BACKGROUND: Ninety-three patients undergoing surgical or endovascular operation 
secondary to aneurysmal subarachnoid hemorrhage (SAH) were retrospectively 
analyzed to determine the influence of the different time points of C-reactive 
protein (CRP) measurement on the prediction of vasospasm and clinical outcome.
METHODS: Laboratory data such as the CRP level and the white blood cell count, 
preoperative demographic and clinical data, intraoperative and postoperative 
data, and complications such as intracerebral hemorrhage, hydrocephalus, 
vasospasm, and surgical decompression were collected at hospital discharge or 
symptomatic vasospasm and used as predictable factors for poor outcome (Modified 
Rankin Scale score 4 to 6).
RESULTS: Twenty-three and 28 patients showed poor outcome and symptomatic 
vasospasm after SAH, respectively. Both preoperative and postoperative CRP 
levels were significantly higher in patients with a poor outcome compared with 
patients with a good outcome (P<0.05). The area under the receiver operating 
characteristic curve of CRP measured on postoperative day 1 or 2 (CRP POD1-2) 
for predicting a poor clinical outcome was 0.870, and its cutoff point of 4 
mg/dL had a sensitivity of 0.826 and a specificity of 0.843. A high CRP level 
after aneurysm treatment was associated with severe neurological deterioration 
on admission, cerebral infarction, intracerebral hemorrhage, and surgical 
decompression (P<0.05). CRP POD1-2, and not the preoperative CRP, was an 
independent factor in predicting symptomatic vasospasm (P<0.05). In patients 
with symptomatic vasospasm, an increase in the postoperative CRP was associated 
with the time profile of developing symptomatic vasospasm.
CONCLUSION: Postoperative CRP, especially CRP POD1-2, can be a useful prognostic 
factor for both poor outcome and symptomatic vasospasm in patients with 
aneurysmal SAH.