Hospital policy on appropriate use of life-sustaining treatment. University of Toronto Joint Centre for Bioethics/Critical Care Medicine Program Task Force.

OBJECTIVE: To describe the issues faced, and how they were addressed, by the University of Toronto Critical Care Medicine Program/Joint Centre for Bioethics Task Force on Appropriate Use of Life-Sustaining Treatment. The clinical problem addressed by the Task Force was dealing with requests by patients or substitute decision makers for life-sustaining treatment that their healthcare providers believe is inappropriate. DESIGN: Case study. SETTING: The University of Toronto Joint Centre for Bioethics/Critical Care Medicine Program Task Force on Appropriate Use of Life-Sustaining Treatment. PARTICIPANTS: The 24-member Task Force included physician and nursing leaders from five critical care units, bioethicists, a legal scholar, a health administration expert, a social worker, and a hospital public relations professional. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Our specific lessons learned include a) a policy focus on process; b) use of a negotiation and mediation model, rather than a hospital ethics committee model, for this process; and c) the policy development process is itself a negotiation, so we recommend equal involvement of interested groups including patients, families, and the public. CONCLUSIONS: This article describes the key issues faced by the Task Force while developing its policy. It will provide a useful starting point for other groups developing policy on appropriate use of life-sustaining treatment.

How to use the results of an economic evaluation.

BACKGROUND: Given the high costs of delivering care to critically ill patients, practitioners and policymakers are beginning to scrutinize the costs and outcomes associated with intensive care. Health economics is a discipline concerned with determining the best way of using resources to maximize the health of the community. This involves addressing questions such as which procedure, test, therapy, or program should be provided, and to whom, given available resources. PURPOSE: The purpose of this article is to review general economic principles that will help intensivists to better interpret published economic evaluations. DATA SOURCES: Selected articles from the health economics and critical care literature. RESULTS: In this article, we use an economic evaluation that examines sedation strategies in critically ill patients. We discuss how learning to critically appraise an economic evaluation is only part of the task for end users. Determining whether and how to apply the results of economic evaluations to local settings presents bigger challenges and remains largely a matter of judgment. CONCLUSIONS: Economic evaluations use analytic techniques to systematically consider all possible costs and consequences of clinical actions. Although they should never form the sole basis for clinical decisions for individual patients, economic evaluations offer potentially useful information at different levels of decision-making.

How to use articles about harm: the relationship between high tidal volumes, ventilating pressures, and ventilator-induced lung injury.

BACKGROUND: Intensivists commonly encounter patients who may be inadvertently harmed by critical care interventions. This article is designed to guide clinicians in the evaluations of an individual article assessing a question of harm, as well as the sum of multiple pieces of evidence. OBJECTIVES: To assess the vaidity of a group of articles about the relationship between high tidal volumes and ventilating pressures on ventilator-induced lung injury; to interpret the results of these studies; and to consider whether they apply in practice. DATA SOURCES: Issues of harm are sometimes measured in randomized trials, but are evaluated more often in myriad observational studies. DATA EXTRACTION: We use critical appraisal guides for experimental studies (e.g., randomized trials) and observational studies (e.g., cohort studies, case-control studies and case series) that evaluate the potentially harmful exposure of high tidal volumes and ventilating pressures. This involves assessing the validity of the research, then determining the strength of association between the putative harmful exposure and adverse outcomes. These study designs and their interpretation using relative risks and odds ratios are reviewed. Finally, the relevance of this information (or lack thereof) to clinical practice needs to be determined. DATA SYNTHESIS: Examining these studies individually and in totality, there appears to be a relationship between high tidal volumes and ventilating pressures, although the strength of inference from this research is limited by design issues and sample sizes. CONCLUSIONS: Critically appraising a body of literature is more challenging than evaluating a single study, but often gives a broader view of the available evidence. Future large, rigorous, randomized trials of different approaches to mechanical ventilation will help to advance our understanding and to better inform our practice.

Effect of noninvasive positive pressure ventilation on mortality in patients admitted with acute respiratory failure: a meta-analysis.

