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Biomedical subjects

W Friesdorf

Publications and source records attributed to W Friesdorf.

At least 19 recordsLinked to original sources
PubMed2000

[Technology in residences for support of a self-determined life style for the elderly. The research project "sentha" and initial results of a social science project].

Sentha is an interdisciplinary research team involving the Technical University Berlin, the Berlin Institute for Social Research GmbH (BIS), the German Centre for Research on Ageing at the University of Heidelberg (DZFA), the School of Fine Arts Berlin (HdK), and the Brandenburg Technical University Cottbus (BTU). Building on empirical investigations of the role of everyday household products in the everyday life of older people, product-independent design and assessment guidelines and new products are being developed in an intensive interdisciplinary process in order to better meet the needs of older people and to enhance their autonomous living. The following paper describes the contributions from the participating disciplines and presents initial results of the social sciences subproject, describing the problems arising in living independently in old age and detecting the demands on new technological solutions. Data are based on a representative survey conducted in 1999 and including a stratified sample of 1417 men and women aged 55 and older.

Activities of Daily Living↗
PubMed1997

Events which will influence intensive care units in future. A Delphi study.

OBJECTIVE: To find out and analyse the events which are expected to influence the future of Intensive Care Units (ICU). DESIGN: Three round Delphi study. SETTING: In a first preparation round 9 events were defined. In the two rating rounds an international panel of 60 experts heads of ICUs) estimated the time when the events may come true and whether they are desired or not. RESULTS: Computer tools are desired and expected in the near future (before the year 2000) for audit, quality assurance, record keeping and telecommunication; complex closed loops and nursing robots will not be used in clinical routine before 2005, they are not desired.

Delphi Technique↗
PubMed1995

[Quality control in anesthesiology. Results of a prospective study following the recommendations of the German Society of Anesthesiology and Intensive Care].

The German Social Law has required quality assurance (QA) procedures since 1989. The measures must be suitable to allow "comparing investigations". In 1992 the German Society of Anaesthesiology and Intensive Care Medicine published recommendations for QA in anaesthesia: most problems during an anaesthetic should be documented in a standardised manner, and thus, a list of 63 pitfalls, events, and complications (PECs) and five degrees of severity were defined. The goal of this study was to determine the frequency of PECs in anaesthesia and to correlate PECs with procedures and preoperative health status. MATERIALS AND METHODS. Demographic data, preoperative findings, type and duration of anaesthesia and operation, and kind and severity of PECs were integrated in an automatically readable anaesthetic data record (ARADR). During 12 months all anaesthetics in our department were documented by the ARADR; the records were read by a reading device and the data stored in a modern SQL database (Informix). Degrees of severity: I. PEC leads to reaction of anaesthetist, no impact for recovery room (RR); II. impact for RR, no impact on transfer to ward; III. significant prolongation of RR stay or additional monitoring on ward; IV. PEC leads to intensive care unit admission; V. disabling damage or death. RESULTS. In all, 18350 anaesthetics were recorded (9055 male, 9295 female); the median age was 41 years (1 day-99 years). In 4251 (23.2%) anaesthetics 5927 PECs occurred, 3412 of them involving the cardiovascular and 949 the respiratory system, the latter with a tendency to higher degrees of severity. PECs caused by technical equipment (126) or lesions caused by anaesthesists (342) had no fatal outcomes and were less severe. Patients in ASA class I had 12.3% anaesthetics with PECs, ASA II 23.3%, ASA III 33.8%, ASA IV 34.9%, and ASA V 58.5%. PECs of degrees IV and V showed a higher incidence in the higher ASA classes. There was no fatal PEC in an ASA class I patient and only one (of 13615) in an elective procedure. Emergency cases had more frequent and more severe PECs: 16 of 19 PECs of degree V were in ASA class IV and V patients and 15 in emergency situations, all of them in surgical patients. Patients with cardiovascular disease had a more frequent incidence of PECs by a factor of 1.39 to 5.93 than those without such disease. CONCLUSIONS. Standardised incident reporting by defined PECs seems a good way to describe problems in anaesthesia. The types of PECs in our study had a similar distribution to those in other investigations, but there was a tendency to less frequent fatal PECs in ASA classes I to IV and more frequent ones in ASA class V. We expect better comparability when multicenter studies are done using identical methods in the next few years. Perhaps different patients collectives with special risks will be detected; efforts in quality improvement could focus on these patients.

