Iuri Corsini

The INSURE method in preterm infants of less than 30 weeks' gestation

Objectives. Our aim was to identify the clinical characteristics which could distinguish infants who can be managed with INSURE (intubatio-surfactant-extubation) method for preventing mechanical ventilation (MV) and which could predict INSURE success or failure. Methods. Inborn infants with gestational age <30 weeks were Infants were categorised into three groups: (1) infants who needed MV in the delivery room; (2) infants spontaneously breathing who were treated only with NCPAP; (3) infants who were treated with INSURE method. Results. We studied 125 infants: 30 (24%) required MV, 75 (60%) received INSURE treatment, and 20 (16%) were treated with NCPAP. Sixty-eight (91%) infants were successfully treated with the INSURE method. Infants in the success group had less severe RDS and less occurrence of sepsis and pneumothorax, lower mortality, and shorter duration of stay in the NICU than infants in the failure group. A birth weight <750 g, pO2/FiO2 <218, and a/ApO2 <0.44 at the first blood gas analysis were independent risk factor for INSURE failure. Conclusions. The INSURE method can be applied to the majority of extremely preterm infants and is followed by a high percentage of success.

The fate of ductus arteriosus in infants at 23–27 weeks of gestation: from spontaneous closure to ibuprofen resistance

Background: Some extremely preterm infants experience spontaneous closure of the ductus arteriosus. On the other side, a high percentage (22–30%) of preterm infants born at the lower gestational age fail to respond to a single course of ibuprofen.

Neonatal morbidity in late preterm and term infants in the nursery of a tertiary hospital

Preterm delivery is the most important determinant of neonatal morbidity and mortality in developed countries (1). Despite the majority of preterm infants ( 74%) is represented by late preterm infants (2), i.e. infants born between 34 ⁄ 7 and 36 ⁄ 7 weeks of gestation (3), few resources have been traditionally employed for their hospital care. In fact, these infants are often assisted in the nursery along with term infants (4) and discharged on the same schedule as term-born infants (5). Nevertheless, recent data evidence that this group of infants has a higher rate of complications such as hypothermia, hypoglycaemia, hyperbilirubinaemia, respiratory distress and poor feeding (5). However, to our knowledge, earlier studies have not evaluated the exact occurrence of these complications and we hypothesized that they were significantly more frequent in late preterm infants than in term infants. To assess this hypothesis, we performed a prospective single centre-based study. The study was carried out in the nursery of the Division of Neonatology of Careggi University Hospital of Florence from January 2008 to December 2008. All infants with a birth weight >2000 g and a gestational age (GA) >34 weeks were enrolled and classified as late preterm infants (born between 34 ⁄ 7 and 36 ⁄ 7 weeks of gestation), or term infants (born after the 37 ⁄ 7 weeks of gestation). For each group birth weight, GA, type of delivery, occurrence of hypernatraemia (Na >145 mmol ⁄ L), hypocalcaemia (Ca <1.00 mmol ⁄ L), hyperbilirubinaemia, respiratory distress, poor feeding and type of feeding (breast, formula or mixed feeding), hypoglycaemia (glucose <45 mg ⁄ dL), weight loss of >10% of birth weight, need of admission in neonatal care units (NCUs), and prolonged hospitalization were recorded. Moreover, the late preterm and term infant groups were stratified by type of delivery and weeks of GA to evaluate the potential effects of these variables on their complication rate. Gestational age was estimated by the association of ultrasound examination before 20 weeks of gestation and last menstrual period. Hyperbilirubinaemia was recorded when infants required phototherapy following the guidelines of American Academy of Pediatrics (6). Respiratory distress was diagnosed in the presence of tachypnoea (respiratory rate >60 ⁄ min) lasting more than 2 h after birth, dyspnoea, grunting and ⁄ or oxygen dependency. Poor feeding was defined as the need of bottle or feeding through oro-gastric tube. Prolonged hospitalization was defined as a hospital stay >4 days for vaginally born infants and >6 days for infants born through caesarean section. Clinical characteristics of the two groups were described by mean values and standard deviations or rate and percentage. Statistical analysis was performed using the Student’s t-test for parametric continuous variables, and Fisher’s exact test for categorical variables such as frequencies. A p-value of < 0.05 was considered statistically significant. Moreover, we estimated the relative risk (RR) with profile likelihood-based 95% confidence limits of developing each complication in the two groups. During the study period, 3202 infants were delivered in our centre, 2845 were admitted in the nursery and 357 required the admission in NCUs. Of infants admitted in the nursery, 137 (4.8%) were late preterm infants and 2708 were term infants. Late preterm infants had lower birth Acta Pædiatrica ISSN 0803–5253

Risk factors for intubation–surfactant–extubation (INSURE) failure and multiple INSURE strategy in preterm infants

The INSURE method, which consists of an intubation-surfactant-extubation sequence, is effective in reducing the need for mechanical ventilation (MV), the duration of respiratory support, and the need for surfactant replacement in preterm infants with respiratory distress syndrome. Although beneficial, the INSURE method fails to avoid MV in selected patients. We demonstrated that body weight <750 g, pO(2)/FiO(2) <218, and a/ApO(2) <0.44 at the first blood gas analysis are independent risk factors for INSURE failure in infants with gestational age <30 weeks. Moreover, we demonstrated that the INSURE treatment can be safely repeated with the aim to avoid MV, since the respiratory outcome did not differ between infants treated with single or multiple INSURE procedures.

