Mobile stroke unit

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Interior view of ambulance with a mobile CT scanner seen at the center. 2016.05.04 MSU, Mobile Stroke Unit interior.jpg
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.

Contents

Purpose

Exterior view of ambulance Mobile-stroke-unit-exterior.jpg
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.

Related Research Articles

<span class="mw-page-title-main">Triage</span> Emergency medical process

In medicine, triage is a process by which care providers such as medical professionals and those with first aid knowledge determine the order of priority for providing treatment to injured individuals and/or inform the rationing of limited supplies so that they go to those who can most benefit from it. Triage is usually relied upon when there are more injured individuals than available care providers, or when there are more injured individuals than supplies to treat them.

<span class="mw-page-title-main">Emergency medical services</span> Services providing acute medical care

Emergency medical services (EMS), also known as ambulance services or paramedic services, are emergency services that provide urgent pre-hospital treatment and stabilisation for serious illness and injuries and transport to definitive care. They may also be known as a first aid squad, FAST squad, emergency squad, ambulance squad, ambulance corps, life squad or by other initialisms such as EMAS or EMARS.

<span class="mw-page-title-main">Paramedic</span> Healthcare professional who works in emergency medical situations

A paramedic is a healthcare professional trained in the medical model, whose main role has historically been to respond to emergency calls for medical help outside of a hospital. Paramedics work as part of the emergency medical services (EMS), most often in ambulances. They also have roles in emergency medicine, primary care, transfer medicine and remote/offshore medicine. The scope of practice of a paramedic varies between countries, but generally includes autonomous decision making around the emergency care of patients.

<span class="mw-page-title-main">Emergency department</span> Medical treatment facility specializing in emergency medicine

An emergency department (ED), also known as an accident and emergency department (A&E), emergency room (ER), emergency ward (EW) or casualty department, is a medical treatment facility specializing in emergency medicine, the acute care of patients who present without prior appointment; either by their own means or by that of an ambulance. The emergency department is usually found in a hospital or other primary care center.

<span class="mw-page-title-main">Pulmonary embolism</span> Blockage of an artery in the lungs

Pulmonary embolism (PE) is a blockage of an artery in the lungs by a substance that has moved from elsewhere in the body through the bloodstream (embolism). Symptoms of a PE may include shortness of breath, chest pain particularly upon breathing in, and coughing up blood. Symptoms of a blood clot in the leg may also be present, such as a red, warm, swollen, and painful leg. Signs of a PE include low blood oxygen levels, rapid breathing, rapid heart rate, and sometimes a mild fever. Severe cases can lead to passing out, abnormally low blood pressure, obstructive shock, and sudden death.

<span class="mw-page-title-main">Thrombolysis</span> Breakdown (lysis) of blood clots formed in blood vessels, using medication

Thrombolysis, also called fibrinolytic therapy, is the breakdown (lysis) of blood clots formed in blood vessels, using medication. It is used in ST elevation myocardial infarction, stroke, and in cases of severe venous thromboembolism.

<span class="mw-page-title-main">Chest pain</span> Discomfort or pain in the chest as a medical symptom

Chest pain is pain or discomfort in the chest, typically the front of the chest. It may be described as sharp, dull, pressure, heaviness or squeezing. Associated symptoms may include pain in the shoulder, arm, upper abdomen, or jaw, along with nausea, sweating, or shortness of breath. It can be divided into heart-related and non-heart-related pain. Pain due to insufficient blood flow to the heart is also called angina pectoris. Those with diabetes or the elderly may have less clear symptoms.

<span class="mw-page-title-main">Stroke</span> Death of a region of brain cells due to poor blood flow

Stroke is a medical condition in which poor blood flow to the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functioning properly.

Mechanical thrombectomy, or simply thrombectomy, is the removal of a blood clot (thrombus) from a blood vessel, often and especially endovascularly as an interventional radiology procedure called endovascular thrombectomy (EVT). It thus contrasts with thrombolysis by thrombolytic medications, as either alternative or complement thereto. It is commonly performed in the cerebral arteries as treatment to reverse the ischemia in some ischemic strokes. Open vascular surgery versions of thrombectomy also exist. The effectiveness of thrombectomy for strokes was confirmed in several randomised clinical trials conducted at various medical centers throughout the United States, as reported in a seminal multistudy report in 2015.

<span class="mw-page-title-main">Acute coronary syndrome</span> Medical condition

Acute coronary syndrome (ACS) is a syndrome due to decreased blood flow in the coronary arteries such that part of the heart muscle is unable to function properly or dies. The most common symptom is centrally located pressure-like chest pain, often radiating to the left shoulder or angle of the jaw, and associated with nausea and sweating. Many people with acute coronary syndromes present with symptoms other than chest pain, particularly women, older people, and people with diabetes mellitus.

<span class="mw-page-title-main">Intracerebral hemorrhage</span> Type of intracranial bleeding that occurs within the brain tissue itself

Intracerebral hemorrhage (ICH), also known as hemorrhagic stroke, is a sudden bleeding into the tissues of the brain, into its ventricles, or into both. An ICH is a type of bleeding within the skull and one kind of stroke. Symptoms can vary dramatically depending on the severity, acuity, and location (anatomically) but can include headache, one-sided weakness, numbness, tingling, or paralysis, speech problems, vision or hearing problems, memory loss, attention problems, coordination problems, balance problems, dizziness or lightheadedness or vertigo, nausea/vomiting, seizures, decreased level of consciousness or total loss of consciousness, neck stiffness, and fever.

