Global cerebral edema after subarachnoid hemorrhage: frequency, predictors, and impact on outcome

Transdermal nicotine replacement therapy in cigarette smokers with acute subarachnoid hemorrhage

BACKGROUND

We evaluated the safety of nicotine replacement therapy (NRT) in active smokers with acute (aneurysmal) subarachnoid hemorrhage (SAH).

METHODS

A retrospective observational cohort study was conducted in a prospectively collected database including all SAH patients admitted to an 18-bed neuro-ICU between January 1, 2001 and October 1, 2007. Univariate and multivariable models were constructed, employing stepwise logistic regression. The primary endpoint was 3-month mortality. Delayed cerebral ischemia (DCI) due to vasospasm, angiographic and TCD evidence of vasospasm, and delirium were secondary endpoints.

RESULTS

Active cigarette smokers admitted with SAH included 128 that received NRT and 106 that did not. Patients were well-matched for age, admission Hunt-Hess Grade, radiographic findings, and APACHE II scores, but those who received NRT were more likely to be heavy smokers (>10 cigarettes daily), diabetic, heavy alcohol users, and to have cerebral edema on admission. NRT was associated in multivariate analysis with a lower risk of death at 3 months (OR 0.12, 95% CI 0.04-0.37, P < 0.001). There were no differences in the frequency of DCI and most other medical complications, but delirium (19 vs. 9%, P = 0.006) and seizures (9 vs. 2%, P = 0.024) were more common in patients who received NRT.

CONCLUSIONS

Despite vasoactive properties, administration of NRT among active smokers with acute SAH appeared to be safe, with similar rates of vasospasm and DCI, and a slightly higher rate of seizures. The association of NRT with lower mortality could be due to chance, to uncontrolled factors, or to a neuroprotective effect of nicotine in active smokers hospitalized with SAH, and should be tested prospectively.

Global cerebral edema and brain metabolism after subarachnoid hemorrhage

BACKGROUND AND PURPOSE

Global cerebral edema is common among patients with poor-grade subarachnoid hemorrhage and is associated with poor outcome. Currently no targeted therapy exists largely due to an incomplete understanding of the underlying mechanisms.

METHODS

This is a prospective observational study including 39 consecutive patients with poor-grade subarachnoid hemorrhage with multimodal neuromonitoring. Levels of microdialysate lactate-pyruvate ratio, episodes of cerebral metabolic crisis (lactate-pyruvate ratio >40 and brain glucose <0.7 mmol/L), brain tissue oxygen tension, cerebral perfusion pressure, and transcranial Doppler sonography flow velocities were analyzed.

RESULTS

Median age was 54 years (range, 45 to 61 years) and 62% were female. Patients with global cerebral edema on admission (n=24 [62%]) had a higher incidence of metabolic crisis in the first 12 hours of monitoring (n=15 [15% versus 2%], P<0.05) and during the total time of neuromonitoring (20% versus 3%, P<0.001) when compared to those without global cerebral edema. There was no difference in brain tissue oxygen tension or cerebral perfusion pressure between the groups; however, in patients with global cerebral edema, a higher cerebral perfusion pressure was associated with lower lactate-pyruvate ratio (P<0.05). Episodes of metabolic crisis were associated with poor outcome (modified Rankin Scale score 5 or 6, P<0.05).

CONCLUSIONS

In patients with poor-grade subarachnoid hemorrhage, global cerebral edema is associated with early brain metabolic distress.

Cerebral perfusion pressure thresholds for brain tissue hypoxia and metabolic crisis after poor-grade subarachnoid hemorrhage

BACKGROUND AND PURPOSE

To identify a minimally acceptable cerebral perfusion pressure threshold above which the risks of brain tissue hypoxia (BTH) and oxidative metabolic crisis are reduced for patients with subarachnoid hemorrhage (SAH).

METHODS

We studied 30 poor-grade SAH patients who underwent brain multimodality monitoring (3042 hours). Physiological measures were averaged over 60 minutes for each collected microdialysis sample. Metabolic crisis was defined as a lactate/pyruvate ratio>40 with a brain glucose concentration≤0.7 mmol/L. BTH was defined as PbtO2<20 mm Hg. Outcome was assessed at 3 months with the Modified Rankin Scale.

