Schofield Maynard posted an update 2 months, 2 weeks ago
The immature circulatory system of the newborn can cause cyanosis of the hands and feet. A fetus has a ductus arteriosus, which connects the pulmonary artery to the aorta. Once born, this ductus begins to constrict, sending blood through the pulmonary artery to the lungs for oxygenation. Once the ductus has fully constricted, it becomes a ligament.
In addition to its thorough coverage of neonatal physiology, this new edition emphasizes the interprofessional approach to learning. Throughout the book, the authors provide helpful advice and incorporate discussion questions to further enhance learning. Learning objectives and mind maps provide a framework for studying the text. Other features include case studies and a discussion of relevant issues. Neonatal physiology is an important part of the curriculum for advanced practice nurses. In addition to providing a thorough background on neonatal physiology, this text also includes chapter summaries, learning objectives, and practical discussion questions.
Understanding fetal circulatory function is essential for the assessment of cardiovascular problems. It is essential to distinguish between normal fetal conditions and those that become pathological later in life. Moreover, fetal physiology is highly complex and can be affected by postnatal changes. Physiological changes that occur in the newborn’s cardiovascular system can lead to severe morbidity or even death. For this reason, it is imperative to understand the functional characteristics of the neonatal circulation and use appropriate hemodynamic interventions. The assessment of the cardiovascular status requires accurate measurement of the micro and macrocirculation.
The respiratory system of the Neonate exhibits several unique features. Its pulmonary vascular resistance is lower and arterial oxygen tension is higher, facilitating gas exchange in the lungs. The heart of the neonate lacks the compliance and myocytes of the adult heart. Its cardiac output depends on heart rate and cannot generate stroke volumes. Furthermore, it has a predominant parasympathetic tone and an inefficient respiratory mechanics. Finally, its alveoli are smaller, and its closing capacity is higher than the respiratory system of adults.
The respiratory system of the neonate has some specific characteristics. First, it has fewer alveoli and dead space than that of an adult. As a result, the lungs have lower gas exchange capacity than the adult. Another important characteristic is that neonates are nose breathers. This is a result of their narrow nasal passages and large head. The airway of the neonate has a floppy omega-shaped epiglottis and long arytenoids.
Neonatal lung development begins in the womb, and the first stages of the pulmonary system involve the formation of the alveolar ducts, which contain the airways. The alveolar ducts develop into mature squamous type I pneumocytes. As the lung develops, the mesenchyme surrounding the saccules develops rapidly, and the lymphatic system is fully developed.
The development of the lungs separates fish and larger terrestrial animals. This rapid adaptation to permanent air breathing is the rate limiting step for extrauterine life. Although fetal lung development is largely predictable, the resulting respiratory problems at term and in infancy are not. The importance of fetal lung development justifies the existence of neonatal intensive care units and the medical specialty of neonatology. Neonate lung maturity can be assessed through noninvasive methods.
The immunological development of the neonate is characterized by a variety of alterations. During the gestation period, the immune system is highly regulated by multiple factors, including cytokines and stromal cells, and transcription factors. Neonatal immune development also involves the maturation of plasma cells and the initiation of a tolerant response to new antigens. However, this development is affected by changes in the intrauterine environment.
Compared to adults, the immune system of a neonate has a tolerogenic bias, increasing its vulnerability to infection. Immune cells in the neonate differ from those of adults, which may explain why the latter have more powerful responses to infections than their neonatal counterparts. Moreover, a neonate’s immune system includes many different factors, including maternal antibodies that partially compensate for impaired B cell activity. In addition, CD4 T cells have a tendency to differentiate toward Th2 and Th17 responses, a sign of decreased antigen-presenting cells. Moreover, neonates have fewer inflammatory cytokines and fewer natural killer cells than adults.
Transporting a neonate
When transporting a neonate, the first priority should be to stabilise the infant. In cases of toxic shock, a neonate may require pediatric advanced life support (PALS). The caregiver must secure the airway, administer oxygen, and monitor the child for signs of distress. If oxygen supplementation is needed, use the appropriate size oxygen delivery equipment. If the neonate requires IV fluids, fluid boluses should be administered judiciously.
Neonatal medicine requires extensive knowledge of neonatal care. While a neonate’s immune system is still developing, it’s still highly susceptible to infections and enteroviral diseases. In addition, neonates have immature blood cells, so bacterial or viral infections can be more severe than other infections in the first few days of life. The current standard of care for febrile, irritable neonates involves a thorough evaluation of the patient and family and intravenous antibiotics are administered to control infection while cultures are obtained.
Treatment of hypoglycemia in a neonate
The goal of the treatment of hypoglycemia in neonates is to increase energy intake by mobilizing energy stores, while maintaining the patient’s blood glucose levels at or above 3.3 mmol/L. The type and level of the underlying diagnosis will determine the appropriate course of treatment. Additional blood tests should be performed, including c-peptide, ammonia, free fatty acids, amino acids, carnitine, and glucose tolerance test. As part of the holistic approach, the parent or guardian should be counseled on how to conduct blood glucose monitoring at home and how to administer medication.
In addition to infants with Beckwith-Wiedemann syndrome, nonsyndromic LGA and IDM infants may be at risk for hypoglycemia. Other factors that contribute to persistent hypoglycemia include late preterm administration of antenatal steroids, maternal labetalol, intrauterine growth restriction, and perinatal asphyxia. Some individuals may experience persistent hypoglycemia and have to undergo treatment.