Patients with congestive heart failure treated by physicians using intravenous nitroglycerin boluses in the emergency department have shorter hospital length of stay

Abstract

Study objectives: Several studies have shown that high-dose nitroglycerin (NTG) is effective in decreasing the incidence of death, myocardial infarction, and need for mechanical ventilation in patients with congestive heart failure (CHF). We postulate that the use of intravenous NTG boluses in the emergency department (ED) would lead to decreased hospital length of stay for patients with CHF. Methods: This was a retrospective cohort in an urban nonteaching hospital with 43,000 annual ED visits. Consecutive patients treated by emergency physicians during a 20-month period who arrived between midnight and 8 am and were admitted for CHF exacerbation were included. We previously had shown that those arriving between midnight and 8 am were more likely to benefit from aggressive NTG therapy in the ED than those arriving at other times. To lessen the influence of outliers on the results, we a priori excluded patients with a length of stay greater than 10 days. On the basis of responses to a structured survey on the treatment of CHF in the ED, we divided emergency physicians into 2 groups: users and nonusers of intravenous bolus NTG. We then assigned CHF patients to 1 of the 2 groups according to their emergency physician categorization and calculated length of stay for each group of patients. We used Student's t test to compare means (α≤.05 taken as statistically significant). Results: The user and nonuser groups had 19 and 105 patients, respectively. The mean age (66±14 and 71±13 years, respectively) and the percentage of female patients (58% and 50%, respectively) was similar between the groups. The mean length of stay for the user and nonuser groups was 3.7±1.5 and 4.6±2.4 days, respectively. The difference of 0.9 days was statistically significant (95% confidence interval 0.0 to 1.7 days, P =.05). Conclusion: CHF patients who arrive between midnight and 8 am spend almost 1 day fewer in the hospital if they are treated by emergency physicians who use intravenous NTG boluses than if they are treated by those who do not.