Marco Pezzati

The role of blood transfusions and iron intake on retinopathy of prematurity

BACKGROUND The role of blood transfusions and iron intake in the pathogenesis or retinopathy of prematurity (ROP) is controversial. AIM To evaluate the influence of packed red cell (PRC) transfusions and iron intake on ROP incidence. STUDY DESIGN Prospective observational study. SUBJECTS Forty-five preterm infants with birthweight <1250 g were studied. After ophthalmological study, they were divided into group A (n=24) that included newborns without ROP, and group B (n=21) that included newborns with ROP. RESULTS Logistic regression analysis demonstrated that gestational age (OR 0.61; 95% C.I. 0.41-0.90), transfusion volume during the first week (OR 1.16; 95% C.I. 1.03-1.3) and during the first 2 months of life (OR 2.93; 95% C.I. 1.52-5.62), and iron intake during the first week of life (OR 1.15; C.I. 1.01-1.32) and during the first 2 months of life (OR 2.93; 95% C.I. 1.52-5.62) were associated with the development of ROP. CONCLUSION Our study showed that gestational age, blood transfusion volume and iron load by transfusions are associated with the risk of occurrence of ROP in infants with a birthweight of less than 1250 g.

Maternal education and the incidence and duration of breast feeding: A prospective study

Introduction Duration of breast feeding and factors possibly affecting duration were studied in a population of 2174 newborn infants, with gestational age of >37 weeks, who were born in the Department of Obstetrics and Gynaecology at the University of Florence Hospital between November 15, 1997, and November 14, 1998. Patients and Methods Nine hundred mothers agreed to participate in the study. Five questionnaires were completed at the end of the 1st, 3rd, 6th, 9th, and 12th postpartum month. These dealt with infant feeding practices, including breast feeding during the previous week. Breast feeding duration was defined as short (1 month); medium-short (>1 month–<3 months); medium (>3–<6 months); medium-long (>6–<9 months), and long (>9 months). Results The authors found that 76.3%, 64.7%, 42.3%, 26.4%, and 17% of mothers were still breast feeding at 1, 3, 6, 9, and 12 months after delivery, respectively. The multivariate analysis of the correspondence shows that lack of breast feeding is associated with a birth weight of less than 3000 g, a low level of maternal education, and maternal profession as a housewife or blue collar worker in the commercial sector. A period of breast feeding defined as short or medium-short is associated with mothers who smoke, primiparous mothers, and absence of maternal allergy. The survival curves highlight how the single factor of smoking is an element that leads to a significant difference in the duration of breast feeding. The multiple Cox regression analysis shows a significant negative influence associated with birth weight of less than 3000 g, maternal smoking, and first parity. Above all, among low–birth-weight infants of mothers who smoke, there is a strong correlation with a shorter duration of breast feeding. Discussion There is still a need for programs that support and encourage breast feeding, focusing particularly on mothers with a low level of education who give birth to a low-weight infant, primiparous mothers, and smokers.

Plasma bilirubin level and oxidative stress in preterm infants

Objective: To assess the hypothesis that changes in plasma total bilirubin levels (Btot) can influence the antioxidant system and oxidative stress in preterm infants. Methods: Twenty two healthy preterm infants who presented with visible non-haemolytic hyperbilirubinaemia were studied at the mean (SD) age of 3.7 (1.5) days. Btot, plasma total hydroperoxide concentration (TH), plasma protein SH group concentration, and total antioxidant capacity of the plasma (TAC) were measured at study entry and after 24 hours. Results: Btot did not correlate with TH, TAC, or protein SH group concentration, but a significant correlation was found between TH and TAC, TH and protein SH groups, and TAC and protein SH groups, both at study entry and after 24 hours. Conclusion: The decrease in plasma bilirubin was contemporary with an increase in plasma antioxidant capacity and decrease in oxidative stress in preterm infants. This may be the result of the pro-oxidant effect of haem oxygenase, mediated by iron release, which may outcompete the antioxidant properties of bilirubin.

