Assessment of a Bayesian Vitrea CT Perfusion Analysis to Predict Final Infarct and Penumbra Volumes in Patients with Acute Ischemic Stroke: A Comparison with RAPID.

BACKGROUND AND PURPOSE: Brain CTP is used to estimate infarct and penumbra volumes to determine endovascular treatment eligibility for patients with acute ischemic stroke. We aimed to assess the accuracy of a Bayesian CTP algorithm in determining penumbra and final infarct volumes. MATERIALS AND METHODS: Data were retrospectively collected for 105 patients with acute ischemic stroke (55 patients with successful recanalization [TICI 2b/2c/3] and large-vessel occlusions and 50 patients without interventions). Final infarct volumes were calculated using DWI and FLAIR 24 hours following CTP imaging. RAPID and the Vitrea Bayesian CTP algorithm (with 3 different settings) predicted infarct and penumbra volumes for comparison with final infarct volumes to assess software performance. Vitrea settings used different combinations of perfusion maps (MTT, TTP, CBV, CBF, delay time) for infarct and penumbra quantification. Patients with and without interventions were included for assessment of predicted infarct and penumbra volumes, respectively. RESULTS: RAPID and Vitrea default setting had the most accurate final infarct volume prediction in patients with interventions ([Spearman correlation coefficient, mean infarct difference] default versus FLAIR: [0.77, 4.1 mL], default versus DWI: [0.72, 4.7 mL], RAPID versus FLAIR: [0.75, 7.5 mL], RAPID versus DWI: [0.75, 6.9 mL]). Default Vitrea and RAPID were the most and least accurate in determining final infarct volume for patients without an intervention, respectively (default versus FLAIR: [0.76, -0.4 mL], default versus DWI: [0.71, -2.6 mL], RAPID versus FLAIR: [0.68, -49.3 mL], RAPID versus DWI: [0.65, -51.5 mL]). CONCLUSIONS: Compared with RAPID, the Vitrea default setting was noninferior for patients with interventions and superior in penumbra estimation for patients without interventions as indicated by mean infarct differences and correlations with final infarct volumes.

A survey of the use of teicoplanin in patients with haematological malignancies and solid tumours.

A significant number of open and comparative studies have now addressed the use of teicoplanin in the treatment of documented or presumed infection in patients with haematological and non-haematological malignancy. Available evidence suggests that teicoplanin is an effective agent against such infections, with an excellent safety profile. The use of teicoplanin and vancomycin may be justified as part of the initial management of clinically infected right atrial catheters in patients with malignancy. The first-line use of glycopeptides may also be appropriate in units where streptococcal and methicillin resistant staphylococcal infections are prevalent. However, such a policy should be reviewed regularly. Except in the above situations, a delay in the introduction of either teicoplanin or vancomycin in cancer patients does not appear to produce any excess mortality, but there may be some additional morbidity in terms of fever and malaise. The introduction of glycopeptides as second-line agents is indicated for sensitive, microbiologically documented infections and for patients who have not responded to empirical, first-line therapy. Non-inpatient treatment with teicoplanin is an area of ongoing interest and may be justified on both humanitarian and pharmacoeconomic grounds. The use of glycopeptides in the prophylactic setting remains controversial and should be avoided while the emergence of resistance, particularly in enterococci, should be monitored closely.

Social work in restructuring hospitals: meeting the challenge.

From bureaucratic to programmatic institutions, hospitals across North America are experiencing restructuring. Using the results of a telephone survey and a semistructured questionnaire, this research study explores the effect of hospital restructuring on the organization and delivery of social work services and the strategies social workers select to manage change in a sample of Ontario hospitals. Respondents identified a number of issues related to control over the nature of work in the organization, social work roles, and the management of structural change. This article discusses the implications for the profession of the move to program management.

Comparison of selection of preoperative laboratory tests: the computer vs the anaesthetist.

HealthQuiz II (HQII) is a computerized history-taking device which can be used by patients before anaesthesia and surgery. HealthQuiz II provides a summary of symptoms, a modified ASA Classification, and a list of suggested laboratory tests. Developed at the University of Chicago, the device has not been evaluated in Canada. The purpose of this study was to compare preoperative evaluation and selection of laboratory tests by a group of Canadian anaesthetists using traditional methods versus using HealthQuiz II. Twenty-seven anaesthetists from three (Western) Canadian University teaching hospitals participated in the study. The subjects were male, aged between 30-50 yr, trained in Canada and practicing in Calgary, Edmonton and Vancouver. They were asked to self-evaluate and select laboratory tests and then to complete the HQII protocol, the day before a proposed mock operation. Results of this comparison showed that the ASA scores assigned by HQII were higher for 11 subjects and lower for two. Eight anaesthetists thought HQII asked questions which they omitted while five thought HQII overlooked items. Thirteen anaesthetists believed HQII would be a useful adjunct to their practice. Only ten anaesthetists requested any tests while HealthQuiz II suggested tests for 23 subjects, with an average of 1.9 tests/subject (anaesthetists) vs 5.4 tests/subject (HQII). The total cost of tests selected by anaesthetists was $272.15 in contrast with $1,513.20 for those suggested by HQII. We conclude that rationale for test selection may have contributed to the difference in number and costs of tests.