RESULTS

Multivariable analyses adjusting for admission Hunt-Hess grade, intraventricular hemorrhage, systemic glucose, and end-tidal CO2 revealed that cerebral perfusion pressure≤70 mm Hg was significantly associated with an increased risk of BTH (OR, 2.0; 95% CI, 1.2-3.3; P=0.007) and metabolic crisis (OR, 2.1; 95% CI, 1.2-3.7; P=0.007). Death or severe disability at 3 months was significantly associated with metabolic crisis (OR, 5.4; 95% CI, 1.8-16; P=0.002) and BTH (OR, 5.1; 95% CI, 1.2-23; P=0.03) after adjusting for admission Hunt-Hess grade.

CONCLUSIONS

Metabolic crisis and BTH are associated with mortality and poor functional recovery after SAH. Cerebral perfusion pressure levels<70 mm Hg was associated with metabolic crisis and BTH, and may increase the risk of secondary brain injury in poor-grade SAH patients.

Characterizing the role of the neuropeptide substance P in experimental subarachnoid hemorrhage

BACKGROUND

Raised intracranial pressure (ICP) following SAH predicts poor outcome and is due to hemorrhage volume and possibly, brain edema, hydrocephalus and increased volume of circulating intracranial blood. Interventions that reduce edema may therefore reduce ICP and improve outcome. The neuropeptide substance P (SP) mediates vasogenic edema formation in animal models of ischemic stroke, intracerebral hemorrhage and brain trauma, and may contribute to development of increased ICP. SP (NK1 tachykinin receptor) blockade using n-acetyl-l-tryptophan (NAT) reduces edema and improves outcome in these models. This study therefore assessed whether SP mediates edema formation in experimental SAH.

METHODS

SAH was induced in rats by either injection of autologous blood into the prechiasmatic cistern (injection SAH) or by arterial puncture of the Circle of Willis (filament SAH). NAT was injected (i.v.) 30min after SAH induction. Subgroups were assessed for brain water content, SP and albumin immunoreactivity, and functional outcome at 5, 24 and 48h or ICP over 5h.

RESULTS

A secondary ICP increase occurred within 2h of SAH. Brain edema followed filament SAH (p<0.001) and correlated with functional deficits (r=0.8, p<0.01). Increased albumin immunoreactivity (p<0.001) indicated vasogenic edema. However, NAT treatment did not improve ICP, edema or outcome.

CONCLUSIONS

Experimental SAH produced secondary ICP elevation, vasogenic brain edema and functional deficits, although it is unclear if edema contributed to ICP. Blockade of SP did not improve any outcome parameters, suggesting that neurogenic inflammation may be less critical than other factors in these models.

The effect of window rooms on critically ill patients with subarachnoid hemorrhage admitted to intensive care

Introduction

Clinicians and specialty societies often emphasize the potential importance of natural light for quality care of critically ill patients, but few studies have examined patient outcomes associated with exposure to natural light. We hypothesized that receiving care in an intensive care unit (ICU) room with a window might improve outcomes for critically ill patients with acute brain injury.

Methods

This was a secondary analysis of a prospective cohort study. Seven ICU rooms had windows, and five ICU rooms did not. Admission to a room was based solely on availability.

We analyzed data from 789 patients with subarachnoid hemorrhage (SAH) admitted to the neurological ICU at our hospital from August 1997 to April 2006. Patient information was recorded prospectively at the time of admission, and patients were followed up to 1 year to assess mortality and functional status, stratified by whether care was received in an ICU room with a window.

Results

Of 789 SAH patients, 455 (57.7%) received care in a window room and 334 (42.3%) received care in a nonwindow room. The two groups were balanced with regard to all patient and clinical characteristics. There was no statistical difference in modified Rankin Scale (mRS) score at hospital discharge, 3 months or 1 year (44.8% with mRS scores of 0 to 3 with window rooms at hospital discharge versus 47.2% with the same scores in nonwindow rooms at hospital discharge; adjusted odds ratio (aOR) 1.01, 95% confidence interval (95% CI) 0.67 to 1.50, P = 0.98; 62.7% versus 63.8% at 3 months, aOR 0.85, 95% CI 0.58 to 1.26, P = 0.42; 73.6% versus 72.5% at 1 year, aOR 0.78, 95% CI 0.51 to 1.19, P = 0.25). There were also no differences in any secondary outcomes, including length of mechanical ventilation, time until the patient was able to follow commands in the ICU, need for percutaneous gastrostomy tube or tracheotomy, ICU and hospital length of stay, and hospital, 3-month and 1-year mortality.

