Cardiac Hypertrophy Associated with Insulin Therapy in Extremely Preterm Infants

BACKGROUND

In the neonatal period, cardiac hypertrophy (CH) has been commonly associated with hyperinsulinemic pathologies, and the first case of CH in an extremely preterm infant treated with insulin infusion has recently been reported. To confirm this association, we report a case series of patients who developed CH after insulin therapy.

METHODS

Infants with gestational age < 30 weeks and birth weight < 1500 g, born from November 2017 to June 2022, were studied if they developed hyperglycemia requiring treatment with insulin and had echocardiographic diagnosis of CH.

RESULTS

We studied 10 extremely preterm infants (24.3 ± 1.4 weeks) who developed CH at a mean age of 124 ± 37 h of life, 98 ± 24 h after the initiation of insulin therapy. All surviving patients had resolution of CH at discharge, while three of four (75%) of the deceased patients had persistent CH.

CONCLUSIONS

Our case series supports the association between the development of CH and insulin therapy in extremely preterm infants and suggests further caution and the need for echocardiographic monitoring when treating these fragile patients with insulin.

Effect on cerebral oxygenation of paracetamol for patent ductus arteriosus in preterm infants

Paracetamol seems to have similar success rates compared with indomethacin and ibuprofen in closing patent ductus arteriosus (PDA) in preterm infants, but with a better safety profile. The aim of our study was to evaluate the possible effects of paracetamol on cerebral oxygenation and cerebral blood flow velocity (CBFV). Infants with gestational age < 32 weeks with hemodynamically significant PDA (hsPDA) were prospectively studied by near infrared spectroscopy (NIRS) after the first dose of paracetamol (15 mg/kg) or ibuprofen (10 mg/kg). Cerebral regional oxygenation (rSO₂C) and fractional oxygen extraction ratio (FOEC) were recorded 30 min before (T₀) and 60 ± 20 min (T₁), 180 ± 30 min (T₂), and 360 ± 30 min (T₃) after the beginning of drug infusion. Moreover, mean flow velocity (Vmean) and resistance index (RI = PSV-DV/PSV) measured with Doppler ultrasound in pericallosal artery were recorded at the same times. Significant changes in rSO₂C and FOEC were not found during the study period within and between the groups. Similarly, Vmean did not vary in infants treated with paracetamol or ibuprofen, while RI decreased in the ibuprofen group.

CONCLUSION

The treatment of hsPDA with paracetamol does not affect cerebral oxygenation in very preterm infants; there were no differences in cerebral oxygenation in infants treated with paracetamol or ibuprofen, although in the ibuprofen group, the possible closure progression of PDA was associated to changes of RI. What is Known: • Paracetamol has similar success rates to indomethacin and ibuprofen in closing PDA with a better safety profile since previous studies did not report adverse effects. What is New: • Paracetamol does not affect cerebral oxygenation and perfusion in very preterm infants with PDA and this confirms its good safety profile.

Nitric oxide for the treatment of preterm infants with severe RDS and pulmonary hypertension

BACKGROUND

Inhaled nitric oxide (iNO) cannot be recommended for the routine treatment of respiratory failure in premature neonates, but it has been suggested that the effectiveness of iNO therapy should be further studied in more select preterm infants, such as those with persistent pulmonary hypertension of the newborn (PPHN).

OBJECTIVE

To evaluate the frequency of PPHN in very preterm infants with severe respiratory distress syndrome (RDS), to assess the effectiveness of iNO in these patients, and to individuate possible predictive factors for the response to iNO in preterm infants with RDS.

STUDY DESIGN

We retrospectively studied infants <30 weeks of gestational age or birth weight <1250 g, who were affected by severe RDS and treated with iNO during the first week of life. Clinical characteristics of infants with or without echocardiographic diagnosis of PPHN were compared, as well as those of responder or no responder to iNO therapy. Effectiveness of iNO was evaluated by recording changes of MAP, FiO₂ , SpO₂ /FiO₂ ratio, and oxygenation index (OI) before, and 3 ± 1, 6 ± 1, 12 ± 3, 24 ± 6, 48 ± 6, and 72 ± 12 h after beginning therapy.

RESULTS

We studied 42 (4.6%) infants, of whom 28 (67%) had PPHN and 14 (33%) did not. iNO therapy was associated with improved oxygenation in both the groups but it was quicker in the PPHN than in the no PPHN group. Multivariate analysis showed that FiO₂ >0.65, diagnosis of PPHN, and birth weight >750 g independently predicts effectiveness of iNO in very preterm infants with RDS.

