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Biomedical subjects

C Popow

Publications and source records attributed to C Popow.

At least 19 recordsLinked to original sources
PubMed2001

Position dependent changes of cerebral blood flow velocities in premature infants.

UNLABELLED: The supine or prone positioning of infants has been a cause of much controversy. Recently it has been postulated that the position dependent hypoperfusion of the brainstem represents a possible cause of sudden infant death. To demonstrate position dependency and maturational changes of cerebral perfusion in premature newborn infants we investigated cerebral blood flow velocities (CBFV) in the main supratentorial and brainstem cerebral arteries. Measurements of CBFV were done with transfontanellar colour-coded Doppler sonography in the internal carotid artery (ICA), basilar artery (BA), and vertebral artery (VA) in the prone (head centered-baseline) and supine positions (maximal rotation to both sides) in 23 premature infants aged between 3-5 days of life. We performed follow-up measurements in 17 infants 7-10 days later and in 16 infants at the corrected age of 1 month. There was no difference in mean CBFVs between the prone and supine position at the first investigation. At the third investigation, CBFVs were significantly higher in the supine compared to the prone position. The CBFVs of the ICA were higher than in the BA and VA. This difference was not influenced by the body position but increased with post-natal age more in the VA (159%) than in the BA (129%) and ICA (128%). Position dependency was not seen in the ICA perfusion. In the prone position, five infants showed an incomplete steal effect in the contralateral VA. There was no significant side difference in the CBFVs of the ICA and VA, but in the resistance indices in the VA (left > right). CONCLUSION: in premature newborns, position dependent changes of cerebral blood flow velocity develop with maturation and are most pronounced in the vertebrobasilar system. These changes are possibly due to compression of the vertebral artery by neck movement and suggest an individual risk of brainstem perfusion deficits that may be aggravated with age and head rotation in a prone position.

Analysis of Variance↗
PubMed2001

Support for fast comprehension of ICU data: visualization using metaphor graphics.

OBJECTIVES: The time-oriented analysis of electronic patient records on (neonatal) intensive care units is a tedious and time-consuming task. Graphic data visualization should make it easier for physicians to assess the overall situation of a patient and to recognize essential changes over time. METHODS: Metaphor graphics are used to sketch the most relevant parameters for characterizing a patient's situation. By repetition of the graphic object in 24 frames the situation of the ICU patient is presented in one display, usually summarizing the last 24 h. RESULTS: VIE-VISU is a data visualization system which uses multiples to present the change in the patient's status over time in graphic form. Each multiple is a highly structured metaphor graphic object. Each object visualizes important ICU parameters from circulation, ventilation, and fluid balance. CONCLUSION: The design using multiples promotes a focus on stability and change. A stable patient is recognizable at first sight, continuous improvement or worsening condition are easy to analyze, drastic changes in the patient's situation get the viewers attention immediately.

Artificial Intelligence↗
PubMed2000

SIDS related anxiety--a risk factor analysis.

BACKGROUND: The growing public interest in the Sudden Infant Death Syndrome (SIDS) has led to a new psychological problem--SIDS related anxiety (SRA). General public awareness, unfavourable experience in the past, present problems with the infant or insufficient support from the family may lead or contribute to SRA. OBJECTIVE: The study was conducted to explore which of these factors contribute most to the development of SRA. PATIENTS AND METHODS: Families visiting our outpatient clinic during 18 months were interviewed by means of a structured questionnaire. We assessed demographic data, obstetric history, experience of child loss, pregnancy and delivery complications, infant morbidity, family-child interaction, family support and the relation of each of these single factors to SRA. RESULTS: Of 169 families, 58% (98/169) admitted to suffer from SRA and 21% (32/156) from severe SRA. We found a strong and significant relationship between previous experience of child loss and SRA (OR: 2.95, 95% CI: 1.43-6.09, P < 0.005) and between pregnancy complications and SRA (OR: 2.19, 95% CI: 1.18-4.08, P < 0.05). There were no significant relationships between SRA and either delivery complications, child morbidity, impaired family-child interaction or insufficient support from the family. CONCLUSIONS: SRA occurs in an unexpectedly large proportion of families visiting a SIDS counseling clinic. SRA must be taken seriously, and psychological or psychotherapeutic help should be offered. Prevention of SRA should include psychological care for families who experience loss of children or high-risk pregnancies.