Conclusions

The presence of a window in an ICU room did not improve outcomes for critically ill patients with SAH admitted to the ICU. Further studies are needed to determine whether other groups of critically ill patients, particularly those without acute brain injury, derive benefit from natural light.

Long-term MRI findings of patients with embolized cerebral aneurysms

BACKGROUND

Long-term follow-up studies after endovascular treatment for intracranial aneurysm are still rare and inconclusive. Parenchymal infarctions related to aneurysms have mostly been studied in patients with subarachnoidal hemorrhage (SAH) but infarction rates in patients with endovascularly treated unruptured aneurysms have been little studied.

PURPOSE

To determine the frequency of permanent parenchymal lesions as detected in magnetic resonance imaging (MRI) in patients treated with endovascular coiling and to assess aneurysm-related infarctions after the initial treatment period.

MATERIAL AND METHODS

A total of 64 patients (32 with primarily ruptured aneurysms) with 69 embolized aneurysms were examined neurologically and by MRI and magnetic resonance angiography (MRA) more than 9 years after the initial endovascular treatment.

RESULTS

A total of 14 out of 32 (44%) SAH patients and 11 (34%) patients with unruptured aneurysms had parenchymal lesions in MRI. Infarctions were detected in 10 (31%) SAH patients and the majority (9/10, 90%) of them were aneurysm-related. All aneurysm-related infarctions were detected at the acute hospitalization stage. A total of six (55%) out of 11 infarctions in patients with unruptured aneurysms were aneurysm-related and two of them appeared after the treatment period. Patients with infarction had poorer clinical outcome than patients with no ischemic lesions in MRI.

CONCLUSION

Nineteen percent of patients with unruptured and 41% with ruptured aneurysms had aneurysm-related parenchymal lesions in MRI. Most of these were detected during acute treatment period. Aneurysm-related infarctions after treatment period are uncommon.

Decompressive hemicraniectomy after aneurysmal subarachnoid hemorrhage

BACKGROUND

The aim of this study was to document the effects of decompressive hemicraniectomy (DHC) on neurologic outcome in patients treated for aneurysmal subarachnoid hemorrhage (SAH) and developing otherwise uncontrollable intracranial hypertension.

METHODS

Sixty-six of the 964 patients (6.8%) treated for aneurysmal SAH underwent DHC and were stratified as follows: Group 1, patients undergoing aneurysm clipping and DHC in one surgical sitting (i.e., primary DHC). Group 2, patients receiving aneurysm embolization and thereafter undergoing DHC. Group 3, patients undergoing standard aneurysm surgery and requiring DHC later in the post-SAH period. Group 4, patients with insufficient primary DHC and later requiring surgical enlargement of the craniectomy.

RESULTS

Outcome was not influenced by the timing of DHC, but depended on the pathology underlying intracranial hypertension (i.e., whether lesions were primary hemorrhagic or secondary ischemic in origin). Patients with large hematomas, undergoing primary, secondary, or repeat DHC (46/66) had significantly better outcomes than the 20 patients treated for edema and delayed ischemic infarctions. There were 16 (34.8%) of the 46 patients in the hematoma group, but only 2 (10.0%) of the 20 patients in the ischemia group had favorable neurologic outcomes, defined as modified Rankin Scale scores 0-3 (P value = 0.038).

CONCLUSIONS

In the largest series of SAH patients to date who received both microsurgical and endovascular treatment of ruptured aneurysms, and who underwent DHC for otherwise uncontrollable intracranial hypertension. Neurologic outcome was significantly correlated with the pathology underlying intracranial hypertension. DHC beneficially affected neurologic outcomes in patients with space-occupying hematomas, whereas patients suffering delayed ischemic strokes did not benefit to the same extent.

