endovascular treatment of large vessel acute ischemic strokes in appropriately selected patients has been endorsed as evidence - based care.1 
 2 the next steps in advancing this therapy are to develop systems of care that can be divided into prehospital and intra - hospital pathways .
other time - dependent treatments , such as trauma and acute myocardial infarction , provide a valuable model for endovascular stroke therapy .
the value of an initial  golden hour in improving outcomes has been shown for treatment of trauma3 to neonatal resuscitation.4 early reperfusion for large vessel strokes is a critical determinant of endovascular therapy outcomes.5 
 6 emergency medicine publications provide useful insight into developing checklists and protocols geared towards seamless resuscitation of injured or sick patients.7 these  pit - crew-type protocols clearly define the role of each team member , allowing for synchronized , parallel delivery of care .
our center has performed endovascular stroke interventions for the past 15  years and participated in several clinical trials .
we had noticed a fall in the volume of patients in the past 3  years as an after effect of negative stroke trials8 
 9 and also because we had decided to offer stroke interventions only in the setting of a randomized clinical trial .
, we instituted a quality improvement ( qi ) process to reduce our door - to - needle times and develop a process that might consistently reduce times to treatments at all hours of the day and all days of the week .
the qi process was based on six - sigma which , although used by corporations for years , has only recently been adopted in medicine.10 this paper provides the results of those efforts , comparing the treatment times before and after implementation of the qi process .
to determine whether our times for different steps in endovascular stroke care improved as a result of the qi process ; the null hypothesis stating that there would be no difference in these times .
our setting was a rural , tertiary level , academic medical center with almost 700 beds , which is also the regional level-1 trauma center . prospectively recorded treatment times before and after the qi implementation provided the data for this analysis .
the pre - qi treatment times included all endovascular patients from 2011 to 2014 who had presented to our emergency room ( er ) . since the project was specifically targeted at improving efficiency between the er and interventional neuroradiology ( inr ) , the following patients were excluded : in - house patients undergoing an intervention for stroke , patients undergoing another procedure in the hospital with a stroke and patients treated with unknown symptom onset .
the post - qi treatment times were those for all patients undergoing endovascular therapy between january 2015 and october 2015 .
the following treatment times were compared : 
 er to imaging ( ct ) ( er  ct)imaging to inr lab ( ct  lab)inr lab to groin puncture ( lab  puncture)imaging to needle ( groin puncture ) ( ct  puncture)door to needle ( er  puncture ) . er to imaging ( ct ) ( er  ct ) imaging to inr lab ( ct  lab ) inr lab to groin puncture ( lab  puncture ) imaging to needle ( groin puncture ) ( ct  puncture ) door to needle ( er  puncture ) .
the qi process was started in the fall of 2014 and incrementally implemented over almost 3  months .
the impetus to initiate the process was treatment delays in stroke interventions , inconsistencies in times and care between working hours and on - call hours , ad hoc roles of different members , and suboptimal handover of patients between different services .
the qi team was led by two six - sigma trained engineers and comprised physicians , allied staff , and management from interventional neuroradiology , neurology , emergency medicine , and anesthesia .
meetings were held to develop a baseline understanding of the existing practice , followed by observance of 
a final protocol was signed off towards the end of 2014 and in 2015 all cases followed the updated protocol .
important features of the protocol ( figure 1 ) included identification of key personnel in the team , definition of a clear role for every member , and emphasis on parallel processing of assigned tasks .
the protocol contained explicit details , such as how a nurse enters the hospital , where a technician would stand , and the position of the detectors in the inr laboratory .
the protocol focused on the three main time - points along the stroke pathway : er  ct , ct  lab , and lab  puncture .
an overview of the protocol is presented along a timeline from patient arrival to arterial puncture .
er , emergency room ; geta , general endotracheal anesthesia , off hours treatment : stroke intervention performed before 7:00 or after 17:00 or at the weekend ; icu , intensive care unit ; inr , neurointerventionalist ; lcfa , left common femoral artery ; lsn , last seen normal ; lvo , large vessel occlusion ; nihss , national institutes of health stroke scale ; onset - er , time from symptom onset to er arrival ; rcfa , right common femoral artery ; rt - pa , recombinant tissue plasminogen activator .
