The goal of this observational study is to assess cystatin c as a predictive biomarker of early acute kidney injury in aneurysmal subarachnoid hemorrhage patients. The main question it aims to answer is:

- Does cystatin c biomarker can predict early acute kidney injury in aneurysmal subarachnoid hemorrhage patients?

Participants will be grouped into Aki and Non-Aki groups based on RIFLE criteria and Cystatin c biomarker will be tested to answer the study question.

Inclusion Criteria:

• Patient admission to hospital within 48 hours of subarachnoid haemorrhage onset.
• Subarachnoid haemorrhage caused by intracranial aneurysm rupture and is confirmed via computed tomography angiography (CTA).
• Medical treatment, microsurgical clipping, or interventional endovascular treatment of aneurysm is performed within 48 hours of subarachnoid haemorrhage onset.

Exclusion Criteria:

• Prior onset of subarachnoid haemorrhage or other neurological diseases such as ischemic stroke, hemorrhagic stroke, or severe head trauma.
• Systemic diseases, such as chronic liver diseases, chronic lung diseases, chronic heart failure, thyroid diseases and cancer.
• Renal impairment at time of admission (creatinine-based eGFR less than 60 ml/min per 1.73 m2 body surface area).
• Patients who are hemodynamically unstable at time of admission.
• Mortality within 10 days after admission (duration of study).

Aneurysmal subarachnoid hemorrhage patients

I keep the IPD information of study participants, based on principle of confidentiality Disclosure after participant permission is allowed