Initial Investigation of choice of subarachnoid hemorrhage: March 2009

Ans. C: CT scan Investigations: Full blood count -- anaemia (sickle cell disease), leucocytosis (after a seizure, systemic infection) Coagulation screen -- underlying coagulopathy Urea and electrolytes -- hyponatraemia is common after subarachnoid haemorrhage due to salt wasting, not inappropriate antidiuretic hormone secretion Serum glucose -- hypoglycaemia needs correction,hyperglycaemia is associated with poor outcome after subarachnoid haemorrhage Serum magnesium -- hypomagnesaemia is common and associated with poor outcome after subarachnoid haemorrhage Chest radiography -- pulmonary oedema, aspiration Twelve lead electrocardiography -- cardiac arrhythmia, ST segment changes,myocardial "stunning" Unenhanced computed tomography of the brain--as soon as possible after onset of headache ( < 24 hours). More than 95% of cases can be diagnosed on high quality non-contrast CT scan obtained within 72 hours. Lumbar puncture--if an unenhanced computed tomogram of the brain is normal Computed tomography angiography-- if subarachnoid haemorrhage is confirmed by computed tomography or lumbar puncture.