OBJECTIVE: To critically appraise and summarize the trials examining the addition of noninvasive positive pressure ventilation to standard therapy on hospital mortality and need for endotracheal intubation in patients admitted with acute respiratory failure. DATA SOURCES: We searched MEDLINE (1966 to September 1995) and key references were searched forward using the Scientific Citation Index (SCISEARCH). Bibliographies of all selected articles and review articles were examined. Authors of all selected and review articles were contacted by letter to identify unpublished work. STUDY SELECTION: a) POPULATION: patients with acute respiratory failure; b) intervention: noninvasive positive pressure ventilation; c) outcome: mortality and/or endotracheal intubation; and d) design: randomized, controlled study. Two of us independently selected the articles for inclusion; disagreements were settled by consensus. Seven (three unpublished) of 212 initially identified studies were selected. DATA EXTRACTION: Two authors independently extracted data and evaluated methodologic quality of the studies. DATA SYNTHESIS: Noninvasive positive pressure ventilation was associated with decreased mortality (odds ratio = 0.29; 95% confidence interval 0.15 to 0.59) and a decreased need for endotracheal intubation (odds ratio = 0.20; 95% confidence interval 0.11 to 0.36). Sensitivity analysis suggested a greater benefit of noninvasive positive pressure ventilation in patients with chronic obstructive pulmonary disease (COPD). The inclusion/exclusion of unpublished trials did not influence these results. CONCLUSIONS: The addition of noninvasive positive pressure ventilation to standard therapy in patients with acute respiratory failure improves survival and decreases the need for endotracheal intubation. However, this effect is restricted to patients whose cause of acute respiratory failure is an exacerbation of COPD. Further research is warranted to determine whether noninvasive positive pressure ventilation confers benefit in patients without COPD who have acute respiratory failure.

Central venous catheter replacement strategies: a systematic review of the literature.

OBJECTIVE: To evaluate the effect of guidewire exchange and new-site replacement strategies on the frequency of catheter colonization and infection, catheter-related bacteremia, and mechanical complications in critically ill patients. DATA SOURCES: We searched for published and unpublished research by means of MEDLINE and Science Citation Index, manual searching of Index Medicus, citation review of relevant primary and review articles, review of personal files, and contact with primary investigators. STUDY SELECTION: From a pool of 151 randomized, controlled trials on central venous catheter management, we identified 12 relevant randomized trials of catheter replacement over a guidewire or at a new site. DATA EXTRACTION: In duplicate and independently, we abstracted data on the population, intervention, outcome, and methodologic quality. DATA SYNTHESIS: As compared with new-site replacement, guidewire exchange is associated with a trend toward a higher rate of catheter colonization (relative risk 1.26, 95% confidence interval 0.87 to 1.84), regardless of whether patients had a suspected infection. Guidewire exchange is also associated with trends toward a higher rate of catheter exit-site infection (relative risk 1.52, 95% confidence interval 0.34 to 6.73) and catheter-related bacteremia (relative risk 1.72, 95% confidence interval 0.89 to 3.33). However, guidewire exchange is associated with fewer mechanical complications (relative risk 0.48, 95% confidence interval 0.12 to 1.91) relative to new-site replacement. Exchanging catheters over guidewires or at new sites every 3 days is not beneficial in reducing infections, compared with catheter replacement on an as-needed basis. CONCLUSIONS: Guidewire exchange of central venous catheters may be associated with a greater risk of catheter-related infection but fewer mechanical complications than new-site replacement. More studies on scheduled vs. as-needed replacement strategies using both techniques are warranted. If guidewire exchange is used, meticulous aseptic technique is necessary.

Documenting life-support preferences in hospitalized patients.

PURPOSE: The purpose of this article was to determine the extent to which patients at high risk of hospital death who undergo cardiopulmonary resuscitation (CPR) have previously had their life support preferences addressed and documented. MATERIALS AND METHODS: We conducted a retrospective chart review of all patients older than 18 years of age hospitalized for more than 24 hours who sustained a cardiac arrest with attempted CPR at our tertiary care university teaching hospital during 1994 (n = 71). We searched all hospital charts specifying ICD-9 codes: Cardiac arrest, ventricular fibrillation, ventricular tachycardia, asystole, electromechanical dissociation, defibrillation, or CPR. Patients were selected if (1) they had a true cardiac arrest (abrupt cessation of spontaneous circulation) and (2) had attempted CPR or defibrillation. Patients were classified as "high risk" if they satisfied at least one of the following: modified prearrest morbidity index > or = 7, moderate/severe dementia, day 1 APACHE II score > 24 or > or = 4 dysfunctional organ systems. RESULTS: We searched 147 charts; of 71 patients meeting inclusion criteria, 53 were high risk. Of patients at high risk of sustaining a cardiopulmonary arrest during the index hospital admission, 3 (6%) had preferences addressed within the first 24 hours of hospitalization, 7 (13%) had delayed discussion of preferences before arrest, 23 (43%) had preferences addressed post arrest, and 20 (38%) had no documented discussions. Of the 23 high-risk patients initially surviving cardiac arrest, all were subsequently given "do not resuscitate" orders. Univariate analysis of factors associated with life-support discussion before cardiac arrest were previous cardiac arrest (OR, 5.9) and APACHE II score > 24 (OR, 1.1), although neither reached statistical significance. None of the 32 patients with a modified PAM index > or = 7 (32 of 71) survived hospitalization. Only 3 patients survived to hospital discharge. CONCLUSIONS: Early communication regarding life-support preferences is important in high-risk patients so that inappropriate or unwanted treatment is not implemented. Given that optimal care includes addressing and documenting life-support preferences in high-risk patients early in their hospitalization, this standard was infrequently met.