The cost of an established quality assurance programme: is it worth it?

Although the literature concerning quality assurance (QA) is voluminous, little information exists about the costs or benefits of departmentally based QA programmes. We measured the direct costs and then investigated the financial and nonfinancial benefits derived from a well-funded QA programme over a period of five years. Data were obtained from departmental budgets, annual reports of the QA programme, and several databases used by the programme. The average annual cost was $79,900, with salaries being the largest component, while $14,300 each year were recovered through the activities of the programme. True costs were higher than those calculated since time volunteered by medical staff and resources shared with other programmes could not be determined. Some of the costs encountered at the outset of this programme were later offset by the use of commercial software and employment of volunteers and casual staff. Fifty-three projects were identified over the five-year period. Most lacked directly measurable financial outcomes (because they were based on education, research, patient or practitioner satisfaction). The benefit of the programme has been greater to the department than suggested from cost analysis alone. Although this programme could not be justified on a simple cost recovery basis, the authors felt it to be worthy of continued support because of the nonfinancial benefits. However, modification is required to minimize costs.

The ethics of cardiopulmonary resuscitation. II. Medical logistics and the potential for good response.

Mismatches between provision of paediatric cardiopulmonary resuscitation (CPR) and potential to benefit are examined. Deficiencies are most likely to occur in peripheral maternity units but futile CPR is more common in emergency departments where the child is unknown. Decision making in individual cases is best retained by the medical profession for the sake of the child and family. American style intervention by the legislature is likely to dissipate scarce resources and perhaps harm infants not capable of benefiting.

Accident analysis of large-scale technological disasters applied to an anaesthetic complication.

The occurrence of serious accidents in complex industrial systems such as at Three Mile Island and Bhopal has prompted development of new models of causation and investigation of disasters. These analytical models have potential relevance in anaesthesia. We therefore applied one of the previously described systems to the investigation of an anaesthetic accident. The model chosen describes two kinds of failures, both of which must be sought. The first group, active failures, consists of mistakes made by practitioners in the provision of care. The second group, latent failures, represents flaws in the administrative and productive system. The model emphasizes the search for latent failures and shows that prevention of active failures alone is insufficient to avoid further accidents if latent failures persist unchanged. These key features and the utility of this model are illustrated by application to a case of aspiration of gastric contents. While four active failures were recognized, an equal number of latent failures also became apparent. The identification of both types of failures permitted the formulation of recommendations to avoid further occurrences. Thus this model of accident causation can provide a useful mechanism to investigate and possibly prevent anaesthetic accidents.

The assessment of treatment response in non-Hodgkin's lymphoma by image guided 31P magnetic resonance spectroscopy.

Serial image guided 31P magnetic resonance spectroscopy (MRS) studies were performed in eight patients with non-Hodgkin's lymphoma to determine the changes in phosphorus metabolites that occur in vivo in response to chemotherapy. Pre-treatment spectral characteristics were different in high and low grade lymphoma. A larger inorganic phosphate (Pi) peak was seen in high grade NHL relative to phosphomonoesters (PME) or beta adenosine triphosphate (beta ATP), producing significant differences in the PME/Pi and Pi/beta ATP metabolite ratios, and probably reflecting a larger hypoxic cell fraction within the high grade lymphomas. Consistent metabolite changes were seen with treatment, and before reductions in tumour bulk had occurred. Alterations in tumour energetics with changes in Pi and beta ATP, and increases in phospholipid turnover reflected as an increase in the phosphodiester (PDE) resonance were detected. Changes were seen between days 10 and 27 in low grade lymphoma treated with oral alkylating therapy and between days 1 and 5 in lymphoma treated with intensive combination chemotherapy. Increases in the PDE/beta ATP metabolite ratio may be an early indicator of response to chemotherapy in human tumours. These studies illustrate the feasibility and clinical potential of image guided 31P MRS as a means of assessing response to therapy.

Occupational bladder tumour cases identified during ten years' interviewing of patients.

All patients attending the Royal Marsden Hospital with urothelial tumours have their occupational histories taken. About 10% of histories suggest a possibility of past exposure to urinary carcinogens, and on examination 4% indicate definite exposures justifying claims for Prescribed Industrial Disease benefit.