A. François

Validity of N-acetyl-beta-D-glucosaminidase (NAG) determination in assessing netilmicin nephrotoxicity in preterm babies

The supposed nephrotoxicity of netilmicin has been assessed in preterm neonates using the urinary excretion of a lysosomal enzyme as marker: N-acetyl-beta-D-glucosaminidase (NAG). 17 male preterm neonates with birth weight appropriate for gestational age were enrolled in a study where 9 received netilmicin therapy since the first day of life and 8 served as control group. We observed a significant increase in urinary NAG/creatinine ratio during the postnatal days in the netilmicin group babies followed by a regular decrease during the days after the end of therapy. If this increase in lysosomal enzymuria such as NAG could reflect netilmicin nephrotoxicity on the proximal tubular cell, many questions remain unanswered about the exact significance of this finding. In particular, its relation with tubular cell dysfunction remains to be established.

Phosphorus intake in preterm babies and variation of tubular reabsorption for phosphate per liter glomerular filtrate

Inadequate low intake of phosphorus can induce a hypophosphatemic depletion syndrome resulting in hypercalcemia, hypercalciuria, hypophosphatemia, and rickets. Tubular reabsorption for phosphate per liter glomerular filtration rate (TP/GFR) has been proposed as a reliable index of renal phosphate handling for all age groups. In the present study, carried out in 12 healthy premature babies fed unmodified pooled human milk and then a preterm formula for two periods of 10 days, we demonstrated clearly that TP/GFR as well as calciuria can reflect the poor phosphorus intake and that the kidney of preterm babies is able to rapidly adapt itself to an increase in phosphorus diet content.

early respiratory changes after surfactant therapy in premature infants assisted by primary high frequency oscillatory ventilation (HFOV)

Early Respiratory changes after Surfactant Therapy in Premature Infants assisted by Primary High Frequency Oscillatory Ventilation (HFOV). 1684

The Once-Daily Concept of Aminoglycoside Administration adapted in Neonatology: The case for Amikacin 1455

Background:The bactericidal efficacy of Aminoglycosides (Ags) is directly related to peak (P) serum concentrations (C), particularly the first one. Transitory high C of Ags do not result in such a high-drug uptake by renal and cochlear tissues because of the saturation of cell binding sites. In most clinical practice using conventional schedule of Ags administration in sick neonates (N), pharmacokinetic profiles remain inadequate (low P and too elevated trough (T) C), which diminishs efficacy, increases risks of toxicity and emergence of bacterial resistance. Objective: Prospective evaluation of a new dosing-chart of Amikacin (Ak),based on a previous pharmacokinetic population study, in high risk N suspected of infection within the 2 first days of life. Study Design: 177 N (69 females and 108 males); mean gestational age (GA) ±1SD: 33.6 ± 4.1 Weeks (W) received Ak regimen dosage according to the following dosing-chart: Group (Gr) 1a GA 0.05) between the treated Gr and the corresponding non-treated control Gr. While the primary aim was not to test the bactericidal efficacy of this new regimen, the recovery was excellent in 37 N with proven or highly suspected infection. Conclusion:The proposed scheme of Ak Administration, even in high-risk N, allows to achieve adequate Ak P and T serum C (whatever the GA at birth), while drug-induced renal and cochlear toxicity is kept minimal. These serum C would allow for a P-Minimal Inhibitory Concentration (MIC) ratio ≥ 8 to be easily reached, which is now considered as optimal for Ags treatment.

high frequency oscillatory ventilation (HFOV) in neonatal respiratory distresse syndrome (RDS): effects of early lung volume optimization (LVO)

High Frequency Oscillatory Ventilation (HFOV) in Neonatal Respiratory Distress Syndrome (RDS): effects of early Lung Volume Optimization(LVO). 1522