Mobile CT: Prehospital Diagnosis and Treatment of Stroke
Mobile CT: Prehospital Diagnosis and Treatment of Stroke
Purpose of review Mobile computed tomography (CT) scanning in specialized ambulances has recently become feasible. Two randomized trials have used mobile CTs for prehospital thrombolysis. This short review summarizes the available literature on this topic and provides an outlook on potential future developments.
Recent findings Mobile CT in acute suspected stoke is feasible and helps to diagnose, triage and treat patients. It is an integral component of a novel and promising stroke research platform in specialized ambulances with telemedicine connection and neurological expertise on board.
Summary Mobile CTs can speed up stroke treatment, especially thrombolysis; they allow for selecting the most adequate hospital destinations; and they offer new means of stroke research.
Prehospital diagnosis and treatment of stroke can be challenging. Presentations of stroke symptoms vary, they may be mimicked by other diseases and decisions have to be made under considerable time pressure. Compared with other body tissues, brain cells are extremely vulnerable to ischaemia. They die within minutes. Thrombolysis with intravenous (i.v.) recombinant tissue plasminogen activator (tPA) is the only effective, evidence-based treatment of acute ischaemic stroke up to 4.5 h of symptom onset. Effects of tPA are time-dependent. With every minute delay, fewer people are saved from disability. Therefore, American and European guidelines recommend giving tPA as fast as possible. However, exclusion of haemorrhagic stroke by brain imaging is mandatory before tPA can be administered. Many hospitals around the world are struggling to keep the time from hospital arrival to treatment start (door-to-needle time) below 60 min. A very fast in-hospital concept was developed in Helsinki and has recently been adopted by the Royal Melbourne Hospital. One of the basic principles of this concept is to do as much as possible in the prehospital phase of a stroke emergency and as little as necessary after arrival in the hospital before tPA treatment.
However, in addition to in-hospital delays, prehospital delays contribute to the total time to treatment. Some patients choose to wait for spontaneous recovery from symptoms prior to calling emergency services. Dispatchers are often challenged by the way patients describe their symptoms. Therefore, they may assign the wrong level of urgency to an emergency call for a stroke patient that has been mistaken for something else. Special stroke algorithms may facilitate the accuracy of these tele-diagnoses. In conventional emergency care, the patient's vital parameters are usually checked after arrival at the scene and prior to transportation, usually to the nearest hospital. The nearest hospital, however, may not be the most adequate hospital. A hospital adequate for stroke patients provides Stroke Unit (or Stroke Center) care and tPA treatment 24/7. Some stroke subtypes, however, require specialized neurosurgical or neurointerventionalist treatment and prehosptial triage could therefore facilitate the delivery to the most appropriate facility.
Recently, several studies have indicated that prehospital stroke care including thrombolysis in specialized ambulances equipped with computed tomography (CT) scanners is feasible. The CT aboard the ambulances does not only allow for thrombolysis but also enables accurate diagnosis and triage in the prehospital setting. This review summarizes the available literature on this topic and provides an outlook on potential future developments.
Abstract and Introduction
Abstract
Purpose of review Mobile computed tomography (CT) scanning in specialized ambulances has recently become feasible. Two randomized trials have used mobile CTs for prehospital thrombolysis. This short review summarizes the available literature on this topic and provides an outlook on potential future developments.
Recent findings Mobile CT in acute suspected stoke is feasible and helps to diagnose, triage and treat patients. It is an integral component of a novel and promising stroke research platform in specialized ambulances with telemedicine connection and neurological expertise on board.
Summary Mobile CTs can speed up stroke treatment, especially thrombolysis; they allow for selecting the most adequate hospital destinations; and they offer new means of stroke research.
Introduction
Prehospital diagnosis and treatment of stroke can be challenging. Presentations of stroke symptoms vary, they may be mimicked by other diseases and decisions have to be made under considerable time pressure. Compared with other body tissues, brain cells are extremely vulnerable to ischaemia. They die within minutes. Thrombolysis with intravenous (i.v.) recombinant tissue plasminogen activator (tPA) is the only effective, evidence-based treatment of acute ischaemic stroke up to 4.5 h of symptom onset. Effects of tPA are time-dependent. With every minute delay, fewer people are saved from disability. Therefore, American and European guidelines recommend giving tPA as fast as possible. However, exclusion of haemorrhagic stroke by brain imaging is mandatory before tPA can be administered. Many hospitals around the world are struggling to keep the time from hospital arrival to treatment start (door-to-needle time) below 60 min. A very fast in-hospital concept was developed in Helsinki and has recently been adopted by the Royal Melbourne Hospital. One of the basic principles of this concept is to do as much as possible in the prehospital phase of a stroke emergency and as little as necessary after arrival in the hospital before tPA treatment.
However, in addition to in-hospital delays, prehospital delays contribute to the total time to treatment. Some patients choose to wait for spontaneous recovery from symptoms prior to calling emergency services. Dispatchers are often challenged by the way patients describe their symptoms. Therefore, they may assign the wrong level of urgency to an emergency call for a stroke patient that has been mistaken for something else. Special stroke algorithms may facilitate the accuracy of these tele-diagnoses. In conventional emergency care, the patient's vital parameters are usually checked after arrival at the scene and prior to transportation, usually to the nearest hospital. The nearest hospital, however, may not be the most adequate hospital. A hospital adequate for stroke patients provides Stroke Unit (or Stroke Center) care and tPA treatment 24/7. Some stroke subtypes, however, require specialized neurosurgical or neurointerventionalist treatment and prehosptial triage could therefore facilitate the delivery to the most appropriate facility.
Recently, several studies have indicated that prehospital stroke care including thrombolysis in specialized ambulances equipped with computed tomography (CT) scanners is feasible. The CT aboard the ambulances does not only allow for thrombolysis but also enables accurate diagnosis and triage in the prehospital setting. This review summarizes the available literature on this topic and provides an outlook on potential future developments.
