Minimally invasive treatment of idiopathic chylothorax in dogs by thoracoscopic thoracic duct ligation and subphrenic pericardiectomy: 6 cases (2007-2010).

OBJECTIVE: To describe a technique and evaluate the outcome of thoracoscopic thoracic duct ligation (TDL) and subphrenic pericardiectomy (SPP) for treatment of idiopathic chylothorax (IC) in dogs. DESIGN: Retrospective case series. ANIMALS: 6 client-owned dogs. PROCEDURES: Medical records of dogs with a diagnosis of IC that were subsequently treated by thoracoscopic TDL and SPP and that had not undergone previous surgical treatment were reviewed. Thoracoscopic TDL was performed via a 3-portal technique with the patient in lateral recumbency. Subphrenic pericardiectomy was subsequently performed via a 3-portal technique with the patient in dorsal recumbency. If visualization during SPP was suboptimal, 1-lung ventilation was used to ensure that pericardial resection was close to the phrenic nerves bilaterally but without risk of iatrogenic nerve injury. RESULTS: All TDL and SPP procedures were completed successfully in a median surgical time of 177 minutes (range, 135 to 210 minutes). All 6 dogs showed resolution of clinical signs of chylothorax with no recurrence during a median follow-up period of 39 months (range, 19 to 60 months). Final postoperative thoracic radiographic evaluation was performed at a median of 14.5 months (range, 7 to 25 months). Complete resolution of pleural effusion occurred in all but 1 dog. In 1 dog, a small volume of pleural effusion was persistent at a 7-month postoperative radiographic follow-up but was not associated with clinical signs and did not require thoracocentesis at any time during the dog's 25-month follow-up period. CONCLUSIONS AND CLINICAL RELEVANCE: From this limited series of patients, results suggested that a minimally invasive TDL-SPP combined surgical technique for management of IC in dogs may be associated with a similarly successful outcome as has been reported for open surgical TDL-SPP.

Use of a self-expanding metallic stent for the treatment of a urethral stricture in a young cat.

A 4-month-old intact male domestic shorthair cat was evaluated for urinary outflow obstruction after several weeks of medical management for traumatic urethral rupture. Positive-contrast retrograde urethrography and anterograde cystoscopy performed 4 weeks after the initial urethral injury confirmed a stricture approximately 1cm distal to the bladder trigone at the site of the initial urethral tear. A self-expanding metallic urethral stent (SEMS) was placed under fluoroscopic guidance to relieve the urethral stricture and re-establish luminal patency. After stent placement, the cat was able to void urine normally with minimal urinary incontinence noted. This resolved several months post-stent placement. No known clinical complications persisted other than mild intermittent hematuria.

Change management of shared and local versions of health-care terminologies.

Local sites that adopt a shared health-care terminology for computer-based systems have local needs that prompt the local-terminology maintainers to make changes to the local version of the shared terminology. If the local site is motivated to conform to the shared terminology, then the burden lies with the local site to manage its own changes and to incorporate the changes of the shared version at periodic intervals. We call this process synchronization. We survey current approaches that address problems of sharing and local modification, and we present the CONCORDIA model, which supports carefully controlled divergence of a local version from a shared terminology. CONCORDIA provides the underlying design and methodology for the implementation of a synchronization-support tool.

Representation of change in controlled medical terminologies.

Computer-based systems that support health care require large controlled terminologies to manage names and meanings of data elements. These terminologies are not static, because change in health care is inevitable. To share data and applications in health care, we need standards not only for terminologies and concept representation, but also for representing change. To develop a principled approach to managing change, we analyze the requirements of controlled medical terminologies and consider features that frame knowledge-representation systems have to offer. Based on our analysis, we present a concept model, a set of change operations, and a change-documentation model that may be appropriate for controlled terminologies in health care. We are currently implementing our modeling approach within a computational architecture.

Representing thoughts, words, and things in the UMLS.

The authors describe a framework, based on the Ogden-Richards semiotic triangle, for understanding the relationship between the Unified Medical Language System (UMLS) and the source terminologies from which the UMLS derives its content. They pay particular attention to UMLS's Concept Unique Identifier (CUI) and the sense of "meaning" it represents as contrasted with the sense of "meaning" represented by the source terminologies. The CUI takes on emergent meaning through linkage to terms in different terminology systems. In some cases, a CUI's emergent meaning can differ significantly from the original sources' intended meanings of terms linked by that CUI. Identification of these different senses of meaning within the UMLS is consistent with historical themes of semantic interpretation of language. Examination of the UMLS within such a historical framework makes it possible to better understand the strengths and limitations of the UMLS approach for integrating disparate terminologic systems and to provide a model, or theoretic foundation, for evaluating the UMLS as a Possible World--that is, as a mathematical formalism that represents propositions about some perspective or interpretation of the physical world.

The guideline interchange format: a model for representing guidelines.