Umbilical cord care: The effect of eight different cord-care regimens on cord separation time and other outcomes

In this study we evaluate the effect of eight cord-care regimens on cord separation time and other secondary outcomes: omphalitis, sepsis, death, cord bleeding, compliance, satisfaction or dissatisfaction with regard to the type of treatment, umbilical cord colonization – in 1,535 healthy term infants. The eight cord-care regimens studied were: 70% alcohol, natural drying, salicylic sugar powder, triple dye, micronized green clay powder, colloid silver-benzyl-peroxide powder, neomycin-bacitracin powder, 1% basic fuchsine. None of the newborns developed sepsis or died and we found only sporadic cases of omphalitis. With regard to cord separation time the best results were obtained with salicylic sugar powder (5.6 ± 2.3 days) and green clay powder (6.7 ± 2.2 days). Both forms of treatment proved to be more effective (p < 0.05) than all the others. We found that salicylic sugar powder allows for early cord detachment resulting in excellent parent treatment compliance and reduction of their concern, notwithstanding higher percentages of cord bleeding. The rate of positive umbilical swabs was low and was significantly higher only than the results obtained with neomycin-bacitracin powder treatment. This study demonstrates that, in hospital nurseries of developed countries, salicylic sugar powder can be effectively and safely used for umbilical cord care of healthy term infants.

Dopamine versus dobutamine in very low birthweight infants: endocrine effects

Objectives: To compare the endocrine effects of dopamine and dobutamine in hypotensive very low birthweight (VLBW) infants. Design: Non-blinded randomised prospective trial. Setting: Level III neonatal intensive care unit. Patients: 35 hypotensive VLBW infants who did not respond to volume loading, assigned to receive dopamine or dobutamine. Measurements: Haemodynamic variables and serum levels of thyroid stimulating hormone (TSH), total thyroxine (T4), prolactin (PRL) and growth hormone were assessed during the first 72 h of treatment and the first 72 h after stopping treatment. Results: Demographic and clinical data did not significantly differ between the two groups. Necessary cumulative and mean drug doses and maximum infusion required to normalise blood pressure were significantly higher in the dobutamine than in the dopamine group (p<0.01). Suppression of TSH, T4 and PRL was observed in dopamine-treated newborns from 12 h of treatment onwards, whereas levels of growth hormone reduced significantly only at 12 h and 36 h of treatment (p<0.01). TSH, T4 and PRL rebound was observed from the first day onwards after stopping dopamine. Dobutamine administration did not alter the profile of any of the hormones and no rebound was observed after stopping treatment. Conclusion: Dopamine and dobutamine both increase the systemic blood pressure, though dopamine is more effective. Dopamine reduces serum levels of TSH, T4 and PRL in VLBW infants but such suppression is quickly reversed after treatment is stopped. Further research is required to assess if short-term iatrogenic pituitary suppression has longer-term consequences.

Inhaled nitric oxide in very preterm infants with severe respiratory distress syndrome.

Aim: To test the hypothesis that inhaled nitric oxide therapy can decrease the incidence of bronchopulmonary dysplasia and death in preterm infants with severe respiratory distress syndrome; to evaluate the possible predictive factors for the response to inhaled nitric oxide therapy. Methods: Preterm infants (less than 30 weeks’ gestation) were randomized to receive during the first week of life inhaled nitric oxide, or nothing, if they presented severe respiratory distress syndrome. Then, the treated infants were classified as non responders and responders. Results: Twenty infants were enrolled in the inhaled nitric oxide therapy group and 20 in the control group. Bronchopulmonary dysplasia and death were less frequent in the inhaled nitric oxide group than in the control group (50 vs. 90%, p=0.016). Moreover, nitric oxide treatment was found to decrease as independent factor the combined incidence of death and BPD (OR=0.111; 95% C.I. 0.02–0.610). A birth weight lower than 750 grams had a significant predictive value for the failure of responding to inhaled nitric oxide therapy (OR 12; 95% C.I. 1.3–13.3).

Effect of blood transfusions on oxidative stress in preterm infants.

Objective: To confirm the increase in non-transferrin bound iron (NTBI) after packed red cell (PRC) transfusion and to evaluate the association with increased oxidative stress in preterm infants. Method: Twenty healthy preterm infants (gestational age 28.2 (2.2) weeks; birth weight 1047 (230) g), who required blood transfusion for anaemia of prematurity were prospectively studied. Serum concentrations of NTBI, total hydroperoxides (TH), and protein SH groups, and plasma total radical trapping antioxidant capability (TAC) were measured within three hours before and after PRC transfusion. The infants were transfused with 38.6 (23) ml PRCs over 5.8 (1.0) hours, at a mean age of 43.3 (25.1) days. Results: After PRC transfusion, haemoglobin concentration increased from 9.2 (1.1) to 14.6 (1.5) g/l. Mean plasma NTBI concentration after transfusion was significantly higher (0.43 (0.45) v 2.03 (1.31) μmol/l; p  =  0.001), while plasma concentrations of TH (212.3 (42.2) v 214.7 (66.3) Carr units/l) and protein SH groups (317.5 (38.8) v 353.8 (57.4) μmol/), and TAC (256.3 (36.1) v 267.1 (42.4) μmol HClO/ml) remained unchanged. Conclusion: For three hours after PRC transfusion, plasma NTBI is significantly increased in preterm infants, but this is not associated with significant changes in oxidative stress.

