Rectal stump management in inflammatory bowel disease: a cohort study, systematic review and proportional analysis of perioperative complications.

BACKGROUND: The aim of this study was to analyse local single-institution data and perform a systematic review of the literature to calculate precise risk estimates of rectal stump-related morbidity and mortality following subtotal colectomy in patients with inflammatory bowel disease (IBD), including Crohn's colitis, ulcerative colitis and indeterminate colitis. METHODS: Institutional information systems were interrogated to obtain local patient data. A systematic review of MEDLINE and EMBASE was performed to identify relevant articles. Fixed-effects or random-effects meta-analysis of proportions was performed to calculate pooled incidence estimates, including local data. RESULTS: Sixty-one patients were included locally and all had their rectal stump closed intra-abdominally. Four patients (8.3%) had a rectal stump perforation and 30-day mortality was 0. Fourteen papers were included in our review alongside local data, with a total of 1330 patients included. Pooled mortality was 1.7% (95% confidence interval, CI 1.0-2.8), pooled incidence of pelvic abscess/sepsis, stump leak and wound infection was 5.7% (95% CI 4.4-7.3), 4.9% (95% CI 3.7-6.6) and 11.3% (95% CI 7.8-16), respectively. Subcutaneous placement of the stump was associated with the highest incidence of stump leak (12.6%, 95% CI 8.3-18.6), and closure of the stump with both staples and suture was associated with the highest incidence of pelvic abscess (11.1%, 95% CI 5.8-20.3). Mortality and the incidence of wound infection were similar across stump closure techniques. There was evidence suggesting considerable heterogeneity and publication bias among studies. CONCLUSIONS: This study provides estimates of morbidity associated with the rectal stump after subtotal colectomy for IBD. A closed intra-abdominal stump seems to be associated with the highest rate of pelvic abscess/sepsis. Further work in form of an international collaborative project would allow individual patient data analysis and identification of risk factors for complications.

High concordance between expert anaesthetists' actions and advice of decision support system in achieving oxygen delivery targets in high-risk surgery patients.

BACKGROUND: Goal-directed therapy has a secure place in perioperative care. Algorithms are based on Starling's law of the heart, notwithstanding that this does not numerically define volume or heart performance variables. These have been developed based on a Guytonian view of the circulation and are implemented in a computerized decision support system (Navigator™). We studied the feasibility and performance of the graphical display of the system in an intervention and a control group of patients undergoing major abdominal surgery. METHODS: Patients were randomized to either graphically (intervention) or numerically (control) guided administration of therapy. Goals were set and treatments and concordance with guidance noted, where applicable. Anaesthesia was provided by one of three experienced anaesthetists well acquainted with Navigator™. The primary objective was to determine whether the use of graphical display decision support more efficiently enables the achievement of oxygen delivery targets. This was quantitated as percentage time in the target zone and averaged standardized distance from the target centre. RESULTS: The mean percentage time in the target zone was 36.7% for control and 36.5% for intervention. The averaged standardized difference was 1.5 in control and 1.6 in intervention. There was no significant difference in fluid balances. There was a high level of concordance between decision support recommendation and anaesthetist action (84.3%). CONCLUSIONS: In experienced hands, the addition of a graphical display for haemodynamic guidance resulted in a similar time in target and averaged standardized difference. The haemodynamic guidance system should be explored in a comparative study to anaesthesia management without guidance.

Prediction of the international normalized ratio and maintenance dose during the initiation of warfarin therapy.

AIMS: A pharmacokinetic/pharmacodynamic model, with Bayesian parameter estimation, was used to retrospectively predict the daily International Normalized Ratios (INRs) and the maintenance doses during the initiation of warfarin therapy in 74 inpatients. METHODS: INRs and maintenance doses predicted by the model were compared with the actual INRs and the eventual maintenance dose. Cases with drugs or medical conditions interacting with warfarin or receiving concurrent heparin therapy were not excluded. As the study was retrospective, model predictions of the maintenance dose were not those that were administered. Mean prediction error (MPE) and percentage absolute prediction errors (PAPE) were used to assess the model predictions. RESULTS: INR MPE ranged from -0.07 to 0.06 and median PAPE from 10% to 20%. Dose MPE ranged from -0.7 to 0.17 mg and median PAPE from 16.7% to 37.5%. Accurate and precise dose predictions were obtained after 3 or more INR feedback's. CONCLUSIONS: This study shows that the model can accurately predict daily INRs and the maintenance dose in this sample of cases. The model can be incorporated into computer decision-support systems for warfarin therapy and may lead to improvement in the initiation of warfarin therapy.

