Intraoperative jugular bulb desaturation during acute aneurysmal rupture.

PURPOSE To describe an episode of acute jugular venous desaturation during intraoperative rupture of a cerebral aneurysm. CLINICAL FEATURES A 57-yr-old patient was scheduled for clipping of a large unruptured basilar tip aneurysm. Abrupt bulging of the brain was observed after bone flap removal, but before dura was opened. This was associated with concurrent development of systemic hypertension to 200/120 mmHg and jugular venous bulb (S(jv)O(2)) desaturation to 13%. Rupture of aneurysm was confirmed by frank blood in cerebrospinal fluid drainage from the lumbar subarachnoid catheter. CONCLUSIONS Abrupt S(jv)O(2) desaturation prior to dural opening may suggest an acute increase in intracranial pressure, which in our case followed aneurysmal rupture; the systemic response to increased intracranial pressure (Cushing's response) may be ineffective in maintaining cerebral perfusion.