Outcomes of ED Physician-Based Thrombolysis for Stroke
Outcomes of ED Physician-Based Thrombolysis for Stroke
Our study shows that thrombolysis for stroke can be achieved in a DGH. Our patient selection and patient outcomes are similar to those achieved across the UK and across Europe.
Using our pathway, we treated 11% of patients presenting with acute ischaemic stroke during the last year of full data collection for this paper, which is similar to the predicted model for UK departments.
Our findings are important to the wider emergency medicine audience for several reasons. First we have demonstrated the feasibility of providing a thrombolysis service outside of a hyper-acute stroke centre. Although we developed this service because of the geographical location of Scarborough, the underlying principle that therapy should be available at the patient's location, as opposed to the patient having to be transferred to where the therapy is, is supported by our findings. In this respect, thrombolysis for stroke is perhaps similar to the initial strategies for thrombolysis in acute myocardial infarction. When initially introduced, thrombolysis for acute myocardial infarction was restricted to specialist centres and under the guidance of cardiologists. With time and experience, it became clear that a treatment that is portable is best given at the point of need, thereby reducing the delay inherent in moving the patient to the treatment. Our experience in Scarborough clearly shows that this is achievable (Table 2).
Second, we have demonstrated that the clinical outcomes in a DGH population are similar to those in a European-wide cohort. Although the numbers of patients in our study is relatively small, our results suggest that outcomes are likely to be comparable. Unfortunately, the number of patients in this study is too small to statistically show equivalence, and indeed it is unlikely that a single centre such as ours will ever acquire a study population large enough to do this. Further work and experience from other units may confirm this, as it eventually did for thrombolysis for myocardial infarction (Table 3).
The Scarborough model depends on cooperative working between different units that already have the basic skills required to perform thrombolysis in stroke patients. Although the majority of strokes seen in the ED are 'barn door', the use of objective scoring systems (NIHSS) and the clinical availability of colleagues in neurology and stroke care have supported decision making in difficult cases. Similarly, an enthusiastic and supportive radiology service has been essential in the early differentiation of cerebral pathology. Although the majority of CT scans are interpreted by senior ED or stroke physicians, timely radiology support is essential in some cases.
Support and enthusiasm for the service has been reinforced by inviting patients who had made significant improvements to visit the emergency and radiological departments. This has rapidly developed a system-wide 'ownership' of the service.
Most patients presented during 'extended office hours', with the bulk of our cases being treated between 07:00 and midnight. Logically, in our semi-rural population, strokes occurring after this time will occur during sleep, and onset can therefore not be identified. Populations with a more extended lifestyle will probably require an overnight service as well.
A number of patients had adverse effects related to the treatment. Catastrophic intracerebral haemorrhage possibly occurred in one case where a poor responder deteriorated suddenly and died before a repeat CT scan could be performed. Five other patients suffered sudden deterioration and had CT findings of massive cerebral oedema. Bleeding from occult gastrointestinal lesions was seen in 10 cases in the early days after treatment, two of these cases from a previously unknown carcinoma. One case of angio-oedema and hypotension was seen (Table 4).
Major complications are therefore not uncommon and we believe that this supports our practice of observing stroke patients receiving thrombolysis on the coronary care unit where nursing staff are experienced in the assessment and management of thrombolysis complications.
The 3-month death rate among the first 40 cases reviewed was higher than in the SITS-MOST database. When this was recognised, the cases were reviewed, and it was found that the deaths were occurring in non-responding patients significantly over 80 years of age. This resulted in a tightening of selection procedures with a resulting fall in death rates in the later cohort. This finding reinforces the value of a national reporting strategy for new interventions.
Our study is clearly limited by being single centre and with a relatively small number of patients. However, our aim was to demonstrate the feasibility and achievability of performing stroke thrombolysis in a DGH setting. We believe that we have demonstrated this and suggest that our model of bringing thrombolysis to the patient, rather than the patient to thrombolysis, is one that could be successfully replicated elsewhere.
