Application of a computerized medical decision-making process to the problem of digoxin intoxication.

A computerized medical decision-making system was used to monitor signs and predisposing factors of digoxin intoxication in patients receiving digoxin. This process automatically reviewed the patient's data base nightly for drug interactions, laboratory data and electrocardiographic findings with known association with digoxin intoxication. These decisions were formated into a "digoxin alert report" and sent to line printers in the nursing division to be placed on the individual patients' charts. To assess the effect of these reports on patient management, a randomized double-blind study was undertaken. Patients were assigned to an alert or nonalert group. Alert reports were withheld from charts of patients in the nonalert group. A medical record review was subsequently carried out, wherein the physician's orders were searched to identify actions taken with possible relation to the digoxin alerts. The computer monitored 396 patients over a 3 month period. Of these, 211 (53%) were randomized to the alert group and 185 (47%) to the nonalert group. Seventy-two percent of patients received at least one alert. The most frequently occurring alerts included: hypoxemia, hypokalemia, concurrent use of a beta-adrenergic blocking agent, renal insufficiency and ventricular arrhythmia. Results from the record review demonstrated a 22% increase in physician actions for the alert group. Specifically, patients in the alert group were 2.7 times more likely to have a serum digoxin determination ordered and 2.8 times more likely to have digoxin withheld on the day of a digoxin alert than were patients in the nonalert group.

Evaluation of a computerized arrhythmia alarm system.

A prospective study of a computerized arrhythmia alarm system was carried out in the coronary care unit during 200 patient hours of monitoring. The computer system was designed to activate an alarm on the development of rhythm and conduction disorders including asystole, ventricular tachycardia, atrial tachycardia, sinus tachtcardia, bradycardia, frequent premature ventricular beats, atrial fibrillation and bundle branch block. Study patients were simultaneously monitored by the computer system and a conventional analog heart rate alarm system. All alarms generated by the two systems were evaluated. Of 79 computer alarms, 42 (53 percent) were true positive alarms; during the same period there were 167 analog alarms of which only 13 (8 percent) were true positive alarms. In both systems, false positive alarms were primarily due to patient movement, but they occurred only 25 percent as often with the computer system as with the analog system. These results indicate that computerized arrhythmia monitoring systems offer significant advantages over conventional monitoring techniques.

Older age and elevated blood pressure are risk factors for intracerebral hemorrhage after thrombolysis.

Intracerebral hemorrhage is an important concern after thrombolytic therapy for acute myocardial infarction, but risk factors are controversial. Accordingly, we assessed risk factors in 107 treated patients of whom 4 had intracerebral hemorrhage. Intracerebral hemorrhage occurred at a mean of 25 hours (range 3.5 to 48) after therapy and was fatal in 2 patients. Significant differences were found between patients with and without intracerebral hemorrhage for age (77 +/- 7 vs 62 +/- 11 years, p less than or equal to 0.01), and initial (161 +/- 23 vs 135 +/- 23 mm Hg, p less than or equal to 0.03) and maximal (171 +/- 30 vs 146 +/- 20, p less than or equal to 0.02) systolic blood pressures. Initial and maximal diastolic blood pressures also tended to be higher (101 +/- 25 vs 86 +/- 16, p less than or equal to 0.07; 104 +/- 24 vs 90 +/- 13, p less than or equal to 0.06). Differences did not achieve significance for comparisons of gender, height, weight, site of infarction, time to therapy, specific thrombolytic agent used, concomitant therapy, interventions and partial thromboplastin time. It is concluded that age (greater than or equal to 70 years) and elevated blood pressure (greater than or equal to 150/95 mm Hg) are important risk factors for intracerebral hemorrhage. The overall balance of benefit and risk of thrombolysis should continue to be assessed by large mortality trials.

Evaluation of size and dynamics of the inferior vena cava as an index of right-sided cardiac function.

