Seminars in perinatology
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Seminars in perinatology · Dec 2000
ReviewEnhancement of mechanical ventilation of neonates by computer technology.
Mechanical ventilation is often required in the extremely small preterm infant because of transient failure of the immature control of breathing system, chest wall instability, weakness of the respiratory pump, and chronic lung disease. To better address some of these issues, computer algorithms have been developed for continuous automated control of the arterial hemoglobin oxygen saturation (by changing the fraction of inspired oxygen), of the tidal volume (by varying peak inspiratory pressure), and of minute ventilation (by changing respirator rate). Feasibility studies have shown that closed-loop computer control of physiologic target variables may stabilize oxygenation, decrease the transpulmonary pressure cost of ventilation, and expedite weaning from mechanical ventilation. ⋯ With this mode, the clinician selects gains for elastic and/or resistive unloading to tailor the ventilator pressure contour to the specific derangement in pulmonary mechanics (restrictive and/or obstructive). Most of these newer ventilatory strategies are as yet unproven and require randomized, controlled clinical study. Similarly, although on-line pulmonary mechanics monitoring during mechanical ventilation has become available with the adent of computer technology, its clinical utility is still not well established.
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Seminars in perinatology · Aug 2000
ReviewInfluence of light in the NICU on the development of circadian rhythms in preterm infants.
The fetal biological clock is an endogenous clock capable of generating circadian rhythms and responding to maternal entraining signals. By at least the third trimester of pregnancy fetal diurnal rhythms are entrainable by maternal day-night rhythms. Maternal illness during pregnancy and premature birth are obvious clinical factors that may adversely affect circadian rhythm development. ⋯ The research on the short- and long-term effects of environmental interventions on circadian, sleep, and neurologic development is discussed. Although an earlier onset of circadian development did not result with cycled lighting in the neonatal nursery, there may still be important biological effects that have not been studied. There are sufficient data to state that there is no reason for continuing a chaotic, noncircadian environmental approach for the care of the prematurely born infant.
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Inhaled nitric oxide (INO) is a novel selective pulmonary vasodilator without significant effects on the systemic circulation. Initial case studies of near-term newborn infants with hypoxic respiratory failure and persistent pulmonary hypertension of the newborn showed that INO was associated with improvements in oxygenation. There have now been at least 11 prospective randomized controlled trials evaluating the use of INO in the near-term neonate with hypoxic respiratory failure, 10 of which have been published. ⋯ The long-term evaluations of near-term and full-term infants who have received INO suggest that this therapy does not increase the incidence of adverse neurodevelopmental sequelae in these high-risk infants. INO is an effective therapy for the hypoxic term neonate and will reduce the occurrence of death or the need for ECMO in this population. Further research is required to evaluate the benefit of this therapy in the hypoxic preterm infant.
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This article outlines the perioperative management of the parturient who presents for fetal surgery. Anesthetic considerations include the physiological changes of pregnancy, preterm labor, the consequences of tocolytic drugs, maternal and fetal anesthesia, and postoperative analgesia.
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Neuroblastoma is the most common malignant neoplasm occurring in the neonate and arguably the most variable in its presentation. This review examines differences in the tumor's clinical course in the context of known biologic determinants of behavior. Tumors that would go undetected except for prenatal ultrasonography or postnatal neuroblastoma screening characteristically undergo spontaneous regression or maturation and require little or no treatment. ⋯ The more bulky locoregional (stage 3) tumors require chemotherapy in addition to surgery. The most challenging tumors are those that are disseminated at birth (stages 4 and 4S). Management plans for these tumors are based on the biological characteristics of the tumor and (in the case of stage 4S tumors) on the presence and extent of functional embarrassment of vital organs.