| TITLE |
| A retrospective audit on the use of neuron specific enolase in neuro-prognostication post cardiac arrest |
| BACKGROUND |
| Neuron specific enolase (NSE) is increasingly being used as a part of multi-modal neuro-prognostication post cardiac arrest, and its use is supported by both national and local guidelines 1,2. Despite this, the NSE assay has only become recently available in our trust. Our audit reviews the use of NSE across four intensive care units after the test became available in our trust, in order to review whether NSE is being requested appropriately and to identify areas for improvement. |
| METHODS |
| We have completed a retrospective audit, with all patients who had an NSE level analysed between 20/9/23-22/11/23 included in this audit. This was compared to agreed clinical criteria for requesting an NSE assay.Data were collected on characteristics of arrest, co-morbidity and frailty scores, timing of all NSE levels taken (including haemolysed samples), GCS at the time of sample taking, and final outcome of care. |
| RESULTS |
| Our cohort was 62.5% male with a mean age of 53 (25-65). 50% had out of hospital cardiac arrests with 62.5% having a witnessed cardiac arrest, 12.5% had a shockable rhythm initially, and mean time to return of spontaneous circulation of 15min (2-41).Survival to discharge was in 12.5% of patients. All included patients had appropriate indications for performing a NSE assay at the time of the initial sample.75% of patients had a NSE level taken at 48hrs with a mean NSE of 76.9 (8.3-177.0), and half of these had a further sample taken at 72hrs with a mean NSE of 175.5 (104-247). 25% of patients had NSE levels taken at the incorrect times (ranging from 24-91hrs).In total, 44% of samples taken were haemolysed and could not be analysed reliably.The only patient with sequentially normal NSE levels was the only patient to survive to discharge.Other factors considered in prognostication were: pupillary/corneal reflexes in 62.5% of cases; EEG in 62.5% of cases; and CT/MRI in 87.5% of cases. Somatosensory evoked potentials were considered, but not available in our trust. |
| DISCUSSION |
| Overall, NSE analysis is being performed with appropriate indication, but adherence to specified timings is still variable. It is likely that samples are not being taken at the correct time due to lack of awareness given this has only recently become available.Even when samples have been taken appropriately, some results have not been able to be used in prognostication due to high rates of haemolysis, and this could limit usefulness and reliability in clinical practice unless able to reduce these rates.This audit is limited by its small sample size, and our methodology may have missed patients who had indications for NSE analysis but in whom the sample was not taken. We would suggest re-audit following departmental education in order to further review this. |
| ACKNOWLEDGEMENTS |
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| REFERENCES |