To define normal criteria of size and dynamics of the inferior vena cava (IVC) and its clinical value in assessing right-sided cardiac function, 2-dimensional (2-D) and M-mode echocardiography (echo) were performed in 175 subjects, who were classified into 3 groups: group 1-80 normal subjects; group IIA--65 patients with documented right-sided cardiac disease, and group IIB--30 patients with cardiac disease but no right-sided abnormality. The IVC was adequately imaged in 175 of 185 subjects (95%). There was good correlation between M-mode and 2-D echo (r = 0.84) and long- and short-axis (r = 0.88) measurements. The IVC diameter during expiration was: group 1-9 to 28 mm (mean 18.2 +/- 4.6); group IIA--15 to 40 mm (mean 23.1 +/- 4.8) and group IIB-8-24 mm (mean 15.6 +/- 3.7). Collapsibility index (inspiratory decrease in diameter) was: group I-37 to 100% (mean 55.8 +/- 15.9); group IIA--0 to 39% (mean 13.5 +/- 10.5); and group IIB--44 to 100% (mean 60.4 +/- 13.1). A and V waves could be measured in 120 of 151 cases (79%). Both A and V waves were less than 125% of its diameter in group I. The A wave was absent in 34 patients; 30 (88%) were in atrial fibrillation. Among 8 patients with tricuspid regurgitation, 5 (63%) had V waves greater than 125%. There was no correlation between diameter or collapsibility index and age, sex, rhythm or body surface area.(ABSTRACT TRUNCATED AT 250 WORDS)

A computer method for visual presentation and programmed evaluation of labor.

Manual graphing of the progress of labor is considered useful but is not often done. The early detection of some deviations requires special graphics aids. Our objective was to develop an easy-to-use computer program for the integrated visual presentation of information characterizing the progress of labor. Through the use of inexpensive personal computers equipped with graphics monitors, the program provides a combined graphics display of timed progressive cervical dilatation, fetal station, and stimulation of uterine activity (oxytocin infusion). For the early detection of abnormalities, phase-specific normal ranges (reference areas) are displayed. In addition, protraction/arrest as well as precipitate labor disorders are highlighted and computer messages are displayed. The program was evaluated through the assessment of 405 labors entered into a local area network of computers. On average, the program identified 1.5 abnormalities per recorded labor (2.0 for labors resulting in vaginal delivery). The graphic presentation of the labor curve, produced within 3 seconds, displayed 27% more information than the tabular format on the same screen area and provided a single-screen display of the labor curve even for patients with excessive data. The computer-generated display of labor curves facilitates visual presentation and interpretation of labor progress and can also help to translate quality assurance criteria into clinical practice.

Building a comprehensive clinical information system from components. The approach at Intermountain Health Care.

OBJECTIVES: To discuss the advantages and disadvantages of an interfaced approach to clinical information systems architecture. METHODS: After many years of internally building almost all components of a hospital clinical information system (HELP) at Intermountain Health Care, we changed our architectural approach as we chose to encompass ambulatory as well as acute care. We now seek to interface applications from a variety of sources (including some that we build ourselves) to a clinical data repository that contains a longitudinal electronic patient record. RESULTS: We have a total of 820 instances of interfaces to 51 different applications. We process nearly 2 million transactions per day via our interface engine and feel that the reliability of the approach is acceptable. Interface costs constitute about four percent of our total information systems budget. The clinical database currently contains records for 1.45 m patients and the response time for a query is 0.19 sec. DISCUSSION: Based upon our experience with both integrated (monolithic) and interfaced approaches, we conclude that for those with the expertise and resources to do so, the interfaced approach offers an attractive alternative to systems provided by a single vendor. We expect the advantages of this approach to increase as the costs of interfaces are reduced in the future as standards for vocabulary and messaging become increasingly mature and functional.

The HELP hospital information system: update 1998.