Do patients with advanced breast cancer benefit from chemotherapy?

This study aimed to assess the proportion of patients with advanced breast cancer who report benefit from first-line palliative chemotherapy using a simple global measure of wellbeing and to identify factors predicting benefit. A consecutive series of women with advanced breast cancer undergoing first-line palliative chemotherapy was evaluated. The main outcome measure was patient report of overall wellbeing assessed at post-treatment interview. Physical, psychological and functional status were assessed using the Rotterdam Symptom Checklist (RSCL) on three occasions (pretreatment, at the start of the third cycle and post treatment). It was planned that treatment would be discontinued after six cycles (i.e. 18-24 weeks). One hundred and sixty patients started treatment, of whom 155 were assessable for quality of life. After treatment, 41 (26%) patients reported they felt better, 29 (19%) felt the same and 34 (22%) felt worse than they did before treatment. The other 51 (33%) patients either died or stopped attending the hospital before the post-treatment interview and were assigned as treatment 'failures'. Patients who reported feeling better after treatment had improvements in psychological distress (P < 0.0001), pain (P = 0.01), lack of energy (P = 0.02) and tiredness (P = 0.02), as well as improvement in functional status (P = 0.07). Feeling better was also correlated with disease response (P = 0.03). Feeling worse after treatment or treatment 'failure' was predicted by the pretreatment presence of a dry mouth (P = 0.003) and high levels of psychological distress (P = 0.03). Pretreatment lack of energy (P = 0.01), dry mouth (P = 0.02), presence of liver metastases (P = 0.03) and breathlessness (P = 0.03) predicted treatment 'failures'. The results of this study suggest that first-line palliative chemotherapy for advanced breast cancer confers benefit on a substantial proportion of patients, with about one-quarter feeling better after treatment and nearly a half feeling better or the same some 4-6 months after the start of treatment. Factors identified in this study may assist clinicians in deciding which patients should not be offered treatment, because of high risk of feeling worse or treatment 'failure'. This work now needs to be validated on a further cohort of women receiving chemotherapy for advanced breast cancer.

Comparison of oral anticoagulant control by a nurse-practitioner using a computer decision-support system with that by clinicians.

With increasing work-loads in anticoagulant clinics different methods of service delivery need evaluation. The quality of anticoagulant control achieved by a nurse-practitioner using a computer decision-support system (CDSS) was compared with that achieved by trainee doctors without CDSS. Eighty-one out-patients (group A, therapeutic range 2-3) and 96 out-patients (group B, therapeutic range 3-4.5) were randomized to management by a nurse-practitioner or by trainee doctors (clinicians). Thirty-seven patients in group A and 50 patients in group B were randomized to be managed by the nurse-practitioner. In group A, patients in the nurse-practitioner group spent a longer time in the therapeutic range than those in the clinician group (60.7% compared with 51.6%). Dose suggestion acceptance in the nurse-practitioner group (88%) was higher compared with agreement between the CDSS and the clinicians (60%). In group B, patients in the clinician group spent a slightly longer time in the therapeutic range (70% compared with 67.6%). Acceptance of dose suggestion was lower in the nurse-practitioner group (67%) compared with agreement between the CDSS and the clinicians (73%). In conclusion, the CDSS can improve the quality of control of warfarin therapy by a nurse-practitioner over that by trainee doctors for the therapeutic range 2-3. Similar quality of control is achieved for the therapeutic range 3-4.5. The CDSS may be used by nurse-practitioners to achieve safe and effective anticoagulation in hospital-based or out-reach anticoagulant clinics.

Evaluation of a decision support system for initiation and control of oral anticoagulation in a randomised trial.

OBJECTIVE: To determine whether a computerised decision support system for initiation and control of oral anticoagulant treatment improves quality of anticoagulant control achieved by trainee doctors. DESIGN: Randomised controlled trial. SETTING: District general hospital in North London. SUBJECTS: 148 inpatients requiring start of warfarin treatment. INTERVENTIONS: Management by trainee doctors (to achieve therapeutic range of international normalised ratio of 2 to 3) with indirect assistance from computerised decision support system (intervention group) or without such assistance (control group). MAIN OUTCOME MEASURES: Median time to therapeutic range, stable dose, and first pseudoevent (excessive international normalised ratio after therapeutic range has been reached) and person time spent in the therapeutic range. RESULTS: 72 patients were randomised to the intervention group and 76 to control group. Median time to reach international normalised ratio of > or = 2 was not significantly different in the two groups (3 days). Median time to achieve a stable dose was significantly lower in intervention group than in controls (7 days v 9 days, P = 0.01) without excessive overtreatment or undertreatment with anticoagulant. Patients in intervention group spent greater proportion of time in therapeutic range, both as inpatients (59% v 52%) and outpatients (64% v 51%). CONCLUSION: The computerised decision support system was safe and effective and improved the quality of initiation and control of warfarin treatment by trainee doctors.

