Pulse oximetry and peroperative monitoring of low birth weight infants

In 2 very low birth weight infants, a Nelcor 100 pulse oximeter was used during surgery. These 2 babies were anesthetized during the first 3 weeks of life, one for patent ductus arteriosus ligation and the other for ventriculo-peritoneal derivation. SaO2 was maintained between 85-95% in the straight portion of hemoglobin dissociation curves, where PaO2 values are from 7 to 10 KPal. During anesthesia, FiO2 was kept between 21 and 30%. Oximeters which have a fast response time seem to be a useful tool for monitoring blood oxygenation when it is difficult to estimate normoxia but very important to avoid hypoxia or over-oxygenation.     

Placental and other perinatal risk factors for chronic lung disease in very low birth weight infants

To clarify the relationship between chorioamnionitis and chronic lung disease (CLD) in very low birth weight (VLBW) infants, we performed a retrospective cohort study of all inborn patients between 1995-1997 with gestational age (GA) less than 32 wk, birth weight less than 1.5 kg, survival to 36 wk adjusted GA, and placentas submitted to pathology (n = 371). Racial distribution as defined by the mother was 40% white/60% nonwhite. Prevalence of CLD, defined as O(2) dependence at 36 wk adjusted GA, was 30%. In a preliminary analysis GA and birth weight for GA (standard deviations from the mean, Z-score), considered together, were inversely related to CLD. After adjustment for GA and Z-score, other risk factors for CLD were white race, acute respiratory distress, pulmonary air leak, patent ductus arteriosus, and septicemia. Two placental lesions were inversely related to CLD: histologic chorioamnionitis and acute atherosis (a placental indicator of preeclampsia). Following multivariate analysis, independent risk factors for CLD were GA (OR, 0.6; 95% CI = 0.5, 0.7), birthweight for GA (OR, 0.4; 95% CI = 0.3, 0.6), white race (OR, 1.9; 95% CI = 1.0, 3.3), patent ductus arteriosus (OR, 2.0; 95% CI = 1.0, 3.5), and pulmonary air leak (OR, 3.0; 95% CI = 1.3, 7.1). Acute atherosis was inversely related to CLD (OR, 0.2; 95% CI = 0.1, 0.8). Chorioamnionitis was stratified by subtype and again no association with CLD was seen in the population as a whole. Finally, chorioamnionitis of all subtypes tended to be increased in white infants and decreased in black infants with CLD. This dichotomy was not explained by differences in death rates, acute respiratory distress, intubation on d 2 of life, or total duration of assisted ventilation. We conclude that while chorioamnionitis was not a risk factor for CLD in our total population, racial differences in its relationship to CLD are worthy of further study.     

Chronic lung disease in infants with very low birth weight. A population-based study

We surveyed outcome in 1095 (95.5%) of 1147 very-low-birth-weight infants born in North Carolina in 1984 to determine the incidence of chronic lung disease (CLD) and to learn whether there are differences in incidence among newborn intensive care units (NICUs). At 30 days of age, 39% of surviving infants who had received mechanical ventilation for more than 48 hours were still respirator dependent; 15% were only oxygen dependent. By 3 months, the rates had fallen to 8% and 7%, respectively. By 6 months of age, only 1.6% were respirator dependent but 3% were oxygen dependent and 9% had died. The NICUs differed widely in incidence of CLD, without relation to number of very-low-birth-weight infants treated or to whether treatment was by pediatric residents. Rates of CLD among survivors at 30 days were not inversely related to prior mortality rates. Incidence varied inversely by birth weight, but differences among NICUs were only partly due to differing weight distributions.     

极低及超低出生体重儿的预后因素分析

目的 分析极低及超低出生体重儿（出生体重≤ 1 200 g）的临床资料,为其预后及临床干预提供预警指标。方法 回顾性分析108 例极低及超低出生体重儿的母孕期病史、新生儿出生时情况、诊治经过及预后,采用非条件logistic 回归分析筛选预后的影响因素。结果 108 例极低及超低出生体重儿,出生体重范围在结论 极低及超低出生体重儿的病死率较高,且随着日龄的增加,影响早产儿生存的预后因素不同,临床上应针对这些因素制定合理的管理方案,提高早产儿生存率。     

Physiology of infants with very low birth weight

Advances in neonatal management have resulted in dramatic increases in survival in infants with birth weights less than 1,500 g. Extensive basic science and clinical research has led to a more comprehensive understanding of the physiological differences between the VLBW infant and larger neonates. Meticulous attention must be paid to appropriate fluid, electrolyte, nutrition, and temperature maintenance to achieve homeostasis and growth. Additionally, the clinician must be aware of the diagnostic and treatment modalities for the common complications seen in the premature infant to minimize mortality and long-term morbidity.     

