Nutrition in very very low birth weight infants

The VVLBW infant's limited nutritional reserves, high requirements for normal growth and development, and gastrointestinal immaturity pose a particularly challenging nutritional problem. Given the potential consequences of inadequate or inappropriate nutritional management, we are obligated to make nutrition a high priority in the overall care of VVLBW infants.     

极低出生体重早产儿动脉导管未闭的治疗

目的探讨极低出生体重早产儿有临床表现的动脉导管未闭的治疗方法方法 本研究为前瞻性队列研究.2008年1月1日至2010年12月31日间出生体重＜1500 g的确诊有临床表现的动脉导管未闭早产儿78例,其中42例采用口服吲哚美辛治疗者作为治疗组,36例未治疗者为对照组.观察吲哚美辛的疗效、副作用以及对早产儿的近远期预后.结果治疗组及对照组在性别比例、胎龄、动脉导管直径、合并心力衰竭、败血症、新生儿呼吸窘迫综合征、脑室内出血的差异均无统计学意义(P均＞0.05).治疗组治疗后动脉导管关闭33例,关闭率为78.6%,高于对照组,自发关闭9例,关闭率25.0%,差异有统计学意义(χ2=22.39,P=0.000).治疗组治疗前后的血肌酐、血小板差异无统计学意义(P均＞0.05).治疗组较对照组有较少的脑室内出血发生比例(z=1.167,P=0.030)、较短的总用氧时间[分别为(8.0±5.5) d和(13.3±9.3) d,t=2.225,P=0.032]及住院时间[(39.0±7.7) d和(43.6±10.6) d,t=2.229,P=0.029],且支气管肺发育不良、坏死性小肠结肠炎的发生情况组间差异无统计学意义(P均＞0.05).治疗组中有5例药物治疗失败后使用胸腔镜钳闭动脉导管,术后3例发生肺部感染,1例出现胸腔积液,无死亡及气胸发生.结论极低出生体重早产儿有临床表现的动脉导管未闭应积极干预,口服吲哚美辛可有效关闭动脉导管,胸腔镜钳闭动脉导管可作为药物治疗失败后的一种选择.

Abstract：

Objective To investigate the treatment of symptomatic patent ductus arteriosus (PDA) in very low birth weight preterm infants. Methods From January 1, 2008 to December 31, 2010, 78 very low birth weight preterm infants (birth weight＜1500 g) were diagnosed as symptomatic PDA. Among which, 42 cases administered orally with indomethacin (0.2 mg/kg, every 12 hrs for three times) were taken as treatment group, while five cases in this group who failed to indomethacin treatment were interrupted with video-assisted thoracoscopic surgery. And 36 cases who did not receive treatment for ductus arteriosus were taken as control group. The clinical outcomes, complications and prognosis of these patients were observed. Results There were no significant differences between the gentle percentage, gestational age, diameter of ductus arteriosus, rate of complicated with heart failure, sepsis, neonatal respiratory distress syndrome and intraventricular hemorrhage of two groups (P>0.05, respectively). The ductus arteriosus closed in 33 patients of treatment group (78.6%) and in nine patients of control group (25.0%)(χ2=22.39,P=0.000). There were no significant differences in serum creatinine level and platelet count between before and after the treatment in treatment group(P>0.05). Compared with control group, the treatment group had lower incidence of intraventricular hemorrhage (z=1.167, P=0.030), shorter duration of oxygen therapy [(8.0±5.5) d vs (13.3±9.3) d, t=2.225, P=0.032] and shorter hospital stay [(39.0±7.7) d vs (43.6±10.6) d, t=2.229, P=0.029]; while the incidence of bronchopulmonary dysplasia and necrotizing enterocolitis were similar (P>0.05). The five cases of PDA who received video-assisted thoracoscopic surgery were successfully interrupted with no residual shunt left, while three of them had lung infections and one had pleural effusion, but no pneumothorax and infant death associated with surgery occurred. Conclusions Symptomatic PDA of very low birth weight preterm infants should be treated actively. Oral indomethacin was an effective and safe method to cure the PDA in these infants. Surgical ligation under video-assisted thoracoscopic surgery after failure of indomethacin treatment might be a good option.     

Outcome of very very low birth weight infants

This review of the literature and selected unpublished data documents normal early outcome in 50 to 81 per cent of tiny infants. Educational outcome described by a few studies is less encouraging, with only 32 to 36 per cent considered normal. Each study investigated the contribution of different perinatal, environmental, or social variables, therefore it is difficult to determine which has most impact on neurodevelopmental outcome.     

