[Child's sudden death in 20th century--hypothesis, dogmas, dead wood]. / Der plötzliche Kindstod im 20. Jahrhundert--Hypothesen, Dogmen, Holzwege.

With the decline of the former main causes of death in early childhood--infections and starvation--sudden infant death syndrome (SIDS) has emerged as the most important single cause of postneonatal infant mortality. It has adopted the role of a major indicator for the standard of public health care. Despite extensive input into research, its pathophysiology has remained rather obscure. The resulting helplessness of scientists and health care professionals have lead to adherence to unconfirmed pathophysiological hypotheses and to pursuit of preventive strategies of doubtful efficacy. In this overview, the medical and technical background of five major hypotheses is being presented. A lot can be learnt from the history of their development, efforts to refute them, and the reasons for unreflected adherence to them. (1) Due to its illustrative nature, the so-called 'status thymico-lymphaticus', the theory of asphixation by an enlarged thymus, could not be eradicated although well-reknowned physicians--including the Austrian pathologist Paltauf--have repeatedly attempted to do so. (2) Assumed familiarity, an aspect which attracted the attention of pediatricians to SIDS initially has been excluded, but an increased risk of SIDS for the siblings of affected babies is still common belief. (3) The sleep-apnea-hypothesis has turned out a complete error with serious consequences, but home apnea monitors are still being widely recommended. (4) The rise of SIDS in the 80ies and its subsequent decline in the 90ies has been interpreted as the advent and successful control of an epidemic although significant numbers of cot death have been reported long before the turn of the century, and the apparent increase which paralleled the introduction of the 9th edition of the ICD code is most likely due to improved registration. (5) Finally, SIDS is still being considered a random event--ignoring all evidence of an obvious role of socioeconomical factors.

Factor V Leiden and prothrombin gene G 20210 A variant in children with ischemic stroke.

OBJECTIVE: To investigate if the factor V Leiden mutation (F-V-LM) and/or the prothrombin gene G 20210 A variant (P-G20210A-V) are risk factors for acute stroke in Austrian children. PATIENTS: 33 children with acute ischemic stroke documented by computer tomography and/or magnetic resonance imaging of the brain were enrolled in an open multicenter survey. RESULTS: 6/33 children had F-V-LM (5 heterozygous, 1 homozygous). This represents 18% (95% CI: 6.7-39.9%) of our pediatric stroke population and thus exceeds the expected prevalence in the Austrian population of 4,6% (Fischer's exact test, p = 0.01). F-V-LM was not found in 11 children with neonatal stroke but in 6/22 children with stroke after the neonatal period. 5/6 children with F-V-LM had an underlying disorder that is a risk factor for stroke in children. The P-G20210A-V was detected in 1/26 (3.85%; 95% CI: 0.1-21.4%) patients. Comparison of the prevalence of P-G20210A-V in our study with that in the general population of Austria of 1% revealed no statistical significance (Fischer's exact test, p = 0.38). CONCLUSION: Our data suggest that the F-V-LM is a risk factor for acute stroke in Austrian children beyond the neonatal period. The P-G20210A-V apparently does not represent a risk factor for stroke in Austrian children.

Effective data validation of high-frequency data: time-point-, time-interval-, and trend-based methods.

Real-time systems for monitoring and therapy planning, which receive their data from on-line monitoring equipment and computer-based patient records, require reliable data. Data validation has to utilize and combine a set of fast methods to detect, eliminate, and repair faulty data, which may lead to life-threatening conclusions. The strength of data validation results from the combination of numerical and knowledge-based methods applied to both continuously-assessed high-frequency data and discontinuously-assessed data. Dealing with high-frequency data, examining single measurements is not sufficient. It is essential to take into account the behavior of parameters over time. We present time-point-, time-interval-, and trend-based methods for validation and repair. These are complemented by time-independent methods for determining an overall reliability of measurements. The data validation benefits from the temporal data-abstraction process, which provides automatically derived qualitative values and patterns. The temporal abstraction is oriented on a context-sensitive and expectation-guided principle. Additional knowledge derived from domain experts forms an essential part for all of these methods. The methods are applied in the field of artificial ventilation of newborn infants. Examples from the real-time monitoring and therapy-planning system VIE-VENT illustrate the usefulness and effectiveness of the methods.

