Effects of nasal continuous airway pressure on pulmonary and systemic output in preterm infants

Objective: Respiratory assistance with nasal continuous positive airway pressure (n-CPAP) is an effective treatment in premature newborns presenting respiratory distress. The aim of the study was to depict cardiac function, systemic (Qs) and pulmonary output (Qp) by echocardiography in stable premature infants requiring prolonged n-CPAP. Our hypothesis was that n-CPAP could reduce pulmonary blood flow. Patients and methods: All premature infants < 32 weeks gestation, > 7 days-old, requiring n-CPAP without severe respiratory compromise nor need for additional oxygen were prospectively included. Every patient had a first echocardiography while on n-CPAP. N-CPAP was then discontinued for two hours and a second echocardiography was performed. Results: 17 premature infants were included. Mean gestational age was 28 ± 2 weeks and mean weight 1.1 ± 0.3 kg. Following retrieval of n-CPAP we observed an increase in Qp of 53 ml/kg/min (95% CI 19-87 ml/kg/min), but no significant change in Qs. Consecutively a significant increase in Qp/Qs ratio of 16% was found (95% CI 7-29%). Conclusions: Nasal continuous positive airway pressure has hemodynamic effects in preterm infants in stable pulmonary and cardiac conditions. It reduces pulmonary output without interference with systemic output.

Anàlisi del recurs pilot "cases d'infants: nou paradigma d'atenció i tractament a la infància i l'adolescència".

El treball que es presenta a continuació és una recerca aplicada, consistent en l’anàlisi descriptiva d’una mostra d’infants i adolescents de 5 a 19 anys atesos al projecte “Cases d’Infants” des del desembre de 2010 fins al juliol de 2013. Aquesta investigació pretén donar a conèixer la nova perspectiva o paradigma d’atenció a la infància i l’adolescència a Catalunya que neix de la Llei dels Drets i les Oportunitats de la Infància i l’Adolescència (LDOIA, maig de 2010): basada en la prevenció, el model sistèmic i de complexitat, la col·laboració de la família com a element de canvi, el treball en xarxa i interprofessionalitat, la participació dels infants i adolescents, i la territorialitat, principalment. Un cop feta aquesta aproximació teòrica, s’ha concretat identificant aquesta nova perspectiva al projecte pilot “Cases d’Infants” (nascut al setembre de 2010), el qual desplega les actuacions que sorgeixen d’aquesta filosofia de treball i suport. Per a elaborar aquesta recerca s’ha emprat un disseny d’investigació no experimental descriptiu, on s’han associat i comparat variables per tal d’identificar interferències en les relacions –a través de proves estadístiques-, i proposar una certa tendència i pronòstic de les característiques del perfil atès al projecte i les interferències d’algunes variables amb el recurs final de l’infant o adolescent. Finalment, s’extreuen unes conclusions en relació a la bibliografia inicial i els resultats obtinguts en l’anàlisi de la mostra estudiada.

Right ventricular dysfunction in children and adolescents conceived by assisted reproductive technologies.

Assisted reproductive technologies (ART) predispose the offspring to vascular dysfunction, arterial hypertension, and hypoxic pulmonary hypertension. Recently, cardiac remodeling and dysfunction during fetal and early postnatal life have been reported in offspring of ART, but it is not known whether these cardiac alterations persist later in life and whether confounding factors contribute to this problem. We, therefore, assessed cardiac function and pulmonary artery pressure by echocardiography in 54 healthy children conceived by ART (mean age 11.5 ± 2.4 yr) and 54 age-matched (12.2 ± 2.3 yr) and sex-matched control children. Because ART is often associated with low birth weight and prematurity, two potential confounders associated with cardiac dysfunction, only singletons born with normal birth weight at term were studied. Moreover, because cardiac remodeling in infants conceived by ART was observed in utero, a situation associated with increased right heart load, we also assessed cardiac function during high-altitude exposure, a condition associated with hypoxic pulmonary hypertension-induced right ventricular overload. We found that, while at low altitude cardiac morphometry and function was not different between children conceived by ART and control children, under the stressful conditions of high-altitude-induced pressure overload and hypoxia, larger right ventricular end-diastolic area and diastolic dysfunction (evidenced by lower E-wave tissue Doppler velocity and A-wave tissue Doppler velocity of the lateral tricuspid annulus) were detectable in children and adolescents conceived by ART. In conclusion, right ventricular dysfunction persists in children and adolescents conceived by ART. These cardiac alterations appear to be related to ART per se rather than to low birth weight or prematurity.

Being Small for Gestational Age: Does it Matter for the Neurodevelopment of Premature Infants? A Cohort Study.