Enriched post-discharge formula versus term formula for bone strength in very low birth weight infants: a longitudinal pilot study

AIM: To initiate a longitudinal pilot study comparing the effect of nutrient-enriched post-discharge formula (PDF) with standard term formula (TF) on bone strength of very low birth weight (VLBW) infants in the first six months post-term. METHODS: Two matched groups of VLBW infants were randomly assigned to enriched PDF (n=10) or TF (n=10) at corrected age of 40 weeks. Anthropometric measurements of growth and measurements of bone speed of sound (SOS) indicating bone strength and bone turnover markers (bone-specific alkaline phosphatase and cross-linked carboxy terminal telopeptide of type I collagen) were taken at term and at three and six months corrected age. RESULTS: The anthropometric measurements of infants fed PDF and TF were comparable at three and six months corrected age. Bone SOS of the PDF group increased from 2760+/-113 m/s at term to 2877+/-90 m/s and 3032+/-60 m/s at three and six months corrected age, respectively (P<0.001). Likewise, bone SOS of the TF group increased from 2695+/-116 m/s at term to 2846+/-72 and 2978+/-83 m/s at three and six months, respectively (P<0.001). No statistically significant difference was found between the groups in terms of growth and bone SOS measurements. The levels of both bone turnover markers decreased significantly during the study period (P<0.001 for both groups). CONCLUSION: Feeding with PDF after term had no short-term beneficial effect on bone strength and bone turn-over of VLBW infants.     

An epidemiologic study of very low and very very low birth weight infants

VVLBW infants constitute only 1 per cent of the total births, but account for 60 per cent of the NMR and 40 per cent of the IMR. While improved technology and refinements in care continue to improve survival for VVLBW infants, questions regarding the lower limits of viability must be considered. The medical community can rightly take credit for improvement in outcome of infants with weight and gestations so small that, just a decade ago, they were considered nonviable; however, an excruciatingly slow pace of decline in the prematurity rate is an agonizing fact. Can anything be done to prevent prematurity and avoid its devastating consequences on the family and society? The recent French experience suggests the answer could be "yes." A similar experience also has been reported in the United States. Although VLBW NMR is a major fraction of total IMR, nearly one quarter of first-year deaths occur in infants who are over 2500 gm at birth. That the postneonatal death of normal birth weight infants is only next in magnitude to the neonatal death of VLBW infants further points to the need for developing preventive child health programs encompassing periods before and during the pregnancy, through the immediate peripartum period, and well into infancy and childhood. Neither a woman's pregnancy experience nor the concerns of the health community end with her taking a baby home.     

147例极低和超低出生体重儿胃肠道内喂养的影响因素

目的 分析影响极低出生体重儿(very low birth weight infant,VLBWI)和超低出生体重儿(extremely low birth weight infant,ELBWI)胃肠道内喂养的相关因素.方法 对147例出院前达到足量胃肠道内喂养,即奶量达到120 ml/(kg·d)的VLBWI和ELBWI的临床资料进行回顾性研究,分析影响胃肠道内喂养的相关因素.对服从双变量正态分布的资料,采用Pearson法进行相关性分析,否则采用Spearman法进行相关性分析;应用t检验进行单因素分析;应用多元线性回归探讨达足量胃肠道内喂养时间的影响因素.结果 147例研究对象的平均胎龄(31.0±2.0)周;平均出生体重(1246±185)g;达到足量胃肠道内喂养的时间为(24.4±10.5)d.单因素分析显示出生体重(r=-0.477,P=0.000)、胎龄(r=-0.405,P=0.000)、机械通气时间(r=0.393,P=0.000)、开奶日龄(r=0.318,P=0.000)、开奶量(r=-0.263,P=0.001)、第3天奶量(r=-0.412,P=0.000)及第7天奶量(r=-0.592,P=0.000)、新生儿呼吸窘迫综合征(t=3.368,P=0.001)、血糖异常(t=3.285,P=0.001)、败血症(t=3.244,P=0.001)、脐静脉置管(t=3.571,P=0.000)、应用氨茶碱(t=4.341,P=0.000)、光疗(t=3.054,P=0.003)与达到足量喂养时间相关.多元线性回归分析显示出生体重(t=4.175,P=0.000)、开奶日龄(t=2.851,P=0.005)、应用氨茶碱(t=2.231,P=0.027)、光疗(t=2.852,P=0.005)、败血症(t=3.895,P=0.000和第7天奶量(t=7.332,P=0.000)与达到足量喂养时间相关.结论 VLBWI和ELBWI的喂养不但受消化道成熟程度影响,还受其他胃肠道外相关因素的影响,因此应综合考虑临床各方面的具体情况,正确实施胃肠道内喂养.

