PHYSIOLOGIC AND BEHAVIORAL ADAPTATIONS OF THE NEWBORN

Transition to Extrauterine Life  First period of reactivity  Lasts up to 30 minutes after birth  Newborn’s heart rate increases to 160 to 180 beats/min  Decreases after 30 minutes to baseline rate. Decreases back to 100-120bpm  Infant is alert and has spontaneous startles, crying, and head movement Baby takes that initial breath when they come out and that opens up their lungs. That allows the vascularity of the pulmonary system for the oxygen exchange. Normal heartrate for newborn 120-140bpm and regular. Fine crackles can be present on auscultation. Transition to Extrauterine Life (Cont.)  Period of decreased responsiveness  Lasts from 60 to 100 minutes. Wants to rest, baby is establishing equilibrium with respiratory, skin, renal, and cardiac.  Infant is pink. A type of cyanosis, acrocyanosis is normal (first 24hrs), usually in the hands and feet. Blueness around their lips is abnormal.  Respirations are rapid and shallow up to 60 breaths per minute. Transient tachypnea (breathing rapidly). Transient baby born through c-section/premature and didn’t get that vaginal squeeze needed to remove fluid/secretion out from the lungs, so the lungs are wet. S&S intercostal retracting, nasal flaring. They go to NICU to be observed.  Sleeps or has a marked decrease in motor activity Transition to Extrauterine Life (Cont.)  Second period of reactivity  Lasts from 10 minutes to several hours  Occurs between 2 and 8 hours after birth  Tachycardia, tachypnea occur  Meconium passed. They’re stressed and bowels have started to move  Increased muscle tone, changes in skin color (pinker), and mucus production because they’re getting the mucus out their lungs, from the nose and it’s good to have a suction ball. Babies that have meconium aspirated have risk of developing pneumonia. Don’t stimulate a baby that has aspirated meconium until all meconium have been suctioned out Physiologic Adaptations  Respiratory system  Initiation of breathing – did the baby take spontaneous breaths  Signs of respiratory distress – S&S: nasal flaring, intercostal retractions, grunting with respirations, cyanosis around the mouth, if prolonged RD, they are docile and just kind of lay there. Central cyanosis is abnormal and signifies hypoxemia. With central cyanosis, the lips and mucous membranes are bluish.  Cardiovascular system  Heart rate and sounds – make sure it’s regular. The heart rate for a term newborn ranges from 120- 160bpm.  Blood pressure – the term newborn normal blood pressure: 60/40 -80/50  Blood volume – blood volume from mother stops. What they have is what they have.  Signs of risk for cardiovascular problems – murmur when baby is feeding. Takes a lot of effort/energy for them to feed. They become cyanotic when feeding because their heart cannot adjust EF. Pallor in the immediate post birth period is often a sign of underlying problems such as anemia or marked peripheral vasoconstriction as a result of intrapartum asphyxia or sepsis. Cyanosis other than in the hands or feet, with or without increased work of breathing, can indicate respiratory and/or cardiac problems. The presence of jaundice can indicate ABO or Rh factor incompatibility problems. Physiologic Adaptations (Cont.)  Hematopoietic system  Red blood cells and hemoglobin  Leukocytes  Platelets  Blood groups – need to know ABO and compatibilities, Rh factor and how it affects mothers and babies. The infant's blood group is determined genetically and established early in fetal life. However, during the neonatal period the strength of the agglutinogens present in the RBC membrane gradually increases. Cord blood samples can be used to identify the infant's blood type and Rh status. Physiologic Adaptations (Cont.)  Thermogenic system. Newborns have a thin layer of subcutaneous fat. The blood vessels are close to the surface of the skin. Newborns have larger body surface–to–body weight (mass) ratios than children and adults.  Heat loss – very prone to heat loss because they have a very large surface area. Their head is the largest surface area that’s why they put caps on babies. Drying the infant quickly after birth is essential to prevent hypothermia. Skin-to-skin contact with the mother is an effective means of reducing conductive and radiant heat loss and enhancing newborn temperature control and maternal-infant interaction. The naked newborn is placed on the mother's bare chest and covered with a warm blanket; a cap may be placed on the infant's head to help conserve heat. Alternatively, the neonate is placed under a radiant warmer to reduce heat loss and promote thermoregulation. 1. Convection is the flow of heat from the body surface to cooler ambient air. Newborns in open bassinets are wrapped to protect them from the cold. A cap may be worn to decrease heat loss from the infant's head. 2. Radiation is the loss of heat from the body surface to a cooler solid surface not in direct contact but in relative proximity. To prevent this type of loss, bassinets and examining tables are placed away from outside windows, and care is taken to avoid direct air drafts. 3. Evaporation is the loss of heat that occurs when a liquid is converted to a vapor. In the newborn, heat loss by evaporation occurs as a result of moisture vaporization from the skin. This heat loss is intensified by failing to completely dry the newborn after birth or with bathing. Evaporative heat loss, as a component of insensible water loss, is the most significant cause of heat loss in the first few days of life. 4. Conduction is the loss of heat from the body surface to cooler surfaces in direct contact. During the initial assessment, the newborn is placed on a prewarmed bed under a radiant warmer to minimize heat loss. The scales used for weighing the newborn should have a protective cover to minimize conductive heat loss.  Thermogenesis  Cold stress – they don’t do well with cold stress. Cold infants may cry and appear restless. When baby is stressed by cold they drop in glucose levels. They get hypothermia (biggest one). When baby is handed to transition nurse, they dry the baby off and regulate their temperature so that the baby doesn’t get cold by convection before stimulating the baby. They put them in warmers so that there’s biofeedback. Normal blood sugar: 40-60mg/dL, S&S of low blood sugar: they get jittery, restless. Treatment: wrap baby up, put cap on head, skin to skin contact. The respiratory rate increases in response to the increased need for oxygen. In the cold-stressed infant, oxygen consumption and energy are diverted from maintaining normal brain and cardiac function and growth to thermogenesis for survival. Metabolic acidosis develops, and, if a defect in respiratory function is present, respiratory acidosis also develops. Excessive fatty acids can displace the bilirubin from the albumin-binding sites and exacerbate hyperbilirubinemia. Hypoglycemia is another metabolic consequence of cold stress.  Hyperthermia – A body temperature greater than 37.5° C (99.5° F) is considered to be abnormally high and is typically caused by excess heat production related to sepsis or a decrease in heat loss. Hyperthermia can result from the inappropriate use of external heat sources such as radiant warmers, phototherapy, sunlight, increased environmental temperature, and the use of excessive clothing or blankets. Sweat glands do not function well. Hyperthermia can cause neurologic injury and increased risk for seizures; severe cases can result in heat stroke and death.  Renal system  Fluid and electrolyte balance  Signs of risk for renal problems – low set ears, have high pitch cry