Brain energy metabolism in patients with spontaneous subarachnoid hemorrhage and global cerebral edema

BACKGROUND

Previous studies of spontaneous subarachnoid hemorrhage (SAH) have shown that global cerebral edema on the first computed tomography scan is associated with a more severe initial injury and is an independent predictor of poor outcome. Effects of secondary ischemic events also influence outcome after SAH.

OBJECTIVE

This study demonstrates that early global edema is related to markers of an increased cerebral energy metabolism as measured with intracerebral microdialysis, which could increase vulnerability to adverse events.

METHODS

Fifty-two patients with microdialysis monitoring after spontaneous SAH were stratified according to the occurrence of global cerebral edema on the first computed tomography scan taken a median of 2 hours after the initial bleed. Microdialysis levels of glucose, lactate, and pyruvate were compared between the global edema (n = 31) and no global edema (n = 21) groups. Clinical outcome was assessed with the Glasgow Outcome Scale score at >/= 6 months.

RESULTS

Patients with global edema showed significantly elevated lactate and pyruvate levels 70 to 79 hours after SAH and marginally significantly higher levels of lactate 60 to 69 hours and 80 to 89 hours after SAH. There was a trend toward worse outcome in the edema group.

CONCLUSION

Patients with global cerebral edema have higher interstitial levels of lactate and pyruvate. The edema group may have developed a cerebral hypermetabolism to meet the increased energy demand in the recovery phase after SAH. This stress would make the brain more vulnerable to secondary insults, increasing the likelihood of energy failure.

Predictors of long-term shunt-dependent hydrocephalus after aneurysmal subarachnoid hemorrhage

Object

The purpose of this study was to identify predictors of shunt-dependent hydrocephalus after aneurysmal subarachnoid hemorrhage (SAH).

Methods

The authors evaluated the incidence of shunt-dependent hydrocephalus in a consecutive cohort of 580 patients with SAH who were admitted to the Neurological Intensive Care Unit of Columbia University Medical Center between July 1996 and September 2002. Patient demographics, 24-hour admission variables, initial CT scan characteristics, daily transcranial Doppler variables, and development of in-hospital complications were analyzed. Odds ratios and 95% CIs for candidate predictors were calculated using multivariate nominal logistic regression.

Results

Admission glucose of at least 126 mg/dl (adjusted OR 1.6; 95% CI 1.0–2.6), admission brain CT scan with a bicaudate index of at least 0.20 (adjusted OR 1.43; 95% CI 1.0–2.0), Fisher Grade 4 (adjusted OR 2.71; 95% CI 1.2–5.7), fourth ventricle hemorrhage (adjusted OR 1.78; 95% CI 1.1–2.7), and development of nosocomial meningitis (adjusted OR 2.2; 95% CI 1.4–3.7) were independently associated with shunt dependency.

Conclusions

These data suggest that permanent CSF diversion after aneurysmal SAH may be independently predicted by hyperglycemia at admission, findings on the admission CT scan (Fisher Grade 4, fourth ventricle intraventricular hemorrhage, and bicaudate index ≥ 0.20), and development of nosocomial meningitis. Future research is needed to assess if tight glycemic control, reduction of fourth ventricle clot burden, and prevention of nosocomial meningitis may reduce the need for permanent CSF diversion after aneurysmal SAH.

Early global brain oedema in relation to clinical admission parameters and outcome in patients with aneurysmal subarachnoid haemorrhage

BACKGROUND

Previous studies on spontaneous aneurysmal subarachnoid haemorrhage (SAH) treatment have found the presence of global cerebral oedema on the first CT scan to be a predictor of poor outcome. We have reviewed our own experience with SAH in order to evaluate the relation of global cerebral oedema to clinical parameters at admission and to functional outcome.

METHODS

One hundred ninety patients with spontaneous aneurysmal SAH were included in the study. The first CT scan for each patient was evaluated for signs of global cerebral oedema. Clinical status on admission was assessed according to the Hunt & Hess score and the World Federation of Neurosurgical Societies (WFNS) grade and functional outcome using the Glasgow Outcome Scale (GOS). Clinical condition at admission was dichotomised as 'better' (Hunt & Hess 1-2, WFNS 1-2) or 'worse' (Hunt & Hess 3-5, WFNS 3-5) and outcome as 'favourable' (GOS 4-5) or 'poor' (GOS 1-3). The amount of blood on the CT scan was assessed using the Fisher scale. Comparisons were made between patients with and without global cerebral oedema on the first CT regarding clinical condition, age, gender, mode of aneurysm treatment, outcome, 6-month mortality, amount of blood on the CT scan and time lag to the first CT scan.

