Mobile stroke unit

Interior view of ambulance with a mobile CT scanner seen at the center.

A mobile stroke unit (MSU) is an ambulance that furnishes services to diagnose, evaluate, and/or treat symptoms of an acute stroke.[1] It may contain, in addition to the normal ambulance equipment, a device for brain imaging (computerized tomography), a point-of-care laboratory and telemedical interaction between ambulance and hospital (videoconferencing, exchange of videos of patient examination and CT scans). Thus, this specialized ambulance includes all the tools necessary for hyperacute assessment and treatment of stroke patients and diagnosis-based triage directly at the emergency site.

Purpose

Exterior view of ambulance

According to the 'time-is-brain' concept in acute stroke, recanalization of the obstructed blood vessels has to be performed within the very first hours after symptom onset. However, patients mostly come too late to the hospital and, therefore, only a minority of patients (5–10%) obtains the time-sensitive recanalizing treatments, and if so, mostly too late.[2] As a potential solution to the problem of detrimental delays in stroke management the MSU concept was developed enabling diagnosis and treatment directly at the emergency site as opposed to awaiting the patient's arrival at hospital for treatment. By bringing imaging technology and stroke clinical expertise to the scene, teams are able to take advantage of the pre-hospital arrival time by focusing team efforts solely on one patient with suspected stroke.[3][4][5][6][7]

Apart from the earlier start of treatment, knowledge about the type of stroke already in the pre-hospital phase of stroke management allows accurate triage decisions in regard to the most appropriate target hospital, e.g., hospital with or without endovascular or neurosurgical treatment options.

History and current evidence

The MSU concept was first published in 2003 and realized in clinical practice in 2008 by Fassbender et al. at Saarland University, Germany, adhering to current guidelines and legislations.[8] It increased treatment rates and improved care of cerebral hemorrhage, when compared to conventional in-hospital care as shown by them and other groups at Berlin, Germany; Houston, Texas, United States; Cleveland, Ohio, United States; New York, New York, United States; or Drøbak and Oslo, Norway.[9] In 2016, more than 20 sites are investigating this concept. In 2021, the preliminary results of the BEnefits of Stroke Treatment Delivered Using a Mobile Stroke Unit (BEST-MSU) were published in the New England Journal of Medicine, demonstrating improved disability outcomes for acute stroke patients treated on a MSU compared to standard transport to the Emergency Department by Emergency Medical Services (EMS). Further studies on long-term outcomes, cost-effectiveness and best setting are underway.

Frazer, Ltd. a Houston, Texas–based emergency vehicle builder, designed and built the 1st MSU in the United States in January 2014. Their specialization in on-board generators for EMS vehicles made them the perfect fit to create an emergency vehicle that could handle the needs of a mobile CT scanner. NeuroLogica Corporation, a subsidiary of Samsung Electronics, provides the mCT, CereTom, enabling the ambulance to do critical CT scans to determine the status of the stroke. With input from leading neurologists, Frazer was able to build a functional space on wheels that helps to drastically cut down the time between onset symptoms and treatment.

References

  1. ^ "Medicare Program; Revisions to Payment Policies Under the Physician Fee Schedule and Other Revisions to Part B for CY 2019; Medicare Shared Savings Program Requirements; Quality Payment Program; and Medicaid Promoting Interoperability Program". July 27, 2018.
  2. ^ Yong E (June 2014). "First response: race against time". Nature. 510 (7506): S5. Bibcode:2014Natur.510S...5Y. doi:10.1038/510S5a. PMID 24964025. S2CID 4389785.
  3. ^ Alexandrov AW, Alexandrov AV (April 2020). "Innovations in Prehospital Stroke Management Utilizing Mobile Stroke Units". Continuum (Minneapolis, Minn.). 26 (2): 506–512. doi:10.1212/CON.0000000000000850. PMID 32224764. S2CID 214732273.
  4. ^ Johansson T, Wild C (April 2010). "Telemedicine in acute stroke management: systematic review". International Journal of Technology Assessment in Health Care. 26 (2): 149–55. doi:10.1017/S0266462310000139. PMID 20392317. S2CID 19248591.
  5. ^ Wahlgren N, Ahmed N, Dávalos A, Ford GA, Grond M, Hacke W, Hennerici MG, Kaste M, Kuelkens S, Larrue V, Lees KR, Roine RO, Soinne L, Toni D, Vanhooren G (January 2007). "Thrombolysis with alteplase for acute ischaemic stroke in the Safe Implementation of Thrombolysis in Stroke-Monitoring Study (SITS-MOST): an observational study". Lancet. 369 (9558): 275–82. doi:10.1016/S0140-6736(07)60149-4. PMID 17258667. S2CID 15461913.
  6. ^ Fonarow GC, Smith EE, Saver JL, Reeves MJ, Bhatt DL, Grau-Sepulveda MV, Olson DM, Hernandez AF, Peterson ED, Schwamm LH (February 2011). "Timeliness of tissue-type plasminogen activator therapy in acute ischemic stroke: patient characteristics, hospital factors, and outcomes associated with door-to-needle times within 60 minutes". Circulation. 123 (7): 750–8. doi:10.1161/CIRCULATIONAHA.110.974675. PMID 21311083.
  7. ^ Meretoja A, Strbian D, Mustanoja S, Tatlisumak T, Lindsberg PJ, Kaste M (July 2012). "Reducing in-hospital delay to 20 minutes in stroke thrombolysis". Neurology. 79 (4): 306–13. doi:10.1212/WNL.0b013e31825d6011. PMID 22622858. S2CID 28263000.
  8. ^ Walter S, Kostpopoulos P, Haass A, Helwig S, Keller I, Licina T, et al. (October 2010). "Bringing the hospital to the patient: first treatment of stroke patients at the emergency site". PLOS ONE. 5 (10): e13758. Bibcode:2010PLoSO...513758W. doi:10.1371/journal.pone.0013758. PMC 2966432. PMID 21060800.
  9. ^ Fassbender K, Balucani C, Walter S, Levine SR, Haass A, Grotta J (June 2013). "Streamlining of prehospital stroke management: the golden hour". The Lancet. Neurology. 12 (6): 585–596. doi:10.1016/S1474-4422(13)70100-5. PMID 23684084. S2CID 10964618.