Small-bowel perforation in very low birth weight neonates treated with high-dose dexamethasone.

INTRODUCTION: Early postnatal treatment with high doses of corticosteroids may be effective in reducing the duration of mechanical ventilation in very low birth weight infants at risk for bronchopulmonary dysplasia. However, serious side effects may occur. MATERIAL AND METHODS: A retrospective study on 5 very low birth weight neonates, mean (+/- SEM): gestational age range 27.5 +/- 2 weeks, mean birth weight (+/- SEM): 836 g +/- 169 referred between April 1997 and October 1998 from a single academic neonatal intensive care unit to our tertiary pediatric surgical center with the diagnosis of intestinal perforation. During the same period, 60 very low birth weight infants have been treated in that unit following a standardized protocol including surfactant for respiratory distress syndrome and high-dose dexamethasone to prevent bronchopulmonary dysplasia. RESULTS: Pneumoperitoneum was diagnosed between 6 to 9 days after birth. Clinically, all babies remained surprisingly stable. An isolated ileal perforation, without sign of necrotizing enterocolitis, was found at laparotomy in each patient. A limited intestinal resection was performed, with primary end-toend anastomosis (3 cases) or with transient ileostomies (2 cases). Surgical outcome was favorable in all patients. CONCLUSION: isolated intestinal perforation may be a complication of the preventive treatment of chronic lung disease with high-dose corticosteroids in very low birth weight infants. Conversely, corticosteroids may reduce the clinical signs and the multiple organ dysfunction associated with an abdominal drama, explaining the very good surgical prognosis of these newborns. Attention must be paid to an insidious pneumoperitoneum.     

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.     

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.     

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.     

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     

Frusemide-induced nephrocalcinosis in very low birth weight infants

Three very low birth weight infants, treated with frusemide for broncho-pulmonary dysplasia are described. They all developed medullary nephrocalcinosis identifiable by real time ultrasound. The sonographic findings of diffuse medullary hyper-echogenicity appears to be specific for nephrocalcinosis.     

极低出生体重儿并发脑室内出血的诊断和治疗

极低出生体重儿 (ＶＬＢＷＩ)并发脑室周围 脑室内出血(ｐｅｒｉｖｅｎｔｒｉｃｕｌａｒｈｅｍｏｒｒｈａｇｅ Ｉｎｔｒａｖｅｎｔｒｉｃｕｌａｒｈｅｍｏｒｒｈａｇｅ ,ＰＶＨ ＩＶＨ)较为常见。根据头颅系列超声检查 ,ＰＶＨ ＩＶＨ发病率约为 40 %～ 5 0 % ,随胎龄及体重降低发病率增加。胎龄 <32周的早产儿约 30 %～ 35 %发病 ,<2 8周者 ,发病率超过 5 0 % ;体重 <5 0 0 ｇ～ 75 0 ｇ者 ,发病率为 6 0 %～70 % ,10 0 0 ｇ～ 15 0 0 ｇ者为 10 %～ 2 0 %。ＰＶＨ ＩＶＨ的发生 ,主要由于ＶＬＢＷＩ室管膜下生发层基质 (尾状核头部脑室周…     

Bronchopulmonary dysplasia in very low birth weight infants

Objective  The developments in newborn care have enabled many more very low birth weight premature infants to live. The aim of our study was to determine the risk factors for bronchopulmonary dysplasia (BPD) development by evaluating mild and moderate/severe BPD in extramural neonates with a birth weight <1501 g. Methods  A case-control study was conducted between January 1, 2004- December 31, 2006 at the Dr. Sami Ulus Children’s Hospital Neonatal Intensive Care Unit. Patients with BPD and without BPD were compared. Bronchopulmonary dysplasia was diagnosed and classified according to the Bancalari criteria. One-hundred and six (106) extramural premature infants with a birth weight <1501 g and admitted to the Neonatal Unit in the first three days of life and survived for more than 28 postnatal days were included. Patients with multiple congenital anomalies and complex cardiac pathologies were excluded. The maternal and neonatal risk factors, clinical features, mechanical ventilation treatment were compared. The principal risk factors for BPD development were analyzed and followed by logistic regression test. Results  The diagnosis was mild BPD in 27 of the 106 patients and moderate/severe BPD in 29. The incidence of BPD was 52.8%. Fifty of 106 patients had no BPD. Analysis of risk factors revealed that gestational age ≤28 weeks (p=0.019), birth weight ≤1000 g (p=0.007), hypothermia (p=0.003), acidosis (p=0.003) and hypotension (p=0.005) at admission, respiratory distress syndrome (RDS) ( p<0.001), mechanical ventilation therapy (p<0.001), surfactant therapy (p=0.005), higher amount of mean fluid therapy on 7^th days (p=0.008), nosocomial infection (p<0.001), higher amount of mean packed red cell transfusions (p<0.001) and more than two packed red cell transfusions (p=0.033) were risk factors associated with the development of BPD. Multivariant logistic regression analysis showed acidosis at admission (OR 5.12, 95%CI 1.17–22.27, p=0.029), surfactant treatment (OR 7.53, 95%CI 2.14–26.45, p=0.002), nosocomial infections (OR 4.66, 95%CI 1.27–17.12, p=0.02) and PDA (OR 9.60, 95%CI 2.23–41.22, p=0.002) were risk factors increasing the severity of BPD. Conclusion  The most important risk factors for BPD development in our study were RDS and nosocomial infections while the presence of acidosis at admission, surfactant administration, nosocomial infections and the presence of PDA were the most important risk factors regarding BPD severity. Presence of acidosis at admission as a risk factor emphasized the importance of suitable transport conditions for premature infants.     

