Cardiac arrest predictability in seizure patients based on emergency medical dispatcher identification of previous seizure or epilepsy history.

OBJECTIVE: To determine predictability of at-scene cardiac arrest from a dispatch determined patient history of seizure or epilepsy ("E" history). DESIGN AND METHODS: A retrospective study of a 1 year dataset from the London Ambulance Service (LAS) National Health Service (NHS) Trust was undertaken. Each of the nine determinant codes on the Medical Priority Dispatch System (MPDS) seizure protocol [Heward A, Damiani M, Hartley-Sharpe C. Does the use of the Advanced Medical Priority Dispatch System affect cardiac arrest detection? Emerg Med J 2004;21:115-8.] was examined for the addition of the "E" suffix finding. The cardiac arrest predictability of cases with reported "E" history was compared to those without using a protocol process to detect the infrequent but predictable presence of seizures caused by anoxic cardiac arrest.
RESULTS: Only protocol codes 12-A-1, 12-D-2, 12-D-3, and 12-D-4 demonstrated significant associations between outcomes and determinant codes (p=0.016, 0.007, <0.001, and 0.048, respectively). These codes showed reduced risk of predicting CA with the "E" suffix protocol determinant codes (RD (95% CI): -0.0025 (-0.0044, -0.0005), chi-square p=0.009; RD (95% CI): -0.0024 (-0.0042, -0.0005), p=0.005; RD (95% CI): -0.020 (-0.029, -0.011), p<0.001; RD (95% CI): -0.01 (-0.017, -0.005), and p=0.034, respectively).
CONCLUSIONS: Knowing whether a seizure patient is an epileptic or has had previous seizures is of clinical value and relevant to dispatch. By improving the discernment of the seizure protocol regarding seizure associated with anoxic cardiac arrest predictability, this information may now be applied at the response level as well as to emergency medical dispatcher's (EMD) decisions to stay on the telephone to enhance the monitoring of these patients.