Only a minority of head injured patients need assessment and treatment at a neurosurgical unit. The proportion transferred varies in different regions. These patients have the most serious injuries and highest risk of complications and of death. The speed with which patients who need neurosurgical care are identified, referred and transferred may critically influence their outcome.^{9, 45, 46, 48, 49, 50, 51, 59, 82, 87, 137, 138} A survey after the introduction in 1978 of guidelines for transfer to neurosurgery showed few deaths in general hospitals occurred in patients who would clearly have benefited from neurosurgical care.¹³⁹ However, there is evidence that delays and other errors in the early management still occur.¹⁴⁰ Evidence level III

In the past, the main reason for transfer to a neurosurgical unit was deteriorating consciousness. If this happens, this is an important reason for transfer. However, the main aim is to take pre-emptive action.

8.1 Reasons for Consultation

The circumstances when consultation about referral is appropriate include when a CT scan has been done and shows an intracranial lesion potentially appropriate for neurosurgical management, or when a CT scan has not been done but there are features indicating a high likelihood of an intracranial lesion requiring urgent attention. Occasionally, consultation may be needed if the patient's condition is causing clinical concern and this has not been resolved by the findings of a CT scan.¹³ The benefits of neurosurgical care, in addition to the skills and facilities for intracranial surgery, include expertise and facilities for patient assessment and investigation, as well as the sophisticated monitoring and management of intracranial conditions that constitute specialised neuro-intensive care. There are also benefits in the access to enhanced knowledge and experience resulting from the concentration of experience.¹³⁷ Evidence level IV

The potential disadvantages of secondary transfer include the possible exposure to secondary insults or added delay in action. These factors are of most concern to patients with serious multiple injuries¹⁴¹ whose continuing care requires ready access to a range of expertise. Evidence level III

In Scotland, each neurosurgical centre is in the campus of a general hospital. In only one is cardiac surgery co-located with neurosurgery, but patients who require both forms of surgical intervention are extremely rare in Scottish practice.

8.2 Indications for Referral

A head injured patient should be discussed with a neurosurgeon: when a CT scan in a general hospital shows a recent intracranial lesion when a patient fulfils the criteria for CT scanning but this cannot be done within an appropriate period irrespective of the result of any CT scan, when the patient has clinical features that suggest that neurosurgical assessment, monitoring, or management are appropriate.

Features suggesting that neurosurgical assessment, monitoring, or management are appropriate include: persisting coma (GCS score 8/15 or less) after initial resuscitation confusion which persists for more than 4 hours deterioration in level of consciousness after admission (a sustained drop of one point on the motor or verbal subscales, or two points on the eye opening subscale of the GCS) progressive focal neurological signs a seizure without full recovery depressed skull fracture definite or suspected penetrating injury a CSF leak or other sign of a basal fracture

8.3 Transfer between a General Hospital and a Neurosurgical Unit

Patients with impaired consciousness are at risk of physiological instability that can result in secondary insults during transport and a worse outcome.⁶⁸, ¹⁴² These adverse events can be minimised by resuscitation before transport and high level monitoring and care in transport.^{20, 69} Evidence level III

Transfer of the patient should follow the principles set out by the Association of Anaesthetists of Great Britain and Ireland and the Neuro-anaesthesia Society of Great Britain and Ireland.

Transfer of a child to a specialist neurosurgical unit should be undertaken by staff experienced in the transfer of critically ill children - i.e. a (Regional) Paediatric Transfer Team.

A standard method of verbal or written communication between referring doctors and neurosurgeons facilitates patient care. Good communication between nursing teams is also important. The guideline development group endorse the proforma developed by the Scottish Trauma Audit Group (see Annex 7).

To facilitate communication between general hospitals and neurosurgical unit staff, a proforma containing the Glasgow Coma Scale and other relevant features should be used.

The details of neurosurgical care are beyond the scope of this guideline, but require an integrated approach which includes operative neurosurgery, neuro-intensive care (including care of potential organ donors), and neuro-rehabilitation. The care of severely head injured patients should follow the guidelines described by a group supported by the Brain Trauma Foundation and recommended by the American Association of Neurosurgeons,¹⁸ and the guidelines of the European Brain Injury Consortium.¹⁹