CONCLUSION

We found that PPHN is a frequent complication of severe RDS in very preterm infants and iNO therapy can improve their oxygenation earlier than in infants without PPHN. iNO therapy is not recommended for the routinely treatment of RDS in premature neonates but in cases of concurrent diagnosis of PPHN it should be considered carefully.

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.

AIM

To assess if there are clinical characteristics effective as predictive factors for spontaneous closure of the ductus arteriosus, development of patent ductus arteriosus (PDA) and ibuprofen-resistant PDA.

METHODS

A cohort of inborn infants less than 28 weeks of gestation were prospectively studied. We distinguished infants who had spontaneous closure of ductus arteriosus, who developed PDA and who developed ibuprofen-resistant PDA.

RESULTS

We studied 34 infants. Eight infants (24%) had spontaneous closure of PDA, 17 infants (50%) had a closure of PDA following the first ibuprofen course, while 9 infants (26%) failed to respond to the first ibuprofen course. Infants born at 23-25 weeks of gestation were found to have lower likelihood of PDA spontaneous closure, and higher risk of developing PDA refractory to ibuprofen therapy. Sepsis was found to increase significantly the risk of ibuprofen failure in closing PDA.

CONCLUSION

An important percentage of extremely preterm infants exhibited spontaneous closure of PDA. Among clinical characteristics lowest gestational ages predict PDA and ibuprofen-resistant PDA, while sepsis predicts only ibuprofen-resistant PDA.

Temporary epicardial pacing in an extremely low-birth-weight infant with congenital atrioventricular block

Congenital atrioventricular block is a rare, but severe occurrence in the newborn can be related to various cardiac malformations or to maternal autoimmune diseases, particularly systemic lupus erythematosus. We report an extremely low-birth-weight infant affected by congenital heart block, due to positive anti-RO/SSA and anti-LA/SSB antibodies of the mother, with progressively increasing respiratory distress syndrome and heart failure. The infant was successfully treated with an external constant-current, single-chamber ventricular (VVI) temporary epicardial pacing, placed on the second day of life, at the weight of 810 g. After this treatment, cardiac failure resolved and respiratory assistance could be rapidly stopped. A single-chamber, rate-responsive, permanent pacemaker was placed at 3 months of life with steroid-eluting, epicardial-pacing leads. We emphasize that early extrathoracic temporary epicardial pacing is able to resolve heart failure in an extremely low-birth-weight infant.

Pulmonary atresia or critical pulmonary stenosis with intact interventricular septum diagnosed in utero: echocardiographic findings and post-natal outcome

BACKGROUND

Survival of neonates with critical pulmonary obstruction depends on cardiac morphology and function but also on proper perinatal management.

METHODS

Postnatal outcome of five neonates with critical pulmonary stenosis or pulmonary atresia detected in utero is reported.

RESULTS

Right ventricular morphology and ratio between tricuspid and mitral annulus at Fetal Echocardiography were the most important prognostic parameters. Increasing severity of obstruction and of right ventricular hypoplasia was documented in two fetuses.

CONCLUSION

Prenatal diagnosis was useful for planning delivery; we hypothesize that it can be of benefit on postnatal outcome. In selected cases, earlier delivery and relief of obstruction could have beneficial effect on prognosis.

Prophylaxis of patent ductus arteriosus with ibuprofen in preterm infants

The aim of our study was to evaluate whether the prophylactic use of ibuprofen would reduce the incidence of significant patent ductus arteriosus (PDA) and to confirm the effectiveness of ibuprofen as rescue treatment in closing PDA. Eighty preterm infants with gestational age less than 34 wk with infant respiratory distress syndrome (iRDS) were randomized to receive intravenous ibuprofen lysine (10 mg/kg, followed by 5 mg/kg after 24 and 48 h) either within 24 h of life (group A) or after echocardiographic diagnosis of PDA (group B). To evaluate the severity of RDS in each patient, we calculated the initial and highest values of Oxygenation Index (O.I. = mean airway pressure x FiO2 x 100/PaO2) and Ventilatory Index (V.I. = O.I. x mechanical respiratory rate). Other studied variables were ventilatory support, renal function, biochemical and haematological profiles, frequency of bronchopulmonary dysplasia (BPD), intraventricular haemorrhage (IVH), necrotizing enterocolitis (NEC) and retinopathy of prematurity (ROP). On the 3rd day of life, 8% (3/40) of patients of group A and 53% of patients (21/40) of group B (p < 0.0001) developed a significant PDA. Between patients of group B who presented PDA at 3 d of life 90% (19/21) had a closure of ductus arteriosus after ibuprofen treatment. Initial and highest values of O.I. and V.I. were similar in both groups A and B. No significant differences between the groups were observed in regard to respiratory support, renal function and frequency of BPD, IVH, NEC and ROP. Ibuprofen was not associated with adverse effects.