the emergency medical services evaluate stroke patients using the cincinnati prehospital stroke scale11 and alert the stroke team ( neurology , radiology , emergency medicine , and laboratory staff ) by paging the group . on arrival ,
the er staff and on - call neurology residents evaluate the patient to confirm the stroke diagnosis .
at least one iv line is placed while the patient is in the er for the purpose of drawing laboratories and for contrast administration .
after a point - of - care creatinine test ( istat ; abbot laboratories , abbott park , illinois ) , the stroke patient is transferred to the ct scanner by a dedicated stroke nurse and the neurology team .
the ct technologists already alerted by the emergency medical services have the scanner ready for the patient .
the radiology resident meets the stroke team in the scanner control room for live review of imaging for all patients presenting within 6  h with a national institutes of health stroke scale ( nihss ) score 6 . before implementation of the qi process
any ct scanner was used , but after the qi process a designated scanner ( aquilion - one , toshiba america medical systems , tustin , california , usa ) was used for all stroke patients .
the scanner is equipped with 3200.5  mm detector rows covering 16  cm of volume per rotation , allowing for a uniform protocol comprising non - contrast ct ( ncct ) , volumetric ct perfusion ( ctp ) imaging , and ct angiography ( cta ) .
this switch was crucial in allowing earlier detection of a large vessel occlusion ( lvo ) and alerting the attending neurointerventionalist  who could then review the ncct and cta ( onsite or offsite ) , while ctp imaging was being carried out and processed .
another critical component was installation of an image router to simultaneously receive and disseminate images while they were being acquired .
this reduced the scanner to transfer time of all images from 12  min to just over 5  min .
the ct stroke scan is performed with a gantry speed of 3 rotations / s .
after the ncct , the cta is initiated from the aortic arch to the cranial vertex with an injection of 4060  ml of optiray 350 ( covidien , hazelwood , missouri , usa ) through an 1820  g antecubital iv  line at a rate of 45  ml / s , followed by a similar volume of saline chaser .
images acquired are automatically sent via the router for immediate review . a volumetric whole brain , time - resolved ctp sequence follows .
the imaging router enables transfer of 6080 ( 19320 ) images to a picture archiving and communication system and the perfusion post - processing software ( vital images , minnetonka , minnesota , usa ) .
iv recombinant tissue plasminogen activator ( rt - pa ; activase , genentech inc , san francisco , california , usa ) is administered if indicated after exclusion of hemorrhage on the ncct .
a collaborative decision about endovascular treatment is made based on clinical presentation , comorbidities , and imaging .
if the decision is to treat , the radiology resident places a single order set .
this was designed to simultaneously trigger multiple tasks with one click of the button  namely , anesthesia ( in our view , use of anesthesia makes the procedure safer ) , intensive care unit ( icu ) bed request , inr order set , foley placement , peripheral iv line , etc .
a single paging system was implemented allowing the resident to contact the neurointerventional team ( one nurse , and two technicians ) with one phone call .
medcom provides the relevant patient information and location in the er . if within 5  min the staff has not responded a repeat page is sent .
the system also documents all paging times , which can be reviewed for qi purposes .
the radiology resident places a preoperative note in the chart documenting the decision to treat .
the neurology resident 's duty running in parallel with this is to notify the icu service of the eventual admission of the stroke patient .
the inr nurse arrives through the er , checks the patient , and alerts the er staff to initiate transfer to the inr suite .
the minimum staffing requirement for all neurovascular procedures is set at two technicians and one nurse .
one technician is scrubbed and one floats . during working hours , a third technician is available for complex elective cases .
when two emergent cases occur simultaneously after hours , the technicians are split and the backup nurse is called in .
improvement in groin puncture times upon patient arrival in the angiography suite required planning to ensure parallel preparation of patient , tray , and anesthesia .
the inr technicians prepare the room for patient arrival by opening pre - packaged stroke trays and devices as indicated by the inr attending .
a separate stroke cart is stocked with the catheters , wires , thrombectomy devices , and syringes to hold everything in one place for this purpose .