Adolescent↗
PubMed1994

Postoperative information transfer: a study comparing two university hospitals.

Several studies have addressed the processing of anesthetic information by paper anesthetic data records or by the electronic storage and transfer of anesthetic data. Our purpose was to analyze the oral transfer of information in the postoperative period. We investigated 198 post-operative transfer situations with 120 patients in a U.S. hospital to compare the results with those of a former study in a German hospital. A great number of parameters were used in both hospitals, but there were remarkable differences. In the U.S. hospital numeric values of current vital functions, including oxygen saturation, were more common during information transfer, whereas in the German hospital the emphasis was on case history and chronic health status. The data from the U.S. hospital and those of the German hospital show that in spite of complete anesthetic records, a short (112.3 +/- 104 sec in the U.S. and 94.1 +/- 83.6 sec in Germany) oral information transfer is inevitable when the patient is transferred from the OR to the recovery room, and from the recovery room to the ward (122.7 +/- 61.4 sec in the U.S. and and 88.0 +/- 73.0 in Germany). Software developers of patient data management systems could learn from this study that in some situations it is necessary and possible to create a small set of data which will reflect the patients status quite well.

Anesthesiology↗
PubMed1994

Decision making in high dependency environments--can we learn from modern industrial management models?

Increasing complexity and increased restraints affect the task of patient management in High Dependency Environments, which has become intricate and difficult. Medical knowledge alone is not enough any longer for proper patient care. Management ability and facilities are required. Current medical knowledge should be expanded by management methods and techniques. By looking at management models in the industry, we found striking similarities between the industrial management situation and clinical patient management. Both systems share complexity in structure, complexity in interaction and evolutionary character. Clinical patient management can be compared with a navigation process. The patient is steered by a control system, and course information is given by control dimensions. Clinical patient management becomes a succession of steering activities influenced by the surrounding systems. This system can be structured in three interacting layers: an operational level, in which information is collected and actions executed; a strategic level in which strategies based on goal-oriented mental anticipation of a probabilistic system are formulated; and a normative level at which principles and norms are defined. It is possible then, to define the tools which have to be developed and implemented to improve clinical management capabilities. At the operational level these tools are addressed to improve clinical decision making by providing information in an ergonomical way. They include artifact elimination, data reduction, increase in meaningful information and unwanted data filtering. At the strategic level, tools to check the feasibility of the applied strategies have to be developed, such as: ideal patient course plots and increased training in strategic thinking.(ABSTRACT TRUNCATED AT 250 WORDS)

Decision Making↗
PubMed1994

Lessons learned while building an integrated ICU workstation.

The project LUCY (Linked Ulm Care sYstem) is described. The goal of this project was to build a research workstation in an Intensive Care Unit which enables evaluation of data/information processing and presentation concepts. Also evaluation of new devices and functions considering not only one device but the workplace as an entirety was an aim of the project. We describe the complete process of building from the stage of design until its testing in clinical routine. LUCY includes a patient monitor, a ventilator, 4 infusion pumps and 8 syringe pumps. All devices are connected to a preprocessing computer via serial interfaces. A high performance graphic workstation is used for central display of physiological and therapeutic variables. A versatile user interface provides touch screen, keyboard and mouse interaction. For fluid administration a bar code based control and documentation facility was included. While our scheduled development efforts were below 4 man-years, the overall man-power needed until the first routine test amounts to 8 man-years. Costs of devices and software sum up to 160,000 US$. First experiences in clinical routine show good general acceptance of the workplace concept. Analysing the recorded data we found 90% of the items to be redundant: individual filtering algorithms are necessary for each of nowaday's devices. The flexibility of the system concerning the implementation of new features is far from our expectations. Technical maintenance of the system during clinical operation requires continuous effort which we cannot afford in the current situation.

Algorithms↗
PubMed1994

Information transfer in high dependency environments: an ergonomic analysis.

