Prophylactic use of Lactobacillus acidophilus/Bifidobacterium infantis probiotics and outcome in very low birth weight infants.

OBJECTIVE: To evaluate outcome data in an observational cohort of very low birth weight infants of the German Neonatal Network stratified to prophylactic use of Lactobacillus acidophilus/Bifidobacterium infantis probiotics. STUDY DESIGN: Within the observational period (September 1, 2010, until December 31, 2012, n=5351 infants) study centers were categorized into 3 groups based on their choice of Lactobacillus acidophilus/Bifidobacterium infantis use: (1) no prophylactic use (12 centers); (2 a/b) change of strategy nonuser to user during observational period (13 centers); and (3) use before start of observation (21 centers). Primary outcome data of all eligible infants were determined according to center-specific strategy. RESULTS: The use of probiotics was associated with a reduced risk for necrotizing enterocolitis surgery (group 1 vs group 3: 4.2 vs 2.6%, P=.028; change of strategy: 6.2 vs 4.0%, P<.001), any abdominal surgery, and hospital mortality. Infants treated with probiotics had improved weight gain/day, and probiotics had no effect on the risk of blood-culture confirmed sepsis. In a multivariable logistic regression analysis, probiotics were protective for necrotizing enterocolitis surgery (OR 0.58, 95% CI 0.37-0.91; P=.017), any abdominal surgery (OR 0.7, 95% CI 0.51-0.95; P=.02), and the combined outcome abdominal surgery and/or death (OR 0.43; 95% CI 0.33-0.56; P<.001). CONCLUSIONS: Our observational data support the use of Lactobacillus acidophilus/Bifidobacterium infantis probiotics to reduce the risk for gastrointestinal morbidity but not sepsis in very low birth weight infants.

Noninvasive pH measurement to monitor changes during suboptimal storage of platelet concentrates.

BACKGROUND: Noninvasive pH measurement of platelet concentrates (PCs) was evaluated as a tool for the quality control of PC storage by simulating worst-case conditions. STUDY DESIGN AND METHODS: PCs from pooling four buffy coats in 70% PAS-3M were both stored in bags wrapped to impair gas permeability and agitated or not until Day 9 of storage. pH values measured both in samples (electrode, blood gas analyzer) and noninvasively by fluorimetry (BCSI pH1000, Blood Cell Storage, Inc.) were compared groupwise and to changes in platelet (PLT) size and biochemical variables. RESULTS: The noninvasive pH measurements agreed well with the results from each of the two reference methods (R(2) >0.9) in a wide range of pH values between 6.4 and 7.5. Changes of the pH of PCs (n=64) by all interventions (agitation or resting plus occlusion by 0, 25, 50, or 100%; n=8/group) were subtle but already significant after 20 to 24 hours of treatment in comparison to the controls. A steady state after Day 6 and reductions up to a mean pH of approximately 6.5 were observed. The extent of manipulation determined both the absolute pH differences to the controls and the interindividual variation of pH changes. Termination of the agitation significantly enhanced pH reduction by surface blockade. Significant changes were also observed for the mean PLT volume, ß-thromboglobulin, and soluble P-selectin. CONCLUSION: Noninvasive pH measurement in PCs using this technique reliably detects pH changes of 0.1 or more. Storage of PLTs in buffered additive solution requires profound impairment of gas exchange to trigger a substantial decline in pH.