OBJECTIVE: To allow exchange of clinical practice guidelines among institutions and computer-based applications. DESIGN: The GuideLine Interchange Format (GLIF) specification consists of GLIF model and the GLIF syntax. The GLIF model is an object-oriented representation that consists of a set of classes for guideline entities, attributes for those classes, and data types for the attribute values. The GLIF syntax specifies the format of the test file that contains the encoding. METHODS: Researchers from the InterMed Collaboratory at Columbia University, Harvard University (Brigham and Women's Hospital and Massachusetts General Hospital), and Stanford University analyzed four existing guideline systems to derive a set of requirements for guideline representation. The GLIF specification is a consensus representation developed through a brainstorming process. Four clinical guidelines were encoded in GLIF to assess its expressivity and to study the variability that occurs when two people from different sites encode the same guideline. RESULTS: The encoders reported that GLIF was adequately expressive. A comparison of the encodings revealed substantial variability. CONCLUSION: GLIF was sufficient to model the guidelines for the four conditions that were examined. GLIF needs improvement in standard representation of medical concepts, criterion logic, temporal information, and uncertainty.

The Unified Medical Language System: toward a collaborative approach for solving terminologic problems.

The approach taken by the Unified Medical Language System (UMLS), in which disparate terminology systems are integrated, has allowed construction of an electronic thesaurus (the Metathesaurus) that avoids imposing any restrictions upon the content, structure, or semantics of the source terminologies. As such, the UMLS has served as a unifying paradigm by providing appropriate links among equivalent entities that are used in different contexts or for different purposes. It accordingly provides a vehicle through which possibly orthogonal semantic models can co-exist within a single framework. This framework provides a model for the collaborative evolution of biomedical terminology and allows a synergistic relationship between the UMLS and its source terminology systems.

Synchronization of diverging versions of a controlled medical terminology.

To share clinical data and to build interoperable computer systems that permit data entry, data retrieval, and data analysis, users and systems at multiple sites need a shared clinical terminology. However, local sites that adopt a shared terminology have local needs that prompt local-terminology maintainers to make changes to the local version. Meanwhile, maintainers of the shared terminology make changes to the shared version, and the two terminologies diverge. I propose a formal model for managing change, with additional features included for the local site. If terminology maintainers follow such a model, the local-terminology maintainer can synchronize the local version with the shared version at periodic intervals. I am implementing a prototype, which I will use to assess the model and to study the synchronization process.

Development of a change model for a controlled medical vocabulary.

Managing change in controlled medical vocabularies is labor intensive and costly, but change is inevitable if vocabularies are to be kept up to date. The changes that are appropriate for a controlled medical vocabulary depend on the data stored for that vocabulary, and those data in turn depend on the needs of users. The set of change operations is the change model; the data stored about concepts comprise the concept model. Because the change model depends directly on the concept model, a discussion of the former necessitates a discussion of the latter. In this paper, we first present a set of tasks that we believe controlled medical vocabularies should handle. Next, we describe our concept model for a controlled medical vocabulary. Then, we review the literature on changes in existing vocabulary systems. Finally, we present our change model. We call our system, which incorporates the concept model and change model, the General Online Dictionary of Medicine (GOLDMINE).

The content coverage of clinical classifications. For The Computer-Based Patient Record Institute's Work Group on Codes & Structures.

BACKGROUND AND OBJECTIVE: Patient conditions and events are the core of patient record content. Computer-based records will require standard vocabularies to represent these data consistently, thereby facilitating clinical decision support, research, and efficient care delivery. To address whether existing major coding systems can serve this function, the authors evaluated major clinical classifications for their content coverage. METHODS: Clinical text from four medical centers was sampled from inpatient and outpatient settings. The resultant corpus of 14,247 words was parsed into 3,061 distinct concepts. These concepts were grouped into Diagnoses, Modifiers, Findings, Treatments and Procedures, and Other. Each concept was coded into ICD-9-CM, ICD-10, CPT, SNOMED III, Read V2, UMLS 1.3, and NANDA; a secondary reviewer ensured consistency. While coding, the information was scored: 0 = no match, 1 = fair match, 2 = complete match. RESULTS: ICD-9-CM had an overall mean score of 0.77 out of 2; its highest subscore was 1.61 for Diagnoses. ICD-10 scored 1.60 for Diagnoses, and 0.62 overall. The overall score of ICD-9-CM augmented by CPT was not materially improved at 0.82. The SNOMED International system demonstrated the highest score in every category, including Diagnoses (1.90), and had an overall score of 1.74. CONCLUSION: No classification captured all concepts, although SNOMED did notably the most complete job. The systems in major use in the United States, ICD-9-CM and CPT, fail to capture substantial clinical content. ICD-10 does not perform better than ICD-9-CM. The major clinical classifications in use today incompletely cover the clinical content of patient records; thus analytic conclusions that depend on these systems may be suspect.

A web-based architecture for a medical vocabulary server.