Adult↗
PubMed2000

[Evaluation of the cardiorespiratory monitor SpiroGuard C for infants. Improved registration of respiratory events by new sensors and intelligent alarm management system].

OBJECTIVES: The SpiroGuard C is a commercially available cardiorespiratory monitor working with field plethysmography, wireless signal transmission and a novel alarm management system. In order to determine the recognition rates for central, mixed and obstructive apneas, a prospective clinical trial was performed comparing frequency and kind of signals from the monitor with those simultaneously registered by polysomnographic studies. DESIGN: Normal respiratory and alarm signals of the monitor under investigation were integrated into a polysomnographic setting. All central, mixed and obstructive apneas lasting more than 10 seconds as well as all alarms obtained from the monitor were evaluated. RESULTS: 47 series of monitor recordings could be evaluated in parallel to polysomnographic studies: the detection rate for central apneas was 298/328 (90.85%), for mixed apneas 9/41 (21.95%) and for obstructive apneas 0/36 (0%). Out of the total of 708 registered alarms 359 (50.71%) were false alarms, 307 (43.36%) were apnea-related and 42/708 (5.93%) were alarms due to technical problems. 177 of the 359 false alarms (49.30%) occurred during apneas that were shorter than 10 seconds, 119 (33.15%) were related to bad signal quality, and 55 (15.32%) were caused by movement artifacts. CONCLUSION: The recognition rate for central apneas was high (> 90%), while sensitivity for mixed and obstructive apneas was not satisfactory. Approximately half of the alarms were false alarms. These could be reduced by setting the apnea detection time to > 15 seconds, by tighter fastening of the respiration belt (improving the signal transmission), and by turning off the instrument when the child is awake and physically active. The wireless system renders the SpiroGuard C an attractive alternative for home monitoring.

Apnea↗
PubMed2000

Effects of endotracheal suctioning in high-frequency oscillatory and conventionally ventilated low birth weight neonates on cerebral hemodynamics observed by near infrared spectroscopy (NIRS).

Adverse changes in cerebral hemodynamics during endotracheal suctioning have been reported in conventionally ventilated newborns, whereas observations on the effect of endotracheal suctioning during high-frequency ventilation have not been reported to date. The present study was designed to investigate the effect of endotracheal suctioning on cerebral hemodynamics in high-frequency and conventionally ventilated infants. Changes in cerebral concentration of oxygenated (cO(2)Hb) and deoxygenated hemoglobin (cHHb) and oxidized cytochrome aa3 (cCyt.aa3) were measured by noninvasive near-infrared spectroscopy. In an open prospective study, 26 suctioning periods in 9 high-frequency and in 6 conventionally ventilated newborn infants were investigated. Heart rate, arterial oxygen saturation (SaO(2)), mean blood pressure (MABP), and transcutaneous carbon dioxide tension (TcpCO(2)) were monitored continuously. In both groups, a marked decrease in heart rate, SaO(2) and in cO(2)Hb, an increase in cHHb, and a variable pattern in the concentration of total hemoglobin were noted during endotracheal suctioning. During suctioning, no statistically significant differences between the two methods of mechanical ventilation could be observed. We conclude that the mode of ventilation had no significant effect on changes in cerebral hemodynamics during endotracheal suctioning.

Brain↗
PubMed1999

Evaluation of an interdisciplinary data set for national intensive care unit assessment.

