Hemorheological and Hemodynamic Analysis of Hypervolemic Hemodilution Therapy for Cerebral Vasospasm After Aneurysmal Subarachnoid Hemorrhage

280

138

Background and Purpose-We examined the neuroprotective efficacy of moderate-dose human albumin therapy in acute focal ischemic stroke and defined the therapeutic window after stroke onset, within which this therapy would confer neurobehavioral and histopathological neuroprotection. Methods-Sprague-Dawley rats were anesthetized with halothane/nitrous oxide and received 2-hour middle cerebral artery occlusion (MCAo) by a poly-L-lysine-coated intraluminal suture. Neurological status was evaluated during occlusion (60 minutes) and daily for 3 days after MCAo. In the dose-response study, human albumin doses of either of 0.63 or 1.25 g/kg or saline vehicle (5 mL/kg) were given intravenously immediately after suture removal. In the therapeutic window study, a human albumin dose of 1.25 g/kg was administered intravenously at 2 hours, 3 hours, 4 hours, or 5 hours after onset of MCAo. Three days after MCAo, brains were perfusion-fixed, and infarct volumes and brain swelling were determined. Results-Moderate-dose albumin therapy significantly improved the neurological score at 24 hours, 48 hours, and 72 hours and significantly reduced total infarct volume (by 67% and 58%, respectively, at the 1.25-and 0.63-g/kg doses). Cortical and striatal infarct volumes were also significantly reduced by both doses. Brain swelling was virtually eliminated by albumin treatment. Even when albumin therapy (1.25 g/kg) was initiated as late as 4 hours after onset of MCAo, it improved the neurological score and markedly reduced infarct volumes in cortex (by 68%), subcortical regions (by 52%), and total infarct (by 61%). Conclusions-Moderate-dose albumin therapy markedly improves neurological function and reduces infarction volume and brain swelling, even when treatment is delayed up to 4 hours after onset of ischemia. (Stroke. 2001;32:553-560.)

Section: Clinical Applicationsmentioning

confidence: 99%

Human Albumin Therapy of Acute Ischemic Stroke

Belayev

Liu

Zhao

et al. 2001

280

138

“…2,3 Hypovolemia accompanied by cerebral salt wasting and a progressive reduction of extracellular fluid volume also occurs frequently within a few days after symptom onset, possibly through central nervous system-mediated mechanisms. 4,5 Brain regions with marginal perfusion and loss of autoregulation, hypotension, and hypovolemia, all of which can exacerbate decreases or reductions in cerebral blood flow, have been shown to increase the incidence of cerebral vasospasm and the related delayed ischemic neurologic deficits resulting from the earlier detrimental effects on blood pressure and cardiac output (CO). In this context, hypervolemia, hypertension, and hemodilution therapy is believed to prevent ischemic events and improve outcome and is central to the medical management of symptomatic vasospasm.…”

mentioning

confidence: 99%

Goal-Directed Fluid Management by Bedside Transpulmonary Hemodynamic Monitoring After Subarachnoid Hemorrhage

Mutoh

Kazumata

Ajiki

et al. 2007

109

Background and Purpose-Optimal monitoring of cardiac output and intravascular volume is of paramount importance for good fluid management of patients with subarachnoid hemorrhage (SAH). The aim of this study was to demonstrate the feasibility of advanced hemodynamic monitoring with transpulmonary thermodilution and to provide descriptive data early after SAH. Methods-Forty-six patients with SAH treated within 24 hours of the ictus were investigated. Specific targets for cardiac index (Ն3.0 L ⅐ min Ϫ1 ⅐ m Ϫ2 ), global end-diastolic volume index (700 to 900 mL/m 2 ), and extravascular lung water index (Յ14 mL/kg) were established by the single-indicator transpulmonary thermodilution technique, and a fluid management protocol emphasizing supplemental colloid administration was used to attain these targets. Plasma hormones related to stress and fluid regulation were also measured. Results-A higher cardiac index (mean value of 5.3 L ⅐ min Ϫ1 ⅐ m Ϫ2 ) and a lower global end-diastolic volume index (555 mL/m 2 ) were observed on initial measurement, for which elevations of plasma adrenaline, noradrenaline, and cortisol were also detected. Cardiac index was progressively decreased (3.5 L ⅐ min Ϫ1 ⅐ m Ϫ2 ) and global end-diastolic volume index was normalized by fluid administration aimed at normovolemia. The extent of the initial hemodynamic and hormonal profile was greater in patients with a poor clinical status (PϽ0.05). The extravascular lung water index was mildly elevated but within the target range throughout the study period. No patients developed pulmonary edema or congestive heart failure. Conclusions-The impact of sympathetic hyperactivity after SAH predisposes patients to a hyperdynamic and hypovolemic state, especially in those whose clinical status is poor. Bedside monitoring with the transpulmonary thermodilution system may be a powerful tool for the systemic management of such patients. (Stroke.

“…31,32 However, both increases 33,34 and decreases 35 in CBF have been reported after volume expansion in SAH patients, and CBF measurements in hypervolemic (HV) and normovolemic (NV) subjects have never been directly compared. We performed this randomized controlled study to test the hypothesis that postoperative HV therapy increases CBF after SAH.…”

mentioning

confidence: 99%

Effect of Hypervolemic Therapy on Cerebral Blood Flow After Subarachnoid Hemorrhage

Lennihan

Mayer

Fink

et al. 2000

397

220

Background and Purpose-Cerebral blood flow (CBF) is reduced after subarachnoid hemorrhage (SAH), and symptomatic vasospasm is a major cause of morbidity and mortality. Volume expansion has been reported to increase CBF after SAH, but CBF values in hypervolemic (HV) and normovolemic (NV) subjects have never been directly compared. Methods-On the day after aneurysm clipping, we randomly assigned 82 patients to receive HV or NV fluid management until SAH day 14. In addition to 80 mL/h of isotonic crystalloid, 250 mL of 5% albumin solution was given every 2 hours to maintain normal (NV group, nϭ41) or elevated (HV group, nϭ41) cardiac filling pressures. CBF ( 133 xenon clearance) was measured before randomization and approximately every 3 days thereafter (mean, 4.5 studies per patient). Results-HV patients received significantly more fluid and had higher pulmonary artery diastolic and central venous pressures than NV patients, but there was no effect on net fluid balance or on blood volume measured on the third postoperative day. There was no difference in mean global CBF during the treatment period between HV and NV patients (Pϭ0.55, random-effects model). Symptomatic vasospasm occurred in 20% of patients in each group and was associated with reduced minimum regional CBF values (Pϭ0.04). However, there was also no difference in minimum regional CBF between the 2 treatment groups. Conclusions-HV therapy resulted in increased cardiac filling pressures and fluid intake but did not increase CBF or blood volume compared with NV therapy. Although careful fluid management to avoid hypovolemia may reduce the risk of delayed cerebral ischemia after SAH, prophylactic HV therapy is unlikely to confer an additional benefit. (Stroke. 2000;31:383-391.)