Biomedical subjects
Publications and source records attributed to B Urlesberger.
The aim of this study was to analyse changes in peripheral oxygenation in healthy term neonates within the first week of life with near-infrared spectroscopy and venous occlusion. Oxygen delivery did not change with increasing age. Oxygen consumption and fractional oxygen extraction increased, whereas tissue oxygenation index decreased with increasing age.
For the first time a multimodal approach to NEC prophylaxis is reported, consisting of early trophic feeding with human breast milk, and enteral administration of an antibiotic, an antifungal agent, and probiotics. A retrospective analysis of local protocol of NEC prophylaxis is presented. Included were all VLBWI admitted to the NICU, including transfers within the first 28 days of life. These infants were divided into two groups, an "inborn group" (infants admitted within the first 24 h of life) and an "outborn group" (infants admitted after the onset of their second day of life). Prophylaxis of NEC according to protocol was started at the day of admission, and was continued until discharge. Between 1998 and 2004, 405 VLBWI were admitted, including all transfers within the first 28 days of life. A total of 334 (82%) infants were admitted within the first 24 h of life (inborn group), and 71 (18%) were admitted after 24 h of life (outborn group). Five infants developed clinical features of necrotizing enterocolitis. The inborn group showed a NEC incidence of 0.7% (two infants), whereas the outborn group showed a NEC incidence of 4.5% (three infants), respectively. This difference was significant (P=0.049, Fisher's exact test). A surgical treatment with bowel resection was performed in two infants (both from the outborn group). The present study used a combination of different strategies, all having shown to have some beneficial effect, but not having brought a clinical breakthrough in single administration studies. Combinated were the beneficial effects of human breast milk feeding, oral antiobiotics, oral antifungal agents, and the administration of probiotics. In a homogenous group of preterm infants, using this protocol of multimodal NEC prophylaxis, there was a very low incidence of NEC, when started within the first 24 h of life.
UNLABELLED: The assessment of forearm oxygen consumption (VO(2)) and forearm blood flow (FBF) by means of near infrared spectroscopy has become widespread in adults, whereas in children and adolescents no data are available. The aim of the present study was to analyze VO(2) and FBF in healthy children and adolescents. METHODS: In a prospective cohort study, 20 male and 20 female healthy children and adolescents were investigated. The measurements of VO(2) and FBF were performed by means of near infrared spectroscopy in combination with the venous occlusion method. RESULTS: Mean VO(2) was 0.08 +/- 0.04 ml 100 g(-1) min(-1) in male and 0.09 +/- 0.05 ml 100 g(-1) min(-1) in female subjects. Mean FBF was 1.95 +/- 1.25 ml 100 g(-1) min(-1) in male and 1.82 +/- 0.98 ml 100 g(-1) min(-1) in female subjects. No significant difference was found between male and female subjects. A significant negative correlation of VO(2) and FBF to age was observed in both groups. CONCLUSION: In the present study we were able to show that VO(2) and FBF decreased with increasing age in children and adolescents without significant differences between male and female subjects.
BACKGROUND: Assessment of neurologic and developmental outcome at 2 years age of infants with gestational age (GA)<27 weeks, born between 1996-2001. PATIENTS: A total of 110 live-born preterm infants with GA<27 weeks. METHODS: Main outcome criterions: Neurologic examination (according to Touwen) and classification of cerebral palsy by using the Gross Motor Function Classification System (GMFCS) at the corrected age of 1 and 2 years; assessment of mental and psychomotor development by using the Griffith Mental Development scales at the corrected age of 2 years; growth assessment at birth, 1 and 2 years. RESULTS: Mortality was 52%. Regular follow up was performed in 48 (91%) of the 53 surviving infants. Neurologic outcome: at 1 year age: 2% nonambulant cerebral palsy, 25% mild neurologic signs and 73% normal; at 2 years age: 4% nonambulant cerebral palsy, 2% ambulant cerebral palsy, 4% mild neurologic signs and 90% normal neurology. Developmental outcome at 2 years age: 40% DQ>-1 SD, 6% DQ between -1 SD and -2 SD (mild delay), 35% DQ between -2 SD and -3 SD (moderate delay) and 19% DQ<-3 SD (severe delay). Overall disability was found in 64%, severe disability in 27% of the infants. Profound growth failure in weight and head circumference<3rd centile at 2 years age was recorded in 39 and 19% of the infants, respectively. CONCLUSION: Developmental delay is very common in preterm infants<27 GA and exceeds the number of neurological disabilities (including cerebral palsy).