OBJECTIVES: To evaluate the ability of an interdisciplinary data set (recently defined by the Austrian Working Group for the Standardization of a Documentation System for Intensive Care [ASDI]) to assess intensive care units (ICUs) by means of the Simplified Acute Physiology Score II (SAPS II) for the severity of illness and the simplified Therapeutic Intervention Scoring System (TISS-28) for the level of provided care. DESIGN: A prospective, multicentric study. SETTING: Nine adult medical, surgical, and mixed ICUs in Austria. PATIENTS: A total of 1234 patients consecutively admitted to the ICUs. INTERVENTIONS: Collection of data for the ASDI data set. MEASUREMENTS AND MAIN RESULTS: The overall mean SAPS II score was 33.1+/-2.1 points. SAPS II overestimated hospital mortality by predicting mortality of 22.2%+/-2.9%, whereas observed mortality was only 16.8%+/-2.2%. The Hosmer-Lemeshow goodness-of-fit test for SAPS II scores showed lacking uniformity of fit (H = 53.78, 8 degrees of freedom; p < .0001). TISS-28 scores were recorded on 8616 days (30.6+/-1.5 points). TISS-28 scores were higher in nonsurvivors than in survivors (30.4+/-0.9 vs. 25.7+/-0.4, respectively; p < .05). No significant correlation between mean TISS-28 per patient per unit on the day of admission and mean predicted hospital mortality (r2 = .23; p < .54) or standardized mortality ratio per unit (r2 = -.22; p < .56) was found. CONCLUSIONS: Implementation of an interdisciplinary data set for ICUs provided data with which to evaluate performance in terms of severity of illness and provided care. The SAPS II did not accurately predict outcomes in Austrian ICUs and must, therefore, be customized for this population. A combination of indicators for both severity of illness and amount of provided care is necessary to evaluate ICU performance. Further data acquisition is needed to customize the SAPS II and to validate the TISS-28.

APACHE↗
PubMed1998

New-born infants with severe hyaline membrane disease: radiological evaluation during high frequency oscillatory versus conventional ventilation.

OBJECTIVE: The aim of our study was to determine the impact of treatment with exogenous surfactant (ES) and high frequency oscillatory ventilation (HFOV) on the radiological appearance and clinical course of hyaline membrane disease (HMD) in new-born infants. MATERIALS AND METHODS: New-born infants (18) (median weight, 1010 g) with severe HMD (stages 3.5 and 4) who were treated with ES and HFOV were matched by birth weight and severity of disease with 18 new-born infants treated with ES and conventional mechanical ventilation (CV). Chest radiograms taken on days 1, 2/3, 4/5, 7, 14 and 28 were analyzed to check for the severity of generalized parenchymal opacities (GPO), local opacifications, pulmonary interstitial emphysema (PIE), gross air leak, general and localized overinflation, bronchopulmonary dysplasia (BPD) and clinical variables such as survival rates, duration of mechanical ventilation, mean airway pressure and inspired oxygen concentration. RESULTS: At 4 weeks of age, new-born infants treated by HFOV had less severe GPO (median degree 1.5 vs. 3), less PIE (1 vs. 7 patients) and fewer signs of BPD (median BPD degree 1.5 vs. 2.6). The incidence of pneumothorax and of local opacifications were similar in both groups. New-born infants on HFOV had a lower mortality rate (5 vs. 13), needed fewer days of mechanical ventilation (median 15 vs. 23 days) and lower inspiratory oxygen concentrations (median FiO2 0.38 vs. 0.64). CONCLUSION: In new-born infants with HMD, treatment with ES and HFOV resulted in a favourable radiological and clinical outcome as compared to treatment with ES and CV.

Bronchopulmonary Dysplasia↗
PubMed1998

Three years experience with a patient data management system at a neonatal intensive care unit.

We report about our experience with the patient data management system (PDMS) Hewlett Packard CareVue 9000 at two neonatal ICUs. We describe our PDMS configuration (hard- and software), local adjustments and enhancements such as knowledge based systems for calculating the parenteral nutrition of newborn infants (VIE-PNN), for advising medication (VIE-Nmed), and for managing mechanical ventilation (VIE-VENT), and the results of a structured interview with our staff members about the acceptance of the system. Despite some criticism nearly all collaborators liked the system, especially because of its time saving automated documentation of vital data and mechanical ventilation parameters. More than 2/3 preferred the computer assisted documentation to charting by hand, only 1/41 would have liked to return to paper documentation. All staff members possessed excellent (15/39) or good (24/39) knowledge of the system. Main points of critique were the system's therapy planning facilities (medication administration records), the restrictive facilities for documenting patient care and the yet unsolved problems of data evaluation and export. PDM systems have to be constantly adapted to the user's needs and to the changing clinical environment. Living with the system asks for an intensive dialog with the system and its functionalities, for creativity and well defined ideas about the future system development.

