Newborn Physiologic Adjustments (Thermogenic System)

Question 1

During the first _____ hrs after birth the neonate attempts to achieve thermal balance in adjusting to eh extrauterine environment temperature.

Answer 1

12 hrs.

Question 2

What is thermoregulation?

Answer 2

Is the maintenance of balance between heat loss and heat production.
Newborns attempt to stabilize their core body temp within a narrow range.

Question 3

What is a common and dangers problem due to excessive heat loss?

Answer 3

Hypothermia

Question 4

Why are newborns so susceptible to hypothermia?

Answer 4

Thin layer of subcutaneous fat.

Blood vessels very superficial.

Question 5

Why does the blood vessels being superficial in newborn cause heat loss?

Answer 5

Changes in environmental temp alter the temp of the blood, thereby influencing temp regulation centers in the hypothalamus.

Question 6

What is the thermo goal for care for newborns?

Answer 6

Neutral thermal environment in which heat balance is maintained.

Question 7

Explain neutral thermal environment.

Answer 7

Is the ideal environmental temp that allows the neonate to maintain a normal body temp that allows the neonate to maintain body temp to minimize oxygen and glucose consumption.

Question 8

Heat loss in newborns occurs by what four modes?

Answer 8

1. Convection
2. Radiation
3. Evaporation
4. Conduction

Question 9

What is convection?

Answer 9

Is the flow of heat from the body surface to cooler ambient air.

Question 10

What are some interventions for convection heat loss?

Answer 10

Nursery is keep at 75.2 F and 24 C.

Cap and swaddle infants to prevent.

Question 11

What is Radiation?

Answer 11

Is the loss of heat from the body surface to a cooler solid surface not in direct contact but in relative proximity.

Question 12

What are some interventions for radiation heat loss?

Answer 12

Cribs and examining tables are placed away from outside windows, and care is taken to avoid direct air drafts.

Question 13

What is Evaporation?

Answer 13

Is the loss of heat that occurs when a liquid is covered to a vapor. In the newborn heat is loss by evaporation occurs as a result of vaporization of moisture from skin.

Question 14

What are some interventions for evaporation heat loss?

Answer 14

Dry the infant quickly and thoroughly.

Question 15

What is the most significant cause of heat loss in the first few days of life?

Answer 15

Evaporation heat loss, as a component of insensible water loss.

Question 16

What infant is more prone to more severe evaporation heat loss?

Answer 16

The less mature newborn.

Question 17

What is conduction?

Answer 17

Is the loss of heat from the body surface to cooler surfaces in direct contact.

Question 18

What are some intervention to prevent conduction heat loss?

Answer 18

Newborns placed in a warmed crib.

Scales warmed or coved before weighing newborn.

Question 19

What is one method for promoting thermoregulation and maternal newborn interaction?

Answer 19

Place naked newborn on mother’s bare chest and over both with a blanket.

Question 20

What does skin-to-skin contact reduce and enhance?

Answer 20

Reduces conductive and radiant heat loss

Enhances newborn temperature control and maternal-infant interaction.

Question 21

In response to cold the neonate attempts to generate heat by increasing muscle activity. What is this called?

Answer 21

Thermogenesis

Question 22

What thermogenesis techniques will infants perform?

Answer 22

Crying
Appearing restless
Position of Flexion
Constriction of blood vessels

Question 23

In an effort to conserve heat, what might an infant do?

Answer 23

Obtain the position of flexion. This reduces body surfaces exposure to the environment.

Question 24

What will an infant do to reduce internal heat loss?

Answer 24

Constricting peripheral blood vessels.

Question 25

Newborns produce heat though…

Answer 25

Non shivering thermogenesis

Question 26

How is non shivering thermogenesis accomplished?

Answer 26

By metabolism of brown fat.

Secondarily by increased metabolic activity in the brain, heart, and liver.

Question 27

Where is brown fat located?

Answer 27

Located in superficial deposits in the inter scapular region and axillae and in deep deposits at the thoracic inlet, along the vertebral column, and around the kidneys.

Question 28

How do reserves of brown fat deplete?

Answer 28

Usually present for several wks after birth, are rapidly depleted with cold stress.

Question 29

What happens to the respiratory rate in response to cold stress?

Answer 29

Increases due to need for O2

Question 30

In the cold-stressed infant O2 consumption and energy are diverted from maintaining normal brain and cardiac function and growth to….

Answer 30

Thermogenesis for survival.

Question 31

What happens if the infant cannot maintain adequate O2 tension?

Answer 31

Vasoconstriction follows and jeopardizes pulmonary perfusion. As a consequences the Po2 is decreased, and the blood pH drops.

Question 32

What can decreased pulmonary perfusion and O2 tension do?

Answer 32

Maintain or reopen the right-to-left shunt across the ductus arteriosus.

Question 33

What is considered hyperthermia in newborns?

Answer 33

Temp greater than 37.5 C or 99.5 F is considered to be abnormally high

Question 34

What is hyperthermia in usually caused by?

Answer 34

Related to sepsis or a decrease in heat loss.

Question 35

Infants who are overheated because of environmental factors such as being swaddled in too many blankets exhibit signs of heat-losing mechanisms:

Answer 35

Skin vessels dilate
Skin appears flushed
Hands and feet are warm to touch
Infant assumes a posture of extension

Question 36

Hyperthermia b/c of sepsis appears stressed:

Answer 36

Vessels in the skin are constricted
Color is pale
Hands and feet are cool

Question 37

Serious overheating of newborn can cause…

Answer 37

Cerebral damage from dehydration or even heat stroke and death.