Furosemide pharmacokinetics in very low birth weight infants

The pharmacokinetics of furosemide were studied longitudinally during long-term administration in 10 very low birth weight infants with bronchopulmonary dysplasia. Mean birth weight of the infants was 829 +/- 217 g, mean gestational age at birth was 26.6 +/- 2.9 weeks, and mean postnatal age at the start of therapy was 2.4 +/- 1.0 weeks. Serial determinations of furosemide pharmacokinetic parameters were performed during 2 weeks to 3 months of long-term therapy. Plasma half-life was prolonged in infants less than 31 weeks postconceptional age (gestational + postnatal age), frequently exceeding 24 hours. All infants less than 29 weeks postconceptional age whose dosing schedule was once every 12 hours accumulated furosemide to potentially ototoxic levels. Furosemide renal clearance increased and plasma half-life decreased in association with increasing postconceptional age. Furosemide secretory clearance was very low in patients less than 31 weeks postconceptional age, resulting in a reliance on glomerular filtration to deliver drug to its main site of action within the lumen of the loop of Henle. Thus elevated plasma levels may be required to ensure adequate luminal delivery and adequate diuresis in these infants with low secretory clearance. Nevertheless, the current dosing schedule (once every 12 hours) of furosemide should be modified to once every 24 hours in infants of low postconceptional age to avoid possible toxic effects.     

Hyperkalemia in very low birth weight infants.

PURPOSE: To assess the frequency and pathogenesis of hyperkalemia in the very low birth weight infant. METHODS: Infants who weighed less than 1000 gm at birth were prospectively entered into the study within 12 hours of birth. Potential risk factors for hyperkalemia were assessed. Body weight, fluid and electrolyte balance, serum levels of sodium and potassium, creatinine clearance, fractional sodium excretion, and urine sodium/potassium ratio were measured every 8 hours for 72 hours. Measurements of plasma renin, serum aldosterone, and plasma atrial natriuretic factor were made at study entry and repeated when hyperkalemia (serum potassium greater than 6.5 mmol/L) occurred or at 72 hours. Infants in whom hyperkalemia developed were compared with those in whom it did not. RESULTS: Thirty-one infants completed the study; hyperkalemia developed in 16 (51.6%). The only difference in the occurrence of perinatal complications was the more frequent occurrence of pH less than 7.20 in infants with subsequent development of hyperkalemia. Creatinine clearance, urine output, and potassium excretion were significantly lower in the hyperkalemia group during the first 24 hours. Serum potassium concentration at 24 hours was inversely related to urine output in the prior 24 hours. Fractional sodium excretion, urine sodium/potassium ratio, and levels of renin, aldosterone, and atrial natriuretic factor did not differ between groups. CONCLUSIONS: Hyperkalemia is a frequent complication in very low birth weight infants. Infants with low urinary flow rates during the first few hours after birth are at greatest risk for the development of hyperkalemia.     

极低出生体重儿坏死性小肠结肠炎

20世纪 70年代以来 ,极低出生体重 (ＶＬＢＷ )儿坏死性小肠结肠炎 (ｎｅｃｒｏｔｉｚｉｎｇｅｎｔｅｒｏｃｏｌｉｔｉｓ ,ＮＥＣ)已经成为发达国家ＮＩＣＵ患儿中 ,最常见的急腹症和肠穿孔的原因。ＮＥＣ的发病机制不明 ,危险因素包括早产、胃肠道缺血、感染和肠道喂养。ＮＥＣ早期缺乏特征性的临床表现。轻、中度患儿药物治疗有效 ,重度患儿需要手术治疗。ＶＬＢＷ儿ＮＥＣ没有特异性的预防措施 ,早期诊断和干预将减轻疾病对患儿的损伤。1　临床表现　　　ＶＬＢＷ儿ＮＥＣ的临床特点是 :①发病率高 ;②病死率高 ;③在胃肠道喂养前就可能…