Nonstationary coupling between heart rate and perfusion index in extremely preterm infants in the first day of life.

Objective.Adaptation to the extra-uterine environment presents many challenges for infants born less than 28 weeks of gestation. Quantitative analysis of readily available physiological signals at the cotside could provide valuable information during this critical time. We aim to assess the time-varying coupling between heart rate (HR) and perfusion index (PI) over the first 24 h after birth and relate this coupling to gestational age (GA), inotropic therapy, and short-term clinical outcome.Approach.We develop new nonstationary measures of coupling to summarise both frequency- and direction-dependent coupling. These measures employ a coherence measure capable of measuring time-varying Granger casuality using a short-time information partial-directed coherence function. Measures are correlated with GA, inotropic therapy (yes/no), and outcome (adverse/normal).Main results.In a cohort of 99 extremely preterm infants (<28 weeks of gestation), we find weak but significant coupling in both the HR → PI and PI → HR directions (P< 0.05). HR → PI coupling increases with maturation (correlationr = 0.26;P = 0.011). PI → HR coupling increases with inotrope administration (r = 0.27;P = 0.007). And nonstationary features of PI → HR coupling are associated with adverse outcome (r = 0.27;P = 0.009).Significance.Nonstationary features are necessary to distinguish different coupling types for complex biomedical systems. Time-varying directional coupling between PI and HR provides objective and independent biomarkers of adverse outcome in extremely preterm infants.

Rigid catheters reduced duration of less invasive surfactant therapy procedures in manikins.

AIM: Different catheters can be used for less invasive surfactant therapy (LIST): feeding tubes inserted with or without Magill forceps, different angiocatheters and centre specific devices, such as umbilical catheters affixed to a stylet. This study compared the effectiveness of LIST devices and endotracheal tubes (ETT). METHODS: Video recordings of 20 neonatologists simulating different LIST techniques on two manikin heads were analysed. Procedural effectiveness was evaluated by the duration of procedures and failure rates. Ease of use was scored. RESULTS: The median procedure time for the Neonatal Intubation Trainer was significantly longer with feeding tubes without Magill forceps. For the more difficult ALS Baby Trainer, successful procedures lasted a median of 24 (17-32) seconds with ETT, 24 (15-36) seconds with stylet-guided catheters and 34 (27-46) seconds and 37 (29-42) seconds with 13-cm and 30-cm angiocatheters, respectively. Both methods using feeding tubes were statistically slower than ETT intubation, lasting 32 (25-44) seconds and 39 (27-95) seconds with or without Magill forceps. Failure rates (7-20%) were no different between the LIST methods. Techniques using feeding tubes were rated as more difficult. CONCLUSION: Only rigid or stylet-guided catheters required tracheal catheterisation times similar to those of endotracheal intubation and neonatologists found them easier.

The use of intravenous magnesium in non-preeclamptic pregnant women: fetal/neonatal neuroprotection.

PURPOSE: To review the effect of intravenous magnesium in obstetrics on fetal/neonatal neuroprotection. METHODS: A systematic review of published studies. RESULTS: Five randomized trials and 4 meta-analyses have shown a significant 32% reduction of cerebral palsy when administering magnesium sulfate in case of preterm delivery. The pathophysiologic mechanism is not fully unraveled: modulation of the inflammatory process, both in the mother and the fetus, and downregulation of neuronal stimulation seem to be involved. After long-term high-dose intravenous administration of magnesium, maternal and neonatal adverse effects such as maternal and neonatal hypotonia and osteoporosis and specific fetal/neonatal cerebral lesions have been described. In case of administration for less than 48 h at 1 g/h and a loading dose of 4 g, these toxic amounts are not achieved. American, Canadian and Australian guidelines recommend the use of intravenous magnesium in any threatening delivery at less than 32 weeks. The "number needed to treat" to avoid 1 cerebral palsy is between 15 and 35. CONCLUSIONS: Intravenous magnesium significantly reduces the risk for cerebral palsy in preterm birth. Open questions remain the optimal dosing schedule, whether or not repeating when delivery has been successfully postponed and a new episode of preterm labor occurs. Some concern has been raised on a too optimistic value for random error which might have led to over-optimistic conclusions in classic meta-analysis. Randomized trials comparing different doses and individual patient data meta-analysis might resolve these issues.

