Cardiac and behavioral responsivity to tactile stimulation in premature and full-term infants.

Attempted to determine whether psychophysiological differences exist between prematurely born and full-term infants in their responsivity to tactile stimulation and in their ability to discriminate among different intensities of such stimulation. The performance of 20 full-term neonates in active sleep was compared with that of 20 premature infants of comparable conceptional age (average, 38.5 wks). Whereas the full-term Ss showed both behavioral responsiveness and heart rate acceleration to the stronger levels of stimulation, the premature Ss showed weaker behavioral responses and no significant cardiac response. Even on those trials where the premature infants did show strong behavioral response, their cardiac response was smaller than that of the full-term infants. A significant sex difference for premature Ss indicated that the lower behavioral responsiveness was due mainly to males. Issues raised were whether the lack of cardiac responsivity in the premature infant is secondary to his/her heightened level of autonomic arousal whether it reflects a lack of integration between motor and autonomic systems. (38 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Learning in premature infants.

Examined instrumental learning in premature infants by using a teddy bear that "breathed" quietly at a rate that reflected the infant's respiration rate. At 33 wks conceptional age (CA), 45 infants were provided with a breathing bear (BRB) or a nonbreathing bear (NBRB). The baby was monitored by time-lapse video for 3-day periods at the beginning and end of a 2-wk intervention period. The BRB babies decreased their latency to contact the bear over time, whereas the NBRB babies showed the opposite pattern. For the BRB babies, decreased contact latencies were correlated with increased total contact and increased contact frequencies. Thus, by 35 wks CA, premature infants learned to find and make contact with a reinforcing source of stimulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hearing in premature infants. Evoked-cochlear microphones

This report summarizes our experience in obtaining microphonic potentials in human beings. Special studies were made to obtain microphonic potentials in premature newborns.     

Behavioral development of premature infants: an ethological approach

This study examines the motor and social development of 21 very small preterm infants up to 34 weeks post-conceptional age. Seven infants were born at 26 to 27 weeks gestation, seven at 28 to 30 weeks and seven at 31 to 32 weeks. They were all physically healthy, as were their mothers. All the infants were observed for 40 minutes twice weekly, using a continuous recording technique. 12 types of infant behavior were recorded. The results indicate that the mean percentage and mean duration of both gross motor movements and 'social' behavior of these small infants do not vary between 26 and 34 weeks post-conceptional age. Moreover, infants born at 26 and 27 weeks gestation showed the same distribution of behaivor during their hospital stay as those born at 28 to 30 or 31 to 32 weeks. There was little individual stability over the weeks in the level of motor activity and social behaivor displayed by the infants, which implies that the behavior of these infants is generally variable as long as they remain physically healthy.     

Hydrocephalus in premature infants

In the light of personal observations from the years 1948-1974 the author discusses the incidence of hydrocephalus in premature babies. The material observed confirms the generally accepted view that the incidence of hydrocephalus is higher in premature babies than in full-term babies. The author analyzes the causes which may be responsible for this finding and concludes that noxious factors during early or late pregnancy are the main cause although perinatal injuries play also a significant role.     

Intervention programs for premature infants. How and do they affect development?

Over the past 30 years, a variety of intervention programs for the enhancement of the neurodevelopmental status of premature infants have been implemented with confusing outcomes. In addition, diametrically different forms of therapy that rest on contrasting theories have led, paradoxically, to similar results. This article systematically examines and analyses the various modes of therapy and their underlying theoretical mechanisms. Skin-to-skin contact (kangaroo care) is suggested as the intervention that most logically meshes the premature infant's need to develop state regulation while facilitating sequential sensory development and promoting mother-infant attachment.     

Perinatal intussusception in premature infants

Intussusception is common in infants aged 5 to 18 months, but there have been only 12 reports of its occurrence among premature infants. Nine of these previously reported cases with adequate data and one new case are reviewed. Many of the infants were believed to have necrotizing enterocolitis, leading to an average 12-day interval between the onset of signs and the operation. Bilious emesis or nasogastric contents, bloody stool, and intestinal dilation without pneumatosis intestinalis were common. A contrast enema showed the intussusception in only 1 of 7 cases. Most cases were diagnosed in the operating room and underwent successful primary anastomosis, with no recurrences. A pathological lead point was identified in 2 of the 10 cases. The overall mortality rate was 23%; the one death since 1970 was secondary to attempted hydrostatic reduction. These cases may represent what, in the absence of premature delivery, would have been the intrauterine development of intussusception likely leading to small bowel atresia.     

Digoxin pharmacokinetics in premature infants

The use of camera renography under experimental conditions is described. The conductivity of the ileo-ureter formed by various surgical techniques in 24 dogs and the function of the operated kidney were studied. The non-invasive examination lasted for 20 minutes and was performed with two different labelled drugs (131I-iodohippurate and 99mTc-DTPA) and a gamma-camera calculator system. The results have shown that the ileo-ureter provided with a direct single layer uretero-ileal anastomosis ensured best the transport of urine and so it seems to be most promising for human application.     

