Effect of the measurement of the work of breathing on the respiratory outcome of preterms

RATIONALE

There are no validated criteria for the choice of the optimal type of noninvasive respiratory support (NRS) and most appropriate settings in preterms.

METHODS

The work of breathing (WOB) during oxygen (O2) alone, nasal continuous positive pressure (nCPAP) and high flow nasal cannula (HFNC) was compared in preterm babies (23-30 weeks' gestation, "physiological group") needing any type of noninvasive respiratory support ("baseline" NRS) at 4 weeks of life. Babies were thereafter treated with the NRS associated with the greatest reduction in WOB ("optimal NRS"). The respiratory outcome at 36 weeks" gestation of these babies was compared to a "control" group treated with NRS based on standard noninvasive parameters. Preterm babies were prospectively enrolled in 3 centers and randomized into the "physiological" or "control" group.

RESULTS

Thirty babies were randomized. WOB with "baseline" NRS was higher than the "optimal" NRS and the consequent NRS chosen by physicians (p = 0.001). WOB was lower during HFNC than during O2 (p = 0.032) but WOB was comparable between nCPAP and HFNC, and between nCPAP and O2. Notably, WOB was near to normal during spontaneous breathing with O2. Respiratory outcome at 36 week' gestation was comparable between the 2 groups.

CONCLUSION

The optimization of NRS by means of the measurement of WOB in preterms requiring any type of NRS at 4 weeks of life was able to decrease the WOB but had no effect on the clinical outcome at 36 weeks' gestation.

Small for Gestational Age Preterm Neonates Exhibit Defective GH/IGF1 Signaling Pathway

Objective: To investigate the impact of fetal growth restriction (FGR) on hormonal regulation of post-natal growth and glucose metabolism [via insulin and growth hormone (GH)/Insulin-like Growth factor 1 (IGF1) axis pathways] in small for gestational age (SGA) neonates. Methods: We conducted a monocentric observational prospective comparative study on 73 singleton babies born with a weight inferior to 2,000 g. We analyzed auxological (weight, height and head circumference), and hormonal (GH, IGF1, and insulin plasma concentrations) data comparing SGA and appropriate for gestational age (AGA) neonates, between day 1 and 60. Results: One third (23/73) of the neonates were SGA. Twenty-five percent (18/73) required insulin for idiopathic hyperglycemia of prematurity and were smaller in weight and head circumference at discharge. In the SGA group compared with the AGA group, GH plasma concentrations were higher at day 3 (70.1 vs. 38.0 mIU/L) and IGF1 plasma concentrations were higher at day 10 (29.0 vs. 18.7 ng/ml). Conclusions: SGA neonates displayed resistance to GH and IGF1, concomitant to insulin resistance. This could partially explain the initial defective catch-up growth and, later in life, the higher prevalence of metabolic syndrome in this population.

Staphylococcus capitis isolated from bloodstream infections: a nationwide 3-month survey in 38 neonatal intensive care units

To increase the knowledge about S. capitis in the neonatal setting, we conducted a nationwide 3-month survey in 38 neonatal intensive care units (NICUs) covering 56.6% of French NICU beds. We demonstrated 14.2% of S. capitis BSI (S.capBSI) among nosocomial BSIs. S.capBSI incidence rate was 0.59 per 1000 patient-days. A total of 55.0% of the S.capBSIs were late onset catheter-related BSIs. The S. capitis strains infected preterm babies (median gestational age 26 weeks, median birth weight 855 g). They were resistant to methicillin and aminoglycosides and belonged to the NRCS-A clone. Evolution was favorable in all but one case, following vancomycin treatment.

Relationship between transcutaneous bilirubin and circulating unbound bilirubin in jaundiced neonates

BACKGROUND

Transcutaneous bilirubin (TcB) consists of the skin-deposited bilirubin. Free bilirubin represents the protein-unbound bilirubin (UB) that is able to pass into the tissues. We aimed to describe the relationship UB-TcB and study the passage of UB into the skin.

METHODS

We prospectively enrolled 194 neonates and we measured TcB, UB, serum bilirubin and albumin. Multiple sites TcB measurement was performed, bilirubin-albumin equilibrium constant and plasma bilirubin avidity (PBA) were calculated.

RESULT

TcB has a similar correlation with UB and TSB. There is a quadratic relationship between UB and TcB (R²=0.48; p<0.001), remaining significant (β for UB²=-0.8; p<0.001. β for UB=1.1; p<0.001) after adjustment for gestational age, birth weight, postnatal age and albumin (Adj-R²=0.72). UB contributes to the skin bilirubin deposition, as there are significant correlations between albumin and TcB (r=-0.202; p=0.01) and between PBA and ΔTcB (r=0.323; p=0.017).

CONCLUSION

TcB assay does not seem to directly replace UB measurement. However, TcB and UB are linked by a quadratic relationship: UB contributes to the skin bilirubin deposition but it is not the only bilirubin species measured by transcutaneous bilirubinometry.