Clinical Trial Details
— Status: Completed
Administrative data
NCT number |
NCT03036020 |
Other study ID # |
NASPP-2 |
Secondary ID |
|
Status |
Completed |
Phase |
N/A
|
First received |
December 1, 2014 |
Last updated |
January 27, 2017 |
Start date |
October 2014 |
Est. completion date |
January 2016 |
Study information
Verified date |
January 2017 |
Source |
Norwegian Air Ambulance Foundation |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
The main aim of the NASPP study is to assess the efficacy and safety of the prehospital
diagnosis of stroke using the Norwegian stroke ambulance concept. NASPP aims to demonstrate
that anesthesiologists trained in pre-hospital critical care may perform acute stroke
diagnostics by clinical assessment and CT scan interpretation and integrating these skills
in the already existing organizational frame of the Norwegian prehospital EMS system.
NASPP will systematically explore the Norwegian model of prehospital acute stroke
diagnostics prior to the implementation of prehospital thrombolytic stroke treatment. NASSP
will equip a regular ambulance staffed with a specially trained anesthesiologist and a
specialized nurse. NASPP will perform the clinical part of the study in close co-operation
with Østfold Hospital, Fredrikstad.
Description:
Background Stroke is the third leading cause of death in most western countries, and the
major cause of adult disability leaving two thirds of stroke survivors struggling with
moderate to severe disability. Stroke affects approximately 15 million people worldwide each
year.
Up to 90% of all strokes are ischemic (cerebral infarction), mostly due to an acute
thromboembolic obstruction of a cerebral artery, whereas around 10 % of strokes are cerebral
hemorrhages. Acute ischemic stroke must be considered as a medical emergency, and early
recanalization of the obstructed artery must be attempted. The intravenous drug alteplase
(Actilyse®), a recombinant human tissue type plasminogen activator, is approved for use
within 4.5 hours after symptom start of an ischemic stroke. The earlier treatment is
initiated, however, the better odds for of a good outcome.
A cerebral infarction cannot be differentiated from a cerebral hemorrhage without
neuroradiological investigation. If a patient with acute cerebral hemorrhage is treated with
thrombolysis it may be fatal. Therefore, and contrary to the setting of a cardiac
infarction, intravenous thrombolysis of cerebral infarction has to be performed in-hospital
after computer tomography (CT), or magnetic resonance imaging (MRI), scanning of the brain.
The consequence of this obligatory radiological examination is an unavoidable time delay and
very few ischemic stroke patients are actually treated within "the golden 90 minutes" after
symptom onset. The only way to avoid this, for the brain, detrimental time delay is logical;
to establish the diagnosis of ischemic stroke outside the hospital and in time as near
symptom onset as possible. Subsequently this will open the possibility for very early
prehospital thrombolytic treatment for a much higher number of patients.
Minimizing prehospital time delay has been proven to positively influence thrombolytic rates
in acute ischemic stroke. However, a recent study with a telemedicine-equipped ambulance
(telestroke ambulance) has shown that prehospital real-time stroke severity assessment by
hospital-based stroke physicians during ambulance transport does not have a technical
acceptable stability for clinical use. In this Berlin study using "actor stroke patients" in
a moving ambulance, an acceptable clinical evaluation of only 40% of the patients was
achieved. A recent clinical stroke study from the University Saarland, Germany has, however,
demonstrated that the concept of prehospital stroke diagnosis is feasible. Using a specially
designed mobile stroke unit (MSU), a car ambulance equipped with a stroke neurologist, a CT
scanner and a point of care biochemical laboratory, time from symptom onset to diagnostic
therapeutic decision for thrombolysis was reduced from 76 to 35 minutes. The CT scanner in
the MSU was shown to provide brain scans of high quality in 95% of cases allowing
differentiation of cerebral infarction and cerebral hemorrhage. No safety radiation issues
occurred for either staff or patients.
The time delay in stroke diagnostics may be reduced with early radiological diagnosis, but
there is also need of reliable clinical recognition of stroke symptoms. The reliability of
the National Institutes of Health Stroke Scale (NIHSS) is established by several clinical
trials when performed by trained neurologists. Dewey et al proved in a 1999 trial
"Inter-rater reliability of the National Institutes of Health Stroke scale: Rating by
Neurologists and Nurses in a Community-Based stroke Incidence study" that the overall
agreement in NIHSS scoring between trained nurses and a trained neurologists were no
different from the agreement between neurologists. The study suggested that trained nurses
could administer the NIHSS with reliability similar to stroke- trained neurologists.
Aims The main aim of the NASPP study is to assess the efficacy and safety of the prehospital
diagnosis of stroke using the Norwegian stroke ambulance concept. NASPP aims to demonstrate
that anesthesiologists trained in pre-hospital critical care may perform acute stroke
diagnostics by clinical assessment and CT scan interpretation and integrating these skills
in the already existing organizational frame of the Norwegian prehospital EMS system.
NASPP will systematically explore the Norwegian model of prehospital acute stroke
diagnostics prior to the implementation of prehospital thrombolytic stroke treatment. NASSP
will equip a regular ambulance staffed with a specially trained anesthesiologist and a
specialized nurse. NASPP will perform the clinical part of the study in close co-operation
with Østfold Hospital, Fredrikstad.