Theophylline for infants with abnormal pneumographic results. A randomized double blind, placebo-controlled trial.

To evaluate the effectiveness of theophylline on density of central apnoeas and on incidence of periodic breathing; to compare the effect with age-related resolution of pneumogram abnormalities. Ninety-six infants (mean age 27.4 days; mean birth weight 2502 gm) with abnormal pneumographic results were randomly allocated to receive theophylline or placebo. The control group consisted of 94 healthy age- and weight-matched infants. After four weeks of treatment infants in the theophylline group had a significantly lower incidence (2.1% vs. 4.3%) and density of apnoeas > or = 15 sec (0.001 vs. 0.003). There were significantly less short apnoeas (> or = 6 sec.) in theophylline treated than in control infants (p < 0.01). The number of periodic breathing episodes showed a significant, presumably age-related reduction in both treatment groups. We conclude that theophylline is an effective agent in reducing the incidence and duration of apnoeas beyond what would be expected from age-related maturation of breathing.

Utilizing temporal data abstraction for data validation and therapy planning for artificially ventilated newborn infants.

Medical diagnosis and therapy planning at modern intensive care units (ICUs) have been refined by the technical improvement of their equipment. However, the bulk of continuous data arising from complex monitoring systems in combination with discontinuously assessed numerical and qualitative data creates a rising information management problem at neonatal ICUs (NICUs). We developed methods for data validation and therapy planning which incorporate knowledge about point and interval data, as well as expected qualitative trend descriptions to arrive at unified qualitative descriptions of parameters (temporal data abstraction). Our methods are based on schemata for data-point transformation and curve fitting which express the dynamics of and the reactions to different degrees of parameters' abnormalities as well as on smoothing and adjustment mechanisms to keep the qualitative descriptions stable. We show their applicability in detecting anomalous system behavior early, in recommending therapeutic actions, and in assessing the effectiveness of these actions within a certain period. We implemented our methods in VIE-VENT, an open-loop knowledge-based monitoring and therapy planning system for artificially ventilated newborn infants. The applicability and usefulness of our approach are illustrated by examples of VIE-VENT. Finally, we present our first experiences with using VIE-VENT in a real clinical setting.

[Incidence and regression of sudden infant death in Austria. Is the change in the SIDS incidence real or virtual?]. / Zunahme und Rückgang des plötzliches Kindestodes in Osterreich. Ist die Entwicklung der SIDS-Inzidenz reell oder virtuell?

After the rise in incidence of the sudden infant death syndrome (SIDS) in the 1980s to a peak of 1.7/1000 live births in Austria in 1988, the SIDS rate more than halved to 0.79/1000 live births in 1994. This trend can be regarded as typical of the epidemiology of SIDS in most Western countries. It is commonly interpreted as a result of preventive measures. However, the decline in incidence of SIDS started several years before systematic preventive activities were undertaken in Austria. Graphical presentation shows that the dynamics of SIDS does not affect the almost linear decline in postneonatal mortality over the past 25 years, as would be expected from the fact that SIDS is the most important cause of death in the postneonatal period. A comparative analysis of trends of postneonatal SIDS and non-SIDS mortality reveals that in Austria the increase of SIDS was accompanied by a rapid fall of non-SIDS mortality, whereas, on the contrary, the decline of SIDS went along with relative increase of non-SIDS mortality. Changing awareness of coroners and forensic pathologists of SIDS, with the resultant changes in frequency and performance of postmortem examinations, and changes in coding practices of causes of death should be taken into consideration as determinants of SIDS incidence before interpreting trends as resulting from public health interventions.

Pulse oximetry in ventilated preterm newborns: reliability of detection of hyperoxaemia and hypoxaemia, and feasibility of alarm settings.