Neuroimaging of premature infants

Neuroimaging of babies born prematurely challenges each member of the imaging team. This article reviews the commonly used modalities for neuroimaging in premature infants (ultrasonography, CT, and MR imaging) and makes recommendations for their optimal implementation based on the imaging literature and the author's experience. Special care of the premature neonate in the imaging department is discussed. Suggestions are made for the proper application of current imaging technology to the frequently encountered problems of intracranial hemorrhage and periventricular leukomalacia in the neonate.     

Metabolic balance studies in premature infants

Many investigators over the past three decades have successfully conducted traditional metabolic balance studies in efforts to determine the retention rates of key nutrients important to the optimal growth of preterm infants. Differences in methodologies discussed in this review may explain the inconsistent results of balance studies reported for some nutrients, particularly calcium. These methodologic differences include (1) variability in nutrient intake and nutritional course prior to the balance period, (2) differences in the method of stool collection (with and without markers), (3) use of single versus repeated balance periods, and (4) different durations of balance periods. The data presented here suggest that the variability of net fat absorptions among VLBW infants was decreased when an acclimation period of nutrient intake supportive of growth was provided prior to a metabolic balance study. In addition, the use of markers affected the estimates of net calcium absorption but not fat absorption. Additional factors that may influence net calcium absorption and methods for the estimation of calcium absorption in VLBW infants warrant further investigation. This review describes the methods of specimen collection for metabolic balance studies in VLBW preterm infants that demonstrated reproducible data. The recent application of stable isotope methodology to metabolic balance studies can be extremely advantageous in identifying the rates of nutrient absorption versus endogenous secretion in the GI tract.     

Thyroid function in premature infants. The hypothyroxinemia of prematurity

Advances of perinatal and neonatal medicine have been associated with a progressive reduction in mortality of premature infants and a progressive increase in number of the surviving very low birth weight (VLBW) cohort less than 28 to 32 weeks gestation age. Hypothalamic-pituitary-thyroid (HPT) function is immature in most premature infants, and this is particularly true of the VLBW group. Accumulated information has allowed development of a unique nosology of HPT system disorders in these infants to facilitate thyroid function testing, test interpretation, and patient management.     

Early discharge of premature infants. A critical analysis

Although significant advances in the medical management of acutely ill preterm infants have resulted in unprecedented rates of survival, issues surrounding the convalescent care, discharge preparation, and readiness of parents or other caregivers have been less well studied and represent the art of medicine. Recent consensus statements provide a degree of content validity; however, important areas of scientific inquiry remain. Much is left to understand about the pathophysiology, management, and outcomes of apnea, bradycardia, and oxygen desaturation episodes continuing at term. Why do the most immature infants have a delay in the maturation of respiratory control? Do breathing studies really provide information that predicts subsequent respiratory control abnormalities? If methylxanthines are used at discharge, what criteria should be adhered to regarding their discontinuation? How is nutrition best provided while transitioning to home? In infants whose mothers desire exclusive breast-feeding, should gavage feeds be used to supplement in order to avoid bottle-feedings? How long should breast milk be fortified, and when should supplemented artificial milks be used and for what period of time postdischarge should these more expensive special-discharge artificial milks be used? What other supplements, such as inositol, vitamins, or antioxidants, should be provided in order to achieve optimal growth and development? Technology-dependent infants pose even greater complexities. Some infants and families adapt to extensive use of technology in the home. In other situations, basic infant care is difficult to achieve. What are the essential components for successful early discharge, and how can the studies involving selected families be made universal? How can NICUs better prepare fathers and mothers for premature parenthood? To what extent are we overwhelming families with additional responsibilities and expectations that may compromise their competency in basic parenting? Furthermore, the degree of provider variation in evaluating and providing for discharge planning is now being more carefully studied. In some circumstances, integrated teams in the NICU have facilitated the discharge process saving days of hospitalization, whereas in others adherence to discharge planning guidelines has lengthened the stay in the NICU and resulted in higher costs. What is the ideal system for achieving coordination of care without co-opting parental choices in assuming more care responsibility than is comfortable? In the design of tertiary care facilities, more attention to space for rooming-in experiences needs to receive greater priority. Furthermore, because of intensity of care, adverse environmental stimuli, and for issues of better resource utilization, should not most previously ill infants be discharged from level II or intermediate care centers? Finally, issues of increasing decision-making responsibility placed on parents (with the reassurance and guiding hand of dedicated physicians and nurses focused on individual infants) must never be made subservient to the economic whims of insurers to decrease costs without understanding the value of the entirety of the care process for critical illness, through convalescence, to it is hoped a supportive and nurturing environment in the home. Our patients deserve no less. The questions posed present a sample of issues yet to be scientifically addressed. These and many other questions need to be answered before we fully understand the optimal process of discharge for the preterm infant.