Spontaneous carotid artery dissection.

The authors reply Thank you for giving us the opportunity to clarify certain points raised by Mr Scholes. The rapid access to computed tomography on a 24 hour basis in the Leicester Royal Infirmary is accomplished by ensuring that at least one of the on site radiographers is trained to use the scanner and they are available to perform emergency scans as a priority when necessary.' As with all hospitals there is an on call radiology service available to interpret scans. In the case of "out of hours" computed tomography the radiologist is informed as early as possible when a patient requires a scan of the head. This usually means that the radiologist arrives either before or during the scanning process. Thus, this system employs a radiographer who is already on site and there are no additional resource implications. It is obviously imperative that at least one of the radiographers who is working in the hospital at any time is trained in the use of computed tomography. This is ensured by training as many radiographers as possible and especially those who cover A&E to use the scanner. Mr Scholes has concentrated on the use of computed tomography in the case of head injury. However, as we have demonstrated, 45% of the emergency scans which we carried out in our department were for medical indications. As A&E staff become more "proactive" in the investigation and management of critically ill patients we would expect our need for and use of computed tomography to increase in this type of patient. It is also important to point out that although there were fewer then 200 scans ordered by A&E staff, many further scans were requested by in house teams particularly on patients admitted directly through the medical and paediatric admission units. Where a hospital has made such a large capital investment in installing a scanner, it seems illogical not to make best use of it on a 24 hour basis. We are in complete agreement that where it is apparent on clinical grounds, and after neurosurgical consultation, that a head injured patient will require neurosurgical transfer, irrespective of the results of the computed tomography, that the transfer should take priority. This is the case however in a small minority of head injured patients. As our data point out, even after scanning only one in six patients requires neurosurgical transfer. Thus five out of six patients avoid an unnecessary and potentially hazardous transfer.'2 Transfers to the regional neurosurgical unit in Nottingham take approximately 30 minutes by road from the Leicester Royal Infirmary. In conclusion, we agree with Mr Scholes that policies and protocols on indications for computed tomography and transfer are dependent on local resources and should be decided upon by consultation between the district general hospital and the neurosurgical centre to which they refer. We have described our system, which does not have significant resource implications as it makes best use of existing on site personnel. As the specialty of A&E moves into the 21st century and becomes a true 24 hour service it is vital that a culture change occurs and that all A&E departments have ready and rapid access to the tools of investigation they require on a 24 hour basis. 1 Hicks IR ,Hedley RM, Razis P. Audit of transfer of head injured patients to a stand alone neurosurgical unit. Injury 1994;25:545-9. 2 Andrews PJD, Piper IR, Deardon NM, et al. Secondary insults during intrahospital transport of head injured patients. Lancet 1990;335:327-30. "Empirical" thrombolysis in catastrophic pulmonary embolism