The objective of this study was to assess minor neurological dysfunction, cognitive development, and somatic development after dexamethasone therapy in very-low-birthweight infants. Thirty-three children after dexamethasone treatment were matched to 33 children without dexamethasone treatment. Data were assessed at the age of 3-7 years. Dexamethasone was started between the 7th and the 28th day of life over 7 days with a total dose of 2.35 mg/kg/day. Exclusion criteria were asphyxia, malformations, major surgical interventions, small for gestational age, intraventricular haemorrhage grades III and IV, periventricular leukomalacia, and severe psychomotor retardation. Each child was examined by a neuropediatrician for minor neurological dysfunctions and tested by a psychologist for cognitive development with a Kaufman Assessment Battery for Children and a Draw-a-Man Test. There were no differences in demographic data, growth, and socio-economic status between the two groups. Fine motor skills and gross motor function were significantly better in the control group (p<0.01). In the Draw-a-Man Test, the control group showed better results (p<0.001). There were no differences in development of speech, social development, and the Kaufman Assessment Battery for Children. After dexamethasone treatment, children showed a higher rate of minor neurological dysfunctions. Neurological development was affected even without neurological diagnosis. Further long-term follow-up studies will be necessary to fully evaluate the impact of dexamethasone on neurological and cognitive development.
AIM: Measurement of cerebral haemodynamics to detect impaired cerebral blood flow and impaired cerebral autoregulation might make prevention of brain lesions and especially periventricular leucencephalomalacia (PVL) achievable. METHODS: Changes in cerebral blood volume (CBV) and the cerebral haemoglobin oxygenation index (cHbD) following tilting up and down in 10 preterm infants with PVL and 25 preterm infants without PVL, measured by near infrared spectroscopy (NIRS), were analysed. Tilting manoeuvres were recorded with a polysomnographic system in combination with NIRS. CBV and cHbD of the baseline phase (1 min before tilting) were compared with data from the post-tilting phase (1 min after tilting). RESULTS: Changes in CBV and cHbD after tilting were significantly pronounced in infants with PVL compared with infants without PVL. CBV decreased in infants with PVL, by -0.099 +/- 0.081 ml 100 g(-1) brain (mean +/- SD) after tilting up, and increased by 0.106 +/- 0.104 ml 100 g(-1) brain after tilting down. CBV decreased in infants without PVL, by -0.041 +/- 0.068 ml 100 g(-1) brain after tilting up, and increased by 0.020 +/- 0.096 ml 100 g(-1) brain after tilting down. cHbD showed similar changes after tilting. CONCLUSION: Changes in CBV and cHbD after tilting were pronounced in preterm infants with PVL and this may indicate reduced cerebral autoregulatory capacity.
The prognosis of very low birth weight infants (birth weight <1,501 g) is correlated with gestational age. Mortality is between 10 and 16%, showing high numbers in infants < or = 26 weeks of gestation. Looking at the low-term outcome, cerebral palsy is the most prevalent major disability with an incidence of 8%. Similar to mortality, the incidence of cerebral palsy is inversely proportional to gestational age. A clinically verified chorioamnionitis increases the risk of developing cerebral palsy by a factor of up to 4.
UNLABELLED: The objective of this study was to examine the cognitive, neurological and somatic developments of children who had in utero an absent or reversed end-diastolic blood flow (ARED) in the umbilical artery or an abnormal cerebroplacental ratio (ABF). METHODS: 16 children with ARED blood flow and 15 children with ABF were each matched to children with the same gestational age, appropriate for gestational age, the same sex and born within 4 months. Data were assessed at the age of 3-6 years. Children with asphyxia, neonatal infection, malformation or major surgical interventions in the neonatal period were excluded. Each child underwent a neuropediatrical examination; furthermore, a Kaufman Assessment Battery for Children, a Snijders-Oomen Intelligence Scale for Children and a Man-Drawing Test were used to evaluate cognitive development. The socioeconomic status was also assessed. RESULTS: Children in the ARED group remained lighter and had a higher frequency of microcephaly. In the Kaufman Assessment Battery for Children and the Snijders-Oomen Intelligence Scale for Young Children, cognitive development was impaired in the ARED and the ABF groups compared to the control group. The ARED and the ABF groups, however, showed no differences. The Man-Drawing Test and the Denver Development Test did not show any differences. DISCUSSION: ARED blood flow and ABF showed impaired cognitive development. The degree of impairment was the same in the ARED and the ABF groups. Long-term follow-up studies until adulthood are necessary to see if impaired cognitive development remains significant in these groups of patients.
