Transitional Assessment – Periods of Reactivity For a Newborn

The newborn exhibits behavioral and physiologic characteristics that can at first appear to be signs of stress. However, during the initial 24 hours changes in heart rate, respiration, motor activity, color, mucous production, and bowel activity occur in an orderly, predictable sequence, which is normal and indicative of lack of stress. Distressed infants also progress through these stages but at a slower rate.

First period

For 6 to 8 hours after birth the newborn is in the first period of reactivity. During the first 30 minutes the infant is very alert, cries vigorously, may suck his fist greedily, and appears very interested in his environment. At this time his eyes are usually open, suggesting that this is an excellent opportunity for mother, father, and child to see each other. For the reason he has a vigorous suck reflex, an opportune time to begin breast-feeding. The mother. This is particularly important for doctors to remember, since it is not unlikely that after this initially highly active states the infant may be quite sleepy and uninterested in sucking. Physiologically the respiratory rate can be high as 80 breaths/minute, rales may be heard, heart rate may reach 180beats/minute, bowel sounds are active, mucous secretions are increased and temperature may decrease.

After this initial stage of alertness and activity the infant’s responsiveness diminishes. Heart and respiratory rates decrease, temperature continues to fall, mucous production decreases, and urine or stool is usually not passed. The infant is in a state of sleep and relative calm. Any attempt to stimulate him usually elicits a minimal response. This second stage of the first reactive period generally lasts 2 to 4 hours. Due to the continued decrease in body temperature, it is best to avoid undressing of bathing the infant during this time.

Second period

The second period of reactivity begins when the infant awakes from the deep sleep following the first period. The infant is again alert and responsive, heart and respiratory rates increase, the gag reflex is active, gastric and respiratory secretions are increased, and passage of meconium commonly occurs. This second period of reactivity lasts about 2 to 5 hours and provides another excellent opportunity for child and parents to interact, This period is usually over when the amount of respiratory mucus has decreased. Following this stage is a period of stabilization of physiologic systems and a vacillating pattern of sleep and activity.

After a discussion of the seemingly erratic patterns of behaviors in the newborn, it is apparent that, in order to identify abnormalities or signs of distress in the respiratory, cardiovascular, or neurological system, the doctor must thoroughly understand normal characteristics. Observation, not machines, is the doctor’s greatest tool for assessment, and the nursing goal is anticipation and prevention of neonatal stress. The timing of nursing care is based on observation of the neonate’s physiologic status. For example, the infant should be dried immediately after delivery to minimize heat loss from evaporation; the initial bath should be postponed until after body temperature has stabilized; eye drops should be instilled after parents and child have established visual contact; and breast-feeding or bottle-feeding should be initiated during one of the two periods of reactivity.