The HELP hospital information system has been operational at LDS Hospital since 1967. The system initially supported a heart catheterization laboratory and a post open heart Intensive Care Unit. Since the initial installation the system has been expanded to become an integrated hospital information system providing services with sophisticated clinical decision-support capabilities to a wide variety of clinical areas such as laboratory, nurse charting, radiology, pharmacy, etc. The HELP system is currently operational in multiple hospitals of LDS Hospital's parent health care enterprise--Intermountain Health Care (IHC). The HELP system has also been integrated into the daily operations of several other hospitals in addition to those at IHC. Evaluations of the system have shown: (1) it to be widely accepted by clinical staff; (2) computerized clinical decision-support is feasible; (3) the system provides improvements in patient care; and (4) the system has aided in providing more cost-effective patient care. Plans for making the transition from the 'function rich' HELP system to more modern hardware and software platforms are also discussed.

The use of medical logic modules at LDS hospital.

The development of medical knowledge bases for use in a clinical information system (HELP) has been an ongoing goal at LDS Hospital in Salt Lake City, Utah, for the past 25 years. In building our medical knowledge base we felt the need to implement a decision support syntax which could capture the logic of our experts in a way that was not only executable, but also easily read and shared by others. During these 25 years we defined several simple syntaxes to express this medical logic. Our current approach is to cooperate with international standards groups (ASTM) and use the Arden Syntax for medical logic modules. We are working with the 3M Corporation in the joint development of an Arden Compiler for HELP. We plan to use the Arden Syntax initially to support our alert/reminder system and computerized management protocols.

ASTM E31.15 on health knowledge representation: the Arden Syntax.

ASTM subcommittee E31.15 on Health Knowledge Representation was formed to promote standards for defining and sharing health knowledge bases. Its first standard, the Ardan Syntax, is focused on knowledge bases that can be represented as a set of independent modules called Medical Logic Modules (MLMs). The standard is in clinical use and has generated significant interest in industry and academics. The Extensions task group plans to extend the syntax where appropriate, to expand to other types of knowledge bases. The Validation/Verification task group is approaching the enormous problem of evaluating knowledge bases and the process of sharing them.

Development of decision support systems.

Use of hospital information systems (HIS) are no longer limited to administrative functions. The addition to these systems of decision support capability is now a necessity. Development of the decision support modules requires a different software architecture than that employed by most HIS systems today. This paper describes the generic uses of decision support throughout the many hospital applications. Several levels of decision support are outlined with examples to illustrate the many areas where decision support is useful. At LDS Hospital in Salt Lake City, Utah we have developed an HIS using a new software architecture which supports the creation of decision support applications. This system uses a frame structure to represent knowledge. Examples of the frames and their syntax is presented. Using the frame tools which are provided, an application developer can easily develop and test decision support modules which interact directly with the clinical user and the patient database.

Computerized nurse charting.

Computerized nurse charting programs have been used at LDS Hospital for over two years. These programs allow the nurse to create nurse care plans for the management of the patient, and chart on the computer actions and information which support the documentation of the management of the patient according to the care plan created for the patient. Computer terminals have been placed at the patient's bedside to facilitate the use of these programs. This paper describes the programs available at LDS Hospital and several evaluation studies which have been performed to measure the efficacy of the programs. The evaluation studies indicated an increase in the level of documentation completeness and accuracy by the nurse but at some minor expense to time available to the nurse for patient care. Evaluation of the need for bedside terminals versus centrally located terminals showed an overwhelming desire by the nurse in favor of the bedside terminal. It was also found that data was entered more timely with less waiting when bedside terminals were available. Physician acceptance of the nurse charting system was found to be favorable.

The Arden syntax for medical logic modules.