Cerebral oxygenation in very low birth weight infants supported with sustained lung inflations after birth

Sustained lung inflations (SIs) immediately after birth might decrease the need for subsequent mechanical ventilation in preterm infants. However, effects of SIs on oxygenation and hemodynamics are undetermined. Our aim was to study immediate effects of SIs on heart rate, arterial oxygen saturation, and cerebral tissue oxygen saturation in preterm infants supported with SIs after birth for lung recruitment. Heart rate, arterial oxygen saturation, and cerebral tissue oxygen saturation using near infrared spectroscopy was measured in 24 preterm infants of 28.0 (26.6-29.3) wk GA [median (interquartile range)] during resuscitation using up to three SIs of 20, 25, and 30 cm H2O of 15 s duration each followed by nasal continuous positive airway pressure (CPAP) as first line approach for respiratory support. During positioning and suctioning immediately after delivery infants became progressively hypoxemic and bradycardic before respiratory support was initiated. In 18 infants (75%), more than one SI were applied. During the last SIs, there was a rapid increase in the infants' heart rate and an increase in cerebral tissue oxygen saturation. Arterial saturation increased with slight delay. In conclusion, effective last sustained inflations increase heart rate and cerebral tissue oxygen saturation to be followed by an increase in arterial saturation.     

Newborn screening levels of 17-hydroxyprogesterone in very low birth weight infants and the relationship to chronic lung disease

OBJECTIVES: 17-Hydroxyprogesterone (17-OHP), an intermediary hormone in cortisol synthesis, has been shown to be elevated in premature infants. However, the relationship between levels of 17-OHP with chronic lung disease (CLD) have not been extensively explored. The objective of this study was to determine whether there is an association between CLD and levels of 17-OHP in a population of very low birth weight infants. STUDY DESIGN: Cohort study of very low birth weight infants cared for at a single level 3 NICU during a 3-year period from July 2001-July 2004, n=435. Infants had a minimum of one screen for 17-OHP. 17-OHP was measured on the 5th day of life and at 2-4 weeks of life as part of the State of Delaware Newborn Screening Program. Statistical analysis included chi-squared, Pearson correlation, and logistic regression. RESULTS: Levels of 17-OHP were higher at the time of the 1st screen compared to the 2nd screen (42.2 +/- 36.7 vs 23.5 +/- 32.3 ng/ml, respectively, p = 0.01). After controlling for potential confounding variables, gestational age and prenatal steroids were independently associated with 17-OHP. However, logistic regression analysis showed no association between a 1 log increase in levels of 17-OHP with the outcomes of CLD (odds ratio 1.7, 95% CI 0.7-3.8), or death and/or CLD (odds ratio 2.1, 95% CI 0.9-4.8). CONCLUSIONS: In our population of very low birth weight infants elevated levels of 17-OHP were not associated with the development of CLD.     

Meconium diseases in infants with very low birth weight

Retained meconium resulting in intestinal obstruction in infants with very low birth weight (VLBW) may cause significant morbidity and even mortality. Immature intestinal neuromuscular function, abnormal meconium composition, and maternal magnesium sulfate therapy results in delay of first meconium passage. This "normal" passage of first meconium may not occur until 1 week of life or later. A spectrum of conditions results from this delayed passage. At the most serious end of this continuum is intestinal obstruction. These patients present with abdominal distension, emesis, and reduced stool frequency. Early diagnosis of this condition using plain abdominal radiographs and contrast enemas where appropriate is imperative. Contrast enemas may be both diagnostic and therapeutic. Most patients do not need surgical intervention. Operation is indicated when enemas fail to relieve the obstruction or perforation occurs. Prompt diagnosis and appropriate management results in a good outcome. Meconium obstruction in VLBW infants does not appear to be associated with cystic fibrosis or Hirschsprung's disease.     

