Alessandra Cecchi

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).

Dopamine infusion: a possible cause of undiagnosed congenital hypothyroidism in preterm infants.

Objective: To describe the possibility that dopamine infusion can prevent early diagnosis of congenital hypothyroidism. Design: Case report. Setting: Medical neonatal intensive care unit of a tertiary academic medical center. Patients: We report four preterm newborns affected by transient primary congenital hypothyroidism who showed low serum thyroxine and normal thyroid-stimulating hormone concentrations on primary screening performed during treatment with dopamine. Interventions: Thyroid reevaluation screening after dopamine discontinuation. Measurements and Main Results: Thyroid reevaluation showed elevated thyroid-stimulating hormone levels. Conclusion: We emphasize that dopamine capacity to suppress thyroid-stimulating hormone could prevent early diagnosis of congenital hypothyroidism. We suggest all newborns to be tested simultaneously for thyroid-stimulating hormone and thyroxine values at primary screening. A reevaluation of thyroid hormones after dopamine discontinuation is advisable in patients treated with dopamine.

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.

Hypernatraemia induced by sodium polystyrene sulphonate (Kayexalate) in two extremely low birth weight newborns.

Hyperkalaemia is a life‐threatening electrolyte disorder that can occur in the first week of life in almost 50% of preterm infants with a birth weight less than 1000 g [extremely low birth weight (ELBW)]. Serum potassium values higher than 7 mmol·l−1 are associated with cardiac arrhythmias and an increased incidence of intraventricular haemorrhage and periventricular leucomalacia. Therapeutic options to treat this dangerous imbalance comprise calcium gluconate, insulin plus glucose, albuterol/salbutamol inhalation. Administration of cation‐exchange resin such as sodium polystyrene sulphonate (Kayexalate®) is effective in lowering plasma potassium, although complications following oral or rectal administration are reported in newborns. We describe two ELBW infants affected by hyperkalaemia, treated with Kayexalate, who developed serious hypernatraemia, that has never been reported before in preterm infants.

Dopamine Infusion and Anterior Pituitary Gland Function in Very Low Birth Weight Infants

Background: Previous studies demonstrated that dopamine infusion reduces plasma concentration of thyroxine (T4), thyroid stimulating hormone (TSH), prolactin (PRL), and growth hormone (GH) in adults, children, and infants. Objectives: The purpose of this prospective observational study was to evaluate the relationship between dopamine infusion and the dynamics of T4, TSH, PRL, and GH in preterm newborns weighing less than 1,500 g (very low birth weight infants, VLBW) admitted in a neonatal intensive care unit of a university hospital over a one year period. Methods: A total of 97 preterm newborns were enrolled and divided into two groups: group B included hypotensive infants treated with plasma expanders and dopamine infusion; group A was the control group including newborns who were never treated with dopamine. The newborns were studied dynamically through blood samples taken every day till 10 days. Newborns of group B were studied during dopamine infusion and after its withdrawal. Results: Among the VLBW newborns who were given dopamine, the four pituitary hormones had different dynamics: a reduction of T4, TSH, and PRL levels was noticed since the first day of treatment, and a rebound of their levels was evident since the first day after its interruption. On the contrary, the postprandial GH levels were roughly constant: GH plasma concentrations were in fact a little lower in newborns treated with dopamine, and a slight increase was observed after its withdrawal. However, observed differences were not statistically significant. Conclusions: The results suggest that dopamine infusion reduces T4, TSH, and PRL plasma levels in preterm VLBW infants and have no effect on postprandial GH rate. This hormonal suppression reverses rapidly after dopamine withdrawal. This observation suggests that the iatrogenic pituitary suppression probably cannot produce long-term injuries.

Behavior of the Newborn during Skin-to-Skin:

Background: Early skin-to-skin contact (SSC) significantly increases the breastfeeding rate in healthy term infants. Objective: This study aimed to confirm previously described behavioral sequences during SSC. Methods: We recorded live and videotaped infant behavioral sequences during SSC in a cohort of healthy term infants, whose outcome was then evaluated. Results: We studied 17 mother-infants dyads. While the majority of infants (59%) had behavioral phases that have been previously reported, some of them had alternative sequences. We observed the infant’s massage of the mother’s breast with its hand during SSC, which had not been previously reported. We found no correlations between behavioral sequence during SSC, breastfeeding, and neonatal outcome. Moreover, maternal pain stimuli did not affect the neonatal SSC behavioral sequence. Conclusion: Our study confirms that immediate and undisturbed postpartum SSC is characterized by specific behavioral phases whose sequence may vary without affecting the suckling rate at the end of SSC, breastfeeding success, or the short-term neonatal outcome.

Association between peak serum bilirubin and severity of respiratory distress syndrome in infants of less than 30 weeks' gestation.

Abstract Introduction: Bilirubin can enter the alveolar space where it could inactivate surfactant and act as an anti-oxidant agent. Objective: To assess the hypothesis that total serum bilirubin level (TSB) may affect the severity of respiratory distress syndrome (RDS) and the need of respiratory supports in preterm infants. Study design: We performed a retrospective study of 184 preterm infants with RDS, whose peak TSB had a median value of 194.8 μmol/L (=11.3 mg/dL). This value was used to stratify patients into two groups: neonates who developed low and high TSB (≤ or >194.8μmol/L, respectively). For each patient the highest values of inspired oxygen fraction (FiO2), arterial to alveolar oxygen tension ratio (a/APO2), oxygenation index (O.I.), ventilatory index (V.I.), and the need and duration of respiratory supports were recorded. Results: Seventy-five infants were included in the low TSB group and 74 were included in the high TSB group. The RDS severity and the need of respiratory supports were similar in both the groups. The first day of life TSB and peak TSB did not correlate with the highest values of FiO2 and a/APO2, and the duration of mechanical ventilation. Conclusions: We did not find any correlation between TSB level and RDS severity. We speculate that this result is because the potential inhibiting effect of bilirubin on surfactant function is neutralized by the exogenous surfactant treatment, while its antioxidant effects do not provide appreciable benefits in the lung tissue.