The aim of our study was to evaluate the reliability of pulse oximetry in detecting both hyper- and hypoxaemic states and to create clinically feasible alarm limits. A total of 792 readings of a pulse oximeter and corresponding values of arterial oxygen tension from 146 (79M, 67F) artificially ventilated preterm newborns with indwelling umbilical artery catheters were compared. Predictive value analysis of pulse oximeter readings related to arterial oxygen tension confirmed the ability of the pulse oximeter to identify both hypoxaemia and hyperoxaemia. However, a clinically feasible and safe range of alarm limits for maintenance of arterial oxygen tension of 40-90 mmHg (5.3-12 kPa) could only be established at a sensitivity level less than 0.9. At a level of 0.85, the alarm range on the pulse oximeter was 92.5-95%. Based on these findings, we are concerned about using pulse oximetry as the sole means of oxygen monitoring for preterm infants receiving supplementary oxygen. A combination of the pulse oximetry with other methods of blood-gas monitoring seems mandatory.

[Obstructive apnea in premature and young infants]. / Obstruktive Apnoen bei Frühgeborenen und Säuglingen.

The occurrence of obstructive apneas in premature and young infants is associated with a higher risk for SIDS. In order to assess the incidence of obstructive apnoeas in infants with different risk for SIDS pneumography was performed including the registration of the nasal air flow in 312 children: 69 preterm infants, 42 children after intensive care, one infant that later died of SIDS, 14 children after ALTE, 84 children after apnoeas observed by their parents, 25 siblings of SIDS-victims and 77 controls. Obstructive apnoeas were found in 24.6% of the preterm infants, in 28.5% of the children after intensive care, in 50% of the children after ALTE and in the one infant that later died of SIDS. Obstructive apnoeas however were registered only in 16.7% in the "apnoea-group", in 12% of the SIDS-siblings and in 11.7% of the controls. We therefore conclude that obstructive apnoeas which were observed more frequently in children with a higher risk for SIDS are of predictive value for the SIDS risk. Pneumography should therefore include the measurement of the nasal air flow. Home monitoring should be performed with devices that are able to assess bradycardias as indirect signs of obstructive apnoeas.

Transcutaneous estimation of arterial carbon dioxide in intensive care. Which electrode temperature?

Transcutaneous and arterial carbon dioxide were measured simultaneously in 57 children (age range 10 days to 14.3 years) undergoing intensive care. All were haemodynamically stable at the time of study. Mean calibration time with 5 and 10% carbon dioxide was 43 (range 38-58) minutes and mean arterialisation time was 10.5 (range 3-30) minutes. Duplicate hourly arterial samples over a four hour period showed that transcutaneous: arterial carbon dioxide correlation was independent of electrode temperatures over the range 42-44 degrees C and was independent of child age. One and a half hours after electrode placement transcutaneous carbon dioxide (kPa) = arterial carbon dioxide X 1.41 + 0.02. Use of a simple ratio (arterial carbon dioxide = transcutaneous carbon dioxide/1.40) resulted in a mean estimate of arterial carbon dioxide within 3% of the actual value with coefficients of variation of 11 and 15% at 1.5 and 4.5 hours, respectively. For prediction of arterial carbon dioxide 95% confidence limits around the regression mean rose from +/- 1.04 kPa (7.8 mm Hg) at 1.5 hours to +/- 1.56 (11.7 mm Hg) at 4.5 hours. Baseline drift was more than +/- 0.67 kPa (5 mm Hg) during 22% of the studies. For a drift of less than 0.67 kPa 95% confidence limits were 0.87 and 1.12 kPa, respectively. Arterial carbon dioxide can be estimated with clinically acceptable tolerances from surface electrodes operating at temperatures between 42-44 degrees C. Improved electrode stability and speed of calibration should make this a valuable monitoring technique.

[Dwarfism in the Alagille syndrome caused by somatomedin C deficiency?]. / Kleinwuchs bei Alagille-Syndrom durch Somatomedin-C-Mangel?

Alagille syndrome (= arterio-hepatic dysplasia) is a rare congenital syndrome consisting of cholestasis with paucity of intrahepatic bile ducts, pulmonary artery stenosis, skeletal anomalies and typical facies. Growth retardation, which is not correlated with vertebral anomalies or the degree of cholestasis, occurs in about two thirds of patients. We report on hormonal aspects of growth retardation in an 8 year old Austrian boy with the typical features of arteriohepatic dysplasia. Thyroid function and a cortisol profile were normal and we found normal HGH response to insulin stimulation. The Somatomedin C-activity was well below the age-adjusted normal range. Even after test-induced HGH peaks no increase in Somatomedin C-activity could be observed. A six month course of phenobarbital-, cholestyramine- and D-penicillamine-therapy led to significant improvement of cholestasis, however Somatomedin C values and growth velocity remained unchanged. Results in our patients show that Somatomedin C-deficiency might be an important cause of growth retardation in children with chronic liver disease, at least in arteriohepatic dysplasia.

