Telemedicine and stroke: Stroke Emergency Mobile Unit - A new approach to stroke care
Correspondence Address: Source of Support: None, Conflict of Interest: None DOI: 10.4103/0028-3886.178050
Source of Support: None, Conflict of Interest: None
Stroke is one of the leading causes of death and the most frequent reason for permanent disability.  Thrombolysis with recombinant tissue plasminogen activator (rtPA) remains the major therapy for acute ischemic stroke. The benefit of this therapy is, however, extremely time sensitive.The number of patients needed to treat to achieve a good outcome (defined as modified Rankin's scale < 2) is 4.5 if treatment starts within 1.5 h. This number doubles to 9 if treatment is initiated between 1.5 to 3 h. , An improvement in the number of patients treated per year has been seen after enhancements in the treatment chain were made.  The "time is brain" concept, that has been derived from such observations, is also supported by earlier experimental animal research ,, and by calculations indicating that for each minute in which stroke remains untreated, as many as 1.9 million neurons and 14 billion synapses may die. 
A specific management in specialized hospital facilities has been shown to improve process quality and outcomes in a variety of diseases. ,, In the context of neurological disorders, this applies to the treatment of acute stroke in stroke units or the management of intracranial hemorrhages in hospitals with organized stroke care or neurosurgical facilities. , A correct pre-hospital diagnosis is important because it avoids admissions to inappropriate hospitals where suboptimal care would be provided. This may also lead to time-consuming secondary patient transfers. In addition, the pre-hospital diagnostic work up can accelerate emergency management by an advanced notification transmitted to the hospital teams. , However, the diagnosis of neurological disorders is often difficult with a wide variety of symptoms, presentations, and causes being found at the initial encounter with the patient. For example, the initial diagnosis of stroke in the Emergency Department (ED) yielded a stroke mimic rate of 19%, based on history and clinical examination only.  If additional laboratory findings and a computed tomographic (CT) scan were available, the stroke mimic rate was only 4%. 
According to the PreHospital Acute Neurological Therapy and Optimization of Medical Care in Stroke (PHANTOM-S) study, the patient care in the stroke emergency mobile (STEMO) units was safe, increased the rate of intravenous thrombolysis in patients with ischemic stroke, and reduced the time-to-treatment.  The PHANTOM-S study has been designed to demonstrate a reduced alarm-to-needle time in STEMO compared with the usual care. Given the close association between time-to-treatment and outcome in acute ischemic stroke patients, the study will show whether this concept should be incorporated as an integral part of the standard stroke care. Future studies may then explore which constituents of STEMO play the most important role in the pre-hospital stroke care.
Recently, 2 groups in Germany have installed a CT scanner on an ambulance, along with either an on-board or remote (via telemedicine) stroke expertise, and point-of-care laboratory testing to take the stroke unit to the patient and to facilitate an early treatment. , This mobile stroke unit (MSU) concept moves the stroke treatment from the ED to the prehospital environment. Performing the assessment in the ED, as is done in the conventional setting, is often associated with inherent delays caused by the processes of ED triage, registration, evaluation and testing of the patients prior to the initiation of treatment.
A STEMO unit is an ambulance staffed with a specialized stroke team and equipped with a computed tomographic scanner and point-of-care laboratory. In a study by Wendt et al., an improved prehospital triage of patients with stroke was established by the use of specialized stroke ambulances for the transportation of the patients.  The study compared the pre-hospital triage of patients with suspected stroke at the dispatcher level. The patients either received STEMO care or conventional care. The study also assessed the transport destination in patients with different diagnoses. Patients who received STEMO care were physically examined by the STEMO neurologist upon arrival in the hospital. If necessary, point-of-care laboratory investigations, including the blood count, glucose, electrolytes, international normalized ratio, and creatinine, were performed. A CT scan was performed, if indicated, for an immediate therapeutic decision making or for conducting the patient's triage. An additional CT angiography was performed whenever additional information about a specific arterial occlusion was requested. Imaging data was sent via tele-radiology to the neuroradiologist on call, who interpreted these images immediately and gave feedback to the STEMO physician. In difficult cases that needed to include decisions regarding thrombolysis, a senior neurologist was also involved via a telephone or video-conferencing. Following this assessment, the patients were transported to the nearest hospital based on the judgment of the emergency physician (respecting the patient's preference). The status at discharge from the hospital was used as a short-term outcome. 
