Effective pre-hospital recognition and management of stroke is an important component of the acute stroke care pathway. The practice of placing a priority (pre-alert) call to hospitals to notify receiving staff that a stroke patient is in transit enables specialist care to be available immediately on the patient's arrival in an attempt to improve timeliness of subsequent treatment.
This research examines the relationship between pre-hospital assessment and management of stroke by ambulance staff on the patient's in-hospital stroke care pathway. The researchers had a particular interest in symptom onset time, stroke recognition using the FAST test, placing a priority call (all extracted from ambulance service records), and examining whether there was an association between these activities and the subsequent time that hospital staff then made the request for a CT scan and the actual time the patient received the scan (taken from in-hospital records).
The study utilised a cohort design involving patients who had a definitive diagnosis of stroke and who had experienced the acute stroke pathway in one of two participating hospitals between November 2010 and July 2011.
In total, 500 patients were admitted to the stroke wards during this time with 210 secondary care records available for analysis. However, only 160 patients travelled to hospital by ambulance and nine of these patient care records were unavailable, leaving 151 records available to be linked to in-hospital data for inclusion in the final analysis.
Of these patients the FAST test was performed in 93% (n=141) and was positive in 114 patients. A priority/pre-alert call was placed in 65 cases (44%). Onset time was recorded by ambulance staff in 61 patients out of 90 where this time was known. In 14 cases onset time was recorded in the ambulance service records but not in the hospital records. There is no indication in the paper as to whether—where there was no onset time recorded in the pre-hospital setting—this was due to the patient (or relative) remembering the onset time at a later stage (in hospital), or whether the ambulance staff did not record this timing.
Results indicate that when onset time was recorded, the patient was FAST+tve, and/or a priority/pre-alert call was placed before arrival then a CT scan was requested and completed within 1 hour of arrival. Median times to request and scan were: FAST+tve 39 and 57 minutes respectively; onset time recorded 37 and 50 minutes; priority call 26 and 39 minutes.
In patients where the onset time was not known/not recorded, who were FAST-tve or the FAST test was not carried out, and/or there was no priority/pre-alert call, the median delay to request and scan was: FAST-tve/not documented 120 and 155 minutes respectively; no onset time 97 and 121 minutes; no priority call 125 and 185 minutes.
Unadjusted ratios indicate that the likelihood of getting a rapid CT response was increased by 33% in those with onset time recorded (HR 0.67, 95% CI 0.48-0.94, p=0.020); by 46% in FAST+tve patients (HR 0.54, 95% CI 0.37-0.80, p=0.002); and by 77% where there was a priority/pre-alert call placed (HR 0.23, 95% CI 0.16 to 0.34, p<0.001). Adjusted analyses gave similar findings other than they found that recording of onset time in relation to timing of request of CT scan was no longer significant.
The authors identify some limitations with the study such as having to extract details from medical records after treatment even though this observational study recruited patients prospectively. One of the strengths of the study included the process of successful data linkage between ambulance service and in-hospital records where this study achieved access to 100% of secondary care records and 94% of ambulance service records of the consenting participants.
Overall the study highlights the importance of accurate recognition of stroke and the documentation of stroke onset time as well as the critical need to pre-alert the hospital prior to arrival so that a specialist team are ready to receive the patient. At the same time, it highlights the challenges of accurate recognition of stroke in the pre-hospital setting emphasising that current tools do not identify all stroke positive patients. The authors suggest that this is why triage in-hospital is also important to increase accuracy of stroke recognition and, equally, they recommend that consideration needs to be given to adoption of assessment tools with greater sensitivity for pre-hospital settings to ensure that all potential stroke patients receive timely specialist treatment, even if this might mean a potential increase in the number of stroke mimics being transferred to specialist resources.
The paper concludes that patients who are not recognised as having a stroke in the pre-hospital setting risk exclusion from rapid, specialist care as they may not be transferred to the most appropriate care facility in the first instance and, in this study, the hospital priority (pre-alert) call appears to be the most influential factor facilitating appropriate and timely acute stroke management for the patient.