Hypothesis Cerebral CT examination by an anesthesiologist trained in prehospital care;
feasible and accurate after a stroke? An anesthesiologist trained in pre-hospital care will
be able to perform, assess and transfer by teleradiology cerebral CT scans from patients
presenting with stroke symptoms lasting no more than 4 hours. The performance of the
anesthesiologists will be compared to independent assessments may by a radiologist or a
neurologist at the admission hospital, and further on with a neuroradiologist.
The prehospital diagnosis of ischemic stroke by an anesthesiologist trained in prehospital
critical care - a new concept. An anesthesiologist trained in pre-hospital critical care
will make an accurate prehospital clinical and radiological diagnosis of acute ischemic
stroke, enabling early prehospital thrombolytic treatment.
Long-term prognostic value of NIHSS assessment in the prehospital phase of ischemic stroke.
To assess if a prehospital NIHSS score may predict long-term (3 months) patient outcome
assessed with the modified Rankin Scale (mRS), in acute stroke patients treated or not
treated with thrombolysis.
Design NASPP is an observational and cross-sectional study, designed to test the efficiency
and accurancy of prehospital diagnostics of acute stroke in a Norwegian stroke ambulance
concept. NASPP is considered a pilot study, due to paucity of data in the literature and
lack of existing medical experience. NASPP will aim to include up to 200 patients.
Methods and material: Clinical study Cerebral CT examination by an anesthesiologist trained
in prehospital care; feasible and accurate after a stroke? Prehospital ischemic stroke
diagnostics by an anesthesiologist trained in prehospital critical care - a new concept.
After completing a preclinical study we aim to prove that anesthesiologists trained in
pre-hospital critical care can perform "state of the art" prehospital acute stroke
diagnostics. Patient care delivery will be conducted in a specially designed stroke
ambulance operating from Østfold Hospital, Fredrikstad. The stroke ambulance will respond to
all patients over the age of 18 in contact with 113 emergency dispatch center presenting
symptoms of paresis of arm and or legs, facial paresis, visual or speech disturbances
(Norwegian Index of medical emergencies chapter 27.03-27.05). The local dispatch center will
send the stroke ambulance for an emergency turnout to the patient. The stroke ambulance will
operate from 08.00 am to 20.00 p.m. during weekdays in the study period, because of
practical and economical considerations. The stroke ambulance will only respond to patients
localized more than 10 -15 minutes drive from the hospital, to make sure that no time is
lost to those living in the very close proximity to the hospital. The dispatch center will
simultaneously alarm the on-call neurologist at Østfold Hospital, Fredrikstad.
The Norwegian Air Ambulance Foundation will organize the training of the stroke ambulance
crew (anesthesiologist and nurse trained in prehospital care). The training course is based
on the preclinical trail, and also including simulation training in the stroke ambulance.
The ambulance anesthesiologist will complete a test in interpretation of cerebral CT scans
in acute stroke, and a NIHSS certification. The anesthesiologist and the nurse will both be
trained to operate the biochemical point of care laboratory (glucose, platelets, INR and Hb)
and the CT machine.
The stroke ambulance will respond to all patients with stroke symptoms meeting the inclusion
criteria. A total of 400 patients will be included, and all patients will be asked for oral
consent. If aphasic, or having reduced consciousness, the patient will be included in the
study. On site the anesthesiologist will do a rapid screening using the ABCDE`s of trauma
care. If the patient is stable and further investigations can proceed the NIHSS score will
be completed. The patient will get two venous lines, and blood samples will be collected.
Blood samples for GFAP and S-100 B will be stored and delivered to the laboratory at the
hospital for further analyses. A circulatory stabile patient will be taken into the stroke
ambulance, were the CT scan can be performed. In circulatory unstable patients the ambulance
anesthesiologist can decide not to perform the CT scan but head directly to the hospital.
While the CT scan is taken the blood samples are analyzed in the point of care laboratory.
The ambulance anesthesiologist assesses the CT scan and fills out the study forms. The CT
scan is simultaneously sent to Østfold Hospital, Fredrikstad for interpretation by the
neurologist and the radiologist on call. The patient transport to the hospital and the
communication with the neurologist on call will follow standard procedures. The
anesthesiologist will not report the results of NIHSS score or CT scans, as the study form
completed by the anesthesiologist is for research purpose only. The ambulance
anesthesiologist will be medically responsible for the patient until hospitalization. The
neurological team on call will provide further medical care, and if appropriate start
thrombolytic treatment after patient admission.
A neuroradiologist will, without any clinical knowledge, review the CT scans after the study
has included at least 400 patients. The results from the initial interpretation by the
ambulance anesthesiologist are held anonymous, and blinded for the neuroradiologist. The
in-hospital written reports will be collected and reviewed. The results will be analyzed
statistically to show distribution of the different categories of inter-rater agreement,
compared to the neurologists and radiologists at the admission hospital.
To test hypothesis the anesthesiologist trained in pre-hospital critical care will decide
upon whether he/she would have given thrombolytic treatment to the patient based upon
clinical findings, anamnestic information, NIHSS score, laboratory test results and CT scan
interpretation. Therapy decision will only be written in the study form, and not reported to
the hospital. Retrospectively the therapy decision made by the anesthesiologist will be
statistically compared to the therapy decision made by the in-hospital stroke team. We aim
to determine the level of inter-rater agreement between the stroke anesthesiologist and the
in-hospital stroke team, with regard to their decision on thrombolysis and diagnostics.