Economic evaluations in the critical care literature: do they help us improve the efficiency of our unit?

OBJECTIVE: To determine the extent to which economic evaluations published in the critical care literature provide information that can help us to improve the efficiency of our unit. DATA SOURCES: We searched computerized bibliographic databases and manually searched key critical care journals to retrieve all economic evaluations. STUDY SELECTION: We included economic evaluations that dealt with clinical problems relevant to the practice of adult critical care and that compared competing healthcare interventions. DATA ABSTRACTION: Included articles were further evaluated using criteria for minimal methodologic soundness, adopted from the literature, and criteria that we developed to assess the generalizability of results to our clinical setting. DATA SYNTHESIS: We screened 4,167 papers manually and > 450 abstracts and titles in our computer search. One hundred fifty-one papers were retrieved for further evaluation; 29 papers met our inclusion criteria. Of these 29 papers, only 14 (48%) adequately described competing healthcare interventions, 17 (59%) provided sufficient evidence of clinical efficacy, six (21%) identified, measured, and valuated costs appropriately, and three (10%) performed a sensitivity analysis. None of the papers met all four of these criteria for a minimum level of methodologic soundness. Four (14%) of 29 studies which adequately dealt with issues of cost and efficacy were evaluated using our generalizability criteria. Different costing methods precluded the application of the results of three of the four studies to our intensive care unit. CONCLUSIONS: In the critical care literature, very little useful economic information exists to help decision-makers maximize efficiency in their own setting.

Maximizing oxygen delivery in critically ill patients: a methodologic appraisal of the evidence.

OBJECTIVE: To systemically review the effect of interventions designed to achieve supraphysiologic values of cardiac index, oxygen delivery (DO2), and oxygen consumption (VO2) in critically ill patients. DATA SOURCES: Computerized bibliographic search of published research, citation review of relevant articles, and contact with primary investigators. STUDY SELECTION: We included all randomized clinical trials of adult intensive care unit (ICU) patients that evaluated interventions (fluids, inotropes, and vasoactive drugs) designed to achieve supraphysiologic values of cardiac index, DO2, and/or VO2. Independent review of 64 articles identified seven relevant studies of 1,016 patients. DATA EXTRACTION: We abstracted data on the population, interventions, outcomes, and methodologic quality of the studies by duplicate independent review. Agreement was high (weighed kappa 0.73); differences were resolved by consensus. DATA SYNTHESIS: Targeting therapy to achieve supraphysiologic end points in critically ill patients is associated with a nonstatistically significant trend toward decreased mortality rates (relative risk 0.86, 95% confidence intervals 0.62 to 1.20). For the two studies in which supraphysiologic goals were initiated preoperatively, the relative risk was 0.20 (95% confidence intervals 0.07 to 0.55). This value differed significantly from the combined estimate of the remaining studies, in which the intervention was started after ICU admission (relative risk 0.98, 95% confidence intervals 0.79 to 1.22; p<.01). However, there are several methodologic problems with the primary studies. In no trials were caregivers or outcome assessors blinded to treatment allocation. Only three of seven trials analyzed patients according to the group to which they were allocated. None adequately controlled for cointerventions, and there was considerable crossover between groups (patients in the control group achieved the goals of the intervention group and vice versa). CONCLUSIONS: Interventions designed to achieve supraphysiologic goals of cardiac index, DO2, and VO2 did not significantly reduce mortality rates in all critically ill patients. However, there may be a benefit in those patients in which the therapy is initiated preoperatively. Methodologic limitations weaken the inferences that can be drawn from these studies and preclude any evidence-based clinical recommendations.