat back
Reduces intraop loss
Not actively providing heat
Fluid warmers
Blood products stored at 34-43F
By immersion in H2O
By IV warming unit
Fluid warmers
Irrigation warmer
From warmed bottles
Maintained at 89-105F
Hemolysis occurs if above 110F
Infrared lights
L&D department
Aka radiant heat
Direct exposure to skin
Conductive warming
Water mattress
Circulates water through the blanket
infection risks
Bair hugger
Convection warmer
Effective prevention/ treatment
Self supporting cocoon
Contraindicated in aortic cross-clamping
Malignant hyperthermia
Rare- reaction to anesthetic agents
Inherited genetic predisposition to MH
Symptoms
- rapid temp increase
- tachycardia
- muscle rigidity
- acidosis
Malignant hyperthermia- tx
MH cart
Drugs dantrolene and ryanodex
Pack groin, axilla, and head with ice
Cold irrigation in body cavities
St role in Malignant hyperthermia
Follow anesthesia directions
Protect sterile field
Acquire cold irrigation
Retrieve MH cart