About 1 out of 100 full term born infants develops intracranial hemorrhage. The study represents an analysis of intracranial hemorrhage over a ten-years period. Diagnosis was based on ultrasound scan. A division into five major bleeding types was done according to the location of the hemorrhage. The neurological outcome was reviewed. Patients were classified into three groups according to their neurological outcome: normal neurological development, mild neurological impairment, and severe neurological impairment. Between 1989-1999, 2019 full-term newborn infants were treated at the neonatal intensive care unit in Graz. 54 of them (2.7%) developed intracranial hemorrhage, of whom 13 (24%) suffered from subdural hemorrhage, 1 (2%) from primary subarachnoid hemorrhage, 14 (26%) from hemorrhage within the choroid plexus, 6 (11%) from intraventricular hemorrhage grade I (IVH I), 11 (20%) from intra- and periventricular hemorrhage (IVH III/PVH), 6 (11%) from hemorrhage within the basal ganglia, and 3 (6%) from intracerebellar hemorrhage. Considering the neurological outcome, 34 (63%) were diagnosed as being developed normally, 15 (28%) developed any neurological impairment, 3 (5%) died, whereas 2 (4%) did not participate our follow up program.
BACKGROUND: The somatic, neurological and cognitive development of children born small for gestational age (SGA) until adulthood was assessed in recent studies. Studies that assessed mortality, morbidity, somatic, neurological and cognitive development of SGA children were compared. MATERIALS AND METHODS: In the studies very low birth weight SGA children were compared to very low birth weight appropriate for age children (AGA, birth weight below 1500 g or 1250 g). Full-term SGA children were compared to full-term appropriate for age children. Growth of SGA children remained under the 10th percentile, if catch up growth did not occur until the end of the second year. Cerebral palsy appeared more often in VLBW-AGA than in VLBW-SGA children. Cognitive development problems appeared in VLBW-SGA and FT-SGA children more often than in VLBW-AGA and FT-AGA children. These cognitive development problems were observed mainly as poor school performance. When reaching adulthood, the differences in cognitive function seem to be less significant. Low socioeconomic status and persistence of microcephaly were associated with problems in neurological and cognitive development. CONCLUSIONS AND DISCUSSION: Growth and cognitive development problems appeared more often in SGA children. More longterm studies are necessary to show, if these cognitive development problems remain significant until adulthood.
The objective of the present study was to evaluate sleeping position-dependent effects on cerebral hemodynamics during apnea in preterm infants. To this end, polygraphic studies were performed on 15 stable preterm infants lying prone and lying supine. Changes in cerebral blood volume (DeltaCBV) and in cerebral hemoglobin oxygenation ((Delta)cHbD) in association with apnea were measured by near infrared spectroscopy. For comparison, apnea in the prone position was matched for duration to apnea in the supine position. A total number of 98 pairs of apnea were compared. The mean duration of apnea was 8.2+/-3 s. In both positions there was a predominance of decrease in CBV and cHbD in association with apnea. The mean decrease of cHbD (-1.57+/-1.82 micromol/l) and of CBV (-0.120+/-0.137 ml/100g brain) in the supine position was significantly pronounced compared to prone position (DeltacHbD: -1.18+/-1.77 micromol/l, DeltaCBV: -0.080+/-0.095 ml/100 g brain). The degree of DeltaCBV and DeltaHbD did not correlate with postconceptional or postnatal age (r2<0.01). In both positions there was a similar small decrease of SaO2 in association with apnea. In the supine position heart rate decreased slightly during apnea, whereas in the prone position no change in heart rate could be observed. The present study revealed a position-dependent different impact of apnea on cerebral hemodynamics. With regard to cerebral blood volume and oxygenation in association with apnea no negative effects of prone sleeping position could be observed in preterm infants.
Tilting is known to cause changes in hemodynamics due to hydrostatic pressure. The present study is an analysis of changes in cerebral hemodynamics measured by near infrared spectroscopy (NIRS) following tilting up and down in preterm and term infants. A significantly different effect of tilting up in comparison to tilting down on total hemoglobin in preterm infants and on the 'hemoglobin oxygenation index' in preterm and term infants was observed. In preterm infants, tilting up and down had a significantly different effect on cerebral blood volume (CBV), with an increase after tilting down and a decrease after tilting up. In term infants, tilting had no significant effect on CBV comparing these two procedures. We think that NIRS provides a good method to measure cerebral hemodynamics following tilting, whereby different reactions in infants of different postconceptional age can be observed.