CONCLUSION

Prophylactic treatment with ibuprofen reduces PDA occurrence in preterm infants with iRDS at 3 d of life in comparison with rescue treatment, but both modes are effective in closing the ductus without significant adverse effects.

Changes in mesenteric blood flow response to feeding: conventional versus fiber-optic phototherapy

OBJECTIVE

To evaluate whether fiberoptic phototherapy influences the postprandial increase in mesenteric blood flow velocity similarly to conventional phototherapy in preterm infants.

PATIENTS AND METHODS

With the use of Doppler color ultrasonography, blood flow velocity in the superior mesenteric artery was measured both preprandially and postprandially in 19 preterm infants during and after conventional phototherapy, and in 20 preterm infants during and after fiber-optic phototherapy. The mean arterial blood pressure/mean flow velocity ratio was calculated as an estimate of relative vascular resistance of the superior mesenteric artery.

RESULTS

The study shows that conventional phototherapy blunts the postprandial mesenteric blood flow response to feeding in preterm infants. Furthermore, it shows that the postprandial increase in intestinal blood flow is not attenuated when fiber-optic phototherapy is administered, and that such postprandial increase of blood flow is significantly greater than in infants receiving conventional phototherapy. During and after fiber-optic phototherapy, a significant reduction in postprandial relative vascular resistance was found; such reduction was significantly greater than during conventional phototherapy.

CONCLUSIONS

Fiber-optic phototherapy is preferable to conventional phototherapy for the treatment of hyperbilirubinemia in preterm infants because it does not affect the physiologic postprandial redistribution of blood flow from the periphery to the gastrointestinal system as does conventional phototherapy.

Effects of indomethacin and ibuprofen on mesenteric and renal blood flow in preterm infants with patent ductus arteriosus

OBJECTIVE

To evaluate the effect of intravenous ibuprofen and indomethacin for treatment of patent ductus arteriosus (PDA) on mesenteric and renal blood flow velocity in preterm infants.

STUDY DESIGN

Seventeen mechanically ventilated preterm infants (<33 weeks' gestation) with PDA received either 0.2 mg/kg indomethacin (n = 8) or 10 mg/kg ibuprofen (n = 9), infused over 15 minutes. Mesenteric and renal blood flow velocity were measured by using Doppler ultrasonography.

RESULTS

Indomethacin caused a significant reduction in mesenteric and renal blood flow velocity 30 minutes after drug administration; mesenteric and renal blood flow velocity did not return to the pretreatment values by 120 minutes. Ibuprofen did not alter blood flow 30 minutes after treatment, and blood flow increased 120 minutes after treatment. Mesenteric and renal blood flow velocity changes were significantly different between the 2 treatment groups.

CONCLUSIONS

Compared with indomethacin, ibuprofen did not significantly reduce mesenteric and renal blood flow velocity.

Quantitative three dimensional echocardiography in patients with pulmonary hypertension and compressed left ventricles: comparison with cross sectional echocardiography and magnetic resonance imaging

OBJECTIVE

To evaluate the accuracy of quantitative three dimensional echocardiography in patients with deformed left ventricles.

DESIGN

Three dimensional and cross sectional echocardiographic estimates of left ventricular volume and ejection fraction were prospectively compared to those obtained from magnetic resonance imaging.

SETTING

Echocardiography laboratory of a university hospital.

PATIENTS

26 patients (9 months to 42 years, median age 11 years) with pulmonary hypertension and fixed reversal of normal interventricular septal curvature.

MAIN OUTCOME MEASURES

Left ventricular end diastolic and end systolic volumes and ejection fraction.

RESULTS

Three dimensional echocardiographic comparison to magnetic resonance imaging (MRI) yielded r values of 0.94 and 0.87 with a bias of -6.9 (SD 6.9) ml and -16 (11.2) ml for systolic and diastolic volumes respectively. Inter-observer variability was minimal (8.3% and 7.6% respectively). Cross sectional echocardiography gave correlation coefficients of 0.62 and 0.80 and bias of 3.1 (14.1) ml and 16.3 (18.3) ml for systolic and diastolic volumes respectively. Ejection fraction by three dimensional echocardiography also had closer agreement with MRI (bias = 1.1 (7.7)%) than cross sectional echocardiography (bias = 4.4 (13.9)%).

CONCLUSIONS

Three dimensional echocardiography provides reliable estimates of left ventricular volumes and ejection fraction, comparable to magnetic resonance imaging in pulmonary hypertension patients with compressed ventricular geometry. Because it eliminates the need for geometric assumptions it shows closer agreement with magnetic resonance imaging in that setting than cross sectional echocardiography.