module 8 Flashcards
evaporation
heat loss due to evaporation of liquid from the body
conduction
transfer of heat by direct contact with a cooler object
convection
heat transfer from the newborn to the surround air
radiation
transfer of heat from or the newborn from or to nearby surface
risk for heat loss
- high body surface to mass ratio
- blood vessels are close to the surface of the skin
how do infants produce heat
brown fat
respiratory : chemical stimuli
- cessation of placenta blood flow
- decreased O2 - mild hypoxia
- increase of carbon dioxide - decrease of pH (acidosis)
- stimulation of respiratory center in medulla
- stimulation of respirations
respiratory : mechanical stimuli
- delivery of face = loss of variable amounts of amniotic fluid from lungs
- delivery of chest = expansion of chest to pre-delivery proportions - negative pressure - passive inspirations of air - first breath
- entry of air into alveoli replacing the expelled amniotic fluid
- lung fluid is reabsorbed via lymphatic system
- neonate crying - intrathoracic positive pressure
- alveoli remain open
what stimulates breathing?
- cord is clamped and placenta cannot provide gas exchange
mechanical mechanism to absorb fluid in lungs
squeezing through the birth canal create a negative pressure and recoil
what helps absorb fluid in lungs?
crying
- once air enters the lung and crying happens, it pushes the fluid out of alveoli
cyanosis : clinical considerations
- acrocyanosis (blue color of the neonate’s hands and feet) = normal in the first 24 h postpartum
- central cyanosis, which is indicated by bluing of the lips and chest, is abnormal
- transient cyanosis when crying is not uncommon immediately after birth
apnea: clinical considerations
- cessation for breathing for 20 s or more is concerning
- shorter periods of apnea in the absence of other signs of distress are considered normal
- apnea over 20 s may indicate sepsis, hypothermia, hypoglycemia, or another problem
tachypnea: clinical considerations
- neonates typically take 30-60 breaths per minute
- sustained tachypnea is abnormal and may indicate respiratory distress syndrome or fluid in the lungs
- it may indicate infection or cardiac metabolic illness
intercostal or substernal retractions: clinical manifestations
- retractions are pulling in of tissue with each breath and indicate reduced pressure inside the lungs, likely because of occlusion of the upper airways
grunting: clinical considerations
- grunting with expiration occurs with a partially closed glottis
- this partial occlusion increases the pressure within the lungs so more oxygen can diffuse into the bloodstream =
- grunting may be auscultated with a stethoscope, or in more severe cases, heard without assistance
nasal flaring: clinical considerations
- nasal flaring expands the airway and reduces airway resistance
seesaw breathing: clinical manifestations
the chest and abdomen rise simultaneously in the absence of respiratory distress
- seesaw breathing, like retractions, suggest partial blockage of the airways
stridor: clinical considerations
- stridor, which is an abnormal, high-pitched breath sound, a sign of upper airway obstruction
gasping: clinical considerations
sign of upper obstruction
adapting to extrauterine life - cardiac
- first breaths dilate pulmonary vasculature = pulmonary vascular resistance = increased blood return from lungs to left atrium (higher pressure than right atrium causes closing of foramen ovale)
- ductus arteriousus closes within a few days after birth
- clamping of the umbilical cord causes decreased blood flow to the ductus venous, which will then begin to atrophy
physiological changes : circulatory system
- initiation of changes
- ductus venosus : closes by day 3
- foramen ovale: closes when pressure is the LA is higher than RA
- ductus arteriosus: closed within 15 hrs/ RT decreased pulmonary resistance
vitamin K
- infants git is sterile and does not have the bacteria needed to make vitamin K, which is used by the body to help blood clot
- an injection of vitamin K is given to prevent a pathologic bleed
GI system: physiological changes
- gastric emptying time 2-4 hrs; babies need to eat every 2-4 hours
- 5-10 mL capacity initially (stomach can only hold this much)