Use of Dopamine in a Statewide Emergency Medical Services System
Background/Introduction: Dopamine is a potent, sympathomimetic medication used in emergency medicine and critical care to improve blood pressure (BP) in selected types of circulatory shock and to treat symptomatic bradycardia refractory to atropine and other interventions. While dopamine has been used by paramedics for many years, the prehospital experience in a statewide EMS system has not previously been reported. Objective/Purpose/Rationale: Describe the prehospital use of dopamine in a statewide EMS system. Materials and Methods: This is a retrospective, observational study of records obtained through the Michigan EMS Information System (MI-EMSIS). MI-EMSIS was filtered for the use of dopamine during 2015. The narrative report was manually reviewed and data were abstracted. In addition to basic demographics, clinical data such as pre/post-dopamine vital signs were obtained as well as post-dopamine adverse effects. Records were excluded for inter-facility transfers, dopamine not given, and when insufficient data existed. Standard descriptive statistical analysis was used. Results and Discussion: During the study period 1.6 million records were included in MI-EMSIS with 303,683 medications (excluding oxygen and intravenous fluids) administered. Dopamine was administered to 136 patients, with 22 patients excluded secondary to being inter-facility transports (18), having inadequate data (1), or no dopamine used (1), or other reason (2). There were 114 cases included for analysis representing <0.01% of all medications administered. The median (IQ) age was 67 (55,82) years and 57% were male. Cardiac arrest was the primary impression in 101 (88.6%) cases with 31 (27.2%) experiencing a post-dopamine cardiac arrest. The median (IQ) pre- and post-dopamine systolic and diastolic BPs were 79/51 (69/42, 101/64) and 93/58 (75/44, 114/74), respectively with the maximum post-dopamine BP 222/142. The median pre- and post-dopamine heart rate was 72 (55,91) and 81 (62, 103), respectively. The maximum post-dopamine heart rate was 179. Significant post-dopamine arrhythmias were noted in 9 (7.9%) patients with ventricular fibrillation (2, 1.8%), ventricular tachycardia (3, 2.6%), and atrial fibrillation (4, 3.5%) reported. A pre-dopamine fluid bolus was documented in 55 (48.2%) cases, with the median (IQ) volume of 500 (400, 1200) mL administered. Dopamine use was highly variable by county and not related to urban or rural location. Conclusion: In a statewide EMS system, prehospital dopamine administration was rarely reported and moist commonly associated with cardiac arrest. Post-dopamine improvements in BP and heart rate were common, although subsequent cardiac arrest was not infrequent. Serious post-dopamine arrhythmias and severe hypertension and tachycardia were uncommon.