The Arden Syntax for sharing medical knowledge bases is described. Its current focus is on knowledge that is represented as a set of independent modules that can provide therapeutic suggestions, alerts, diagnosis scores, etc. The syntax is based largely upon HELP and the Regenstrief Medical Record System. Each module, called a Medical Logic Module or MLM, is made of slots grouped into maintenance, library, and knowledge categories. The syntax has provisions for querying a clinical database and representing time. Several clinical information systems were analyzed and appear to be compatible with the syntax. The syntax has been tested for syntactic ambiguities using the tools lex and yacc. Seventeen institutions are currently in the process of adopting the Arden Syntax for their decision-support systems. A subcommittee of ASTM has been formed to develop standards for sharing medical knowledge bases. The Arden Syntax has been published by ASTM as a initial standard for sharing medical knowledge.

Sharing MLM's: an experiment between Columbia-Presbyterian and LDS Hospital.

The use of Arden syntax for development of shareable medical logic modules (MLM's) has developed as an ASTM standard. To test the feasibility of sharing MLM's between institutions a study was conducted between Columbia-Presbyterian Medical Center and LDS Hospital. In this study seven MLM's clinically executing at Columbia-Presbyterian were used to test the sharing potential of the Arden syntax. The study was limited to measuring the modifications necessary to make executable at LDS Hospital the shared MLM's. Because of the site specific nature of the data variables, multiple modifications were required. Three classes of modifications were necessary. The simplest involved only data variable mappings. The other classes required either minor modifications to the logic or relatively major modifications. Over 50% of the modifications were in the minor or major classes. While the sharing of decision logic was possible and facilitated by the use of the MLM's at the two sites, the absence of standard medical vocabularies limited the utility of the MLM as a mechanism for directly sharing medical knowledge.

Development of a computerized laboratory alerting system.

Using the capabilities of the HELP medical information system at LDS Hospital, a Computerized Laboratory Alerting System (CLAS) was developed. CLAS monitors and alerts for the presence of life-threatening conditions in hospitalized patients which are indicated by laboratory test results. Alerts are posted on computer terminals on the hospital's nursing divisions, where they are reviewed and acknowledged by hospital staff so that appropriate treatment can be rapidly instituted. CLAS was evaluated to determine its effectiveness in relaying alerts to the clinical staff, and improvements were made to develop an effective user interface. Initial average alert response times on nursing divisions ranged from 5.1 to 58.2 hr. The average alert response time dropped to 3.6 hr when alert review was integrated with laboratory result review, and to 0.1 hr after installation of a flashing light to notify hospital staff of the presence of new alerts.

Pick from thousands: a collaborative processing model for coded data entry.

Methods for optimizing coded data entry in clinical systems are a frequent topic of system design. We have developed a new mechanism for this type of data entry that we call "Pick From Thousands" (PFT). It combines several known methods, including menu selection, keyword entry, and initial character matching, but adds a new string matching algorithm. The PFT method is more selective than initial character matching for a given number of keystrokes if entries in the coded list have more than one word. Collaborative processing between a PC workstation and the central HELP system computer is used to optimize ease of maintenance and increase the flexibility and performance of the system.

Integrating Radiology and Hospital Information Systems: the advantage of shared data.

Information management is central to modern patient care. Computerization of information management has resulted in both departmental systems which serve information needs in locations such as the Radiology Department and in hospital-wide information systems which seek to integrate management of clinical data from many departments. For each of these systems to achieve the goal of maximizing both the effectiveness of health care workers and the quality of patient care, they need to share the data that they capture. Below we discuss a variety of applications, both currently available and in the realm of research protocols, that depend on a high level of communication between Radiology Information Systems and Hospital Information Systems. These examples suggest the benefits of integrating the medically relevant data collected by all of the computer-based information systems in the hospital setting.

The potential for medical informatics in the Eastern Mediterranean Region.

This article assesses the potential value of an integrated medical/ hospital information system (IMIS) for the members of the Eastern Mediterranean Region of the World Health Organization, and describes the preliminary results of a feasibility study questionnaire done in December 1989 at Salmaniya Medical Center (SMC) in the state of Bahrain.