Thermoregulation + Cellular Regulation

Normothermia

97-100 F (36.2 -37.6 C)

Hypothermia

Less than 97 F (36.2 C)

Mild hypothermia

34-36 C (93.2-96.9 F)

Moderate hypothermia

30-34 C (86-93 F)

Severe hypothermia

Less than 30 C (86 F)

Hyperthermia

More than 100 F (37.6 C)

Fever

Temporary elevation in the body due to a change in the hypothalamic set point

Fever patterns

Remittent→ Temp spikes and falls w/o returning to normal temp

Intermittent→ Spikes are mixed(interspersed) w/normal levels at least once a day

Sustained → stays consistently high w/normal levels during change

Relapsing → high w/alternate of normal temp

Hyperpyrexia

Extremely high body temperature 106.7 F (41.5 C)

• Medical emergency

How does a fever occur?

1. Microorganisms release Pyrogens (endotoxins) into the blood

2. Pyrogens trigger the hypothalamus

3. The hypothalamus triggers prostaglandins fever response

Symptoms: High HR, fatigue, body aches, decrease Urine Output, potential seizures, dry mucous membranes, etc.

What is the sequence of a fever

1. Hypothalamus

2. Anterior Pituitary→ Release of TSH

3. Thyroid→ Release of Thyroxine

4. Epinephrine release from the adrenal medulla→ Increase in BMR and Vasoconstriction

What does epinephrine do from the adrenal medullar

Increase BMR and vasoconstricts

Body’s thermostat

Hypothalamus

Factors affecting heat production

Chemical/metabolic activity

Skeletal contraction

Chemical thermogenesis

Chemical/metabolic activity

Eating/digesting requires energy and produces heat

• Our Basal metabolism releases heat

Skeletal contraction

More muscle tone=more heat

• Shivering causes contractions to produce heat

Chemical thermogenesis

Release of catecholamines (epinephrine and norepinephrine)

• Thyroxine increases BMR

Factors affecting heat loss

1. Vasoconstriction

• radiation, conduction, convection, evaporation, and vaporization

2. Reduced muscle activity

3. Increased respiration

What is dangerous about hyperthermia?

It does not respond to antipyretics, only external cooling

Radiation

Emits heat from the skin

• Air temperature, skin temperature, exposure

Conduction

Direct contact between surfaces

• Vasoconstriction (increased blood volume to body surface)

Convection

Air currents across skin

• Wet skin/clothing accelerates

Evaporation

Perspiration 600 mL/day, continuous evaporation of moisture from the respiratory tract, mucosa of the mouth, and skin

Reduced muscle activity

Reduction in muscle tone and muscle activity

Increased respirations

Cool ambient air, warm air exhaled

Thermoregulation risk factors

Age, environment, and physiologic condition of the individual

Why is conduction a major issue with babies

Baby’s vessels are closer to the skin so heat loss via conduction is a high-risk issue. ALWAYS KEEP THE BABY DRY AND WARM

What is the goal in neonates/infants

Minimize O2 and glucose consumption

Why are babies prone to hypothermia

1. Proximity of vessels to the skin

2. Little subQ fat

3. Large SA to body weight (mass) ration

• Cellular metabolism may increase to cool the baby (O2 and glucose increase)

What is non-shivering thermogenesis

Baby’s can’t shiver, so they use brown adipose tissue that helps protect organs from extreme temperature changes and transfer heat to the peripheral circulation

Consider this in a child

• They lack the knowledge to protect themselves

• Fever can last +4 days, decrease activity, give toxic appearance, and change behavior

• Seizures

Consider this in a pregnant lady

Hormone levels an first trimester risks

Consider this in older adults

• more sensitive to environmental temp changes

• Slow circulation → decreased vasoconstriction responses, low heat production (slow metabolic rate), decreased shivers, reduced perception of environmental temperatures

• Look for ALOC (first sign of infection instead of fever)

What’s frostbite?

Deep, high exposure to freezing temperatures

• Paraesthesia (numbing) and stiffness are visible

• Ranges from grade 1-4

What is frostnip?

