postterm infant
infant
[in´fant]Development of muscular control proceeds from the head downward (cephalocaudal development). The infant controls the head first and gradually acquires the ability to control the neck, then the arms, and finally the legs and feet. Movements are general and random at first, beginning with use of the larger muscles and progressing to specific smaller muscles, such as those needed to handle small objects. Factors that influence growth and development are hereditary traits, sex, environment, nationality and race, and physical makeup. See also growth.
At the time of delivery, whether cesarean or vaginal, a skilled neonatal team should be present to provide immediate care. After resuscitation measures under a radiant warmer are completed and the newborn is stabilized, transfer to the NICU is done without interruption of warming and oxygen therapies.
Among the problems associated with low birth weight are hypothermia, respiratory distress, hyperbilirubinemia, fluid and electrolyte imbalance, susceptibility to infection, and feeding problems.
Very-low-birth-weight newborns and infants are at significant risk for hypothermia because of their small body mass, large surface area, thin skin, minimal subcutaneous tissues, and posture. Thermoregulation is provided through the use of a standard incubator or a radiant warmer. Radiant warmers have the advantage of accessibility for caregivers and improved visibility of the infant. Their chief disadvantage is increased insensible water loss.
respiratory distress syndrome" >Neonatal respiratory distress syndrome is the major cause of death in newborns. Atelectasis can lead to hypoxemia and elevated serum carbon dioxide levels and all the problems related to inadequate gas exchange. Oxygen therapy must be administered with caution because of the danger of retinopathy.
The treatment of hyperbilirubinemia remains a challenge because of lack of consensus on the level of serum bilirubin concentration at which therapy should begin, the uncertain diagnosis of kernicterus, and the currently limited knowledge of the blood--brain barrier. It is believed that these infants are at critical risk for bilirubin-related brain damage at serum concentrations as low as 6 to 9 mg/dl. Phototherapy is the treatment of choice and may be given prophylactically in some institutions to all infants weighing less than 1000 grams.
The management of fluid and electrolyte administration to maintain proper balance is highly complex. Factors taken into consideration are proportion of body, composition of water, renal function, and insensible water loss. Fluid and electrolyte status must be closely monitored. Overhydration is a hazard because it has been implicated in the development of such serious complications as pulmonary edema, patent ductus arteriosus, and necrotizing enterocolitis in these infants.
Low-birth-weight and very-low-birth-weight infants are particularly susceptible to infection because their immunologic system is deficient. Additionally, equipment and care related to long-term respiratory and nutritional support, together with frequent laboratory testing, increase exposure to infectious agents. Infection control measures must be adhered to faithfully. In some NICUs reverse isolation is required for all infants weighing less than 1000 grams.
Since the skin of these infants is highly permeable and easily traumatized, every effort must be made to preserve its integrity. Routine care to preserve the integrity of the skin, caution in the use of topical ointments and antiseptic preparations, and minimal handling also are essential.
At the beginning, nutritional support in the form of total parenteral nutrition may be necessary until enteral feedings are feasible. Oral feedings usually are initiated by the end of the first week of life. Continuous gastric feedings via infusion pump have the advantage of preventing vomiting and aspiration and abdominal distention associated with intermittent feedings of larger amounts. The enteral feedings given in this manner include breast milk (donor or mother) and special formulas.
Discharge planning and follow-up care are begun upon admission to the NICU. Individual family needs should be assessed and available community resources identified. Parental education and support are provided throughout the time the infant is in the NICU. At the time of discharge parents should be confident of their ability to care for the infant, knowledgeable about sources available to them, and able to utilize those resources to the fullest.