The present study is an analysis of changes in cerebral oxygenation and cerebral blood volume (CBV) during periodic breathing in healthy term infants by means of near infrared spectroscopy (NIRS). Polygraphy included electrocardiogram, electrooculogram, heart rate, oxygen saturation, side stream capnography, two respiratory effort sensors, a movement sensor, and NIRS. During periodic breathing analysis of behaviour of total haemoglobin (cHbtot), deltaCBV, the haemoglobin oxygenation index (cHbD), and cytochrome oxidase (CytOx) was performed. In ten healthy term infants 30 cycles of periodic breathing with a mean of 10 apnoeas per cycle were analysed. Corresponding cyclical variations of cHbD appeared in 98%, cyclical variations of cHbtot appeared in 42% of all apnoeas. During phases of apnoea, a mean decrease of cHbD of -3.45 micromol/l occurred 1.75 seconds after onset of apnoea, and a mean decrease of cHbtot of -0.79 micromol/occurred 0.74 seconds after onset of apnoea. During these apnoeas, the deltaCBV was -44 microl/100 g brain. During phases of ventilation, there was an increase of cHbD and cHbtot to the pre-apnoeic levels. There was a tendency that CytOx values decreased during periodic breathing, the amount of decrease was -0.32 micromol/l. In conclusion, the present study was able to show for the first time that there is cyclical desaturation and reoxygenation of cerebral blood during periodic breathing. Cyclical changes in CBV in association with periodic apnoea occurred only in 42% of apnoea.
OBJECTIVE: To investigate the effect of the combination of kinetic therapy (KT) with partial liquid ventilation (PLV) on gas exchange, lung mechanics and hemodynamics in acute lung injury (ALI). DESIGN: Prospective, randomized, controlled pilot study. SETTING: University research laboratory. SUBJECTS: Eleven piglets weighing 8.3+/-0.9 kg. INTERVENTION: ALI was induced by the infusion of oleic acid (0.08 ml/kg) and repeated lung lavages with 0.9% NaCl (20 ml kg(-1)). Thereafter the animals were randomly assigned either for PLV or a combination of PLV with KT (PLV/KT). The dose of perfluorocarbon administered was 30 ml/kg, evaporative losses were substituted with 5 ml/kg per h. MEASUREMENTS AND MAIN RESULTS: Airway pressures, tidal volumes, dynamic compliance (Cdyn), expiratory airway resistance and arterial blood gases were measured. Hemodynamic monitoring included right atrial, mean pulmonary artery, pulmonary capillary wedge and mean systemic arterial pressures, and continuous flow recording of the pulmonary artery. In both groups the induction of ALI significantly reduced PaO2/FIO2 Cdyn and cardiac output, and significantly increased pulmonary artery pressure. After the initiation of PLV there was a significant increase of PaO2/FIO2, and Cdyn, and a significant decrease of pulmonary artery pressure in both groups. Except the PaCO2, which showed significantly lower values in the PLV/KT group, no variables showed any differences between the two groups. CONCLUSION: The additional use of KT did not show beneficial effects on oxygenation and lung mechanics during PLV. However, at constant minute ventilation PaCO2 levels were significantly lower during PLV/KT, indicating some positive influence on the ventilation/perfusion distribution within the lung. Extreme body positions during PLV/KT did not show any significant hemodynamic side effects.
The aim of this study was to analyse the behaviour of cerebral oxygenation and cerebral blood volume (CBV) in preterm infants during apnoea by means of near-infrared spectroscopy (NIRS). The sum of oxygenated and deoxygenated haemoglobin, the total cerebral haemoglobin (Hbtot) corresponds to CBV, whereas the difference of oxygenated minus deoxygenated haemoglobin (HbD) represents a value for cerebral oxygenation. During 2 hours of daytime sleep, 72 polygraphic tracings (including NIRS) were done in 58 premature infants. The main criteria for study entry were clinically evident episodes of apnoeas and prematurity. According to their length, apnoeas were divided into two groups: apnoeas of 5-14 seconds (Group 1) and apnoeas > or = 15 seconds (Group 2). Periodic breathing was excluded from analysis. A total number of 1345 apnoeas in Group 1 and 74 apnoeas in Group 2 were recorded, 647 (46%) fulfilled criteria for further analysis. We observed different patterns of CBV behaviour, but the majority, namely 94% in Group 1 and 87% in Group 2, showed a decrease of CBV during apnoea. There was always a cerebral deoxygenation (decrease in HbD) in association with apnoeas, which was significantly increased in apnoeas of longer duration.