RESULTS

Global cerebral oedema was observed in 57% of patients admitted with aneurysmal SAH, which is a much higher frequency than has been reported previously. Patients with oedema were admitted in a worse clinical status, but there was no difference between patients with and without oedema regarding other clinical parameters or outcome. The median time between the haemorrhage and the first CT scan was short compared to earlier studies, 2.5 h for those with oedema and 3.4 for those without. This difference was significant, suggesting that global cerebral oedema can be a very early phenomenon after SAH, and may be missed in later CT scans.

SUMMARY

Early global brain oedema, occurring within a few hours of bleeding, may be more common than previously thought. In aneurysmal SAH patients, the presence of global cerebral oedema was associated with a worse clinical condition at admission which in turn could indicate a more severe initial injury. The clinical significance of early oedema may differ from that of late oedema, which may explain the lack of an association between global oedema and poor outcome in this study. However, the nature of the oedema as well as its relation to the clinical course has to be further studied in separate studies.

Medical complications after subarachnoid hemorrhage

The prevention and management of medical complications are important for improving outcomes after subarachnoid hemorrhage (SAH). Fever, anemia requiring transfusion, hyperglycemia, hyponatremia, pneumonia, hypertension, and neurogenic cardiopulmonary dysfunction occur frequently after SAH. There is increasing evidence that acute hypoxia and extremes of blood pressure can exacerbate brain injury during the acute phase of bleeding. There are promising strategies to minimize these complications. Randomized controlled trials are needed to evaluate the risks and benefits of these and other medical management strategies after SAH.

Mechanisms of osteopontin-induced stabilization of blood-brain barrier disruption after subarachnoid hemorrhage in rats

BACKGROUND AND PURPOSE

Osteopontin (OPN) is an inducible, multifunctional, extracellular matrix protein that may be protective against blood-brain barrier (BBB) disruption after subarachnoid hemorrhage (SAH). However, the protective mechanisms remain unclear.

METHODS

We produced the endovascular perforation model of SAH in rats and studied the time course of OPN induction in brains by Western blotting and immunofluorescence (n=50). Then, 34 rats were randomly assigned to sham (n=3), sham+OPN small interfering RNA (siRNA, n=3), SAH+negative control siRNA (n=14), and SAH+OPN siRNA (n=14) groups, and 109 rats were allocated to sham+vehicle (n=17), sham+recombinant OPN (n=17), SAH+vehicle (n=33), SAH+recombinant OPN (n=31), and SAH+recombinant OPN+L-arginyl-glycyl-L-aspartate motif-containing hexapeptide (n=11) groups. The effects of OPN siRNA or recombinant OPN on BBB disruption and related proteins were studied.

RESULTS

OPN was significantly induced in reactive astrocytes and capillary endothelial cells, peaking at 72 hours after SAH, during the recovery phase of BBB disruption. Blockage of endogenous OPN induction exacerbated BBB disruption and was associated with a reduction of angiopoietin-1 and mitogen-activated protein kinase (MAPK) phosphatase-1 (an endogenous MAPK inhibitor), activation of MAPKs, and induction of vascular endothelial growth factor-A at 72 hours after SAH, whereas recombinant OPN treatment improved it and was associated with MAPK phosphatase-1 induction, MAPK inactivation, and vascular endothelial growth factor-A reduction, which was blocked by L-arginyl-glycyl-L-aspartate motif-containing hexapeptide at 24 hours after SAH. Vascular endothelial growth factor-B and angiopoietin-2 levels were unchanged.

CONCLUSIONS

OPN may increase MAPK phosphatase-1 that inactivates MAPKs, upstream and downstream of vascular endothelial growth factor-A, by binding to L-arginyl-glycyl-L-aspartate-dependent integrin receptors, suggesting a novel mechanism of OPN-induced post-SAH BBB protection.

