Asphyxia

Asphyxia is the most common clinical insult in the perinatal period. As many as 10% of newborns require some degree of active resuscitation to stimulate breathing at birth (Cunningham et al., 2018). According to the WHO (2019b), up to 10 million cases of neonatal asphyxia occur annually worldwide, accounting for approximately 23% of all newborn deaths. More than a million newborns who survive asphyxia at birth develop long-term problems such as cerebral palsy, intellectual disability, and speaking, hearing, visual, and learning disabilities (WHO, 2019b). Pathophysiology Physiologically, asphyxia can be defined as impaired gas exchange resulting in a decrease in blood oxygen levels (hypoxemia) and an excess of carbon dioxide (hypercarbia) or hypercapnia that leads to metabolic acidosis. Any condition that reduces oxygen delivery to the fetus can result in asphyxia. These conditions may include maternal hypoxia, such as from cardiac or respiratory disease, anemia, or postural hypotension; maternal vascular disease that leads to placental insufficiency, such as diabetes or hypertension; cord problems such as compression or prolapse; and post-term pregnancies, which may trigger meconium release into the amniotic fluid. Initially, the newborn uses compensatory mechanisms including tachycardia and vasoconstriction to help bring oxygen to the vital organs for a time. However, without intervention, these mechanisms fail, leading to hypotension, bradycardia, and eventually cardiopulmonary arrest. With failure to breathe well after birth, the newborn will develop hypoxia (too little oxygen in the cells of the body). As a result, the heart rate falls, cyanosis develops, and the newborn becomes hypotonic and unresponsive. Newborn resuscitation is needed to help initiate breathing in newborns who fail to breathe spontaneously at birth. Think back to Kelly, described at the beginning of the chapter. She gives birth to a son weighing approximately 2,500 g; he appears post-term and small for gestational age. His skin is stained yellow-green and he is limp, cyanotic, and apneic at birth. The initial assessment once he is under the radiant warmer indicates resuscitation and tracheal suctioning are needed. What is the nurse’s role during resuscitation? What assessments will be needed during this procedure? Nursing Assessment The key to successful treatment of newborn asphyxia is early identification and recognition of newborns who may be at risk. Review the perinatal history for risk factors, including: Trauma: injury to the central or peripheral nervous system secondary to a long or difficult labor, a precipitous birth, multiple gestation, abnormal presentation, cephalopelvic disproportion, shoulder dystocia, or extraction by forceps or vacuum Intrauterine asphyxia: fetal hypoxia secondary to maternal hypoxia, diabetes, hypertension, anemia, cord compression, fetal bradycardia, or meconium aspiration Sepsis: acquired bacterial or viral organisms from infected amniotic fluid, maternal infection, or direct contact while passing through the birth canal Malformation: congenital anomalies including facial or upper airway deformities, renal anomalies, pulmonary hypoplasia, neuromuscular disorders, esophageal atresia, or NTDs Hypovolemic shock: secondary to placental abruption, placenta previa, or cord rupture resulting in blood loss to the fetus Medication: drugs given to mother during labor that can affect the fetus by causing placental hypoperfusion and hypotension; use of hypnotics, analgesics, anesthetics, narcotics administered to the mother within 4 hours of birth, oxytocin, and street drugs during pregnancy At birth, a rapid assessment of the newborn should be done immediately. Observe the infant’s color, noting any pallor or cyanosis. Assess the work of breathing. Be alert for apnea, poor muscle tone, tachypnea, gasping respirations, grunting, nasal flaring, or retractions. Evaluate heart rate and note bradycardia. Assess the newborn’s temperature, noting hypothermia. Based on the initial assessment if poor, begin resuscitation measures until the Apgar score is above 7. Anticipate diagnostic testing to identify etiologies for the newborn’s asphyxia. For example, a chest x-ray may identify structural abnormalities that might interfere with respiration. A blood culture may identify an infectious process. A blood toxicology screen may detect any maternal drugs in the newborn. Severe fetal and neonatal asphyxia impair the physiologic transitions to extrauterine life (Groenendaal & van Bel, 2019). Nursing Management Management of the newborn experiencing asphyxia includes immediate resuscitation. Ensure the equipment needed for resuscitation is readily available and in working order. Essential equipment includes: Wall suction apparatus Stethoscope Oxygen source Newborn ventilation bag Infant warmer Pulse oximeter leads Surgical blue towels Endotracheal tubes (2 to 3 mm) Laryngoscope Ampules of naloxone (Narcan) and epinephrine with syringes and needles for administration Effective ventilation is the key to successful newborn resuscitation. Ventilation is frequently initiated with a manual resuscitation bag and face mask followed by endotracheal intubation if respiratory depression continues. (See Chapter 23 for a more detailed discussion of resuscitation.) Dry the newborn quickly with a prewarmed towel and then place them under a radiant heater to prevent rapid heat loss through evaporation. Handling and rubbing the newborn with a dry towel may be all that is needed to stimulate breathing. If the newborn fails to respond to stimulation, active resuscitation is needed. The procedure for newborn resuscitation is easily remembered by the ABCD—airway, breathing, circulation, and drugs (see Chapter 23, Box 23.3). Continue resuscitation until the newborn has a pulse above 100 bpm, a healthy cry, or good breathing efforts and a pink tongue. This last sign indicates a good oxygen supply to the brain (Ohning, 2019). TAKE NOTE! The goals of resuscitation are to assist with the initiation and maintenance of adequate ventilation and oxygenation, adequate cardiac output and tissue perfusion, and normal core temperature and serum glucose (Ohning, 2019). Provide continued observation and assessment of the newborn who has been successfully resuscitated. Monitor the newborn’s vital signs and oxygen saturation levels closely for changes. Maintain a neutral thermal environment to prevent hypothermia, which would increase the newborn’s metabolic and oxygen demands. Check the blood glucose level and observe for signs of hypoglycemia; if this develops, it can further stress the newborn. The need for resuscitative measures can be extremely upsetting for the parents. Explain to them the initial resuscitation activities being performed and offer ongoing explanations about any procedures being done, equipment being used, or medications given. Provide physical and emotional support to the parents through the initial crisis and throughout the newborn’s stay. When the newborn is stable, allow family to spend time with the newborn to promote bonding (Fig. 24.1). Point out the newborn’s positive attributes (color, activity level, healthy cry) and give frequent updates on their status. Role model techniques for holding, interacting with, and caring for the newborn to decrease the parents’ anxiety post-resuscitation.