Improving time-sensitive processes in the intensive care unit: the example of 'door-to-needle time' in acute myocardial infarction

Objective. To assess and reduce delays in coronary thrombolysis in patients with acute myocardial infarction. Design. Prospective, descriptive study using statistical process control. Setting. Interdisciplinary intensive care unit of a 300-bed community hospital. Subjects. Thirty-seven consecutive patients with acute myocardial infarction who were receiving thrombolytic therapy. Interventions. To perform an interdisciplinary formal process analysis aimed;it detecting delay-causing factors, review of existing house rules, generation and implementation of new practice guidelines Main outcome measures. Comparison of 'door-to-needle times' of patients admitted before, during and after formal process analysis and implementation of new guidelines. Results. Mean 'door-to-needle time' fell significantly from 57 minutes (+/- 25.4) in 16 patients studied before, to 32 minutes (+/-9.0) in 16 patients studied after the formal process analysis and the implementation of new guidelines (P < 0.002). An even more pronounced but transient decrease to 24 minutes (+/- 3.8) was observed in five patients studied during the phase of formal process analysis (P < 0.004). Delay-causing factors were identified in the areas 'communication', 'people' and 'methods/rules/guidelines'. Equipment failure was never responsible for delays. Conclusions. Formal process analysis, followed by implementation of revised guidelines resulted in a significant reduction of 'door-to-needle time'. An initial dramatic but transient reduction of 'door-to-needle time' was considered observational and must not be mistaken as the definite new level of performance. We conclude that formal process analysis techniques are suited to improve processes in the intensive care unit.