Abstract：

Objective To summarize and analyze the impact factors on enteral feeding in very low birth weight infants (VLBWI) and extremely low birth weight infants (ELBWI). Methods A retrospective study was carried out in VLBWI and ELBWI who had achieved full enteral feeding prior to discharge. The impact factors correlated to the time of achieving full enteral feeding were analyzed. If the data underwent bi-variable normal distribution, they were analyzed with Pearson correlation test; otherwise they would be analyzed with Spearman correlation test. T test was used for single factor analysis and multiple linear regression analysis was carried out to determine the significant risk factors associated with the time of achieving full enteral feeding. Results One hundred and forty-seven infants with mean gestational age of (31.0±2.0) weeks, mean birth weight of (1246±185) g and mean time of achieving full enteral feeding of (24. 4± 10. 5) days were admitted. With the single factor analysis, it was found that birth weight (r=- 0. 477, P = 0. 000), gestational age (r = - 0. 405, P= 0. 000), mechanical ventilation duration (r= 0. 393, P = 0. 000), the time began to enteral feeding (r = 0. 318, P = 0. 000), initial milk volume (r = - 0. 263, P = 0. 001 ), the milk volume on the third day (r= -0. 412, P=0. 000) and the seventh day (r= -0. 592, P=0. 000),neonatal respiratory distress syndrome (t = 3. 368, P = 0. 001), umbilical catheterization (t = 3. 571,P=0. 000), abnormal blood glucose level (t=3. 285, P=0. 001), aminophylline using (t=4. 341,P=0. 000), phototherapy (t=3. 054, P=0. 003) and sepsis (t=3. 244, P=0. 001) were correlated to the time of achieving full enteral feeding. Multiple linear regression showed that the birth weight (t=4. 175, P= 0. 000), the time began to enteral feeding (t= 2. 851, P = 0. 005), aminophylline using (t=2. 231, P=0. 027), sepsis (t=3. 895, P=0. 000), phototherapy (t=2. 852, P=0. 005)and the milk volume on the seventh day (t= 7. 332, P=0. 000) were significantly correlated with the time of achieving full enteral feeding. Conclusions The enteral feeding of VLBWI and ELBWI was not only influenced by maturity of gastrointestinal tract, but also by other parenteral correlation factors. Multiple factors associated with all around clinical conditions should be considered when providing enteral feeding for VLBWI and ELBWI.     

Unconjugated hyperbilirubinemia in very low birth weight infants.

In very low birth weight infants, the occurrence of bilirubin-related brain damage has been repeatedly observed at low serum bilirubin concentrations in close association with altered pathophysiologic status (hypoxia, acidosis, hypothermia, and so on). This increased susceptibility is accompanied by increased severity and duration of unconjugated hyperbilirubinemia as compared with more mature infants. Clinical manifestations of kernicterus in very low birth weight infants are almost always nonspecific. No single biochemical or physiologic measurement is sufficient to predict the risk for development of the bilirubin-related brain damage in this group. Prevention of bilirubin-related brain damage in very low birth weight infants requires not only the maintenance of physiologic and biochemical milieu within normal limits, but also specific therapy to alleviate unconjugated hyperbilirubinemia. Although exchange transfusion has been the mainstay of therapy for unconjugated hyperbilirubinemia, the increased morbidity and mortality associated with exchange transfusion in these immature infants and the need to maintain very low serum bilirubin concentrations suggest that prophylactic phototherapy may be more beneficial for this group.     

Non-sinus bradyarrhythmias in very low birth weight infants.

Transient bradycardias occur frequently in preterm infants with apnea of prematurity. However, occurrence of non-sinus bradyarrhythmias in very low birth weight (VLBW) infants has received very little attention. This case series documents transient bradyarrhythmias in VLBW infants. Most frequently observed arrhythmia was a non-sinus atrial rhythm followed by junctional escape rhythm. Ventricular rhythm with wide QRS complexes occurred rarely. The majority of these episodes occurred in the absence of oxygen desaturation. Increase in vagal tone is presumed to mediate this response.     

Nephrotoxic medication exposure in very low birth weight infants

Abstract

Objective: To quantify exposure to potentially nephrotoxic medications among very low birth weight (VLBW) infants and determine the relationship of nephrotoxic medication exposure to acute kidney injury (AKI) in this vulnerable population.

Methods: We reviewed 107 VLBW infants who survived to discharge from April 2011 to March 2012 and measured exposure to the following nephrotoxic medications: acyclovir, amikacin, amphotericin B, gentamicin, ibuprofen, indomethacin, iohexol, tobramycin and vancomycin. Acute kidney injury was determined by the KDIGO guidelines.

Results: Exposure to ≥1 nephrotoxic medication occurred in 87% of infants. The most common exposures were gentamicin (86%), indomethacin (43%) and vancomycin (25%). There was an inverse linear relationship between birth weight and nephrotoxic medications received per day (R^2?=?0.169, p?<?0.001). Infants with AKI received more nephrotoxic medications per day than those who did not (0.24 versus 0.15; p?=?0.003).