[Transcutaneous oxygen and carbon dioxide measurement in pediatric intensive care patients]. / Transkutane Sauerstoff- und Kohlendioxidmessung bei pädiatrischen Intensivpatienten.

Transcutaneous partial pressures of oxygen (PtcO2) and carbon dioxide (PtcCO2) were measured in 16 haemodynamically stable patients of a paediatric intensive care unit and were compared with simultaneously measured arterial partial pressures (PaO2 and PaCO2). For the transcutaneous measurement a sensor temperature of 44 degrees C was chosen, blood gas analysis was performed on 2 different automatic blood gas analysers. Comparisons of 82 pairs of oxygen and 60 pairs of carbon dioxide partial pressures were made. Our data show a tight linear correlation between cutaneous and arterial partial pressures of oxygen and carbon dioxide, defined by regression equations and correlation coefficients: PtcO2 = 1.22 + 0.8 X PaO2 (r = 0.93) and PtcCO2 = 5.52 + 1.26 X PaCO2 (r = 0.88). We conclude that transcutaneous measurements of oxygen and carbon dioxide partial pressures are reliable noninvasive techniques for monitoring arterial gas tensions in haemodynamically stable paediatric patients.

Transcutaneous oxygen and carbon dioxide monitoring in intensive care.

Transcutaneous oxygen (TcPo2) and carbon dioxide (TcPco2) tensions were compared with arterial values in 23 children aged 4 months to 14 years, all requiring some form of respiratory support, but not in shock. Electrodes were placed on the upper chest and were heated to 45 degrees C. For TcPo2 and arterial oxygen (Pao2) a tight linear correlation over the range 6 to 14 kPa was found. Arterial carbon dioxide (Paco2) ranged between 2.63 and 6.8 kPa, and over this range a linear regression adequately described the relation of TcPco2 to Paco2. No effects of age were found for the relation between TcPo2 and Pao2. Over a four hour period, the mean ratio TcPo2/Pao2 rose significantly from 0.96 to 1.04, while the mean ratio of TcPco2/Paco2 fell from 1.65 to 1.62. Five children developed superficial burns which were still present at 48 hours. In children who require respiratory support but are not in shock, TcPo2 and TcPco2 bear a constant and predictable relation to Pao2 and Paco2, and can predict arterial values within clinically acceptable tolerances.

[Transient hypoplasia of the intrahepatic bile ducts. Clinical and morphologic studies]. / Passagere Hypoplasien der intrahepatischen Gallengänge. Klinische und morphologische Beobachtungen.

Two boys were thriving normally up to the age of three and nine weeks respectively when obstructive cholestasis developed. Liver biopsy revealed paucity of intrahepatic bile ducts. Extrahepatic bile ducts were not occluded. In both cases cholestasis completely disappeared after five and nineteen weeks respectively. Control liver biopsis showed normal numbers of intrahepatic bile ducts. We conclude that paucity of intrahepatic bile ducts may be transient.

[Epidemiology and clinical aspects of Campylobacter enteritis in childhood]. / Epidemiologie und Klinik der Campylobacter-Enteritis im Kindesalter.

Stool specimens of 478 children with enteritic symptoms were screened for enteropathogenic bacteria over a 5-month period. 28 cases of infection due to Campylobacter jejuni were found. The incidence of Campylobacter enteritis exceeded that of salmonella and shigella infections recorded over the same period (17 and 11 cases, respectively). Infected children-aged between 2 months and 15 1/2 years-presented with symptoms of mild gastroenteritis. 18 patients had bloody diarrhoea, whilst 4 children aged between 4 and 9 years with abdominal pain showed a clinical picture mimicking acute appendicitis. Two severely dehydrated infants required parenteral fluids, but in the remaining cases dietetic treatment alone proved satisfactory.