<span class="mw-page-title-main">Cerebral infarction</span> Stroke resulting from lack of blood flow

Cerebral infarction, also known as an ischemic stroke, is the pathologic process that results in an area of necrotic tissue in the brain. In mid to high income countries, a stroke is the main reason for disability among people and the 2nd cause of death. It is caused by disrupted blood supply (ischemia) and restricted oxygen supply (hypoxia). This is most commonly due to a thrombotic occlusion, or an embolic occlusion of major vessels which leads to a cerebral infarct. In response to ischemia, the brain degenerates by the process of liquefactive necrosis.

<span class="mw-page-title-main">Paramedics in the United States</span> Overview of paramedics in the United States of America

In the United States, the paramedic is an allied health professional whose primary focus is to provide advanced emergency medical care for patients who access Emergency Medical Services (EMS). This individual possesses the complex knowledge and skills necessary to provide patient care and transportation. Paramedics function as part of a comprehensive EMS response under physician medical direction. Paramedics often serve in a prehospital role, responding to Public safety answering point (9-1-1) calls in an ambulance. The paramedic serves as the initial entry point into the health care system. A standard requirement for state licensure involves successful completion of a nationally accredited Paramedic program at the certificate or associate degree level.

Door-to-balloon is a time measurement in emergency cardiac care (ECC), specifically in the treatment of ST segment elevation myocardial infarction. The interval starts with the patient's arrival in the emergency department, and ends when a catheter guidewire crosses the culprit lesion in the cardiac cath lab. Because of the adage that "time is muscle", meaning that delays in treating a myocardial infarction increase the likelihood and amount of cardiac muscle damage due to localised hypoxia, ACC/AHA guidelines recommend a door-to-balloon interval of no more than 90 minutes. As of 2006 in the United States, fewer than half of STEMI patients received reperfusion with primary percutaneous coronary intervention (PCI) within the guideline-recommended timeframe. It has become a core quality measure for the Joint Commission on Accreditation of Healthcare Organizations (TJC).

<span class="mw-page-title-main">Acute limb ischaemia</span> Occurs when there is a sudden lack of blood flow to a limb

Acute limb ischaemia (ALI) occurs when there is a sudden lack of blood flow to a limb, within 14 days of symptoms onset. It is different from another condition which is more chronic called critical limb ischemia (CLD). CLD is the end stage of peripheral vascular disease where there is still some collateral circulation (alternate circulation pathways} that bring some blood to the distal parts of the limbs. While limbs in both acute and chronic limb ischemia may be pulseless, a chronically ischemic limb is typically warm and pink due to a well-developed collateral artery network and does not need emergency intervention to avoid limb loss.

<span class="mw-page-title-main">Reperfusion therapy</span> Restoring blood flow post-heart attack

Reperfusion therapy is a medical treatment to restore blood flow, either through or around, blocked arteries, typically after a heart attack. Reperfusion therapy includes drugs and surgery. The drugs are thrombolytics and fibrinolytics used in a process called thrombolysis. Surgeries performed may be minimally-invasive endovascular procedures such as a percutaneous coronary intervention (PCI), which involves coronary angioplasty. The angioplasty uses the insertion of a balloon and/or stents to open up the artery. Other surgeries performed are the more invasive bypass surgeries that graft arteries around blockages.

<span class="mw-page-title-main">Management of acute coronary syndrome</span>

Management of acute coronary syndrome is targeted against the effects of reduced blood flow to the affected area of the heart muscle, usually because of a blood clot in one of the coronary arteries, the vessels that supply oxygenated blood to the myocardium. This is achieved with urgent hospitalization and medical therapy, including drugs that relieve chest pain and reduce the size of the infarct, and drugs that inhibit clot formation; for a subset of patients invasive measures are also employed. Basic principles of management are the same for all types of acute coronary syndrome. However, some important aspects of treatment depend on the presence or absence of elevation of the ST segment on the electrocardiogram, which classifies cases upon presentation to either ST segment elevation myocardial infarction (STEMI) or non-ST elevation acute coronary syndrome (NST-ACS); the latter includes unstable angina and non-ST elevation myocardial infarction (NSTEMI). Treatment is generally more aggressive for STEMI patients, and reperfusion therapy is more often reserved for them. Long-term therapy is necessary for prevention of recurrent events and complications.

<span class="mw-page-title-main">Pre-hospital emergency medicine</span>

Pre-hospital emergency medicine, also referred to as pre-hospital care, immediate care, or emergency medical services medicine, is a medical subspecialty which focuses on caring for seriously ill or injured patients before they reach hospital, and during emergency transfer to hospital or between hospitals. It may be practised by physicians from various backgrounds such as anaesthesiology, emergency medicine, intensive care medicine and acute medicine, after they have completed initial training in their base specialty.

Stroke centers are medical centers having health professionals specially trained in emergency stroke care. They are considered preferred first responders in the diagnosis and treatment of strokes. Certifying authorities recognize four levels of certification, highest to lowest, as follow:

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