the biplane detectors are positioned in such a way as to facilitate patient transfer to the angiography table .
once the patient is placed on the table , a coordinated effort is made between the anesthestist working at the head of the patient and left arm ( which is positioned out ) , and one of the inr technicians working at the groins for sterile preparation .
the inr nurse assists the anesthesiologist , if required , prepares the flushes , and performs documentation .
an 8 fr right common femoral arterial sheath is placed as soon as the groin is prepped . if by that time a radial arterial line has not been established by the anesthesiologist , a second 4 fr sheath is immediately placed in the left common femoral artery for invasive blood pressure monitoring .
the 8 fr sheath is removed at the end of the procedure and , if placed , the second 4 fr sheath is sutured in place to be used in the icu .
an anesthesia cart and ventilator is permanently stationed in each of two adjacent biplane angiography suites , allowing performance of parallel emergent cases .
small coordinated steps in the patient preparation process were designed to emulate defined roles and parallel tasks seen in trauma resuscitation .
inr : neurointerventionalist , t1 : technician-1 , t2 : technician-2 , t3 : technician-3 , n1 : nurse-1 , n2 : nurse-2 , a1 : anesthesiologist / certified registered nurse anesthetist ( crna)-1 , a2 : anesthesiologist / crna-2 . during the patient preparation stage ( a ) , t1 sets up the procedure trays and prepares the devices and catheters .
t2 prepares the patient and helps the attending technician , who punctures the right femoral artery and typically places an 8 fr sheath .
the patient 's left arm is extended out on an arm board for simultaneous access to anesthesia for placement of lines and administration of drugs .
if there is no radial arterial access by the time the right femoral sheath is placed , the inr punctures the left femoral artery and places a 4 fr sheath for invasive blood pressure monitoring .
even though it is possible to obtain arterial tracing via the 8 fr right femoral sheath , placement of the 4 fr sheath allows removal of the larger right femoral sheath at the end of the procedure .
the patient is transferred to the intensive care unit with the 4 fr sheath in place for pressure monitoring .
the nurse takes a report , prepares the continuous flush lines , assists the anesthesiologist , and charts all times .
the a - plane detector is stationed in such a way as to allow easy positioning over the groin in case fluoroscopy is required .
for the interventional stage ( b ) , t2 scrubs up and functions as the float .
one anesthesiologist ( a1 ) stays to cover the case , assisted by the nurse .
this setup with stocked anesthesia cart is duplicated in an immediately adjacent second interventional biplane room . during working hours an additional technician ( t3 ) and nurse ( n2 )
if two simultaneous emergent cases occur after hours , the technicians split and the backup nurse ( n2 ) is called in . the patient demographics and stroke severity
the significance of simple bivariate associations was assessed using the fisher exact test for categorical variables .
wilk w test demonstrated a non - normal distribution of the continuous time - point data .
non - parametric wilcoxon rank sum tests were thus performed to compare the time - point means 
all statistical analysis was performed using the jmp pro 12.0.1 software package ( sas institute inc , cary , north carolina , usa ) .
to determine whether our times for different steps in endovascular stroke care improved as a result of the qi process ; the null hypothesis stating that there would be no difference in these times .
our setting was a rural , tertiary level , academic medical center with almost 700 beds , which is also the regional level-1 trauma center . prospectively recorded treatment times before and after the qi implementation provided the data for this analysis .
the pre - qi treatment times included all endovascular patients from 2011 to 2014 who had presented to our emergency room ( er ) . since the project was specifically targeted at improving efficiency between the er and interventional neuroradiology ( inr ) , the following patients were excluded : in - house patients undergoing an intervention for stroke , patients undergoing another procedure in the hospital with a stroke and patients treated with unknown symptom onset .
the post - qi treatment times were those for all patients undergoing endovascular therapy between january 2015 and october 2015 .
the following treatment times were compared : 
 er to imaging ( ct ) ( er  ct)imaging to inr lab ( ct  lab)inr lab to groin puncture ( lab  puncture)imaging to needle ( groin puncture ) ( ct  puncture)door to needle ( er  puncture ) .