We have studied the information flow in HDE (with special focus on the information transfer process) using data provided by a group of experienced health care professionals. A model of the information flow in HDE was built up. It postulates the existence of quanta of information (due to the artificial fragmentation of the information flow produced by the clinical working processes: organization in shifts, demand of simultaneous activities from different staff members, etc.). This fragmentation is described by using the so-called Clinical Information Process Units (CIPUs), which correspond to patient care activities going on in parallely and serially linked blocks, performed by the staff in the specific environments. Due to a transfer in responsibility over the patient the CIPUs are linked by information transfer events which are described using transfer modules (TraMs). We exemplified 32 CIPUs related to the clinical environments (PreOp, Surgery, Recovery Intensive Care, Ward, Diagnostics, Outpatient) and the health care professional groups (Anesthesiologist/Intensivist, Surgeon, Nurse, Physician, Diagnostic Physician, Physical Therapist). A matrix was established providing the transfer situations among the CIPUs enabling a systematic classification of the TraMs. The contents of the TraMs are built up of information link elements, which are assembled according to the specific settings of the transfer situation given by the emitter, receiver and purpose. In summary we modelled the process of information transfer in HDE through CIPUs, TraMs and information links in a way, which may be useful to design information technology applications or to reorganize the information management in HDE.

Anesthesiology↗
PubMed1994

Data quality of bedside monitoring in an intensive care unit.

Computerized record keeping promises complete, accurate and legible documentation. Reliable measurements are a prerequisite to fulfill these expectations. We analyzed the physiological variables provided by bedside monitoring devices in 657 bedside visits performed by an experienced Intensive Care nurse during 75 Intensive Care rounds. We registered which variables were displayed. If a variable was displayed, we assessed whether it could be used for documentation or should be rejected. If a value was rejected the reason was registered as: the measurement was not intended (superfluous display), the current clinical situation did not allow proper measurement, or other reasons. Basic variables (vital signs and respiration related variables) were displayed in more then 90%, specific variables (e.g. intracranial pressure) were displayed in less than 50% of the situations. Displayed variables were superfluous on an average of 11% because measurement was not intended. Variables like heart rate, temperature, airway pressure, minute volume of ventilation, arrhythmia, pulmonary arterial pressure, non-invasive blood pressure, and intracranial pressure provide high quality measured values (acceptance of more than 90%). Invasive arterial pressure, central venous pressure, respiration rate and oxygen saturation (via pulse oximetry) provided lower quality values with a rejection rate higher than 10%. Inappropriate sensor technology to match the clinical environment seems to be the root cause. In future the request for automatic documentation will increase. In order to avoid additional staff workload and to ensure reliable documentation, sensor technology especially related to respiration rate, blood pressure measurements, and pulse oximetry should be improved.

Data Collection↗
PubMed1994

System ergonomic analysis of the morning ward round in an intensive care unit.

OBJECTIVE: Our objective was to find out what is discussed during a bedside morning ward round (MWR), whether there are any weak points, and if a standard work process structure can be recommended. METHODS: An intensive care unit (ICU) consultant recorded in a predefined form the topics that were discussed in 225 bedside discussions. RESULTS: The median length of discussions was 5 min. In more than 60% of the discussions, items were considered related to the respiratory, neurological, and cardiovascular systems, as well as to surgical and nursing problems. Specific variables relating to organ system conditions were seldom used (e.g., inspired O2 concentration, 35%; temperature, 28%; ventilation mode, 25%). We recorded two interruptions per MWR; only 17% of them were related to urgent decisions. Information that could not be found in the patient's file usually concerned microbiology findings (10%) or surgical procedures (6%). CONCLUSIONS: We recommend the following structure: (1) Addressing the patient by saying "hello"; (2) presentation of information related to case history, acute status (findings and strategy) (including the function of the main organ systems), infection status, and nursing problems; (3) patient-related discussion; and (4) discussion of general treatment rules, triggered by individual patient condition.

Communication↗
PubMed1993

Ergonomics applied to anaesthesia record keeping.

