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Three Part Question

In [patients with confirmed subarachnoid haemorrhage] does [transfer to a neurosurgical unit] improve [morbidity and mortality]?

Clinical Scenario

A 37 year old male presents to the emergency department. Subarchnoid haemorrhage is confirmed by CT. You wish to transfer this patient to a nearby neurosurgical unit so you contact the neurosurgical SPR to see if he will accept the patient. The SPR asks for the patients GCS which is currently 7. He says that there is a shortage of bed he will not accept this patient and asks for him to be referred to the medics. You wonder if by not being in a specialised neurosurgical unit this patients' outcome will be comprimaised.

Search Strategy

Medline 1966 to July Week 1 2006
Embase 1980 to 2006 Week 28
CINAHL 1982 to July Week 2 2006
Cochrane
Medline
[(exp Intracranial Aneurysm/ or exp Subarachnoid Hemorrhage/) OR (((subarachnoid adj (hemorrhage$ or haemorrhage$ or bleed$)).mp.)OR (SAH.mp.)] AND [(exp Neurosurgery/) OR (((Neurosurgical$ adj (Unit$ or Centre$ or Center$ or Ward$ or Hospital$)).mp.) OR (NSU.mp.)] AND [(exp Prognosis/) OR (Mortality$ or Morbidity$ or Prognosis$ or Outcome$).mp.)]
Embase and CINAHL
[(exp Subarachnoid Hemorrhage/) OR (((subarachnoid adj (hemorrhage$ or haemorrhage$ or bleed$)).mp.)OR (SAH.mp.)] AND [(exp Neurosurgery/) OR (((Neurosurgical$ adj (Unit$ or Centre$ or Center$ or Ward$ or Hospital$)).mp.) OR (NSU.mp.)] AND [(exp Prognosis/) OR (Mortality$ or Morbidity$ or Prognosis$ or Outcome$).mp.)]
Cochrane
[(MeSH descriptor Subarachnoid Hemorrhage explode all trees) OR ((subarachnoid* hemorrhage*) or (subarachnoid* haemorrhage*) or (SAH))] AND [(MeSH descriptor Neurology explode all trees) OR ((neurosugical unit*)* or (neurosugical* centre*) or (neurosugical* center*) or (neurosurgical* ward*) )]

Search Outcome

Medline 122 papers 1 relevant
Embase 535 papers 2 relevant
CINALH 7 papers 0 relevant
Cochrane 8 papers 0 relevant
A total of 2 papers were found

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Cross III DT et al 2003 USA	9290 patients with SAH admitted to 1312 hospitals	Retrospective cohort study. Level 2b	Mortality rates at hospitals with different annual case volumes. Quartile 1 was 1-9 patients;Quartile 2 was 10-18 patient;Quartile 3 was 19-35 patients;Quartile 4 was 36-158 patients.	The mortality rates for different quartile is as follows:Quartile 1 was 38.7%;Quartile 2 was 34.7%;Quartile 3 was 30.8%;Quartile 4 was 27%. The p value calculated for this difference was 0.0001	Although the exclusion criteria was well explained the final number of patients excluded did not add up correctly. There was no follow up of patients and classification was on mortality alone and did not include functional outcome.
Naso WB 2001 USA	Patients with cerebral aneurysm at a low volume cerebral aneurysm practice	Prospective Cohort Study. Level 3b	GOS at an average of 6 months GOS 4-5 favourable, GOS 2-3 poor, GOS 1 dead.	With unruptured aneurysms (26) 92.3% had a favourable outcome, 3.8% had a poor outcome and 3.8% died. In patients with SAH hunt&hess grades 1-3 (42) 90.5% had a favourable outcome, 2.4% had a poor outcome and 7.1% died. In patients with SAH grades 4-5 (11) 45.5% had a favourable outcome, 18.2% had a poor outcome and 36.4% died.	The results were not statically analysed to see if they were valid. There was no comparison of the data with that from a high volume aneurysm practice. The number of patients involved in the study was small (79). No patient selection method is stated.

Comment(s)

Whilst there has been much research into if surgery should be carried out and what type of surgery should be carried out there is very little data to support the transfer of all patients with subarachnoid haemorrhage to a neurosurgical unit. Whilst neither of the papers answer my question completely Cross III et al do demonstrate there is a significant decline in mortality rates amongst hospitals with a higher volume of admission for patients with subarachnoid haemorrhage. However, this may be due to case selection by the NSU, who reject patients with very poor prognoses.

Clinical Bottom Line

Based on this evidence I would recommend the transfer of all patients with subarachnoid haemorrhage to a specialist neurosurgical unit.

References

1. Cross III DT et al Mortality rates after subarachnoid hemorrhage: variations according to hospital case volume in 18 states Journal of neurosurgery 2003;810-817
2. Naso WB et al Management and Outcomes in a Low -volume Cerebral Aneurysm Practice Journal of Neurosurgery 2001; 91-100