Management of hypotension in preterm infants (The HIP Trial): a randomised controlled trial of hypotension management in extremely low gestational age newborns.

BACKGROUND: Extremely preterm babies (delivered at <28 completed weeks of gestation) are frequently diagnosed with hypotension and treated with inotropic and pressor drugs in the immediate postnatal period. Dopamine is the most commonly used first-line drug. Babies who are treated for hypotension more frequently sustain brain injury, have long-term disability or die compared to those who are not. Despite the widespread use of drugs to treat hypotension in such infants, evidence for efficacy is lacking, and the effect of these agents on long-term outcomes is unknown. HYPOTHESIS: In extremely preterm babies, restricting the use of dopamine when mean blood pressure (BP) values fall below a nominal threshold and using clinical criteria to determine escalation of support ('restricted' approach) will result in improved neonatal and longer-term developmental outcomes. RESEARCH PLAN: In an international multi-centre randomised trial, 830 infants born at <28 weeks of gestation, and within 72 h of birth, will be allocated to 1 of 2 alternative treatment options (dopamine vs. restricted approach) to determine the better strategy for the management of BP, using a conventional threshold to commence treatment. The first co-primary outcome of survival without brain injury will be determined at 36 weeks' postmenstrual age and the second co-primary outcome (survival without neurodevelopmental disability) will be assessed at 2 years of age, corrected for prematurity. DISCUSSION: It is essential that appropriately designed trials be performed to define the most appropriate management strategies for managing low BP in extremely preterm babies.

Effect of NaCl reduction and replacement on the growth of fungi important to the spoilage of bread.

The effect of NaCl and various NaCl replacers (CaCl(2), MgCl(2), KCl and MgSO(4)) on the growth of Penicillium roqueforti and Aspergillus niger was evaluated at 22 degrees C. In addition, challenge tests were performed on white bread to determine the consequences of NaCl reduction with or without partial replacement on the growth of P. roqueforti. From the results obtained it can be concluded that at equivalent water phase concentrations the isolates exhibited differing sensitivities to the salts evaluated with NaCl and MgCl(2) having the greatest inhibitory action on the growth of A. niger and P. roqueforti, respectively. MgSO(4) had the least antifungal activity. At equivalent molalities, CaCl(2) had in general the largest antifungal activity. Although the water activity (a(w)) lowering effects of the compounds studied play a large role in explaining the trends observed, at equivalent water phase concentrations MgCl(2) was found to have a smaller inhibitory effect on A. niger than that expected from its a(w) depressing effect. The challenge tests revealed that no difference occurred in the growth of P. roqueforti on standard white bread, bread with 30% less NaCl and bread in which 30% of the NaCl has been partially replaced by a mixture of KCl and Sub4Salt. These results are of importance in assessing the possible microbiological consequences of NaCl reduction or replacement in bread and similar bakery products.

[Disorders of the sensitivity of the anterior teeth in children and adolescents]. / Sensibilitätsstörungen der Frontzähne bei Kindern und Jugendlichen.

1435 permanent incisors and canines were examined in 134 children and juveniles undergoing orthodontic treatment. Nearly 50% of the subjects had sustained trauma to their anterior teeth with equal numbers of boys and girls. Girls, however, were less often injured by direct contact. Pulp testing with dry ice from liquid CO2 showed disturbed sensitivity mainly of the upper anterior teeth. In the group with trauma the frequency of this phenomenon was increased compared to the group without trauma. The electric pulp tester did not prove suitable for sensitivity tests compared with dry ice testing.