er to imaging ( ct ) ( er  ct ) imaging to inr lab ( ct  lab ) inr lab to groin puncture ( lab  puncture ) imaging to needle ( groin puncture ) ( ct  puncture ) door to needle ( er  puncture ) .
the qi process was started in the fall of 2014 and incrementally implemented over almost 3  months .
the impetus to initiate the process was treatment delays in stroke interventions , inconsistencies in times and care between working hours and on - call hours , ad hoc roles of different members , and suboptimal handover of patients between different services .
the qi team was led by two six - sigma trained engineers and comprised physicians , allied staff , and management from interventional neuroradiology , neurology , emergency medicine , and anesthesia .
meetings were held to develop a baseline understanding of the existing practice , followed by observance of 
a final protocol was signed off towards the end of 2014 and in 2015 all cases followed the updated protocol .
important features of the protocol ( figure 1 ) included identification of key personnel in the team , definition of a clear role for every member , and emphasis on parallel processing of assigned tasks .
the protocol contained explicit details , such as how a nurse enters the hospital , where a technician would stand , and the position of the detectors in the inr laboratory .
the protocol focused on the three main time - points along the stroke pathway : er  ct , ct  lab , and lab  puncture .
an overview of the protocol is presented along a timeline from patient arrival to arterial puncture .
er , emergency room ; geta , general endotracheal anesthesia , off hours treatment : stroke intervention performed before 7:00 or after 17:00 or at the weekend ; icu , intensive care unit ; inr , neurointerventionalist ; lcfa , left common femoral artery ; lsn , last seen normal ; lvo , large vessel occlusion ; nihss , national institutes of health stroke scale ; onset - er , time from symptom onset to er arrival ; rcfa , right common femoral artery ; rt - pa , recombinant tissue plasminogen activator .
the emergency medical services evaluate stroke patients using the cincinnati prehospital stroke scale11 and alert the stroke team ( neurology , radiology , emergency medicine , and laboratory staff ) by paging the group . on arrival ,
the er staff and on - call neurology residents evaluate the patient to confirm the stroke diagnosis .
at least one iv line is placed while the patient is in the er for the purpose of drawing laboratories and for contrast administration .
after a point - of - care creatinine test ( istat ; abbot laboratories , abbott park , illinois ) , the stroke patient is transferred to the ct scanner by a dedicated stroke nurse and the neurology team .
the ct technologists already alerted by the emergency medical services have the scanner ready for the patient .
the radiology resident meets the stroke team in the scanner control room for live review of imaging for all patients presenting within 6  h with a national institutes of health stroke scale ( nihss ) score 6 . before implementation of the qi process
any ct scanner was used , but after the qi process a designated scanner ( aquilion - one , toshiba america medical systems , tustin , california , usa ) was used for all stroke patients .
the scanner is equipped with 3200.5  mm detector rows covering 16  cm of volume per rotation , allowing for a uniform protocol comprising non - contrast ct ( ncct ) , volumetric ct perfusion ( ctp ) imaging , and ct angiography ( cta ) .
. this switch was crucial in allowing earlier detection of a large vessel occlusion ( lvo ) and alerting the attending neurointerventionalist  who could then review the ncct and cta ( onsite or offsite ) , while ctp imaging was being carried out and processed .
another critical component was installation of an image router to simultaneously receive and disseminate images while they were being acquired .
this reduced the scanner to transfer time of all images from 12  min to just over 5  min .
the ct stroke scan is performed with a gantry speed of 3 rotations / s .
after the ncct , the cta is initiated from the aortic arch to the cranial vertex with an injection of 4060  ml of optiray 350 ( covidien , hazelwood , missouri , usa ) through an 1820  g antecubital iv  line at a rate of 45  ml / s , followed by a similar volume of saline chaser .
images acquired are automatically sent via the router for immediate review . a volumetric whole brain , time - resolved ctp sequence follows .
the imaging router enables transfer of 6080 ( 19320 ) images to a picture archiving and communication system and the perfusion post - processing software ( vital images , minnetonka , minnesota , usa ) .
iv recombinant tissue plasminogen activator ( rt - pa ; activase , genentech inc , san francisco , california , usa ) is administered if indicated after exclusion of hemorrhage on the ncct .