For health care providers to share computing resources and medical application programs across different sites, those applications must share a common medical vocabulary. To construct a common vocabulary, researchers must have an architecture that supports collaborative, networked development. In this paper, we present a web-based server architecture for the collaborative development of a medical vocabulary: a system that provides network services in support of medical applications that need a common, controlled medical terminology. The server supports vocabulary browsing and editing and can respond to direct programmatic queries about vocabulary terms. We have tested the programmatic query-response capability of the vocabulary server with a medical application that determines when patients who have HIV infection may be eligible for certain clinical trials. Our emphasis in this paper is not on the content of the vocabulary, but rather on the communication protocol and the tools that enable collaborative improvement of the vocabulary by any network-connected user.

Extraction of SNOMED concepts from medical record texts.

Clinicians have traditionally documented patient data using natural language text. With the increasing prevalence of computer systems in health care, an increasing amount of medical record text will be stored electronically. However, for such textual documents to be indexed, shared, and processed adequately by computers, it will be important to be able to identify concepts in the documents using a common medical terminology. Automated methods for extracting concepts in a standard terminology would enhance retrieval and analysis of medical record data. This paper discusses a method for extracting concepts from medical record documents using the medical terminology SNOMED-III (Systematized Nomenclature of Human and Veterinary Medicine, Version III). The technique employs a linear least squares fit that maps training set phrases to SNOMED concepts. This mapping can be used for unknown text inputs in the same domain as the training set to predict SNOMED concepts that are contained in the document. We have implemented the method in the domain of congestive heart failure for history and physical exam texts. Our system has a reasonable response time. We tested the system over a range of thresholds. The system performed with 90% sensitivity and 83% specificity at the lowest threshold, and 42% sensitivity and 99.9% specificity at the highest threshold.

Indexing guidelines: applications in use of pulmonary artery catheters and pressure ulcer prevention.

In a busy clinical environment, access to knowledge must be rapid and specific to the clinical query at hand. This requires indices which support easy navigation within a knowledge source. We have developed a computer-based tool for trouble-shooting pulmonary artery waveforms using a graphical index. Preliminary results of domain knowledge tests for a group of clinicians exposed to the system (N = 33) show a mean improvement on a 30-point test of 5.33 (p < 0.001) compared to a control group (N = 19) improvement of 0.47 (p = 0.61). Survey of the experimental group (N = 25) showed 84% (p = 0.001) found the system easy to use. We discuss lessons learned in indexing this domain area to computer-based indexing of guidelines for pressure ulcer prevention.

Providing clinicians with problem-based access to knowledge: troubleshooting pulmonary artery catheter waveforms.

This paper describes a microcomputer system for providing computer-based access to expert knowledge in the area of troubleshooting pulmonary artery (PA) catheter waveforms. The system is used by both nurses and physicians in an 18-bed medical intensive care unit. Its dominant features are 1) problem-focused access to knowledge, and 2) heavy use of graphics and images to explicate knowledge. The system is used by both nurses and physicians in an 18-bed medical intensive care unit. An evaluation protocol is in place to examine the impact of the system on clinicians' knowledge, their decision-making skills, their satisfaction with the system, and costs of orientation related to PA waveform troubleshooting.

Casebook: a system for tracking clinical encounters.

Casebook is a clinically oriented database, written in MUMPS, and designed for recording the clinical encounters of medical students at Harvard Medical School. Its main goals are to 1) increase student use of computer technology, 2) help faculty evaluate the diversity of clinical experiences on their service, 3) provide data to the faculty on the "typical" experience of medical students on their service to aid in the evaluation of the curriculum and, 4) provide report-generation capabilities for the students to improve dialog with their preceptors. Students are able to enter information on "Problems" and "Procedures" selecting from a pop-up menu of medical terms or by entering free text. Casebook is currently in use in the Medicine, OB/GYN, Pediatric and Ambulatory rotations. At sites where the faculty take an active interest in the use of Casebook students perceive it to be valuable and subsequently use it more frequently. It is currently being expanded for use by medical students in their second, third, and fourth years of school.

Effects of smoking on the prevalence and intraoral distribution of Candida albicans.

To find out whether smoking affects the prevalence and intraoral distribution of Candida albicans, swabs and saliva samples from 100 healthy persons, smokers and non-smokers were cultured for the presence of this fungus. The prevalence was the same (35%) in both smokers and non-smokers. Among carriers, the mean concentration of C. albicans colony-forming units in saliva of smokers was twice that of the non-smokers, and the isolation frequency of C. albicans at each of 5 mucosal sites was also higher in smokers than in non-smokers. However, a wide variation was found, and these differences were not significant at the 0.05 level. Men were carriers more often than women (p less than 0.025), and the mucosal site from which C. albicans was recovered most often was the posterior dorsum of the tongue. Although it has previously been claimed that cigarette smoking influences the carrier state of C. albicans, the present study suggests that the effect is only slight.