Discussion
Our study shows that thrombolysis for stroke can be achieved in a DGH. Our patient selection and patient outcomes are similar to those achieved across the UK and across Europe.
Using our pathway, we treated 11% of patients presenting with acute ischaemic stroke during the last year of full data collection for this paper, which is similar to the predicted model for UK departments.
Our findings are important to the wider emergency medicine audience for several reasons. First we have demonstrated the feasibility of providing a thrombolysis service outside of a hyper-acute stroke centre. Although we developed this service because of the geographical location of Scarborough, the underlying principle that therapy should be available at the patient's location, as opposed to the patient having to be transferred to where the therapy is, is supported by our findings. In this respect, thrombolysis for stroke is perhaps similar to the initial strategies for thrombolysis in acute myocardial infarction. When initially introduced, thrombolysis for acute myocardial infarction was restricted to specialist centres and under the guidance of cardiologists. With time and experience, it became clear that a treatment that is portable is best given at the point of need, thereby reducing the delay inherent in moving the patient to the treatment. Our experience in Scarborough clearly shows that this is achievable (Table 2).
Second, we have demonstrated that the clinical outcomes in a DGH population are similar to those in a European-wide cohort. Although the numbers of patients in our study is relatively small, our results suggest that outcomes are likely to be comparable. Unfortunately, the number of patients in this study is too small to statistically show equivalence, and indeed it is unlikely that a single centre such as ours will ever acquire a study population large enough to do this. Further work and experience from other units may confirm this, as it eventually did for thrombolysis for myocardial infarction (Table 3).
The Scarborough model depends on cooperative working between different units that already have the basic skills required to perform thrombolysis in stroke patients. Although the majority of strokes seen in the ED are 'barn door', the use of objective scoring systems (NIHSS) and the clinical availability of colleagues in neurology and stroke care have supported decision making in difficult cases. Similarly, an enthusiastic and supportive radiology service has been essential in the early differentiation of cerebral pathology. Although the majority of CT scans are interpreted by senior ED or stroke physicians, timely radiology support is essential in some cases.
Support and enthusiasm for the service has been reinforced by inviting patients who had made significant improvements to visit the emergency and radiological departments. This has rapidly developed a system-wide 'ownership' of the service.
Most patients presented during 'extended office hours', with the bulk of our cases being treated between 07:00 and midnight. Logically, in our semi-rural population, strokes occurring after this time will occur during sleep, and onset can therefore not be identified. Populations with a more extended lifestyle will probably require an overnight service as well.
A number of patients had adverse effects related to the treatment. Catastrophic intracerebral haemorrhage possibly occurred in one case where a poor responder deteriorated suddenly and died before a repeat CT scan could be performed. Five other patients suffered sudden deterioration and had CT findings of massive cerebral oedema. Bleeding from occult gastrointestinal lesions was seen in 10 cases in the early days after treatment, two of these cases from a previously unknown carcinoma. One case of angio-oedema and hypotension was seen (Table 4).
Major complications are therefore not uncommon and we believe that this supports our practice of observing stroke patients receiving thrombolysis on the coronary care unit where nursing staff are experienced in the assessment and management of thrombolysis complications.
The 3-month death rate among the first 40 cases reviewed was higher than in the SITS-MOST database. When this was recognised, the cases were reviewed, and it was found that the deaths were occurring in non-responding patients significantly over 80 years of age. This resulted in a tightening of selection procedures with a resulting fall in death rates in the later cohort. This finding reinforces the value of a national reporting strategy for new interventions.
Our study is clearly limited by being single centre and with a relatively small number of patients. However, our aim was to demonstrate the feasibility and achievability of performing stroke thrombolysis in a DGH setting. We believe that we have demonstrated this and suggest that our model of bringing thrombolysis to the patient, rather than the patient to thrombolysis, is one that could be successfully replicated elsewhere.