a collaborative decision about endovascular treatment is made based on clinical presentation , comorbidities , and imaging .
if the decision is to treat , the radiology resident places a single order set .
this was designed to simultaneously trigger multiple tasks with one click of the button  namely , anesthesia ( in our view , use of anesthesia makes the procedure safer ) , intensive care unit ( icu ) bed request , inr order set , foley placement , peripheral iv line , etc .
a single paging system was implemented allowing the resident to contact the neurointerventional team ( one nurse , and two technicians ) with one phone call .
medcom provides the relevant patient information and location in the er . if within 5  min the staff has not responded a repeat page is sent .
the system also documents all paging times , which can be reviewed for qi purposes .
the radiology resident places a preoperative note in the chart documenting the decision to treat .
the neurology resident 's duty running in parallel with this is to notify the icu service of the eventual admission of the stroke patient .
the inr nurse arrives through the er , checks the patient , and alerts the er staff to initiate transfer to the inr suite .
the minimum staffing requirement for all neurovascular procedures is set at two technicians and one nurse .
one technician is scrubbed and one floats . during working hours , a third technician is available for complex elective cases .
when two emergent cases occur simultaneously after hours , the technicians are split and the backup nurse is called in .
improvement in groin puncture times upon patient arrival in the angiography suite required planning to ensure parallel preparation of patient , tray , and anesthesia .
the inr technicians prepare the room for patient arrival by opening pre - packaged stroke trays and devices as indicated by the inr attending .
a separate stroke cart is stocked with the catheters , wires , thrombectomy devices , and syringes to hold everything in one place for this purpose .
the biplane detectors are positioned in such a way as to facilitate patient transfer to the angiography table .
once the patient is placed on the table , a coordinated effort is made between the anesthestist working at the head of the patient and left arm ( which is positioned out ) , and one of the inr technicians working at the groins for sterile preparation .
the inr nurse assists the anesthesiologist , if required , prepares the flushes , and performs documentation .
an 8 fr right common femoral arterial sheath is placed as soon as the groin is prepped . if by that time a radial arterial line has not been established by the anesthesiologist , a second 4 fr sheath is immediately placed in the left common femoral artery for invasive blood pressure monitoring .
the 8 fr sheath is removed at the end of the procedure and , if placed , the second 4 fr sheath is sutured in place to be used in the icu .
an anesthesia cart and ventilator is permanently stationed in each of two adjacent biplane angiography suites , allowing performance of parallel emergent cases .
small coordinated steps in the patient preparation process were designed to emulate defined roles and parallel tasks seen in trauma resuscitation .
inr : neurointerventionalist , t1 : technician-1 , t2 : technician-2 , t3 : technician-3 , n1 : nurse-1 , n2 : nurse-2 , a1 : anesthesiologist / certified registered nurse anesthetist ( crna)-1 , a2 : anesthesiologist / crna-2 . during the patient preparation stage ( a )
t2 prepares the patient and helps the attending technician , who punctures the right femoral artery and typically places an 8 fr sheath .
the patient 's left arm is extended out on an arm board for simultaneous access to anesthesia for placement of lines and administration of drugs .
if there is no radial arterial access by the time the right femoral sheath is placed , the inr punctures the left femoral artery and places a 4 fr sheath for invasive blood pressure monitoring .
even though it is possible to obtain arterial tracing via the 8 fr right femoral sheath , placement of the 4 fr sheath allows removal of the larger right femoral sheath at the end of the procedure .
the patient is transferred to the intensive care unit with the 4 fr sheath in place for pressure monitoring .
the nurse takes a report , prepares the continuous flush lines , assists the anesthesiologist , and charts all times .
the a - plane detector is stationed in such a way as to allow easy positioning over the groin in case fluoroscopy is required . for the interventional stage ( b ) ,
one anesthesiologist ( a1 ) stays to cover the case , assisted by the nurse .
this setup with stocked anesthesia cart is duplicated in an immediately adjacent second interventional biplane room . during working hours an additional technician ( t3 ) and nurse ( n2 )
if two simultaneous emergent cases occur after hours , the technicians split and the backup nurse ( n2 ) is called in .
