Greg Hoskins


June 2008

Document Type


Degree Name



Dept. of Public Health and Preventive Medicine


Oregon Health & Science University


Background: Vasopressin increases peripheral vascular resistance and volume retention, without increasing myocardial oxygen demand and ischemia. It therefore has theoretic advantage over epinephrine for the treatment of cardiac arrest. Preliminary animal and human trails supported this theory, however larger randomized trials failed to show an overall benefit. One large human trial suggested that a subgroup of cardiac arrest, those with asystole, uniquely benefited from vasopressin therapy. Our analysis uses data from a large urban EMS system that added vasopressin to standard therapy in the setting of asystole in January 2005. Our study compared the rate of return of spontaneous circulation (ROSC) in patients treated by this EMS system for asystole before and after the protocol change. Methods: A historical cohort study design was used to determine if the addition of vasopressin to the asystole protocol improved return of spontaneous circulation (ROSC). Two county EMS electronic databases were queried for all patients treated for out-of-hospital asystole from January 2004 through September 2006, one year prior, and one year following the protocol change. Patients were excluded if they suffered traumatic arrest, were younger than 15 years old, or had treatment withheld due to “do not resuscitate” orders. The proportion of ROSC was compared in patients treated before the protocol change (standard treatment) with those treated after the protocol change (vasopressin added treatment). Other variables were collected and according to the Utstein style, and were tested for inclusion in the final model. Logistic regression analysis was used to calculate an adjusted odds ratio. Results: There was no difference between the two protocol groups in the rate of ROSC [OR = 1.18 (0.72-1.93), standard therapy = ref.). Other secondary independent variables were found to have significant association with ROSC: arrest witnessed by bystander [OR = 2.72 (1.70-4.36)], witnessed by EMS [OR = 4.21 (1.69-10.51)], and time from call to scene greater than 8 minutes [OR = 0.42 (0.21-0.85)]. Conclusion: Our study fails to demonstrate improved return of spontaneous circulation from vasopressin therapy for the treatment of asystole. The study results are consistent with the results of other studies of vasopressin for cardiac arrest.




School of Medicine



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