A prototype computer decision support system for the management of asthma.

Asthma is a chronic disease estimated to affect 6-7% of the total UK population. In addition, a number of studies have shown that asthma has become commoner since the 1970s, especially in children. The diagnosis of asthma can be difficult and its management requires the involvement of patients in a long-term treatment plan, something which general practitioners may be unable to achieve easily in the average 10-min consultation. As a consequence, asthma is underdiagnosed and undertreated. Deaths from the disease are often avoidable with timely and sufficient use of the available medication. In order to support this, the British Thoracic Society (BTS) has published guidelines for asthma management based upon a stepwise approach, in which a patient is categorized as being on one of five steps according to the severity of his or her asthma. The guidelines give "rules of thumb" for deciding when the patient should move up or down the steps. The most recent version of the guidelines also included special rules for children. Within a recent European Community project on Advanced Informatics in Medicine (AIM), we developed a prototype decision support system for asthma management targeted at the primary care setting and based on the British Thoracic Society guidelines. This paper reports this development, and describes the further work needed on the prototype. Plans for evaluation of the knowledge bases and for future full application production are also described.

Validation of an algorithm for oral anticoagulant dosing and appointment scheduling.

Computer clinical decision-support systems require validation before clinical use. This study compared recommendations on warfarin dosage adjustment and timing of the next appointment made by an algorithm with those made by experienced and inexperienced clinicians. Data abstracted from the records of 125 patients seen regularly in the anticoagulant clinic were used. The algorithm recommended dose changes and next appointment for cases with INRs between 1.8 to 4.2 (therapeutic range 2.0-3.0) and between 2.3 to 5.3 (therapeutic range 3.0-4.5). Beyond these values the algorithm referred the cases to "see doctor'. Compared to experienced clinicians, the algorithm was better at "recognising' difficult patients than inexperienced clinicians (kappa = 0.43 and 0.32 respectively). There was no statistically significant difference between all decision makers in dosage recommendations for the non-difficult cases, but there was much more variation amongst the inexperienced clinicians. The interval recommendations were statistically different between and within the different decision-makers. The inexperienced clinicians tended to give relatively longer intervals for a given dose change. In conclusion, the algorithm performs better than inexperienced clinicians and as well as experienced clinicians for the non-difficult cases.

Burnout and psychiatric disorder among cancer clinicians.

The prevalence and causes of 'burnout' and psychiatric disorder among senior oncologists and palliative care specialists have been measured in a national questionnaire-based survey. All consultant non-surgical oncologists in the UK were asked to participate. Sources of work-related stress and satisfaction were measured using study-specific questions which were aggregated into factors. Psychiatric disorder was estimated using the 12-item General Health Questionnaire. The three components of 'burnout'--emotional exhaustion, depersonalisation and low personal accomplishment--were assessed using the Maslach Burnout Inventory. Three hundred and ninety-three out of 476 (83%) consultants returned their questionnaires. The estimated prevalence of psychiatric disorder in cancer clinicians was 28%, and this is similar to the rate among British junior house officers. The study group had equivalent levels of emotional exhaustion and low personal accomplishment to those found in American doctors and nurses, but lower levels of depersonalisation. Among cancer clinicians, 'burnout' was more prevalent among clinical oncologists than among medical oncologists and palliative care specialists. Psychiatric disorder was independently associated with the stress of feeling overloaded (P < 0.0001), dealing with treatment toxicity/errors (P < 0.004) and deriving little satisfaction from professional status/esteem (P = 0.002). 'Burnout' was also related to these factors, and in addition was associated with high stress and low satisfaction from dealing with patients, and with low satisfaction from having adequate resources (each at a level of P < or = 0.002). Clinicians who felt insufficiently trained in communication and management skills had significantly higher levels of distress than those who felt sufficiently trained. If 'burnout' and psychiatric disorder among cancer clinicians are to be reduced, increased resources will be required to lessen overload and to improve training in communication and management skills.

From guidelines to decision support in the management of asthma.