Superficial, limited exposure to freezing temperatures

• Exhibit numbness, pain, and pallor

What can be done in frostbite cases?

• Pain meds, anti-inflammatory and tetanus immunizations

• Rewarming whirlpool therapy

• Bedrest w/affected parts elevated

• Internal rewarming (Warm IV, heated O2, peritoneal/pleural/gastric/bladder lavage)

• In extreme cases: Use hemodialysis (blood rewarmed outside the body)

Highest temp to administer fluid

113 F (45C)

What must you NOT do during frostbite cases

• DONT massage affected area

• DONT compress (may form compartment syndrome)

• NECROTIC TISSUE MAY REQUIRE AMPUTATION so ACT FAST

What does hyperthermia not respond to?

Anti-pyretics (use external cooling techniques instead)

Hyperthermia treatment (cooling techniques)

• Cool blankets, fans, reduce room temp, remove clothing

• Tepid sponge bath (convection)

• Monitor I&O

• Reduce physical activity

• Use antipyretics (except in Heat Exhaustion/Heat Stroke since they don’t work in these cases)

• Induced hypothermia

What is induced hypothermia

Manually lowering temp to 32-36 C (89-96 F)

• Reduced metabolic rate

• Lowers cellular demand for O2 in tissues (esp. brain)

• Reduced neuro damage after CPR, head trauma, stroke, or cardiac surgery

• NOT RECOMMENDED DURING PREGNANCY

Acetaminophen

Antipyretic

• Side effect: Liver Damage

NSAIDSs

Antipyretic

• Side effect: Upset stomach, bleeding, and ulcers

Aspirin

Antipyretic

• Side effect: Reye syndrome

What is malignant hyperthermia

Inherited disorder

• Response to inhalation of anesthetic gases and succinylcholine

• First sign: Increased amount of expired CO2 levels (tachycardia + tachypnea often follow w/fever showing at the last minute)

What can malignant hyperthermia cause

Dysrhythmia, hypotension, hypoxemia, hyoerkalemia, CNS symptoms, DIC, renal injury, coma, and cardiac arrest

Priority interventions

• stop all inhalation anesthetic agents

• Prepare for endotracheal intubation

• Administer 100% oxygen

What had decreased mortality rate caused by malignant hyperthermia in patients

Introduction of Dantrolene (Ryanodex) prevents them from dying

2 screening methods to identify malignant hyperthermia

1. Genetic history/testing

2. Muscle biopsy w/ caffeine halothane contracture test (CHCT)

What is heat exhaustion

Temp may not be elevated but dehydration, HA, weakness, nausea, and vomiting may show up first

What is heat stroke

Can be exertional or nonexertional and caused by heat exhaustion

• Body temp can elevate and cause mental status changes, seizures, coma, hypotension, tachycardia, tachypnea, and elevated troponin levels

• Temp is usually +104 F (40 C)

Hyperthermia vs febrile

During hyperthermia, the brain’s target temperature does not change, the body is just producing or absorbing more heat.

• Febrile is when the body’s set point (brain thermostat) raises the body’s target temperature on purpose to fight off and illness

Cellular regulation

Functions carried out by a cell to maintain homeostasis

• Includes extracellular signals and intracellular responses

How does growth occur

Replication→ Copy of cell

Mitosis→ Cell division

Meiosis→ Sex cell reproduction

Differentiation→ Normal process that allows cells to specialize in certain tasks after many cycles

What if growth doesn’t stop?

Normal cell growth → Dysplasia→ Malignant Neoplasia

Neoplasia

A normal/progressive multiplication of cells (forms neoplasms or tumor)

Neoplasm (tumor)

Benign (non-cancerous) or malignant (cancerous)

Malignant neoplasm

Abnormal growth, disseminates (spreads) to distant sites

What is the process of dissemination (spreading) of cancer cells called

Metastasis

Metastasis (step 1)

Malignant transformation

• Tumor area is formed

Metastasis (step 2)

Tumor vascularization

• Cancerous cells secrete VEGF, stimulates blood vessels to form new channels growing into the tumor area

Metastasis (step 3)

Blood vessel penetration

• Enzymes in tumor cells make holes in the blood vessels. These then enter the blood vessels and travel around the body