Austria↗
PubMed1997

[Definition and evaluation of a documentation standard for intensive care medicine: the ASDI(Working Group for Standardization of a documentation system for Intensive care medicine) pilot project].

OBJECTIVES: A comparison of data from different intensive care units (ICUs) needs standardized documentation. In this study the ASDI documentation standard for intensive care was tested in clinical practice. Goal of the study was to evaluate parameters and functionality required for a national, interdisciplinary documentation system for intensive care. DESIGN: 13 ICUs participated in a 4-week trial using the provided program for documentation of all admitted patients during the observation period. In addition, a questionnaire was distributed to the unit coordinators. RESULTS: 376 patients were documented in 1591 patient days. Valid SAPS II scores were found in only 29% of the discharged patients (39.1 +/- 15.5 points). Time needed for data entry exceeded preset limits (ten minutes per patient and day) in 38% of the cases. All participants affirmed the necessity of a documentation standard for intensive care, giving quality control and cost analysis as the most important reasons. CONCLUSION: The ASDI data set fitted existing needs very closely. Only 7 out of 122 parameters (5.7%) were found to be superfluous and thus removed. Measures to reduce documentation effort to the default limits were a) a new, date orientated concept for manual recording, b) rede-sign of the user interface with new, user friendly data entry possibilities, and c) the integration of statistical analysis and reports in the documentation system. The revised data set represents a broad-based consensus, which seems to be well-suited as foundation for the national quality assurance program.

Adolescent↗
PubMed1997

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.

Artificial Intelligence↗
PubMed1996

Effects of umbilical arterial catheterization on mesenteric hemodynamics.

Impairment of mesenteric blood flow due to the use of umbilical artery catheters (UAC) may increase the risk of necrotizing enterocolitis (NEC) in newborn infants. We used Duplex Doppler sonography to investigate the degree of vessel obstruction due to UAC and their effect on visceral hemodynamics in 12 newborn infants. Ultrasonography was performed before and immediately after removal of the UAC, which was positioned above the ostia of the celiac and superior mesenteric arteries (SMA). Vessel diameter, peak systolic blood flow velocity (PSFV), end diastolic blood flow velocity (EDFV), and Pourcelot's resistance index (RI) were measured in the celiac trunk and the SMA within 1 cm of their origins. Removal of the UAC led to a significant increase in mean PSFV (celiac trunk: 50 cm/s +/- 15 vs 62 cm/s +/- 0.22, P < 0.05; SMA: 52 cm/s +/- 0.17 vs 72 cm/s +/- 0.21, P < 0.05). RI increased from 0.7 +/- 0.14 to 0.74 +/- 0.13 and from 0.73 +/- 0.1 to 0.76 +/- 0.13 for the celiac trunk and SMA, respectively. The EDFV and vessel diameters did not change significantly after UAC removal. Our results suggest that UAC cause a decrease in mesenteric blood flow. Therefore, their use in hemodynamically unstable neonates or in those with gastrointestinal disease should be very carefully considered.

Blood Flow Velocity↗
PubMed1996

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.

Algorithms↗
PubMed1996

[Ethical questions in neonatology].

Rapid scientific progress in the fields of prenatal diagnostics, obstetrics and neonatology has enabled severe malformations and hereditary diseases to be detected at a very early fetal stage and has also led to the survival of very immature newborn infants in increasing numbers. Parents, doctors and nurses must all participate in the difficult decision making with regard to therapeutic alternatives and due respect must be paid to the intersects of the child, the impact on the family, but also to the professional opinion of the attending doctors and carers. Problems of the ethical limits of prenatal diagnostics, as well as the severity of malformations or organ failure justifying termination of pregnancy or intensive care measures are discussed with reference to clinical cases. Likewise, the question of precedence of the rights of the parents and siblings to quality of life versus the right of the infant to live is broached. From the neonatological point of view candid discussion with the parents, painstaking efforts to build up an atmosphere of confidence and the provision of supportive measures on the one hand, whilst avoiding the expression of dogmatic opinions and patronizing attitudes on the other hand, are essential prerequisites in dealing with the ethical dilemmas arising in the pre- and neonatal management of such cases.

