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PenCHORD - North Devon Thrombolysis Pathway: Bottleneck Analysis

Who is involved?

Theme: PenCHORD
Status: Complete


This project followed the work completed at the Royal Devon and Exeter Hospital (RD&E) on increasing the proportion of acute ischemic stroke patients (part of the brain is starved of oxygen due to a blocked blood vessel) that are treated by thrombolysis. 

The only drug for treatment of acute stroke - alteplase - is licensed for use in the first three hours of stroke after onset. Treating patients within this limited time window has proved difficult in practice and the uptake and provision of thrombolysis remains limited across the UK along with the rest of Europe and the US.  In addition to increasing the proportion treated it is also highly desirable to treat patients more quickly, as early thrombolysis for acute ischemic stroke is essential to maximise the proportion of patients with no disability post treatment. 

The work with the RD&E identified that many patients arrive to hospital in time to be treated, however, in-hospital delays, particularly those a patient experiences during the time between arrival and brain scanning, reduce the proportion of acute stroke patients treated.

Project aims

PenCHORD collaborated with the acute stroke unit and emergency department at the North Devon district hospital to identify areas and understand the causes of major bottlenecks within their emergency thrombolysis pathway. PenCHORD sought to answer three research questions:

1. Are patients arriving to hospital in time for treatment?

2. What could have been achieved over the last few years?

3. Where are patients delayed in the pathway?


PenCHORD ran a series of workshops with the trust that supported the discussion with data analysis of both local and national thrombolysis data.  Project work was divided into three phases:

1. Analysis of ambulance trust data to identify similarities and differences of North Devon to other trusts within the South West Peninsula;

2. Analysis of data collected for the Stroke Improvement National Audit Program (SINAP)

  • Estimation of the proportion of patients arriving within the thrombolysis treatment window at North Devon

  • Identification of areas of substantial delay within the pathway at North Devon

3. Detailed process mapping of patient flow and use of information within the pathway to understand reasons for delay.


1. Are patients arriving to hospital in time for treatment?

The comparison of ambulance travel times between stroke patients in North Devon and other nearby hospitals illustrated no substantial differences in durations due to the geography of North Devon.  Analysis of time from onset of a stroke to arrival illustrated that a substantial proportion of patients do arrive at hospital within 4.5 hours (alteplase license).  However, not all of these patients are eligible due to co-morbidities and contra-indications (such as age).

2. What could have been achieved over the last few years?

The analysis of co-morbidities and onset to arrival times revealed that a there were patients eligible for thrombolysis who experienced a delay within hospital and could not be treated.

3. Where are patients delayed in the pathway?

The process mapping revealed that the pathway could work very efficiently after patients were identified as potential strokes.  The main difficulty for the clinicians was early identification of strokes.  There were three contributing factors:

  • There was no system in place for paramedics to pre-alert the emergency department of the imminent arrival of a FAST positive patient.

  • There was a delay in handover times of patients from paramedics to emergency department staff

  • There was variation in the use of (and the recording of the use of) the Recognition of Stroke in the Emergency Room (ROSIER) diagnostic tool at triage.

Once a patient had been identified as potentially eligible for stroke thrombolysis there was also some scope to reduce the time taken to make the final treatment eligibility decision.  A potential means to do this was some form of telemedicine support for the emergency department physians responsible for thrombolysis.


Allen M, Pearn K, Monks T, Bray BD, Everson R, Salmon A, James M, Stein K. Can clinical audits be enhanced by pathway simulation and machine learning? An example from the acute stroke pathway BMJ Open 2019;9:e028296.

Further projects

PenCHORD are currently conducting similar analyses at Derriford Hospital in Plymouth and Royal Cornwall Hospital in Truro.

Related projects

View more PenCHORD projects