For almost 100 years, the anaesthesia record has been the sole information tool trying to fulfill an ample catalogue of functions related to the anaesthesia information processes. Automated anaesthetic record systems have evolved around data being available online, as an imitation of the handwritten record. None has developed an information tool capable of an efficient utilization of the wide range of resources provided by modern technology to fulfill the information requirements of the anaesthetic environment. We used a system ergonomic analysis trying to find the best solutions. As a result of it we drafted an Anaesthesia Information Concept (AIC) in which the complexity of data & information (D&I) processes is broken down to modules called Clinical Information Process Units (CIPUs). A CIPU is mainly defined by the responsibility of a staff member and focuses on the basic system patient, staff and machine (all devices). The internal functions of a CIPU are treatment control and medicolegal documentation. The external functions are fulfilled by transferring required sets of D&I for subsequent treatment control (next CIPU), audit, quality control, cost calculation, etc. Using such an approach, an Anaesthesia Information Concept (AIC) can be realized by a wide range of modular and hybrid systems (combination of different tools such as paper records, computers, etc), as opposed to universal and single automated documentation systems, which up to now have failed to fulfill the information demands of the anaesthetic environment.

Anesthesia Department, Hospital↗
PubMed1993

[Preoperative risk factors and intraoperative and postoperative risk management in 11,890 anesthesias. Initial results of a prospective study].

OBJECTIVE: The relation of the frequency and severity of pitfalls, events and complications (PECs) was analysed in respect of preoperative risk factors. The epidemiological data were gathered as a contribution to a current project of the German Society for Anaesthesiology and Intensive Care. METHOD: Preoperative data (age, sex, preexisting diseases, pathological findings, grade of urgency and ASA-class) were integrated in a paper record, as well as the perioperative interventions and directly postoperative events, type of anaesthesia, and kind of operation. The automatically readable paper records were routinely in use for every patient. After control and correction the data were stored in a modern data base. MAIN RESULTS: From October 1, 91 to May 20, 92 11,890 anaesthesias were recorded. 2,959 of them with a total of 4,184 PECs. 2,397 PECs were cardiovascular, 875 respiratory. PECs of grade I (no impact on treatment in the recovery room [RR]) occurred in 14% of patients, grade II (impact on treatment in RR, but no impact on discharge to ward) 7.2%, grade III (prolonged stay in RR or special monitoring in the ward) 2.88%; grade IV (PEC leads to transfer to the ICU) 0.63%, and grade V (PEC leads to disabling damage or death) 0.13%. 13 of 15 patients suffering from PECs grade V were of ASA class 4 or 5. PECs had a certain relation to the ASA-classification of anaesthetic risk. But this relation is quite different in several surgical disciplines. CONCLUSIONS: Preoperatively known risk factors of the patient and the measures taken by specialists of various disciplines contribute to the incidence of PECs. Available data could be processed multicentrally and in standard form for producing prognostic data for risk prediction. Since PECs of grade II or higher are cost- relevant, requiring an interdisciplinary approach, it appears meaningful to base costing on such an interdisciplinary approach in accordance with the requirements of diagnosis and treatment.

Adolescent↗
PubMed1992

Patient-related data management.

Patient-related data management (PDM) has become an increasingly important and time-consuming task in intensive care medicine. Currently, all data are usually collected in a poorly structured patient chart consisting of forms and pictures, with about 400 manual entries a day. To handle this amount of data, we have designed a three-level patient system: level 1, summarizing the whole patient; level 2, summarizing one organ system or one isolated problem; and level 3, variables describing morphology and function of organ systems. PDM must be adapted to different clinical situations. We observed three different scenarios: (1) Exploratory PDM, where the clinician learns about the patient and builds up an individual patient model in his or her mind. (2) Operational PDM, where in routine care clinicians are part of a feedback control system, in which they use the patient-related model. (3) Summary PDM, where a clinician summarizes all the information gathered during a period when he or she was responsible for the patient. Computing tools based on clinical thinking and adapted to different situations can ensure accurate, clear, and concise patient care communication among the members of the intensive care staff.

Computer Systems↗
PubMed1992

Can a clinician predict the technical equipment a patient will need during intensive care unit treatment? An approach to standardize and redesign the intensive care unit workstation.