Metastasis (step 4)

Arrest and invasion

• Cancer cells clump on blood vessels and invade new tissue areas that, if good to support growth, can cause new turbos (metastatic tumors) at different sites

Stage 0

Carcinoma in situ (pre-cancer)

• Abnormal cells that COULD grow into cancer but has not spread

Stage 1

Early-stage cancer

• Cancer present/not spread

Stage 2-3

Cancer is present AND has spread to NEARBY tissue

• In level 3 the tumor is larger and further

Stage 4

Advanced/metastatic cancer

• Cancer has spread to distant parts of the body

Common tests

Radiography→ X-rays, MRI, CT, Ultrasound, mammograms, and PET scan (done when cancer is known and stage is to be determined)

Direct visualization (colonoscopy)

Lab→ CBC, genetic/tumor marker, chemistry panel

Pathology→ examination of cells and tissue for a diagnosis of malignancy, tissue type, and bone marrow

Treatment goal for neoplasm (tumor) depends on stages, but can be:

1. Curative

2. Control of disease

3. Palliative (may have antibiotics, still treatable)

4. Hospice (comfortable to the end)

3 main treatments for cancer

Surgery, radiation, and drug therapy

4 categories of drug therapy

Cytotoxic agents

Hormone + hormone antagonists

Biological response modifiers

Targeted drugs

What does proper PPE include

• gown and gloves worn within FIRST 48 hrs of admin.

• Face shield if splash may occur

• Wash hands w/soap and water after using gloves + IMMEDIATELY AFTER CONTACTING body fluids and chemo drugs

• Use linen (double and mark linen bath) (use w/gloves if med spills or body fluids are present)

Type of collaborative interventions

Chemotherapy

Radiation

Targeted therapy

Biological therapy

Hormonal therapy

Bone marrow and stem cell transplant

Radiation therapy

Used to damage and kill cancer cells in targeted areas.

• Many forms of delivery and SE management

Targeted therapy

Uses genetic/molecular biology connected to cell functioning. Prevents tumor growth by blocking processes responsible for the growth + spread of the disease

Biological therapy

Uses biological agents to activate the immune system, such as:

• angiogenesis

• Vaccines

• Gene therapy

• Colony-stimulating factors

Hormonal therapy

Treats hormonally responsive cancer

• breast, prostate, and uterine

Hormones act as anti/agonists to block specific receptors w/target tissue

Bone marrow and cell stem transplantation

Replaces diseased/destroyed cells from the bone marrow w/normal healthy cells.

• must be a close match (autologous or allogeneic)

Chemotherapy

Pharmacological agents used to prevent cancer from multiplying, invading, and METASTASIZING

• Gives metastasizing treatment

Obstacles in chemo

• Toxic to normal cells

• Requires 100% cell kill

• Absence of early detection

• Drug resistance

• Bone marrow suppression

Neutropenia

Reduction in neutrophils causing MORE INFECTIONS, fevers, and cultures

• Place in neutropenic isolation

• Neupogen can stimulate granulocytes

Thrombocytopenia

Reduction in circulating platelets causing MORE BLEEDING

• Interluekin 11 may be used w/platelet infusion

• Avoid anticoagulants/antiplatelets

Anemia

Reduction in circulating red blood cells

• Erythropoietin 2/PRBC transfusion

• May cause fatigue, lose weight, etc

Vesicants

Drugs that can result in tissue necrosis or blisters when infused into tissue surrounding veins

Extravagation

Infiltration of chemotherapy into the subQ or subDerm tissue surrounding IV or intra-arterial administration site

common central lines

Subclavian vein

Internal jugular vein

Femoral vein

PICC

Power port vs matter port

Power port can have dyes inserted for pet scans or others without damaging the device

What does phenergan do

Must be placed in an IV that is not leaking to prevent extravagation of an organ

Tumor lysis syndrome

Rapid destruction of tumors can cause large amounts of intracellular contact to be released into the blood than what the body can eliminate

• use fluids, hydration, and drug therapy to prevent this

What does zofran do

Used on chemo and post-op patients