Two Years In With the Nation’s First Mobile Stroke Unit

The first mobile stroke unit (MSU) in the United States was created in 2014 by the McGovern Medical School at the University of Texas Health Science Center at Houston (UTHealth).

“It is a research study,” explains Stephanie Parker, RN, program manager for UTHealth’s MSU. “We want to compare the treatment of stroke patients that are brought into the stroke receiving hospitals by the Houston Fire Department (HFD) ambulances versus those treated by the MSU. It is a controlled, randomized study. The mobile unit is on for seven days and off for seven days. This is a collaboration with the other four comprehensive stroke centers within the city of Houston: Harris Health, Memorial Hermann, Houston Methodist and St. Luke’s Baylor. We are looking at the cost-effectiveness, patient outcomes and if permanent MSUs are feasible.”

The MSU is funded by donations. There is no grant funding for the program. Many organizations, businesses and individuals donated money to fund the equipment and personnel. The EMS module was donated by Frazer Ltd., a Houston-based emergency vehicle manufacturer.

“We build mobile health vehicles and all the electrical components that go with them,” says Scott Harrell, Frazer’s marketing supervisor. “We specialize in putting on-board generators on EMS vehicles, which would be needed for a mobile CT scanner. The generator handles all the electrical needs of the box, including the CT unit and the powerful air conditioning system. It was not a difficult fit. We needed to modify the floor and the back wall of the box. The strength needed to support the weight of the scanner was already built into the module. The captain’s chair was removed and the floor was laser-leveled to make sure it was absolutely flat. The chassis, a Chevrolet C3500 with a 6-liter gasoline engine, was bought with other donated funds.”

The MSU is based out of the UTHealth Medical Center and embedded within the Houston 9-1-1 system. It is dispatched immediately if a stroke is suspected within an eight-mile radius of the hospital. If first responders suspect a stroke on a scene that’s been dispatched as something else, they will add the MSU to the call. If the HFD ambulance is ready to leave the scene with the patient before it arrives, the MSU will meet them en route to a stroke center.

“We are considered just another apparatus of the HFD,” says Parker. “We have developed a fantastic working relationship. They consider us one of their own. It is really a collaboration between us.”

For the project’s first two years, the MSU’s crew included a neurologist. That’s since been scaled back. Staffing now consists of two off-duty HFD paramedics, Parker or another neurology critical care-trained nurse, and a CT technician. Technology now links them to a remote physician.

“When we get on scene with Houston FD units,” explains Parker, “I will be wearing a headset and have a telemedicine camera in my hand. So the telemedicine doctor, the paramedic on scene and I will all assess the patient for a stroke. If they meet the stroke protocol, we will put them in the MSU. Once the CT scan is done, it is transmitted to the doctor, and they read it and give orders. It is very protocol driven. We also transmit the scan to the receiving hospital physician. If the scan is negative and they are still having symptoms, we will start the tPA. We have an average on-scene time of 20 minutes. We will transport the patient based on their home healthcare provider. So far we have treated about 160 patients with tPA on the MSU.

“We can also assess for large-vessel occlusions and triage those patients to a comprehensive stroke center,” Parker adds. “We can then alert the endovascular team at whatever comprehensive stroke center is our destination. We are also collecting that data and hopefully are getting those patients into the cath lab faster. In 2014–15 there were five endovascular studies published that showed the fastest average symptom-onset-to-groin-puncture time was 270 minutes. Our average has been 172 minutes. So we are saving a significant amount of time with these patients.

“We are hoping to show better outcomes with faster treatment. If we can, it will show a cost savings to the healthcare industry. If we could prove this, we could get a higher reimbursement for MSUs on the front side and will provide an increase in the quality of life for the patient and save money long-term. That would show the value of the MSU and make the program sustainable.”

Barry D. Smith is an instructor in the Education Department at the Regional Emergency Medical Services Authority (REMSA) in Reno, NV. Contact him at bsmith@remsa-cf.com.