Unit 3: Hypothermia

Question 1

Thermoregulation

Answer 1

• physiological response that occurs in the anterior (cooling) and posterior (heating) hypothalamus
• hypothalamus responds to temperature information sent to the brain from peripheral and central thermoreceptors in the skin, limb muscles, and spinal cord

Question 2

Convection

Answer 2

• heat is dissipated through convection

- being exposed to cool air or water

Question 3

Conduction

Answer 3

-loss of heat to cold object

Question 4

Evaporation

Answer 4

-loss of heat through sweating

Question 5

Risk Factors in Hypothermia for Older Adults

Answer 5

• ability to regulate body temperature and to sense cold lessens with age
• likely to have a medical condition that will affect temperature regulation
• may not be able to communicate when they are cold
• may not be mobile enough to get to a warm location

Question 6

Risk Factors for Hypothermia in the Very Young

Answer 6

• children loose heat faster than adults b/c of a larger percentage of body surface area for their weight
• children loose more heat through their head
• children may not have the judgment to dress properly in cold weather or to get out of the cold when they should
• infants have less efficient mechanisms for generating heat

Question 7

Risk Factors for Hypothermia in Psychiatric Problems/Diminished Capacity

Answer 7

• condition(s) interfere with judgment (e.g. may not dress appropriately for the weather or understand the risk of cold weather)
• people w/ dementia may wander from home or get lost easily, more likely to be stranded outside in cold or wet weather

Question 8

Risk Factors for Hypothermia in alcohol and drug use

Answer 8

• alcohol may make your body feel warm inside, but it causes your blood vessels to dilate, resulting in more rapid heat loss from the surface of your skin
• using alcohol or recreational drugs can affect your judgment about the need to get inside or wear warm clothes in cold weather
• if a person is intoxicated and passes out in cold weather, the risk of hypothermia is high

Question 9

Risk Factors for Hypothermia in Certain medical conditions

Answer 9

• some medical conditions affect the body’s ability to regulate body temperature such as hypothyroidism, poor nutrition, stroke, sever arthritis, Parkinson’s disease, trauma, spinal cord injuries, and burns
• some medical conditions affect sensation in the body’s extremities, such as peripheral neuropathy with diabetes, dehydration, or any condition that limits activity or restrains the normal flow of blood

Question 10

Risk Factors for hypothermia in Medications

Answer 10

some medications can change the body’s ability to regulate such as certain antidepressants, antipsychotics, and sedatives

Question 11

Mild Hypothermia

Answer 11

body’s core temperature drops to 89.6 to 95 degrees F
-human body tries to compensate for decreases in body temperature by stimulating the sympathetic nervous system to shiver and increase HR, BP, Respirations, and promote peripheral vasoconstriction

Question 12

Clinical Manifestations of Mild Hypothermia

Answer 12

• Shivering
• Tachypnea; causing a decrease in CO2, resulting in respiratory alkalosis
• Hyperglycemia b/c of a decrease in glucose use by the cells and a decrease in insulin secretion d/t an increase in corticosteroid levels
• Cold diuresis develops as a result of peripheral vasoconstriction, hyperglycemia, and decreased renal tubular absorption
• mild confusion, ataxia (impaired balance and coordination), and diminished fine motor movements

Question 13

Moderate Hypothermia

Answer 13

body’s core temperature drops to 82.4 to 89.6 Degrees F

• shivering becomes more violent and eventually stop
• deterioration in the patients mental status (agitation, hallucination) that, if left untreated, progresses to coma

Question 14

Clinical Manifestations of Moderate Hypothermia

Answer 14

• shivering more violent; eventually stops
• deterioration in mental status (agitation, hallucination) that, if left untreated, progresses to coma
• pupils dilate, and movements become less coordinated as a result of CNS depression
• blood shunts away from the skin surface to preserve heat (compensatory mechanism)
• compensatory mechanisms begin to fail; bradycardia, hypoventilation, and hypoxemia
• myocardial irritability begins to develop w/ increasing bradycardia and decrease in spontaneous depolarization of the pacemaker cells; increases risk for dysrythmias such as atrial fib, ventricular fib, and ventricular tachycardia
• metabolic rate slows and respiratory and lactic acidosis develops
• develop hypokalemia b/c potassium shifts into the cell

Question 15

Severe Hypothermia

Answer 15

body’s core temperature is lower than 82.4 Degrees F

• body begins to shut down
• compensatory mechanisms that cause vasoconstriction ad shunting blood away from the skin to vital organs in an effort to retain heat completely fail
• there is a massive dilation of vessels moving blood back to the surface of the skin, causing further cooling and also resulting in further deterioration of cardiovascular, respiratory, and neurological functions

Question 16

Clinical Manifestations of Severe Hypothermia

Answer 16

• compromised cardiovascular, respiratory, and neurological functions
• compensatory mechanisms completely fail
• decreased CO, arterial pressure, and basal metabolic rate, resulting in severe cerebral hypoperfusion
• severely hypotensive
• myocardial irritability worsens
• muscle rigidity develops
• eventually body completely shuts down and patient dies

Question 17

Diagnosis: What to assess

Answer 17

• Mechanism of Exposure; ambient temperature, enclosed or opened space (was the person in a protected area or out in the open), did the exposure include water?
• Time of exposure
• Length of time since the incident
• Predisposing factors such as mental status, alcohol, drugs
• Past medical hx that may predispose patient to hypothermia