BACKGROUND: Whether being small for gestational age (SGA) increases the risk of adverse neurodevelopmental outcome in premature infants remains controversial. OBJECTIVE: to study the impact of SGA (birthweight < percentile 10) on cognition, behavior, neurodevelopmental impairment and use of therapy at 5 years old. METHODS: This population-based prospective cohort included infants born before 32 weeks of gestation. Cognition was evaluated with the K-ABC, and behavior with the Strengths and Difficulties Questionnaire (SDQ). Primary outcomes were cognitive and behavioral scores, as well as neurodevelopmental impairment (cognitive score < 2SD, hearing loss, blindness, or cerebral palsy). The need of therapy, an indirect indicator of neurodevelopmental impairment, was a secondary outcome. Linear and logistic regression models were used to analyze the association of SGA with neurodevelopment. RESULTS: 342/515 (76%) premature infants were assessed. SGA was significantly associated with hyperactivity scores of the SDQ (coefficient 0.81, p < 0.04), but not with cognitive scores, neurodevelopmental impairment or the need of therapy. Gestational age, socio-economic status, and major brain lesions were associated with cognitive outcome in the univariate and multivariate model, whereas asphyxia, sepsis and bronchopulmonary dysplasia were associated in the univariate model only. Severe impairment was associated with fetal tobacco exposition, asphyxia, gestational age and major brain lesions. Different neonatal factors were associated with the use of single or multiple therapies: children with one therapy were more likely to have suffered birth asphyxia or necrotizing enterocolitis, whereas the need for several therapies was predicted by major brain lesions. DISCUSSION: In this large cohort of premature infants, assessed at 5 years old with a complete panel of tests, SGA was associated with hyperactive behavior, but not with cognition, neurodevelopmental impairment or use of therapy. Birthweight <10th percentile alone does not appear to be an independent risk factor of neurodevelopmental adverse outcome in preterm children.

Population pharmacokinetic study to evaluate dosing strategies of imipenem in neonates and infants

Objective: Imipenem is a broad spectrum antibiotic used to treat severe infections in critically ill patients. Imipenem pharmacokinetics (PK) was evaluated in a cohort of neonates treated in the Neonatal Intensive Care Unit of the Lausanne University Hospital. The objective of our study was to identify key demographic and clinical factors influencing imipenem exposure in this population. Method: PK data from neonates and infants with at least one imipenem concentration measured between 2002 and 2013 were analyzed applying population PK modeling methods. Measurement of plasma concentrations were performed upon the decision of the physician within the frame of a therapeutic drug monitoring (TDM) programme. Effects of demographic (sex, body weight, gestational age, postnatal age) and clinical factors (serum creatinine as a measure of kidney function; co-administration of furosemide, spironolactone, hydrochlorothiazide, vancomycin, metronidazole and erythromycin) on imipenem PK were explored. Model-based simulations were performed (with a median creatinine value of 46 μmol/l) to compare various dosing regimens with respect to their ability to maintain drug levels above predefined minimum inhibitory concentrations (MIC) for at least 40 % of the dosing interval. Results: A total of 144 plasma samples was collected in 68 neonates and infants, predominantly preterm newborns, with median gestational age of 27 weeks (24 - 41 weeks) and postnatal age of 21 days (2 - 153 days). A two-compartment model best characterized imipenem disposition. Actual body weight exhibited the greatest impact on PK parameters, followed by age (gestational age and postnatal age) and serum creatinine on clearance. They explain 19%, 9%, 14% and 9% of the interindividual variability in clearance respectively. Model-based simulations suggested that 15 mg/kg every 12 hours maintain drug concentrations over a MIC of 2 mg/l for at least 40% of the dosing interval during the first days of life, whereas neonates older than 14 days of life required a dose of 20 mg/kg every 12 hours. Conclusion: Dosing strategies based on body weight and post-natal age are recommended for imipenem in all critically ill neonates and infants. Most current guidelines seem adequate for newborns and TDM should be restricted to some particular clinical situations.

Neonates with Bartter syndrome have enormous fluid and sodium requirements.

AIM: Managing neonatal Bartter syndrome by achieving adequate weight gain is challenging. We assessed the correlation between weight gain in neonatal Bartter syndrome and the introduction of fluid and sodium supplementations and indomethacin during the first 4 weeks of life. METHODS: Daily fluid and electrolytes requirements were analysed using linear regression and Spearman correlation coefficients. The weight gain coefficient was calculated as daily weight gain after physiological neonatal weight loss. RESULTS: We studied seven infants. The highest weight gain coefficients occurred between weeks two and four in the five neonates who either received prompt amounts of fluid (maximum 810 mL/kg/day) and sodium (maximum 70 mmol/kg/day) or were treated with indomethacin. For the two patients with the highest weight gain coefficient, water and sodium supplementations were decreased in weeks two to four leading to a significant negative Spearman correlation between weight gain and fluid supplements (r = -0.55 and -0.68) and weight gain and sodium supplementations (r = -0.96 and -0.72). The two patients with the lowest weight gain coefficient had positive Spearman correlation coefficients between weight gain and fluid and sodium supplementations. CONCLUSION: Infants with neonatal Bartter syndrome required rapid and enormous fluid and sodium supplementations or the early introduction of indomethacin treatment to achieve adequate weight gain during the early postnatal period.