Volume guarantee versus high-frequency ventilation: lung inflammation in preterm infants.

BACKGROUND: Appropriate ventilation together with improvement of clinical care of premature babies can contribute to reducing lung inflammation, known to represent the "primum movens" of bronchopulmonary dysplasia (BPD). High-frequency oscillatory ventilation (HFOV) and volume-guarantee (VG) ventilation are effective in the treatment of neonatal respiratory distress syndrome (RDS). OBJECTIVE: To assess the potential of HFOV and VG to prevent BPD in the acute phase of RDS, by a randomised clinical study evaluating lung inflammation in premature infants. STUDY DESIGN: Forty infants (gestational age 25-32 weeks) with RDS were assigned to assist-control ventilation plus VG (Vt = 5 ml/kg) or HFOV (both with a Dräger Babylog 8000 plus ventilator). Levels of interleukin (IL) 6, IL8 and tumour necrosis factor were determined in tracheal aspirate on days 1, 3 and 7 of life. RESULTS: In the HFOV group IL6 levels were significantly higher on day 3 (0.5 (0.2) vs assisted-control ventilation plus VG group 0.1 (0.2) ng/ml) and oxygen dependency was significantly longer (36 (23) vs assisted-control ventilation plus VG group 19 (11) days). CONCLUSION: VG ventilation is an effective lung-protective strategy to be used in acute RDS, inducing a lower expression of early inflammation markers than HFOV. Whether the use of this initial ventilatory strategy contributes to the prevention of BPD requires further studies.

Assessing mortality risk in very low birthweight infants: a comparison of CRIB, CRIB-II, and SNAPPE-II.

BACKGROUND: Illness severity scores are increasingly used for risk adjustment in clinical research and quality assessment. Recently, a simplified version of the score for neonatal acute physiology (SNAPPE-II) and a revised clinical risk index for babies (CRIB-II) score have been published. AIM: To compare the discriminatory ability and goodness of fit of CRIB, CRIB-II, and SNAPPE-II in a cohort of neonates < 1500 g birth weight (VLBWI). METHODS: Data from 720 VLBWI, admitted to 12 neonatal units in Lombardy (Northern Italy) participating in a regional network, were analysed. The discriminatory ability of the scores was assessed measuring the area under the receiver operating characteristic curve (AUC). Outcome measure was in-hospital death. RESULTS: CRIB and CRIB-II showed greater discrimination than SNAPPE-II (AUC 0.90 and 0.91 v 0.84, p < 0.0004), partly because of the poor quality of some of the data required for the SNAPPE-II calculation-for example, urine output-but also because of the relative weight given to some items. In addition to each score, several variables significantly influenced survival in logistic regression models. Antenatal steroid prophylaxis, singleton birth, absence of congenital anomalies, and gestational age were independent predictors of survival for all scores, in addition to caesarean section and not being small for gestation (for SNAPPE-II) and a five minute Apgar score of > or = 7 (for SNAPPE-II and CRIB). CONCLUSIONS: CRIB and CRIB-II had greater discriminatory ability than SNAPPE-II. Risk adjustment using all scores is imperfect, and other perinatal factors significantly influence VLBWI survival. CRIB-II seems to be less confounded by these factors.

Inhibition of in vitro adherence of antibody-coated red cells to monocytes by the dialyzable leukocyte extract.

The red cell-monocyte assay (RMA), which has been used to evaluate the clinical significance of red cell (RBC) antibodies, was employed to test the effect of the dialyzable leukocyte extract (DLE) on in vitro adherence to monocytes of human RBCs coated with alloantibodies or autoantibodies. The total association index (TAI) of the RMA, expressing the number of RBCs adhering to or phagocytosed by 100 monocytes, indicated a potent inhibitory activity of DLE in the test system. TAI values of 100.4 +/- 20.1 (mean +/- SD) in the control sample, consisting of RBCs coated in vitro with anti-D, dropped to 4.0 +/- 2.1 when DLE was present in the assay medium at a concentration of 0.5 U per mL. Similar results were obtained with RBCs coated with IgG antibodies in vivo. The inhibition was dose dependent and was associated with a thermolabile component of DLE. This study establishes that DLE can modulate monocyte function by inhibiting the recognition of IgG sensitized red cells.