Head injury is a common condition presenting to Accident and Emergency departments. The rate audited in this report represents an annual presentational incidence of 1520 per 100,000 people for the locality. The extrapolated annual hospitalised incidence rate is 126 per 100,000, much lower than other published data . However, four factors may influence this. Firstly extrapolating from one month may lead to bias in estimates, either under- or over estimating incidence presented. Secondly, incidence is known to vary considerably by locality, predicated on demographic and socio-economic factors  and, thirdly, some of the most severe patients may be triaged by the ambulance service directly to the regional neurosurgical centre. Nevertheless, the latter will be relatively few in number. Finally, the changing management of people presenting, with greater emphasis on sending people home with information cards, rather than admitting for observation, possibly as a result of a reduction in short stay "observation" beds over the last decade. This may be having a general effect in reducing admission rates and thus reducing the viability of historical compatibility.
It is likely that the guidelines introduced in 1984 and since modified have contributed much to the increase in the number of CT scans requested and performed on head injured patients in the UK [1, 8]. This has been made possible by the greater availability of 24 hour CT scanning in the UK. Nevertheless, current practice in the UK CT scanning is reserved for patients considered to be at high risk of intracranial complications, whereas in the USA, CT scanning is performed in 75–100% of patients with a normal GCS and loss of consciousness . The results of this audit show that only a small number of CT scans were done, but should the NICE guidelines be implemented then the number would be increased at least four-fold in these two hospitals.
Another important finding of the audit was the incomplete recording of information within the A&E departments, despite both using the same protocol. Those patients who decide to go home before any information can be recorded will contribute to this loss of information. The absence of recorded information does not of course imply the absence of the action, but in a busy A&E some mechanism must be introduced to facilitate accurate recording of activities. One solution would be to introduce a standardised proforma for head injured patients in A&E . This could have a checklist of tests, procedures, and interventions, which may be required for management, including collecting the relevant indicators for a CT scan. A reminder to ask about amnesia, including distinction between ante grade and retrograde amnesia may be prompted for, as required by the NICE guidelines. However, in the two hospitals audited, this would require a radical overhaul of existing documentation, which currently contains only a designated area for recording GCS and pupil reactivity and even these, as we have seen, are not always completed.
A number of patients do not wait to be seen in the A&E department after initial triage, some of whom do not have their GCS recorded, yet if the NICE guidelines are going to be followed then a number of these people may require scanning. This raises potential medico-legal issues. Another important point is that admission decisions appear to be made on other criteria apart, or additional to initial GCS, as equal proportions of those where the GCS was recorded or not were admitted. Thus the potential impact of the implementation on the NICE guidelines on admission criteria and hence use of resources will also need to be considered. Likewise, some thought will need to the impact on the admission of children with head injuries. Whereas just two children were given a scan during the audit period, our results would imply that 10 would be eligible, 80% of whom had been given a skull x-ray.
The audit has a number of limitations. There were some problems in case ascertainment with finding the A&E cards. In both A&E departments some cards could not be found. The study relied on the accuracy of the identification and recording of head injury by the A & E staff. They were filed in alphabetical order by hand, making it easy for cards to be filed in the wrong place due to human error. In one hospital all the casualty cards were filed together in drawers, whereas at another cards for children under the age of 16 years were filed separately. There is also no way of telling whether or not these two hospitals are in any way representative of District General Hospital A&E departments in general viz. staffing, skill levels and local protocols, all of which may be highly variable throughout the UK. The variables chosen to record were those most frequently recorded at the time of the audit, to take a snapshot of the impact of the guidelines. A more complete picture of the CT scanning and admission policy may have been given if we had screened for those (albeit more rare) factors such as a dangerous mechanism of injury or those with a suspected coagulopathy. Given accurate recording of such factors, a future audit would look at their incidence over a longer time frame.
The audit process, from presentation at A&E to discharge at the two hospitals, has also shown that what practitioners believe happens in their department is not borne out by data, most strikingly the recording of the GCS. The senior consultant in A&E for the trust remarked that the disparity between what they thought had been done and what had actually been recorded, but commented that the increased requirements for CT scanning was not surprising. Furthermore, if careful documentation of CT indicators is required for all patients presenting with head injury, this must have a resource implication for the numbers of staff on duty, or the wait times, or both. It is possible that medical informatics systems may be able to make a substantial contribution to the information processing and management of those presenting with a head injury, relieving hard pressed staff of some of the burden of data recording and ensuring (perhaps through touch screen technology) that relevant data is recorded. However, once again there are developmental and equipment resource implications in seeking such a solution.
Although senior clinicians in Accident and Emergency medicine are aware of the NICE guidelines, it is possible that in many places it has not been integrated into medical practice. The reasons for this may be lack of knowledge amongst junior staff, which could be addressed by the adoption of protocols for recording information or, perhaps at the present time, the availability of radiology services, particularly out of hours.
Future developments to facilitate better management of those presenting with a minor head injury may also include the identification of patients at risk of longer-term sequelae [10, 11]. Such a process may utilise the power of informatics systems using recent developments in measurement technologies  to minimise the burden of assessment for both staff and patients.