The results from May 2011 to January 2013 revealed that 1804 of 6182 (29%) patients received the STEMO care and 4378 of 6182 (71%) patients received the conventional care. Two hundred and forty-five of the 2110 (11.6%) patients with cerebrovascular events were sent to hospitals that did not have a stroke unit in the conventional care subgroup, when compared with 48 of 866 (5.5%; P < 0.01%) patients in the STEMO care subgroup. In patients with ischemic stroke, the STEMO care reduced transport to hospitals without a stroke unit from 10.1% (151 of 1497) to 3.9% (24 of 610; P < 0.01). The delivery rate of patients with intracranial hemorrhage to hospitals without the neurosurgery department was 43.0% (65 of 151) in the conventional care subgroup, and 11.3% (7 of 62) in the STEMO care subgroup (P < 0.01). There was a slight trend toward higher rates of neurological patients being discharged to undergo domiciliary care in the STEMO subgroup when compared with the conventional care subgroup (63.5% versus 60.8%; P = 0.096). It was concluded that the triage of patients with cerebrovascular events to specialized hospitals might be improved by STEMO ambulances. 
The idea of the MSU has actually been around for quite some time, but it is now that the technology has become advanced enough for us to actually be able to realize and utilize its potential applications. Germany had introduced the first MSUs. The doctors at the University of Saarland were the pioneers of the concept of MSUs and have probably been applying it in their practice for the last 7-8 years. They have a significantly different model in which physicians and often neuroradiologists accompany the MSUs to interpret the imaging. This concept, of course, is not practical in India or even in the United States.
In addition to having CT scanners that are small enough to fit inside an ambulance, we now also have better technology for transmission of images. Using long-term evolution (LTE) networks and the fourth generation (4G) of mobile telecommunication technology, we are able to transmit images much more quickly so that they may be read at a remote location. In addition, we can use telemedicine to allow our physicians to beam into the vehicle and actually assess the patient, make a tele-examination, and talk to the family and the crew in the ambulance.
Everybody is concerned about the cost of this venture, so this is a question that needs to be addressed. There is the cost of the physical unit, which is probably around $1 million and then there is the recurring cost of staffing these units. It would have to be unequivocally shown that improvements in outcomes and disability translates to significant cost-savings down the line. I think in the current healthcare environment, where people are very concerned about the rising costs of treatment, it would have to be proven that introduction of this facility is going to be cost-effective.
By using systems for bidirectional audiovisual video-conferencing and exchange of videos of the examination of the patient and of CT scans, the non-specialized regional hospitals can obtain guidance in stroke treatment from hospitals designated as stroke centers.  Previous studies have not only shown that such telemedicine interactions between the two hospitals are reliable and safe, ,,, but also that they exert a positive effect on the thrombolysis rates and clinical outcome.  More importantly, these telemedicine technologies could, in principle, also allow a bidirectional communication to take place between the emergency medicine services team at the emergency site and the stroke center. Such strategies have been investigated for many years; , however, technical problems such as the temporary loss of signals impair a reliable interaction between the ambulance and the hospital even in the recent times. ,
The major obstacles to successfully establishing the concept of MSU include obtaining adequate funding, the licensure procedures involved, implementing radiation safety protocols, and establishing a smooth communication system within the emergency medical services network. The preliminary data during the run-in phase indicate that there are no significant complications, with roughly two patients being treated with rtPA per week, and one-third within the first 60 min. Further studies are underway to determine the time-saving benefits, clinical outcomes, telemedicine reliability, and cost effectiveness of the MSU strategy. 
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