Abortion, Eugenic↗
PubMed1995

Successful treatment of severe neonatal lobar emphysema by high-frequency oscillatory ventilation.

We successfully used high-frequency oscillatory ventilation (HFOV) for treating severe acquired lobar emphysema in two premature newborn infants (birth weights, 1,450 and 1,300 g). After successful weaning from mechanical ventilation for hyaline membrane disease, they needed additional ventilatory support because they developed severe lobar emphysema compressing the residual lung. In both patients, radiographic signs of lobar emphysema disappeared completely after 3 days of HFOV. Diagnosis and follow-up were confirmed by high-resolution computed tomography. We conclude that HFOV may be a useful noninvasive method for treating severe lobar emphysema.

High-Frequency Ventilation↗
PubMed1995

Computer assisted data analysis in intensive care: the ICDEV project--development of a scientific database system for intensive care (Intensive Care Data Evaluation Project).

INTRODUCTION: Patient Data Management Systems (PDMS) for ICUs collect, present and store clinical data. Various intentions make analysis of those digitally stored data desirable, such as quality control or scientific purposes. The aim of the Intensive Care Data Evaluation project (ICDEV), was to provide a database tool for the analysis of data recorded at various ICUs at the University Clinics of Vienna. SETTINGS: General Hospital of Vienna, with two different PDMSs used: CareVue 9000 (Hewlett Packard, Andover, USA) at two ICUs (one medical ICU and one neonatal ICU) and PICIS Chart+ (PICIS, Paris, France) at one Cardiothoracic ICU. CONCEPT AND METHODS: Clinically oriented analysis of the data collected in a PDMS at an ICU was the beginning of the development. After defining the database structure we established a client-server based database system under Microsoft Windows NI and developed a user friendly data quering application using Microsoft Visual C++ and Visual Basic; RESULTS: ICDEV was successfully installed at three different ICUs, adjustment to the different PDMS configurations were done within a few days. The database structure developed by us enables a powerful query concept representing an 'EXPERT QUESTION COMPILER' which may help to answer almost any clinical questions. Several program modules facilitate queries at the patient, group and unit level. Results from ICDEV-queries are automatically transferred to Microsoft Excel for display (in form of configurable tables and graphs) and further processing. CONCLUSIONS: The ICDEV concept is configurable for adjustment to different intensive care information systems and can be used to support computerized quality control. However, as long as there exists no sufficient artifact recognition or data validation software for automatically recorded patient data, the reliability of these data and their usage for computer assisted quality control remain unclear and should be further studied.

Austria↗
PubMed1995

[VIE-PNN: an expert system for calculating parenteral nutrition of intensive care premature and newborn infants].

Daily renewed composition of parenteral nutrition for premature and full-term newborn infants in intensive care is time consuming and prone to inherent calculation errors. We developed a knowledge based system, VIE-PNN (Vienna Expert System for Calculating Parenteral Nutrition of Neonates) for calculating the proposed composition of parenteral nutrition on the basis of the calculating algorithm used at our neonatal intensive care unit. The system needs manual input on postnatal age, body weight, serum electrolytes (or normal values if not available), amount and content of additional oral feeds, venous access (peripheral or central), total amount of fluid intake, and complications such as sepsis (reduced lipid supply) or cholestasis (reduced amino acid supply). The parenteral nutrition proposal may interactively be modified by the attending physician. There are possibilities for error detection to reduce the probability of typing or calculation errors. The system was developed to run on IBM compatible PCs and has been tested clinically. We describe the problem domain, system structure, clinical evaluation of VIE-PNN and the calculation of a standard parenteral nutrition solution from the data stored in the system's database.

Algorithms↗