the significance of simple bivariate associations was assessed using the fisher exact test for categorical variables . a shapiro 
wilk w test demonstrated a non - normal distribution of the continuous time - point data .
non - parametric wilcoxon rank sum tests were thus performed to compare the time - point means 
all statistical analysis was performed using the jmp pro 12.0.1 software package ( sas institute inc , cary , north carolina , usa ) .
before ( n=64 ) and  after ( n=30 ) group based on the implementation of the qi process .
there were no differences in baseline demographics , stroke severity , symptom onset , comorbidities , and the use of iv rt - pa or general endotracheal anesthesia ( geta ) between the two groups ( table 1 ) .
a comparison of the time intervals showed a significant reduction in times in the  after qi implementation group across all parameters ( figure 3 ) .
the time intervals were separately compared for interventions performed during working hours that is , 7:00 to 17:00 on weekdays ( table 2 ) , and for off - hours and at weekends ( table 3 ) .
there was significant reduction in times for both working hours and off - hours interventions .
we found no correlation between age , nihss , onset to er or any of the comorbidities and the door - to - needle time .
we also looked at the impact of geta on the patient preparation and puncture time after the implementation of the qi process .
the mean time from inr room arrival to groin puncture was 15 ( 4 ) min in patients who received geta versus 15 ( 3 ) min in patients treated without geta ( p=0.87 ) , indicating that geta caused no delays .
comparison of baseline demographics , comorbidities and treatment variables afib , atrial fibrillation ; dm , diabetes mellitus ; er , emergency room ; geta , general endotracheal anesthesia , off hours treatment : stroke intervention performed before 7:00 or after 17:00 or at the weekend ; hpl , hyperlipidemia ; htn , hypertension ; nihss , national institutes of health stroke scale ; onset - er , time from symptom onset to er arrival ; rt - pa , recombinant tissue plasminogen activator ; smk , smoking .
comparison of time parameters during working hours on weekdays er , emergency room ; qi , quality improvement .
comparison of time parameters after hours or on weekends er , emergency room ; qi , quality improvement .
the six - sigma process , developed at motorola in the 1980s because quality was lagging behind that of japanese companies , was adopted by many corporations as a qi practice .
however , healthcare is neither of those and preventable errors cause 44  00098  000 deaths a year.12 six - sigma has been applied in medicine to improve many processes from catheter - related10 and surgical - site infections13 to er,14 surgery,15 and behavioral health systems.16 six - sigma achieves higher levels of quality by understanding and improving a process and decreasing , if not eliminating , variability .
control.17 each step in the dmaic chain is fundamental to the success of the qi process.18 in our setting , the  process of endovascular stroke therapy required improvement of treatment times . the first step was to define specific goals for example , door - to - needle time of no more than 120  min , split into key intervals such as er  ct , ct  lab , and lab  puncture . different members of the team were clearly identified for each stage and unambiguous roles assigned to each of them .
the process was refined over a period of almost 3  months at weekly meetings , where all stroke interventions performed during that week were dissected , with iterations based on feedback from all involved .
the performance of the different subprocesses and of the overall process was measured and incrementally improved .
our protocols mandated that processes should be performed simultaneously and not sequentially . for example , once it is decided to proceed with an intervention , the radiology and neurology residents perform their tasks independently and concurrently . likewise , once the patient is in the inr suite , the nurse , the technicians , the attending physician , and the anesthesia team move at the same time .
furthermore , this reduction in time is consistent regardless of the type of anesthesia used .
our overall door - to - needle times are now at just over 90  min and the reduction in times is significant for both working hours ( 7:0017:00 on weekdays ) and off - hours interventions ( tables 2 and 3 ) . our goal is to reduce this to 60  min .
this may require the presence of an in - house interventional team , which could bring down the technicians / nurses response time from 30  min to < 5 min . that alone will allow treatment  to start within an hour of patient arrival .
we have significantly reduced our times for image acquisition , processing , and dissemination through a separate informatics project and it now takes about 10  min from placing the patient on the table to display of images ; this includes ncct , cta , and ctp .
