Circulatory volume expansion for aneurysmal subarachnoid hemorrhage

Nicardipine prolonged-release implants for preventing cerebral vasospasm after subarachnoid hemorrhage: effect and outcome in the first 100 patients

Vasospasm following subarachnoid hemorrhage (SAH) remains difficult to prevent despite extensive investigative efforts. Nicardipine prolonged-release implants (NPRIs) have been used to prevent vasospasm in patients with SAH since October 1999. The present study analyzed the efficacy and safety of NPRIs in 100 patients with SAH and thick subarachnoid clot (mainly Fisher group 3) treated with NPRIs (diameter 2 mm, length 10 mm, containing 4 mg of nicardipine) during surgery after clipping of the aneurysm. The number and location of pellets depended on the amount and site of the subarachnoid clot on preoperative computed tomography and on the type of craniotomy. Two to 12 pellets were implanted in the cisterns of the internal carotid artery, middle cerebral artery, and/or anterior cerebral artery, where thick clots were present and vasospasm related to delayed ischemic neurological deficit (DIND) was highly likely. Only seven patients developed DIND and five patients suffered cerebral infarction. Angiography performed on days 7-12 revealed no vasospasm in any of the arteries close to the site of NPRI placement. NPRI placement can completely prevent vasospasm in arteries within the cisterns containing thick clots, but is less effective in remote locations.

Cerebral Vasospasm Following Subarachnoid Hemorrhage

Cerebral vasospasm and related ischemic stroke continue to be significant complicating factors in the course of many patients with subarachnoid hemorrhage from berry aneurysm rupture. The risk of this well-recognized but poorly understood complication can be estimated on the basis of patient medical history, neurologic examination, and head CT findings. Every patient with possible risk needs specialized neurologic intensive care unit care after aneurysm obliteration. Surgical and pharmacologic wash-out of subarachnoid blood around the basal arteries, proper management of intracranial pressure and fluid status, hyponatremia, hypomagnesemia, and fever, as well as use of calcium channel blockers, have been considered helpful in patient management prior to and with the symptomatic vasospasm development. Transcranial Doppler (TCD) ultrasound is important in detecting vasospasm before the patient suffers ischemic neurologic deficit or infarct. Elevated TCD velocities often initiate the use of triple-H (HHH: hypertension, hemodilution, and hypervolemia) therapy and subsequently guide it. Up to the end of the first 3 weeks after subarachnoid hemorrhage and aneurysm obliteration, development of any focal neurologic deficit or mental deterioration, unless convincingly proven otherwise, is assumed to be from cerebral vasospasm. When a hemodynamically significant vasospasm in the arterial segments of clinical concern is suggested, emergency cerebral angiography with balloon dilatation angioplasty or intra-arterial infusion of vasodilating agents may be helpful in relieving ischemic symptoms.

Antioxidants in critical care medicine

Critically ill patients in the intensive care unit (ICU) present with a variety of different pathologies, and mortality is high despite extensive multi-organ supportive treatment. Reactive oxygen species (ROS) are believed to play a pivotal role in the pathophysiology of organ dysfunction in the ICU. In particular, the role of ROS as a final common pathway of cell damage has been increasingly emphasised in the adult respiratory distress syndrome (ARDS), in central nervous system traumatic and hypoxic states, and as a cause of ischaemic neurological deficits after subarachnoid haemorrhage. Measurement of total antioxidant status (TAS) has shown improved survival of patients with high TAS and poorer outcomes for those with lower values. Attempts to supplement endogenous antioxidant defences have not demonstrated clear benefits in randomised clinical trials, and the use of free radical scavenging agents have had similar mixed results. Considering the wide variation in the nature and severity of illness in the intensive care population, it is not surprising that clear evidence of the efficacy of antioxidant therapies in improving survival has not been clearly demonstrated. However, single component therapies for complex pathophysiological processes are rarely successful, and the role of antioxidants in the critically ill should be thought of as only part of a rational and logical therapeutic approach.