Question 18

Treatment

Answer 18

• Focus on ABCs!
• ensure adequate airway and effective ventilation
• insert an IV line
• start IV fluids
• Passive external rewarming for mild hypothermia
• Active external rewarming for mild to moderate hypothermia
• Internal rewarming for moderate to severe hypothermia

Question 19

Complications In Rewarming the Patient with Hypothermia

Answer 19

• rewarming too rapidly can cause hyperkalemia as potassium shifts out of the cells and a condition known as “afterdrop”
• limit invasive procedures and overall movement of the patient when severely hypothermic b/c of a greater susceptibility to dysrythmias
• cardiac arrest can be suspected

Question 20

“Afterdrop”

Answer 20

• a precipitous reduction in core temperature due to redistribution of body heat to improperly warmed peripheral tissues, with rapid shunting of cold blood from the periphery to the core as the direct result of vasodilation
• causes a bolus of cold, hyperkalemic, acidotic blood to return from the periphery to the heart, which results in biochemical injury that leads to severe hypotension and dysrythmias

Question 21

Nursing Management: Assessment and Analysis

Answer 21

• Shivering is the body’s first compensatory mechanism in an attempt to raise the body’s temperature
• Muscle groups around the vital organs begin to shake in small movements in an attempt to create warmth by expending energy
• other mechanisms are activated as core body temperature decreases, such as vasoconstriction to shunt blood away from the skin to vital organs
• as compensatory mechanisms fail, massive vasodilation occurs, resulting in profound changes in neurological, respiratory, and cardiovascular status

Question 22

Nursing Diagnoses

Answer 22

• Ineffective airway clearance
• Impaired gas exchange
• Deficient fluid volume
• Impaired skin integrity

Question 23

Nursing Assessments for Hypothermia

Answer 23

• Vital signs including temperature (rectal, or automatic continuous temperature probe) and pulse oximetry
• Neurological Status
• Lab values: ABGs, Potassium, and Glucose

Question 24

Assessment: Vital Signs

Answer 24

• initial temperature to determine degree of hypothermia, then ongoing vital sign monitoring to assess effectiveness of treatment
• initial vital signs reflect tachycardia and hypertension resulting from stimulation of the SNS in an attempt to compensate for the hypothermia
• hypotension and bradycardia may eventually occur b/c of massive dilation

Question 25

Assessment: Neurological status

Answer 25

profound hypothermia produces a deterioration in neurological status

Question 26

Assessment: Arterial Blood Gases

Answer 26

• may reflect a metabolic acidosis secondary to decreased flow and shunting
• may reflect respiratory alkalosis d/t tachypnea

Question 27

Assessment: Potassium

Answer 27

• hypokalemia occurs initially b/c of cellular shifts

- later during rewarming, hyperkalemia may occur

Question 28

Assessment: Glucose

Answer 28

b/c risk for hyperglycemia and hypoglycemia

Question 29

Nursing Actions

Answer 29

• Administer O2; prepare to intubate w/ severe respiratory depression
• Continuous cardiac monitoring
• Establish IV Access
• Prepare for appropriate rewarming technique
• Cardiopulmonary bypass/extracorporeal membrane oxygenation (ECMO)

Question 30

Actions: Administer O2; prepare to intubate w/ severe respiratory depression

Answer 30

-airway compromise may be present b/c of decreased LOC

Question 31

Actions: Continuous Cardiac Monitoring

Answer 31

• myocardial irritability develops w/ a decrease in spontaneous depolarization of the pacemaker cells
• change in excitability increases risk for dysrythmias such as atrial fibrillation, ventricular fibrillation, and ventricular tachycardia

Question 32

Actions: Establish IV access

Answer 32

-necessary for administration of warm fluids and medications

Question 33

Actions: Prepare for appropriate rewarming techniques

Answer 33

• remove from cold environment
• remove wet clothing
• dry patient
• warm blankets
• heat lamp
• warmed IV fluids
• peritoneal, bladder, and thoracic lavage w/ warmed fluids

Question 34

Actions: Cardiopulmonary bypass/extracorporeal membrane oxygenation (ECMO)

Answer 34

warming techniques increase in complexity and invasiveness as hypothermia worsens

Question 35

Patient Teachings

Answer 35

• Signs and symptoms of early hypothermia

- The risk of overindulgence in alcohol or recreational drugs and hypothermia

Question 36

Teaching: The risk of overindulgence in alcohol or recreational drugs and hypothermia

Answer 36

• alcohol may make the body feel warm inside, but it causes blood vessels to dilate, resulting in more rapid heat loss from the surface of the skin
• using alcohol and drugs can affect judgment about the need to get inside or wear warm clothes in cold weather conditions

Question 37

Evaluating Care Outcomes

Answer 37

• successful tx requires prompt assessment, continuous monitoring, and careful rewarming
• well-managed patient is discharged with a normal temperature, dysrhythmia free, and an understanding of how to avoid future occurrences

Question 38

Connection Check: The nurse should monitor for which clinical manifestations in the patient diagnosed with mild hypothermia? (select all that apply)
A. Ataxia
B. Shivering
C. Cardiac dysrhythmias
D. Oliguria
E. Hypoglycemia

Answer 38

A. Ataxia

B. Shivering