Asthma is a common chronic disease of the lungs caused by inflammation of the airways affecting 6-7% of the population. Asthma is becoming commoner and there is evidence of under-diagnosis and poor management. Guidelines have been developed aimed at improving quality of care and in reducing social costs of asthma. The paper discusses an approach to implementing guidelines through decision-support system in primary care, based on methods developed in the AIM GAMES-II project. We also describe a prototype system that has been developed and a programme of clinical evaluation.

GAMES II Project: a general architecture for medical knowledge-based systems.

GAMES II aims at developing a comprehensive and commercially viable methodology to avoid problems ordinarily occurring in KBS development. GAMES II methodology proposes to design a KBS starting from an epistemological model of medical reasoning (the Select and Test Model). The design is viewed as a process of adding symbol level information to the epistemological model. The architectural framework provided by GAMES II integrates the use of different formalisms and techniques providing a large set of tools. The user can select the most suitable one for representing a piece of knowledge after a careful analysis of its epistemological characteristics. Special attention is devoted to the tools dealing with knowledge acquisition (both manual and automatic). A panel of practicing physicians are assessing the medical value of such a framework and its related tools by using it in a practical application.

Computer system for assisting with clinical interpretation of tumour marker data.

OBJECTIVE: To design and evaluate a computer advisory system for the treatment of gestational trophoblastic tumour. DESIGN: A comparison of clinicians' treatment decisions with those of the computer system. Two datasets were used: one to calibrate the system and one to independently evaluate it. SETTING: Department of medical oncology. PATIENTS: Computerised records of 290 patients with low risk gestational trophoblastic tumour for whom the advisory system could predict the adequacy of treatment. The calibration set comprised patients admitted during 1979-86(227) and the test set patients during 1986-89(63). MAIN OUTCOME MEASURES: The system's accuracy in predicting need to change treatment compared with clinicians' actions. The mean time faster that the system was in predicting the need to change treatment. RESULTS: On the calibration dataset the system was 94% (164/174) accurate in predicting patients whose treatment was adequate, recommending change when none occurred in only 10 (6%) patients. In patients whose treatment was changed the system recommended change earlier than clinicians in 39/53 cases (74%), with a mean time advantage of 14.9 (SE 2.02) days. On the test dataset the system had an accuracy of 91% (31/34) in predicting treatment adequacy and a false positive rate of 9% (3/34). The system recommended change earlier than clinicians in 22/29 cases (76%), with a mean time advantage of 12.5 (2.22) days. CONCLUSIONS: The computer advisory system could improve patient management by reducing the time spent receiving ineffective treatment. This has implications for both patient time and clinical costs.

Inform: conceptual modelling of intensive care information systems.

Intensive care of a patient requires heavy monitoring and versatile therapeutic actions. These produce a huge amount of patient information. A problem exists in managing this data and other information from all supporting activities creating a need for an automated information management system. To have a sound basis for future automated information systems in intensive care unit (ICU), a conceptual model is created to cover both the clinical and other activities of the ICU. The conceptual model consists of data flow diagrams and entity-relationship diagrams with underlying common data dictionary. A modern CASE tool is utilized to build the model. The work forms a part of AIM-INFORM project, which has a purpose to develop information management and decision support systems for high dependency environment.

Decision support for patient management in oncology.

In this paper a novel approach to the development of the architecture of a knowledge-based decision support system for the management of patients with cancer of the breast is described. Its initial design and subsequent realization in a prototype version was facilitated by examining closely the overall clinical task and identifying its associated activities and related knowledge. Implementation in KEE highlights the value of rigorous conceptual modelling that leads to a design able to assess treatment response and disease progression as well as providing specific therapy advice. The approach is general and may be applied to the development of decision support systems for other areas of cancer and medicine.

A system for compartmental modelling and simulation.

The paper describes a software package for modelling and simulating compartmental systems based upon a generalisation of the equations of compartmental systems. The aim is a versatile package which can be used for rapid model development. Its use is first illustrated in a number of simple classical examples. The power of the software--and more generally the methodology--is demonstrated by showing its application in developing a model-based system for insulin planning for diabetic patients. The software has been written in Pascal and runs on IBM PC and compatible computers.

A data model for intensive care.

The paper describes a model of clinical management data in a typical general intensive care unit, intended as a generic database specification for advanced intensive care computer systems. The data model was developed as part of the INFORM project. The INFORM project is summarised and the relevance of the data model to the objectives of the project are discussed. An object oriented extension to the entity relationship diagram methodology is presented. The methodology is illustrated with reference to some specific aspects of the data model including: the principle clinical entities; classification of patient state related data and the homogeneous patient group system. It is suggested that such a model will contribute to the better understanding of the data in the system, to the better design of future intensive care computer systems and to the setting of standards for medical data.