Natural surfactant combined with beclomethasone decreases oxidative lung injury in the preterm lamb

We performed a randomized study in preterm lambs to assess the hypothesis that the treatment with natural surfactant combined with beclomethasone might decrease pulmonary oxidative stress in an animal model of respiratory distress syndrome (RDS). Animals received 200 mg/kg of porcine natural surfactant or 200 mg/kg of natural surfactant combined with 400 or 800 µg/kg of beclomethasone. Lung tissue oxidation was studied by measuring total hydroperoxide (TH), advanced oxidation protein products (AOPP), and non‐protein bound iron (NPBI) in bronchial aspirate samples. In addition, lung mechanics was evaluated. TH was lower in the groups treated with surfactant plus 400 or 800 µg/kg of beclomethasone than in the surfactant group; AOPP was lower in the group treated with surfactant plus 800 µg/kg of beclomethasone than in the other groups; NPBI was similar in all groups. Surfactant treatment was followed by a sustained improvement of tidal volume (TV) and airway resistance, while dynamic compliance did not vary. However, the mean airway pressure needed to obtain similar values of TV was lower in the group treated with surfactant plus 800 µg/kg of beclomethasone than in other groups. We concluded that natural surfactant combined with beclomethasone at 800 µg/kg is effective in reducing the oxidative lung stress and improving the respiratory function in an animal model of RDS. Pediatr Pulmonol. 2009; 44:1159–1167.

Superoxide dismutase and catalase activity in naturally derived commercial surfactants

Despite the role of reactive oxygen species in the development of respiratory distress syndrome (RDS) and bronchopulmonary dysplasia (BPD) in preterm infants, the anti‐oxidant properties of commercial surfactants have never been studied. We measured the superoxide dismutase (SOD) and catalase (CAT) activity, the scavenger activity against hydrogen peroxide (H2O2), and its changes after the addition of SOD and CAT in four natural surfactants, namely Infasurf, Curosurf, Survanta, and Alveofact. We found that they contain measurable amount of SOD and CAT. Curosurf and Survanta seem to have higher antioxidant effect than Infasurf and Alveofact. Moreover, the highest phospholipid concentration and recommended dose of Curosurf imply that its scavenger activity for each treatment dose in preterm infants is likely higher than that of Survanta. Finally, the supplementation with SOD and CAT induced a remarkable increase of antioxidant action in all studied surfactants. Pediatr Pulmonol. 2009; 44:1125–1131. ©2009 Wiley‐Liss, Inc.

Effects of red blood cell transfusions during the first week of life on acid‐base, glucose, and electrolytes in preterm neonates

BACKGROUND: More than 90 percent of extremely low‐birth‐weight infants receive one or more transfusions of red blood cells (RBCs). The objective was to assess if RBC transfusions may induce significant changes of plasma acid‐base, electrolyte, and glucose status in extremely preterm infants.

Effect of multiple INSURE procedures in extremely preterm infants

Abstract Objectives. Our aim was to evaluate whether single and multiple intubation-surfactant-extubation (INSURE) procedures have similar effects on the need of mechanical ventilation (MV) and occurrence of bronchopulmonary dysplasia (BPD) in extremely preterm infants. Methods. We studied infants of <30 weeks of gestation with respiratory distress syndrome (RDS) who were treated with single (FiO2 > 0.30 without need of MV) or multiple (FiO2 > 0.40 without need of MV) INSURE procedures. Results. Seventy-five infants were studied: 53 (71%) received single INSURE and 22 (29%) received multiple INSURE procedures. Infants in the single and multiple groups had similar rates of need of MV (15 vs. 23%) and occurrence of BPD (9 vs. 9%), although the latter were more immature and affected by more severe RDS (higher FiO2, lower a/ApO2, and pO2/FiO2) than the former. Conclusions. Single and multiple INSURE procedures were followed by similar respiratory outcome in a cohort of extremely preterm infants. Further studies are warranted to evaluate whether the multiple INSURE strategy enhances the success rate of INSURE in preventing the need of MV and the occurrence of BPD.

Brain haemodynamic effects of nasal continuous airway pressure in preterm infants of less than 30 weeks' gestation

Aim: To evaluate the hypothesis that increasing levels of nasal continuous positive airway pressure (NCPAP) may decrease cerebral blood volume (CBV) and cerebral oxygenation in infants with gestational age (GA) less than 30 weeks.

Natural Surfactant Combined with Beclomethasone Decreases Lung Inflammation in the Preterm Lamb

Background: Natural surfactant combined with beclomethasone decreases pulmonary oxidative stress in preterm lambs with respiratory distress syndrome (RDS). Objectives: To test the hypothesis that this occurs through a decrease in pulmonary inflammation. Methods: Preterm lambs received 200 mg/kg of natural surfactant or 200 mg/kg of natural surfactant combined with 400 or 800 µg/kg of beclomethasone. Interleukin 8 (IL-8) and macrophage migration inhibitory factor (MIF) were assayed in bronchial aspirate samples and lung mechanics were evaluated. Results: IL-8 increased in all the groups, but the increase was lower in the groups treated with surfactant plus 400 and 800 µg/kg of beclomethasone. MIF decreased in the surfactant group, did not vary in the surfactant plus 400 µg/kg beclomethasone group, and decreased in the surfactant plus 800 µg/kg beclomethasone group. MIF concentration was higher in the surfactant plus 800 µg/kg beclomethasone group than in the other groups. Conclusions: Natural surfactant combined with beclomethasone at 800 µg/kg is effective in reducing lung inflammation in an animal model of RDS, thus explaining the associated decrease in lung oxidative stress. The increase in MIF in animals treated with surfactant plus 800 µg/kg of beclomethasone might be an important maturative and protective factor for neonatal lungs.