Cardiac surgery in infants with very low birth weight

Congenital heart defects in low birth weight infants are typically managed with supportive therapy or palliative surgery, and definitive repair is delayed. However, the morbidity of such an approach has been shown to be high. Recent reports emphasize early surgical repair with good results in low birth weight and premature babies. However, there are no data on the outcomes in infants with very low birth weight (<1,500 g). Since 1990, the authors performed complete repair of congenital heart defects (other than isolated patent ductus arteriosus) in 20 infants weighing 1,500 g or less. Defects included aortic coarctation (n = 6), ventricular septal defect (n = 5), tetralogy of Fallot (n = 2), transposition of great arteries (n = 2), truncus arteriosus (n = 2), total anomalous pulmonary venous return (n = 1), double outlet right ventricle (n = 1), and pulmonary atresia with intact ventricular septum (n = 1). Preoperative morbidity was more common in patients who were referred late for corrective surgery. Modification of techniques of neonatal cardiopulmonary bypass were used. There were 2 early deaths (10%) caused by foot gangrene (n = 1), and pulmonary complications (n = 1). No patient had evidence of postbypass intracranial hemorrhage. At a median follow-up of 40 months, there was 1 late death, and 4 patients underwent a total of 5 surgical and catheter reinterventions. There was no evidence of neurological sequelae attributable to surgery. In most cases, delaying repair of congenital heart defects in low and very low birth weight infants does not confer any benefit and is associated with a higher incidence of preoperative morbidity. Complete repair of both simple and complex congenital heart lesions can be performed successfully in such patients with good early and medium-term results. Postoperative growth after repair approximates the normal growth curve for low birth weight infants without congenital heart disease. It is recommended that with few exceptions, such infants, especially when symptomatic, undergo early surgical correction rather than prolonged medical management or other forms of palliation.     

Inguinal hernia in infants with very low birth weight

Inguinal hernias (IH) are among the most commonly encountered surgical problems in infants with very low birth weight (VLBW, <1,500 g) with a reported incidence of 16%. A trend toward earlier operation has emerged in recent years, with most now being repaired before discharge from the neonatal intensive care unit. The authors review the many special concerns regarding the management of IH in this patient population, including the timing of repair, the risk of incarceration, anesthetic management, the frequency of bilaterality, the high incidence of undescended testes, and the technical aspects and complications associated with IH repair in the VLBW infant.     

Necrotizing enterocolitis in infants with very low birth weight

Necrotizing enterocolitis (NEC) is a disease in which the primary risk factor is prematurity. Despite, and partially as a result of, the tremendous strides neonatal care has taken, it is a major cause of morbidity and mortality of the newborn. The infant with very low birth weight is particularly susceptible, and the management of the condition in this group differs somewhat from other neonates. The outcomes continue to improve, but there are significant sequelae. Prevention, which would be the best "cure," is elusive, in no small part because of the multifactorial nature of the etiology of NEC.     

Esophageal atresia in infants with very low birth weight

Infants with esophageal atresia (EA), with or without a tracheoesophageal fistula (TEF) frequently are of low birth weight. With advances in neonatal, respiratory, surgical, and anesthetic care, more infants with very low birth weight (VLBW; birth weight less than 1.5 kg) are surviving. The therapy of the VLBW neonate with EA is not longer automatically staged. Primary or delayed primary anastomosis can be performed safely if the patient is stable. This report will review the epidemiology, pathophysiology, treatment, and prognosis of EA in VLBW infants. The authors present their own experience in dealing with the VLBW with EA and review the world literature.     

Postural development in very low birth weight and normal birth weight infants

In this study the seven postural responses selected by Vojta to evaluate neuromotor development were applied to 68 very low birth weight (VLBW) (greater than 1500 g) infants and to 28 healthy infants of normal birth weight (less than 2500 g). Of the 68 VLBW infants, 41 were small for gestational age and 27 appropriate for gestational age. All infants were examined between 37 and 40 weeks postmenstrual age. They were all later assessed on the Griffiths Mental Developmental Scale at 12 and 18 months. There were significant differences in postural reactions between the two groups which confirmed the lower tone and greater extension previously described in very low birth weight infants. An important finding in the study was that poor head and trunk righting noted at four months corrected age in very low birth weight infants, was associated with less developed locomotion at 12 and 18 months as assessed by the Griffiths Mental Developmental Scale. Thus, a delay in maturation in very low birth weight infants which was apparent from the assessment of postural responses in early infancy was still identifiable on the locomotor subscales at 12 and 18 months. Five of Vojta's responses were shown to be useful as part of the neurological assessment of high risk infants.     

极低体重儿呼吸暂停的有关问题

早产儿呼吸暂停 (ａｐｎｅａｏｆｐｒｅｍａｔｕｒｉｔｙ ,ＡＯＰ)常发生于矛盾睡眠期 ,与呼吸中枢调节功能不成熟有关 ;呼吸暂停发生的频率及严重程度常与胎龄成反比。当呼吸暂停 >15～ 2 0ｓ ,或呼吸显著不规则时 ,可影响组织的氧合状态 ,尤其是在极低体重儿 ,呼吸暂停与发生