Conclusions: VLBW infants are frequently exposed to nephrotoxic medications, receiving approximately two weeks of nephrotoxic medications before discharge or 1 for every 6?d of hospitalization. The greatest exposure occurred among the smallest, most immature infants and those who experienced AKI.     

Procalcitonin as a screening test for late-onset sepsis in preterm very low birth weight infants.

OBJECTIVE: To compare the utility of procalcitonin (PCT) vs C-reactive protein (CRP) as indicators of late-onset neonatal sepsis in very low birth weight (VLBW) infants. METHODS: PCT and CRP levels were measured in VLBW infants with suspected sepsis and controls. Comparisons were made between infected vs noninfected infants. Using cutoff values of 0.5 and 1.0 ng/ml for PCT and 0.8 mg/dl for CRP, sensitivity, specificity, positive and negative predictive values were calculated to evaluate these assays as potential predictors of late-onset sepsis. RESULTS: A total of 67 infants were evaluated. Mean PCT levels were significantly higher in the infected group (5.41 ng/ml) compared to the noninfected group (0.43 ng/ml) (p < 0.001). At a cut off value of 0.5 ng/ml, the sensitivity of PCT was 97%, whereas that of CRP was 73% in predicting late-onset sepsis. At a PCT cutoff of 1.0 ng/ml, sensitivities of PCT and CRP were similar (72% each). CONCLUSION: PCT (0.5 ng/ml) is more sensitive than CRP in predicting late-onset sepsis in VLBW infants.     

两种辅助通气方式早期应用于早产极低出生体重儿的临床效果比较

目的 比较鼻塞持续气道正压通气(nasal continuous positive airway pressure,nCPAP)与气管插管接呼吸机通气在早产极低出生体重儿生后早期应用的临床效果. 方法 选择生后60 min内出现呼吸窘迫症状的早产极低出生体重儿共123例纳入本前瞻性随机对照研究,nCPAP组63例,气管插管接呼吸机通气组(对照组)60例.采用卡方检验和t检验比较2组患儿支气管肺发育不良发生率、病死率、用氧、辅助通气使用和临床并发症情况. 结果 nCPAP组与对照组比较,支气管肺发育不良发生率[4.8％(3/63)与3.3％(2/60)]和病死率[7.9％(5/63)与6.6％(4/60)]差异均无统计学意义(x2 =0.16和0.07,P＞0.05).nCPAP组肺表面活性物质使用率(27.0％,17/63)低于对照组(83.3％,50/60),差异有统计学意义(x2=39.34,OR=0.3,90％ CI:0.2～0.6,P＜0.05).生后28 d时,nCPAP组辅助通气的比例(17.5％,11/63)低于对照组(25.0％,15/60)(OR=0.7,90％ CI:0.4～1.4);至纠正胎龄36周时,nCPAP组辅助通气比例(6.3％,4/63)仍低于对照组(8.3％,5/60)(OR=0.8,90％ CI:0.2～2.4),但差异均无统计学意义(x2分别为1.05和0.01,P均＞0.05).nCPAP组气漏发生率(11.1％,7/63)低于对照组(33.3％,20/60),差异有统计学意义(x2=8.86,OR=0.3,90％ CI:0.2～0.7,P＜0.05). 结论 与气管插管接呼吸机通气相比,在早产极低出生体重儿中早期使用nCPAP,不能降低病死率或支气管肺发育不良发生率,但可缩短辅助机械通气时间,降低气漏和使用肺表面活性物质的比例.     

Hematological profile of Korean very low birth weight infants

For very low birth weight (VLBW) infants, diagnostic and therapeutic decisions widely depend on hematological values. Although ethnic differences for hematologic parameters have been reported, few studies have been reported for Korean VLBW infants. This study aimed at defining the hematological reference values for medical research and clinical practice. Retrospectively we selected 149 infants confirmed as healthy at birth and had no medical conditions that may have affected the hematological profile. Hematological values obtained within the first 4 h after birth were classified into gestational age and we determined the influence of gender, mode of delivery, sampling site, 1-min and 5-min Apgar scores on these values. Red blood cell (RBC), hemoglobin (Hb) and hematocrit (Hct) values increased, whereas the white blood cell (WBC) and platelets decreased as the gestational age increased. In relation to the mode of delivery and the 5-min Apgar score, WBC, neutrophil, mean corpuscular volume (MCV), RBC, Hb, Hct and the platelets differed selectively. No differences in any hematological values were observed in relation to gender, sampling site, and the 1-min Apgar score. This study should be useful as a guide to the reference range of these hematological values for Korean VLBW infants.     

Fluid and electrolyte balance in very low birth weight infants.

Correct fluid and electrolyte concentrations are essential to reduce mortality in critically ill infants. The authors list considerations in calculating the necessary maintenance volumes and emphasize the importance of continuous monitoring of data and a review and retabulation every eight hours, because requirements vary from one infant to the other, and in the same infant under different circumstances.