As an illustrative example, the coronary care unit was introduced in the mid-1960s with the expectation that these specialized care units would reduce hospital mortality associated with AMI in part by rapidly detecting and treating ventricular fibrillation. Acceptance of this approach to the management of AMI by clinicians was relatively slow at first followed by rapid acceptance and widespread utilization of such units. However, following the publication of two randomized trials in Great Britainthat failed to show any advantage of coronarycare units over home care in patients with mildto moderate AMI, debate ensued as to the appropriate use of these units and their cost-effectiveness. A period of waning enthusiasm then followed and expectations were reassessed for patient outcomes that might be favorably influenced by hospitalization in a coronary care unit and for those services and therapies that were associated with hospitalization in these units. canadian drug mall
In the present nonrandomized observational study, the decisions to place these catheters were made by physicians with varying levels of skill in the use of the PA catheter at each of the 16 teaching and community hospitals during a 15-year study period. It is unlikely that in this multisite setting there was a uniform or consistent pattern of practice related to the utilization of PA catheterization throughout the period of study (1975 to 1990). The reasons for the decline in use of PA catheterization in all patients with AMI studied and for the more recent decline in use observed in patients with complicated AMI are unknown. These changes may reflect efforts at cost containment, changes in physicians* practice and decision-making patterns, as well as the lack of published data demonstrating the efficacy of PA catheterization on mortality patterns following AMI.
Although there is a lack of convincing evidence for the indications of PA catheterization in critically ill patients, an expert panel on indications for PA catheterization has been proposed recently to encourage research into the most appropriate clinical use of this catheter, as well as to provide encouragement for randomized controlled trials of PA catheterization. The tendency toward decreased use of PA catheterization in all patients with AMI in more recent years and an increase in the use of this procedure in more severely ill patients may reflect more refined and selective use of this technique by physicians; whether this more refined use results in improved patient outcome remains unknown.
Following a multivariate analysis to adjust for differences in factors associated with PA catheter use in patients with AMI, the findings of the present study suggest that PA catheterization is most frequently used in younger patients, in patients with more extensive myocardial necrosis, and in those with left ventricular dysfunction. These results are similar to previous findings reported from this study when the utilization of the PA catheter was examined from 1975 to 1984.
In summary, the results of this population-based study provide insights into changes over time in the use of PA catheterization in patients with AMI and of patient-related factors associated with the use of this procedure. Surveillance of trends in the use of this procedure and of patient factors associated with PA catheterization remains of importance, and should be encouraged to determine how effective the usage of PA catheterization is. Proper consideration should be given to randomized controlled trials of PA catheterization and of the impact of this procedure on selected outcomes in critically ill patients.