Transition Assessment – Periods of Reactivity for a Newborn

The newborn exhibits physiological and behavioral characteristics that may at first appear to be signs of stress. However, during the first 24 hours, changes in heart rate, respiration, motor activity, color, mucus production, and bowel activity occur in an orderly and predictable sequence, which is normal and indicates the absence of stress. Distressed babies 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 child is highly alert, cries vigorously, may suck his fist avidly, and seems very interested in his surroundings. At this time, his eyes are usually open, which suggests that this is an excellent opportunity for the mother, father and child to see each other. For this reason he has a vigorous sucking reflex, an opportune moment to initiate lactation. Mother. This is particularly important for clinicians to remember, as it is not unlikely that after these initially very active states, the baby may be quite sleepy and uninterested in suckling. Physiologically, the respiratory rate may be as high as 80 breaths/minute, rales may be heard, the heart rate may be as high as 180 beats/minute, bowel sounds are active, mucous secretions are increased, and the temperature may be decreased.

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

second period

The second period of reactivity begins when the baby awakens from the deep sleep that followed the first period. The infant becomes alert and responsive again, heart and respiratory rates increase, the gag reflex is active, gastric and respiratory secretions increase, and meconium expulsion usually occurs. This second period of reactivity lasts about 2-5 hours and provides another excellent opportunity for the child and parent to interact. This period usually ends when the amount of respiratory mucus has decreased. After this stage there is a period of stabilization of the physiological systems and a faltering pattern of sleep and activity.

After a discussion of apparently erratic behavior patterns in the newborn, it is clear that in order to identify abnormalities or signs of distress in the respiratory, cardiovascular, or neurological systems, the clinician must thoroughly understand the normal features. Observation, not machines, is the physician’s greatest assessment tool, and the nursing goal is anticipation and prevention of neonatal stress. The moment of nursing care is based on the observation of the physiological state of the newborn. For example, the baby should be dried immediately after delivery to minimize evaporative heat loss; the initial bath should be postponed until the body temperature has stabilized; eye drops should be applied after parent and child have established eye contact; and breastfeeding or bottle feeding should be initiated during one of the two periods of reactivity.