EBQ:Perry Subarachnoid Haemorrhage Study
incomplete Journal Club Article
Perry JJ et al. "High risk clinical characteristics for subarachnoid haemorrhage in patients with acute headache: prospective cohort study". BMJ. 2010. 28(341):c5204.
PubMed Full text PDF
PubMed Full text PDF
Clinical Question
What is the sensitivity of non-contrast head CT for detecting spontaneous subarachnoid hemorrhage (SAH), when performed on a third-generation CT scanner within 6 hours of headache onset?
Conclusion
Third-generation non-contrast head CT is highly sensitive for detecting spontaneous SAH when performed within 6 hours of headache onset and interpreted by a radiologist experienced in reading head CT.
Major Points
Within 6 hours of headache onset, CT had:
Sens = 100% (95% confidence interval: 97%-100%)
Spec = 100% (99.5%-100%)
For all patients studied, CT had:
Sens = 92.9% (89%-95.5%)
Spec = 100% (99.9%-100%)
Population
ED patients in 11 tertiary care centers
Patient Demographics
- Mean age = 45
- 60% women
Inclusion Criteria
- >15 years old
- Acute headache reaching peak intensity within one hour
- Normal neurologic exam
- CT ordered by the treating physician to rule out SAH
Exclusion Criteria
- Focal neurologic deficits
- Papilledema
- History of SAH
- History aneurysm
- Previous VP shunt
- Brain neoplasm
- Onset of headache >14 days ago
- Recurrent headache (≥3 similar)
- Transfer from outside hospital with confirmed diagnosis of SAH
Interventions
Outcome
Primary Outcomes
- To diagnose SAH based on CT, xanthochromia in CSF, or any RBCs in final tube of CSF collected with positive results on cerebral angiography (digital subtraction, CT, or MR angiography)