Nursing 568 Flashcards
You’ve put your blood sweat and tears into studying. Which of the prior would be antagonized by Atropine? (Select 2.)
Sweat & Tears are Correct!
*Blocks the action of ACH.
Inhibit parasympathetic Nervous System (aka antiparasympathetic).
*Inhibiting salivary & mucous glands.
*Atropine (AKA antimuscarinic agent since antagonizes muscarinic affects of ACH)
*Muscarinic (exocrine glands, smooth muscle and cardiac muscle)
*What blocks atropine? Need to increase ACH at receptor site: anticholinesterase agent
*Parasympathetic Nervous System (rest and digest system) responsible for involuntary movement of muscles in GI tract, Lungs, urinary tract
*Anticholinergic Can cause DECREASE IN SWEATING WHICH INCREASES BODY TEMPERATURE
What are the physiologic effects of hypothermia?
- Increased SVR and myocardial depression
- Increased blood viscosity
- Impaired coagulation/thrombocytopenia
- Increased metabolic rate (shivering)
- Increased cardiac work
- Increased oxygen requirements
- Decreased oxygen consumption
- Decreased cutaneous blood flow
- Cardiac dysrhythmias
What is the Inter-threshold range in which the body does NOT initiate thermoregulation?
- Range .2 to 0.4 degrees C
- GA depress hypothalamic responses which widens the inter-threshhold range up to 4 degrees C
- Patients under anesthesia are less able to adjust to temperature changes that occur during treatment.
What are the guidelines for temperature monitoring and thermal management?
- Core body temperature should be measured in most patients given general anesthesia for longer than 30 minutes.
- Temperature should also be measured during regional anesthesia when changes in body temperature are intended, anticipated, or suspected.
- Unless hypothermia is specifically indicated (e.g., for protection against ischemia), efforts should be made to maintain intraoperative core temperature higher than 36° C.
What are the objectives of temperature monitoring and thermal management?
The objectives of temperature monitoring and perioperative thermal management are to detect thermal disturbances and to maintain appropriate body temperature during anesthesia.
Describe Efferent Responses (Motor) phase of thermoregulatory processing.
- Behavior is the most effective response for thermoregulation: dressing appropriately, modifying environmental temperature, assuming positions that appose skin surfaces, and moving voluntarily
- Efferent outputs from the hypothalamus regulate body temperature by altering SQ blood flow, sweating, skeletal muscle tone and overall metabolic activity
- Heat Loss: promoted by vasodilation and sweating (heat is conserved by inhibiting these processes)
- Production of heat (thermogenesis) is promoted by shivering and increase in metabolic rate
- When specific effector mechanisms are inhibited (e.g., when shivering is prevented by administration of muscle relaxants), the tolerable range is decreased
Describe Central Regulation phase of thermoregulatory processing.
- Temperature is regulated by the hypothalamus
- Temperature control involves several neurotransmitters: norepinephrine, dopamine, 5-hydroxytryptamine (serotonin), acetylcholine, prostaglandin E1, and neuropeptides.
- Additional factors such as circadian rhythm, exercise, food intake, infection, thyroid dysfunction, menstrual cycle, anesthetic and other drugs (including alcohol, sedatives, and nicotine), and cold and warm adaptation alter threshold temperatures.
Describe Afferent Input (Sensory) phase of thermoregulatory processing.
- Afferent input is triggered by thermal sensitive cells found not only in skin but throughout the body.
- Cold receptors primarily travel via Aδ nerve fibers and warm receptors by unmyelinated C fibers
- The C fibers also detect pain sensation, and that is why intense heat cannot be distinguished from sharp pain.
- Thermal information traverses the spinothalamic tracts to the primary thermoregulatory centers within the hypothalamus.
How do general anesthetics impact temperature regulation?
- Impair the body’s ability to regulate core temperature by inhibiting central nervous system temperature control and peripheral temperature conservation mechanism.
- Most General Anesthetics cause direct vasodilation, increasing skin blood flow, skin temperature and surface heat loss.
- More vasodilation with Propofol than with Inhaled Anesthetics (IA).
- Minimum alveolar concentration (MAC) is reduced by 5% for each degree in C below normal
Describe Thermoregulation
*Thermoregulation is a process that involves a continuum of neural structures and connections extending to and from the hypothalamus and limbic system through the lower brainstem and reticular formation to the spinal cord and sympathetic ganglia.
*Temperature maintained between 36-38 *C
(core body temperature)
Hypothermia <36 *C
Hyperthermia >38 *C
Normothermia= 37 *C
What quality measure project allows us to compare hospitals care?
Surgical Care Improvement Project (SCIP)
The SCIP National Quality Core Measures are evidence-based clinical care guidelines that are audited and reported to a national database and have been used as a quality measure to compare hospitals.
Initially, the SCIP measures were created to reduce the incidence of hospital-acquired infection, deep venous thrombosis, pulmonary embolus, and ischemic cardiovascular events.
Medicare Pay for performance measure outcome (temperature) & performance (warming)
What initiative strives to improve U.S. healthcare quality and reduce costs?
Pay for Performance (P4P). The Centers for Medicare & Medicaid Services (CMS) and America’s Health Insurance Plans (AHIP) released their first set of clinical quality measures as part of their Core Quality Measures Collaborative – an initiative that aims to reach consensus among public health plans, commercial insurers, physician groups and other stakeholders on major quality measurements. The collaborative supports the recent shift toward value-based care, which stems from America’s predicament of high costs and subpar quality in health care.
American Healthcare: Higher Cost and Lower Quality
What is the major cause of hypothermia in most patients?
core-to-peripheral redistribution of body heat.
How is Sweating Mediated?
Sweating is mediated by postganglionic, cholinergic nerves.19 It thus is an active process that is prevented by nerve block or atropine administration.20 Even untrained individuals can sweat up to 1 L/hour, and athletes can sweat at twice that rate. Sweating is the only mechanism by which the body can dissipate heat in an environment exceeding core temperature. Fortunately, the process is remarkably effective, dissipating 0.58 kcal/g of evaporated sweat.
Identify examples of how heat is lost through Radiation, Convection, Evaporation and Conduction.
Heat can be lost through the processes of conduction, convection, radiation, and evaporation. Conduction is the process of losing heat through physical contact with another object or body. For example, if you were to sit on a metal chair, the heat from your body would transfer to the cold metal chair. Convection is the process of losing heat through the movement of air or water molecules across the skin. The use of a fan to cool off the body is one example of convection. The amount of heat loss from convection is dependent upon the airflow or in aquatic exercise, the water flow over the skin. Radiation is a form of heat loss through infrared rays. This involves the transfer of heat from one object to another, with no physical contact involved. For example, the sun transfers heat to the earth through radiation. The last process of heat loss is evaporation. Evaporation is the process of losing heat through the conversion of water to gas (evaporation of sweat).