INFORM: development of information management and decision support systems for High Dependency Environments.

The long-term aim in the INFORM Project is to develop, evaluate and implement a new generation of Information Systems for hospital High Dependency Environments (HDE-Intensive Care Units, Neonatal Units, Burns Units. Operating and Recovery Rooms, and other specialised areas). The distinguishing feature of the HDE is the very large amount of data that is collected through monitors and paper records about the state of critically ill patients; this has made the role of the staff a technical one in addition to a caring one. The INFORM System will integrate Decision Support with on-line, off-line and observed patient data and, in addition, will incorporate and integrate unit management features. In the Exploratory Phase of the Project, functional requirements have been set out. These are based on four components: conceptual model of the HDE; evaluation of existing HDE Information Systems; development of a novel software architecture using a Knowledge-Based Systems (KBS) methodology, and based on a critical review of KBS applied to the HDE: monitoring of appropriate leading-edge technological developments. The conceptual model has two components: a patient-related information model, and a department-related cost model. The patient-related model is identifying key and difficult areas of decision making. A key aspect of INFORM is integration of clinical Decision Support for these areas into the Information System through a layered software architecture. The lower layers are concerned with monitoring and alarming and the higher levels with patient assessment and therapy planning. The functionality and interconnection of these layers are being determined.

Uptake and processing of glycoproteins by isolated rat hepatic endothelial and Kupffer cells.

Mannose-(Man) and N-acetylglucosamine- (GlcNAc)-terminated glycoproteins are cleared from blood by carbohydrate-specific receptors present on both hepatic endothelial and Kupffer cells. It is not known whether the same receptors are present on each cell type or the relative contributions to glycoprotein metabolism made by Kupffer and endothelial cells. Here we report experiments where data from glycoprotein metabolism by purified populations of isolated rat hepatic endothelial and Kupffer cells have been analyzed by mathematical modelling and parameter estimation. Kupffer cells had significantly higher binding rate constants (k'21) than endothelial cells for agalactoorosomucoid (AGOR) and hyaluronidase, but lower k12 ('off-rate') indicating that Kupffer cells had higher affinities for Man/GlcNAc-terminated glycoproteins than endothelial receptors. Furthermore, although endothelial cells had similar affinities (k'21 and k12) for AGOR and hyaluronidase, the 'off-rate' of Kupffer cells was significantly greater for AGOR than for hyaluronidase, indicating that Kupffer cell receptors have lower affinity for AGOR. Internalization and ligand catabolic rates also differed between the two cell types. The data indicate that Kupffer and endothelial cells appear to have different Man/GlcNAc receptors and that the destination of a glycoprotein and its subsequent processing is determined by the structure of a glycoprotein's oligosaccharide.

Uptake and processing of glycoproteins by rat hepatic mannose receptor.

A linear compartmental model has been developed for the in vivo metabolism of glycoproteins. The model is applied to the interpretation of dynamic data from the rat on agalactoorosomucoid (AGOR), an N-acetylglucosamine (GlcNAc-)-terminated glycoprotein, and three neoglycoproteins terminating in mannose [mannose36-bovine serum albumin (Man-BSA)] or glucose [maltose29-BSA (Mal29-BSA) and maltose8-BSA (Mal8-BSA)]. All of these proteins are taken up by the Man/GlcNAc receptor on hepatic sinusoidal cells. The rate of uptake was found to be determined by sugar type (Man-BSA, 0.78 min-1 greater than Mal29-BSA, 0.13 min-1), sugar density (Mal29-BSA greater than Mal8-BSA), and the geometry of the sugar display (AGOR, 0.51 min-1 greater than Mal29-BSA). Intracellular transport from the cell membrane to the lysosomes was slower for Man-BSA (approximately 3 min) than for the other ligands (approximately 0 min), suggesting that receptor-ligand uncoupling was slower for Man-BSA for which the receptor had the highest affinity or that extralysosomal catabolism of the other ligands occurred. Catabolism was also determined by the carbohydrate moiety of the ligand; it was greater for Mal29-BSA and Mal8-BSA (greater than or equal to 0.8 min-1) than for Man-BSA (0.27 min-1), and AGOR, with a complex oligosaccharide, was most resistant to degradation (0.14 min-1). An understanding of these structural features of glycoproteins that influence hepatic uptake, transport, and catabolism will be of value in drug targeting and for enzyme replacement in lysosomal storage disorders.(ABSTRACT TRUNCATED AT 250 WORDS)