Brain Hemodynamic Effects of Doxapram in Preterm Infants

Background: Doxapram is a respiratory stimulant widely used for the treatment of idiopathic apnea of prematurity, although it has been demonstrated that it can induce a transient decrease of cerebral blood flow and that isolated mental delay in infants weighing <1,250 g is associated with the total dosage and duration of doxapram therapy. Objectives: To evaluate the effects of doxapram on cerebral hemodynamics in preterm infants using cerebral Doppler ultrasonography and near-infrared spectroscopy. Methods: Preterm infants who required treatment with doxapram for apnea of prematurity unresponsive to caffeine were treated with doxapram at an hourly dose of 0.5 mg·kg–1·h–1, followed by 1.5 and 2.5 mg·kg–1·h–1. Results: 20 preterm infants were studied. Doxapram induced a significant decrease of oxygenated hemoglobin (O2Hb) and cerebral intravascular oxygenation (HbD = O2Hb – HHb) and an increase of HHb and CtOx concentrations, while cerebral blood volume and cerebral blood flow velocity did not change. Conclusions: Doxapram infusion induces the increase of cerebral oxygen consumption and requirement and the contemporary decrease of oxygen delivery probably mediated by a decrease of cerebral blood flow. Caution must be recommended in prescribing this drug for apnea of prematurity.

Prediction of early tolerance to enteral feeding by measurement of superior mesenteric artery blood flow velocity: appropriate- versus small-for-gestational-age preterm infants.

Aim: To evaluate whether serial Doppler measurements of superior mesenteric artery blood flow velocity could predict early tolerance to enteral feeding in preterm infants. Methods: In a prospective study, 54 healthy preterm neonates were assigned to one of the following groups: neonates with birthweight appropriate for gestational age (group 1), neonates small for gestational age without (group 2) and with prenatal haemodynamic disturbances (group 3). We studied Doppler blood flow velocity and resistance index before and after the first feed. Results: Contrary to patients of group 3, infants in groups 1 and 2 showed a significant increase in blood flow velocity and a significant decrease in resistance index from the preprandial values after the first feed. At each postprandial time, we found significant differences in all velocity and resistance measurements between patients of group 3 and patients of both groups 1 and 2. In all patients, we found that the value of mean velocity measured 30 min after the first feed was the most predictive of early feed tolerance, with 95% sensitivity and 94% specificity when mean velocity >0.38 m/s.

Fusidic acid and heparin lock solution for the prevention of catheter-related bloodstream infections in critically ill neonates: a retrospective study and a prospective, randomized trial.

Objective: Catheter-related bloodstream infections (CRBSIs) are one of the main morbidities in critically ill neonates. The objective of the present study was to assess the efficacy of a fusidic acid-heparin lock in the prevention of CRBSIs. Design: A preliminary retrospective study showed that staphylococcal infections were largely prevalent. We planned a prospective, randomized trial to ascertain whether fusidic acid and heparin lock of central venous catheters would reduce the incidence of CRBSIs. Setting: Level III neonatal intensive care unit. Patients: One hundred three neonates were enrolled and randomly assigned to a treatment group (n = 50) or control group (n = 53). Interventions: Fusidic acid (4 mg/mL) and heparin (10 IU/mL) lock in the treatment group. Measurements and Main Results: The treatment group showed significantly lower incidence of CRBSIs (6.6 vs. 24.9 per 1000 catheter days; p < .01; relative risk 0.28; 95% confidence interval 0.13–0.60). No staphylococcal infections occurred in the treatment group, while in the control group Staphylococcus remained the main agent of CRBSI. Cost analysis comparing the present study and for the treatment of CRBSIs proved that antibiotic lock is financially favorable. Conclusions: Fusidic acid-heparin lock solution reduced the incidence of CRBSIs in our neonatal intensive care unit. However, we recommend basing antibiotic lock on local CRBSI epidemiology. With regard to fusidic acid, further and broader studies could be useful to confirm our results.