The technical equipment of today's intensive care unit (ICU) workstation has been characterized by a gradual, incremental accumulation of individual devices, whose presence is dictated by patient needs. These devices usually present differently designed controls, operate under different alarm philosophies, and cannot communicate with each other. By contrast, ICU workstations could be equipped permanently and in a standardized manner with electronically linked modules if the attending physicians could reliably predict, at the time of admission, the patient's equipment needs. Over a period of 3 1/2 months, the doctors working in our 20-bed surgical ICU made 1,000 predictions concerning outcome, equipment need, duration of artificial ventilation, and duration of hospitalization for 300 recently admitted patients. The interviews were made within the first 24 hours after admission. The doctors being interviewed were usually (i.e., in over 90% of cases) unfamiliar with the patient. Information concerning the patient's general state of health, special pre-ICU events, and complications was offered to the interviewed clinician because this information represents standard admission data. It was found that the equipment need (represented by two different setups, "high tech" and "low tech") could be predicted most reliably (96.4% correct predictions) compared with a prediction on outcome of ICU treatment (94.5%), on duration of artificial ventilation (75.4%), and on duration of stay (43.4%). There was no significant (p greater than 0.05) difference in the reliability of predictions between residents and consultants. Factors influencing the postoperative equipment need varied with surgical specialty.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia Department, Hospital↗
PubMed1992

[Experimental studies on the recovery of anesthetic gases].

The volatile anesthetic agents halothane, enflurane, and isoflurane are chlorofluorocarbons (CFC) and contribute to ozone depletion. Although the contribution is small, its importance is rising, as technical CFCs will be phased out according to the Montreal protocol (1987) and the London conference (1990) by the year 2000. Alternative procedures and CFC-free volatile agents such as des- and sevoflurane do not contribute to depletion of the ozone layer, but will not replace standard methods using volatile anesthetic agents in the near future. METHODS. In an experimental setup, we filtered anesthetic waste gases from scavenging systems of rebreathing circles by activated carbon filters. The filtered substances were desorbed by a heat chamber and condensed in a cold trap. RESULTS. By this method, it was possible to retrieve 50%-60% of the applied gases. Gas chromatographic analysis showed halothane containing traces of pollutants and isoflurane and enflurane as pure substances. DISCUSSION. The retrieval of anesthetic waste gases is easy; no sophisticated technical equipment is necessary. Purity of substances could make recycling possible and offer a method to avoid environmental pollution by volatile anesthetics.

Anesthetics↗
PubMed1991

[The "preoxygenation" special function in mechanical ventilators. Medically necessary and an ergonomic plus?].

Hypoxia-related cardiovascular complications and unnecessary monitor and ventilator alarms are well-known problems during tracheobronchial suctioning. Preoxygenation together with temporary muting of acoustic alarms for tracheobronchial suctioning are provided by a single operational control of the ventilator "Evita", software release 9 (Drägerwerk AG). This integrated function was evaluated in medical and ergonomic respects. METHODS. Thirty tracheobronchial suctioning procedures each, with or without preoxygenation, were evaluated. The subjects were patients in our anesthesiological intensive care unit who were under continuous positive-pressure ventilation with FIO2 between 0.25 and 0.6. They ranged in age from 18 months to 72 years. Each patient served as her/his own control after about 1-h delays. Depending on the preference of the nurse, the procedures were either both on-ventilator (via the catheter port) or both off-ventilator suctionings. Arterial samples for blood gas analyses as well as arterial oxygen saturation (SaO2) determinations were taken before preoxygenation, at the moment of disconnection or opening of the catheter port, at reconnection or closure of the port, and 5 min later. Moreover, the number of changes in position of the performing nurse, the number of acoustic ventilator alarms, and the duration of the procedure were recorded. Finally, assessments of the integrated ventilator feature by the 28 participating nurses were collected both as a score from 1 ("most useful and innovative") to 5 ("completely superfluous and distracting") and as detailed statements. RESULTS. Arterial blood gas results and SaO2 courses differentiated as to procedures with or without preoxygenation as well as on-ventilator and off-ventilator suctioning are shown in Table 1 (values are mean +/- standard deviation). Without preoxygenation, most patients did not exhibit threatening drops in SaO2 (values fell from 98.2%) to 97.0% on the average). Nevertheless, preoxygenation provided an additional safety margin (100% saturation throughout the procedure in all patients). Under certain conditions, e.g., low functional residual capacity as in small children or patients with adult respiratory distress syndrome (in 1 of these cases we observed a SaO2 drop to 87%), it is mandatory. Although occurring far less frequently, unnecessary acoustic alarms were not completely excluded by the integrated function because the ventilator would not recognize the insertion of the suction catheter via the catheter port as the expected disconnection. Thus, coughing was able to trigger the "high airway pressure" alarm. As expressed by an average score of 2.8, approval of the integrated ventilator function prevailed among the involved nursing staff.

Adolescent↗