by eliminating cta and ctp we will gain , at most , 58  min .
we do not think it is worth losing the large amount of information obtained from cta / ctp merely to reduce the time by an additional 58  min .
information about clot location and burden , vascular anatomy , tandem lesions , access , and state of collaterals can make the subsequent intervention safer and faster .
endovascular stroke therapy is entering its next phase of growth , which will require streamlining of both prehospital and intra - hospital care processes .
delivery of endovascular stroke therapy is resource intensive and costly,19 requiring round - the - clock readiness .
similar processes have been developed for acute coronary syndromes , specifically st segment elevation myocardial infarctions ( stemis).20 however , the number of current and projected future endovascular stroke interventions is much lower than stemi interventions,21 owing to a higher prevalence of ischemic heart disease than stroke.22 this means that while both stemi and lvo interventions require similar resources and investments to operate a round - the - clock service , the cost of lvo interventions will be lower owing to the smaller number of procedures performed .
it may be beyond the capability of smaller hospitals ( defined as 300 beds ) to invest in high - quality round - the - clock stroke therapy but the temptation could be there from a marketing perspective and a perceived financial benefit .
add to that an oversupply of physicians21 and we might find small regional hospitals with one to two physicians offering endovascular stroke care , not realizing that the postoperative care by dedicated neurospecialists and allied staff is as important as the procedure itself .
the consequences of such a model could be dire with patients scattered among competing hospitals with variable standards of care and inconsistent quality metrics .
additionally , the comparatively lower prevalence of ischemic stroke will result in multiple centers carrying out a small volume of procedures instead of a regional high - volume center to which all such patients could be efficiently transferred and treated .
the process at our institution was developed based on the manpower and resources within our system  a tertiary level academic medical center with in - house resident teams .
we realize that our specific methodology may not be applicable to other systems with different resources .
the process at our institution was developed based on the manpower and resources within our system  a tertiary level academic medical center with in - house resident teams .
we realize that our specific methodology may not be applicable to other systems with different resources .
time - critical interventions such as endovascular stroke therapy can benefit from a systemically implemented protocol - driven approach . while the methodology can be different in different places based on available resources ,
as the field grows it is important to regionalize systems of care based on population densities , facility capabilities , and health system networks .
 backgrounddelays in delivering endovascular stroke therapy adversely affect outcomes . 
 time - sensitive treatments such as stroke interventions benefit from methodically developed protocols . clearly defined roles in these protocols allow for parallel processing of tasks , resulting in consistent delivery of care.objectiveto present the outcomes of a quality - improvement ( qi ) process directed at reducing stroke treatment times in a tertiary level academic medical center.methodsa six - sigma - based qi process was developed over a 3-month period . after an initial analysis , 
 procedures were implemented and fine - tuned to identify and address rate - limiting steps in the endovascular care pathway . prospectively recorded treatment times 
 were then compared in two groups of patients who were treated  
 before ( n=64 ) or  
 after ( n=30 ) the qi process . 
 three time intervals were measured : emergency room ( er ) to arrival for ct scan ( er  ct ) , ct scan to interventional laboratory arrival ( ct  lab ) , and interventional laboratory arrival to groin puncture ( lab  puncture).resultsthe er  ct time was 40 ( 29 )  min in the  before and 26 ( 15 )  min in the  
 after group ( p=0.008 ) . 
 the ct  
 lab time was 87 ( 47 )  min in the  
 before and 51 ( 33 )  min in the  
 after group ( p=0.0002 ) . the lab  puncture time was 24 ( 11 )  min in the  before and 15 ( 4 )  min in the  
 after group ( p<0.0001 ) . 
 the overall er  arrival to groin - puncture time was reduced from 2  h , 31  min ( 51 ) min in the  
 before to 1  h , 33  min ( 37 ) min in the  
 after group , ( p<0.0001 ) . 
 the improved times were seen for both working hours and off - hours interventions.conclusionsa protocol - driven process can significantly improve efficiency of care in time - sensitive stroke interventions . 
Introduction
Methods
Objective
Patient population
The QI process
ERCT
CTLab
Labpuncture
Data analysis
Results
Discussion
Limitations
Conclusion