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OBJECTIVES: To investigate the effects of positive end-expiratory pressure (PEEP) application during partial liquid ventilation (PLV) on gas exchange, lung mechanics, and hemodynamics in acute lung injury. DESIGN: Prospective, randomized, experimental study. SETTING: University research laboratory. SUBJECTS: Six piglets weighing 7 to 12 kg. INTERVENTIONS: After induction of anesthesia, tracheostomy, and controlled mechanical ventilation, animals were instrumented with two central venous catheters, a pulmonary artery catheter and two arterial catheters, and an ultrasonic flow probe around the pulmonary artery. Acute lung injury was induced by the infusion of oleic acid (0.08 mL/kg) and repeated lung lavage procedures with 0.9% sodium chloride (20 mL/kg). The protocol consisted of four different PEEP levels (0, 5, 10, and 15 cm H2O) randomly applied during PLV. The oxygenated and warmed perfluorocarbon liquid (30 mL/kg) was instilled into the trachea over 5 mins without changing the ventilator settings. MEASUREMENTS AND MAIN RESULTS: Airway pressures, tidal volumes, dynamic and static pulmonary compliance, mean and expiratory airway resistances, and arterial blood gases were measured. In addition, dynamic pressure/volume loops were recorded. Hemodynamic monitoring included right atrial, mean pulmonary artery, pulmonary capillary wedge, and mean systemic arterial pressures and continuous flow recording at the pulmonary artery. The infusion of oleic acid combined with two to five lung lavage procedures induced a significant reduction in PaO2/FI(O2) from 485 +/- 28 torr (64 +/- 3.6 kPa) to 68 +/- 3.2 torr (9.0 +/- 0.4 kPa) (p < .01) and in static pulmonary compliance from 1.3 +/- 0.06 to 0.67 +/- 0.04 mL/cm H2O/kg (p < .01). During PLV, PaO2/FI(O2) increased significantly from 68 +/- 3.2 torr (8.9 +/- 0.4 kPa) to >200 torr (>26 kPa) (p < .01). The highest PaO2 values were observed during PLV with PEEP of 15 cm H2O. Deadspace ventilation was lower during PLV when PEEP levels of 10 to 15 cm H2O were applied. There were no differences in hemodynamic data during PLV with PEEP levels up to 10 cm H2O. However, PEEP levels of 15 cm H2O resulted in a significant decrease in cardiac output. Dynamic pressure/volume loops showed early inspiratory pressure spikes during PLV with PEEP levels of 0 and 5 cm H2O. CONCLUSIONS: Partial liquid ventilation is a useful technique to improve oxygenation in severe acute lung injury. The application of PEEP during PLV further improves oxygenation and lung mechanics. PEEP levels of 10 cm H2O seem to be optimal to improve oxygenation and lung mechanics.
OBJECTIVE: Our purpose was to investigate how many preterm infants with a birth weight </=1,250 g and how many newborns with one >1,250 g with clinical symptoms had Ureaplasma urealyticum in their endotracheal tube aspirates, and how many of them had pneumonia. METHODS: The patients were divided into two groups (group 1: birth weight </=1,250 g, n = 25; group 2: birth weight >1,250 g, n = 45), and these two groups were subdivided into two subgroups (subgroup a: U. urealyticum in aspirate without pneumonia; subgroup b: U. urealyticum in aspirate with pneumonia). RESULTS: In group 1, there were 25 patients. Nine patients (36%) had U. urealyticum in their aspirates, 5 patients (20%) had pneumonia (group 1b), and 4 patients (16%) did not (group 1a). Infants with pneumonia showed a significant increase in parameters of mechanical ventilation, in the duration of mechanical ventilation, and in the duration of oxygen dependence as compared with subgroup 1a. In group 2, there were 45 patients. Six patients of group 2 (13%) had U. urealyticum in their aspirates, 2 patients (4.4%) had a pneumonia (group 2b), and 4 patients (8.8%) did not (group 2b). CONCLUSIONS: In preterm infants as well as in term newborns one should consider U. urealyticum as a potential cause of neonatal pneumonia.