Potential risk factors for the development of acute renal failure in preterm newborn infants: a case-control study

AIMS

To determine in a case-control study possible associations between the development of acute renal failure in preterm newborns and therapeutic interventions, particularly drug treatments.

METHODS

The study population was 172 preterm infants of <38 weeks gestation; 71 had acute renal failure and 101 were controls closely matched for gestational age and birth weight. Maternal and neonatal information was collected for both groups through questionnaires and interviews. Routine data on renal variables were also collected. Univariate and multivariate logistic regression analyses were performed.

RESULTS

Very low birthweight infants were at high risk of acute renal failure (79% of cases were <1500 g). However, the acute renal failure was transient. Mothers of infants with acute renal failure received more drugs during pregnancy and delivery (mainly antibiotics and non-steroidal anti-inflammatory drugs). Of the possible therapeutic interventions, intubation, catheterisation, and phototherapy were mainly applied to case subjects. A low Apgar score and patent ductus arteriosus were diagnosed in a greater percentage of neonates with acute renal failure. Moreover, in the first few days of life and before diagnosis of acute renal failure, case subjects received more drugs (antibiotics, non-steroidal anti-inflammatory drugs, and diuretics) and for a longer time. In the multivariate logistic analysis, medullary hyperechogenicity (odds ratio (OR) 4.491; 95% confidence interval (CI) 1.879 to 10.731) and ceftazidime administration (OR 5.082; 95% CI 1.493 to 17.297) were associated with a greater risk of acute renal failure.

CONCLUSIONS

The results suggest the need for careful monitoring of very low birthweight infants and attention to drug treatments, as it is difficult to differentiate between normality and renal failure in the first few days of life.

Foetal growth of kidneys, liver and spleen in intrauterine growth restriction: "programming" causing "metabolic syndrome" in adult age

BACKGROUND/AIMS

Epidemiological studies in humans link adult disease to abnormal growth in utero. In addition to general malnutrition of the foetus, preferential blood flow to the brain and heart may furthermore deprive organs such as the liver, spleen and kidneys of oxygen and macro- and micronutrients. As a consequence, these organs may not develop normally, which predisposes the individual to the so-called metabolic syndrome (syndrome X) in later life. The effects of foetal undernutrition on the growth of some abdominal organs were investigated by comparing the volume of the kidneys, spleen and liver in small-for-gestational-age (SGA) newborn infants with that in appropriate-for-gestational-age (AGA) newborn infants.

METHODS

In 25 randomly selected AGA infants and 25 SGA infants, who were subdivided into three gestational age groups (<30, 30-36 and 37-40 wk) the volumes of the liver, kidneys and spleen were determined by ultrasonography. Organ volumes were estimated using the standard ellipsoid formula (longitudinal x anteroposterior x transverse diameter x pi/6). Liver/kidney, liver/spleen and kidney/spleen volume ratios were also determined.

RESULTS

The volumes of the kidneys and liver differed significantly between AGA and SGA infants in all three gestational age groups (p < 0.0018 and p < 0.029, respectively). The fact that the spleen volume differed only in the 37-40 wk group (p = 0.0002) may indicate that there is a graded relationship across the whole range of normal birthweight. The correlation between the liver volume and birthweight differed significantly between SGA and AGA infants (r = 0.56 vs 0.84, p = 0.04). On the other hand, the volume ratios between the three organs were the same in all groups (p > 0.15).

CONCLUSION

In intrauterine growth retarded infants, foetal growth of the liver and kidneys is more impaired than the body as a whole. Retarded foetal development of these organs may cause metabolic dysfunction, which predisposes to the group of diseases included in the so-called metabolic syndrome or syndrome X.

Scintigraphic evaluation of gastroesophageal reflux in newborns

OBJECTIVES

This study was carried out to verify whether during neonatal stage gastroesophageal scintigraphy, may be useful not only to diagnose gastroesophageal reflux (GER), but also to detect pulmonary aspiration, at times responsible for respiratory symptoms frequently associated with GER.

PATIENTS AND METHODS

Gastroesophageal scintigraphy was performed on 50 newborns admitted to NICU of Brindisi in the last two years who presented symptoms as cyanosis, apnoea, bradycardia, laringeal stridor, wheezing, not related to respiratory or cardiac problems, but suspected to be clinical suggestive symptoms of "pathological" GER. After administration of 99mTC mixed with the usual meal formula, we obtained a recording period of 60-90 minutes and a later recording at 4 and 24 hours to document radioactive material in lungs.

RESULTS

Scintigraphy showed GER in 40/50 cases and despite frequent observation of respiratory symptoms (39/40 cases) in these newborns never radiation in pulmonary fields.

CONCLUSIONS

Our results could indicate that scintigraphy, noninvasive and low in radiation, may be considered effective and reliable to diagnose GER in newborns. The absence of radiation in pulmonary fields could indicate that respiratory symptoms frequently associated with GER could depend on involuntary mechanism of vagal type and not on pulmonary aspiration.

[Therapy of neonatal infection caused by group B beta-hemolytic Streptococcus]

Expectant therapy for early Group B Streptococcus onset septicemia must provide coverage against other microorganism, such as L. Monocytogenes, H. Influenzae and S. Pneumoniae. It is possible to administer a combination of antimicrobial agents with activity against all or the most likely pathogens. Thus initial expectant therapy includes a broad spectrum semisynthetic penicillin (e.g. ampicillin) and an aminoglycoside (e.g. netilmicin). Vancomicin, teicoplanin and cefotaxime may also be used. Supportive therapy consists on temperature control, i.v. administration of fluids, acid-base balance and electrolytes monitoring, seizures control and ventilation. IV immunoglobulins, granulocyte and serum transfusion are also used. The G-Colony Stimulating Factor (G-CSF, filgastrim) usage is also reported.

[Effects of recombinant human erythropoietin in the treatment of anemia of prematurity]

13 premature babies (gestational age 31.1 +/- 0.9 weeks and birth weight 1586 +/- 261 g) were randomly assigned to receive recombinant human erythropoietin (200 U/kg i.v. three times a week during 4 weeks) or no (13 babies) as soon as haematocrit decrease < 30% between second and seventh week (TO). The two groups had similar gestational age, birth weight, Apgar score 1' and 5', O2-therapy, IPPV and volume of packed erythrocytes transfused before TO. Treatment was started at 30 +/- 0.5 days (range 21-42). At TO all subjects had not cardiopulmonary compromission, sepsis, O2-dependence, GMH-IVH > or = 2 degree grade and received iron and Vit. E by i.m. Result were evaluated through determination of hemoglobin, haematocrit, reticulocytes and volume of packed erythrocytes before and on days 7, 14, 21 and 28 of therapy. After rHuEPO the number of reticulocytes increased on days 21 and 28 of therapy (on day 21: 92.4 +/- 34.2 x 1000/L vs. 71.8 +/- 21.0, p < 0.10; on day 28: 116.2 +/- 42.9 vs. 83.8 +/- 23.2, p < 0.05); otherwise the number of transfusion (0.2 +/- 0.4 vs. 1.0 +/- 1.2, p < 0.10) and volume of packed erythrocytes (3.0 +/- 6.3 ml/kg vs. 14.9 +/- 15.9, p < 0.05) were reduced. Serum erythropoietin levels did not change during treatment, probably because, reducing the lowering of hemoglobin, hypoxic stimulus to increase of erythropoietin was suppressed.