Assessment Final - Thermoregulation

Front 1

Babies at risk for temp instability (12!)

Back 1

-Inappropriate environment

-Malfunctioning equipment

-Transported babies

-Preterms

-SGA (not enough fat)

-Endocrine problems

-Cardiorespiratory abnormalities

-Abdominal wall defects

-Spinal defects

-CNS abnormalities / damage

-Neuromuscular abnormalities (hypotonia = not flexed = loss of heat)

-Sepsis

Front 2

Clinical presentation of hypothermia (9)

Back 2

-Pale

-Cool to touch

-Acrocyanosis

-Central cyanosis

-Apnea

-Bradycardia

-Respiratory distress

-Irritability --> lethargy

-Feeding intolerance

Front 3

Defenses against heat loss (4)

Back 3

1. flexed position of healthy term infant

2. Peripheral vasoconstriction

3. Shivering thermogenesis

4. Nonshivering thermogenesis

Front 4

Shivering thermogenesis

Back 4

Poorly developed in NBN

Cold --> brain stem --> spinal cord --> anterior motor neurons --> increased muscle tone --> increased muscle metabolism --> heat production

Front 5

Non shivering thermogenesis

Back 5

Main method of heat production for newborn

Cold stress --> hypothalamus -->epinephrine --> brown fat metabolism (TEMPORARY, only in nbn)

Front 6

What is the function of brown fat? When does it develop?

Back 6

ONLY function is heat production

Develops ~ 26 weeks GA through 3-5 weeks post-birth

Accounts for 1/10th adipose tissue in full term

Appearance: smaller vacuoles than white fat (increased glucose, mitochondria, sympathetic nerves, blood supply)

Front 7

Location of brown fat metabolism

Back 7

mid scapula

back of neck

under clavicles

abdominal aorta

esophagus

mediastinum

trachea

heart

liver

kidneys

adrenal glands

Front 8

Brown fat ______ releases heat into the _______

Back 8

Brown fat lipolysis releases heat into the circulating blood

- transfers heat to other parts of body

-NEEDS increased O2 and glucose

Front 9

What happens if body can't keep up with the metabolic demands of cold stress?

Back 9

increased metabolism 100% by 15-30 min, increased to 170% by 1 week of age (term infant)

--> leads to respiratory distress, loss of weight, failure to gain weight, decreased surfactant production, pulmonary vasoconstriction, hypoxia

Front 10

Classifications of hypothermia (mild/mod/severe)

Back 10

Mild - 36.0-36.4

Moderate - 32-35.9

Severe - < 32

Front 11

Mild vs severe thermal stress effects

Back 11

Mild - helps establish respiration, thyroid and catecholamine surge

Severe - acidosis, hypoxia, hypoglycemia, DIC, IVH, shock, death

Front 12

Why tub bath over sponge bath?

Back 12

Tub bath - decreases temperature loss, no differences in umbilical cord healing, behavior more content

Front 13

What should you do in delivery room for babies < 1500 gm or at high risk of hypothermia?

Back 13

-Bowel bag / plastic wrap

-Place on blanket covered thermal mattress

-Double hat

Front 14

Conduction

Back 14

direct contact with scales, blankets, diapers, etc

Minimize: prewarm incubator, cover scales/xray plates, prewarm hands, stethoscopes, blankets, and equipment

Front 15

Convection

Back 15

Depends on air temp, air flow, relative humidity, clothes, hat

Head is 21% of body surface (brain produces 44% of heat)

Minimize: increase environmental temperature, eliminate drafts, cover baby's head, dress baby, heat O2

Front 16

Evaporation

Back 16

Loss of heat when water evaporates from skin & respiratory tract; depends on air flow and humidity

BIGGEST SOURCE OF HEAT LOSS

58 calories lost for every gram of H20 evaporated

Minimize: Dry and remove wet blankets or use plastic, increase temp, increase humidity, no drafts, heat & humidify O2, warm solutions before contact with baby, delay 1st bath until temp stable

Front 17

Radiation

Back 17

Radiation to walls, windows, objects NOT in direct contact

Minimize: keep baby away from outside walls & windows, dress baby, use double walled incubator, mylar blankets for transport

Front 18

Major concern with rewarming too quickly

Back 18

BP may drop as baby re-warms

Vasoconstriction ---> Vasodilation

Front 19

What is the recommendation for re-warming?

Back 19

1 degree C / hr

OR

0.5 degree C/ hr if < 1200 gm, < 28 weeks, if temp is < 32

*Set control temp 1-1.5 C higher than infant's current skin temperature

Front 20

Weaning from isolette requirements

Back 20

After 30-32 weeks and/or 1500 gms

When temp stable at 28 C or less in an isolette for at least 12-24 hrs

Front 21

Can you warm a cold preemie by putting more clothes on or more blankets?

Back 21

NO!!! Need external heat source / skin to skin warmth

Front 22

Hyperthermia clinical presentation (6)

Back 22

-Hypotension

-Apnea

-Tachypnea

-Dehydration

-Seizures

-Sweating