Human Albumin for Clinical Outcome in Aneurysmal Subarachnoid Hemorrhages

Overview

Aneurysmal subarachnoid hemorrhage (aSAH) is a dreadful acute neurological condition with overwhelmingly high rate of associated morbidities and mortality. Despite leaping advancement in neurosurgical techniques and imaging modalities, there is no substantiative improvement in overall prognosis for aSAH. Cerebral vasospasm remains the predominant cause of associated morbidities. Human albumin has been used in different neurological conditions including head trauma, intracerebral hemorrhages, and ischemic strokes with favorable outcome. However, its beneficial use in aSAH has not been sufficiently explored until recently a published systematic review by our team. In view of scarcity of published data and lack of robust evidence, our group has designed for the first ever RCT to compare the use human albumin-enhanced fluid management versus standard fluid therapy with crystalloids in patients with aSAH. This single center open label, prospective, parallel group randomized control trial will be conducted at Hamad General Hospital, Doha-Qatar from August 2024 to July 2027. A sample size of 84 (42 in each arm) has been calculated to detect as sufficient to detect a clinically significant difference in modified Rankin Scale good score between two groups (human-albumin induced volume expansion therapy versus crystalloid only) for fluid management in aneurysmal subarachnoid hemorrhages patients. Primary outcome will be based on dichotomized modified Rankin scale \[(Good grades (0-2) and poor grades (3-6)\], while secondary outcome will include symptomatic vasospasm, transcranial doppler velocities, and Pulse Index Contour Cardiac Output (PiCCO) parameters. The trial aims to provide firsthand evidence on the beneficial use of human albumin to achieve optimal fluid management regime to explore its potential role to improve clinical outcome in patients with aSAH.

Aneurysmal subarachnoid hemorrhage (aSAH) is a fatal neurosurgical emergency that may reach to a mortality of up to nearly 60% within one month of symptoms onset in untreated cases. Accounting for almost 5% of all stroke cases, aSAH predominantly affects the working age population with significant socioeconomic effect due to its impact on their quality of healthy life. Despite refined contemporary neurosurgical techniques and advancements in neurocritical care, secondary/delayed ischemia neurological deficits due to cerebral vasospasm, have been implicated as the main contributing factor, related to poor clinical outcome in nearly 30% of the patients. Although, over the years, many different treatment modalities have been used to counter the detrimental effects of vasospasm including calcium channel blockers and triple-H therapy (hypervolemic, hemodilution, hypertension) with no substantiative improvement in clinical outcome and a search for an effective management strategy continues. In aSAH, hyponatremia due to increased release of natriuretic factors and reduction in intravascular volume have been attributed to cause clinical vasospasm and delayed ischemic neurological deficits as a part of natural course of the disease. Reduced cerebral blood flow during aSAH has been explained based on two etiological factors. Firstly, immediately with the clinical onset of aSAH, there is a generalized decrease in brain oxidative metabolism that contributes to drop in global cerebral blood flow (CBF). This disruption in brain metabolic harmony is primarily caused by presence of toxic blood products in subarachnoid spaces although other contributing factors including acute hydrocephalus, brain edema and rise in intracranial pressure may also play their roles to already compromised CBF. Secondly, during the course of subsequent days to weeks when cerebral vasospasm sets in, it can further cause drop in CBF and cerebral metabolism. This drop in CBF is topographically heterogenous in brain parenchyma and this manifests as the delayed cerebral ischemia causing neurological deficits. Based on these pathophysiological mechanisms, the standard use of hypervolemic therapy was rationalized in neurosurgical practice in the past to mitigate the detrimental effects of hypoperfusion and it used to be achieved by routine use of crystalloids/isotonic solutions and complementary colloidal agents including dextran, hypertonic saline and human albumin in neurocritical care. In animal studies with rat models for acute focal ischemia, albumin treatment has effectively reduced size of penumbra. In contemporary clinical practice, the beneficial effects of human albumin has been investigated in cerebral strokes, acute brain injury, intracranial hemorrhages, including aSAH with promising results. In a pilot study conducted by Suarez et al (ALISAH) for a clinically safe dosage regimen for aSAH, it has also been observed that the use of albumin may be effective to prevent the deleterious effects of cerebral vasospasm by enhanced CBF leading to improvements in neurological outcome in aSAH patients. Ali A. et al recently published a systematic review that underscores obvious gaps in literature for the use of human albumin with no randomized control trial published to-date and highlighting the lack of any robust clinical evidence for the role of albumin to treat cerebral vasospasm in aSAH This single center RCT will aim to explore potential beneficial role of human albumin to improve clinical outcome in patients with aSAH.