Early infarction detected by diffusion-weighted imaging in patients with subarachnoid hemorrhage

PURPOSE

Early infarction that occurs at the time of initial subarachnoid hemorrhage (SAH) due to rupture of an aneurysm is a poorly understood phenomenon. We investigate the frequency of early infarction using diffusion-weighted images (DWI) at the time of admission. We then discuss the pathogenesis of infarction.

MATERIALS AND METHODS

This study included 85 SAH patients who underwent serial DWI on admission. Early infarction detected by DWI and clinical features were investigated retrospectively.

RESULTS

The overall incidence of DWI-detected early infarction at the time of SAH onset was 8% (7 of 85 cases). In all seven patients, early infarctions were asymptomatic on admission. Types of early infarction seen on DWI included infarcts occurring in the territory of the vessel harboring a ruptured aneurysm (solitary, three cases) and infarcts occurring outside the territory of the vessel (multiple, two cases; solitary, two cases). Six of seven patients eventually developed delayed ischemic neurological deficit (DIND) and computed tomography (CT)-detected and DWI-detected delayed extensive infarction. Four of seven patients with early infarction had an unfavorable outcome. The occurrence of DWI-detected early infarction on admission was significantly correlated with delayed angiographic vasospasm, DIND, CT-detected delayed infarction, DWI-detected delayed infarction, and unfavorable outcome.

CONCLUSIONS

In the present study, DWI-detected early infarction at the time of SAH onset was correlated with the occurrence of delayed extensive ischemic lesions. We believe that performing DWI at the time of admission is useful for evaluating the primary ischemic insult, which might play an important role in the pathogenesis of early brain injury and delayed vasospasm-related complications.

Prognostic value of biochemical markers of brain damage and oxidative stress in post-surgical aneurysmal subarachnoid hemorrhage patients

The aim of this study is to determine effective biochemical markers and optimal sampling timing for prediction of neurological prognosis in post-surgical aneurysmal subarachnoid hemorrhage (SAH) patients. Subjects were a sequential group of SAH patients admitted to our centre who underwent aneurysm clipping before Day 3 and who received a cerebrospinal fluid (CSF) drain. CSF samples from 32 patients were collected on Days 3, 7, and 14. Neurological outcome was assessed by neurosurgeons using the Glasgow outcome scale (GOS) at 6 months after onset. CSF levels of neuron-specific enolase (NSE), S100B, and glial fibrillary acidic protein (GFAP) were determined using enzyme-linked immunosorbent assay, and the CSF concentrations of malondialdehyde (MDA) were determined using spectrophotometric assay. In univariate analysis, S100B on Days 3 and 14, GFAP on Days 3 and 7, and MDA on Day 14 were significantly higher in the poor outcome group (GOS 1-4) than in the good outcome group (GOS 5). In multivariate analysis, only MDA on Day 14 was identified as a significant predictor of poor neurological outcome at 6 months after onset. The area under the receiver-operating characteristic (ROC) curve for MDA on Day 14 was 0.841. For a threshold of 0.3 microM, sensitivity and specificity were 0.875 and 0.750, respectively. Our findings suggest that these biochemical markers, especially MDA, show significant promise as predictors of neurological outcome in clinical practice.

Protective effects of recombinant osteopontin on early brain injury after subarachnoid hemorrhage in rats

OBJECTIVE

Accumulated evidence suggests that the primary cause of poor outcome after subarachnoid hemorrhage is not only cerebral arterial narrowing but also early brain injury. Our objective was to determine the effect of recombinant osteopontin, a pleiotropic extracellular matrix glycoprotein, on early brain injury after subarachnoid hemorrhage in rats.

DESIGN

Controlled in vivo laboratory study.

SETTING

Animal research laboratory.

SUBJECTS

One hundred seventy-seven male adult Sprague-Dawley rats weighing 300 to 370 g.

INTERVENTIONS

The endovascular perforation model of subarachnoid hemorrhage was produced. Subarachnoid hemorrhage or sham-operated rats were treated with an equal volume (1 microL) of pre-subarachnoid hemorrhage intracerebroventricular administration of two dosages (0.02 and 0.1 microg) of recombinant osteopontin, albumin, or vehicle. Body weight, neurologic scores, brain edema, and blood-brain barrier disruption were evaluated, and Western blot analyses were performed to determine the effect of recombinant osteopontin on matrix metalloproteinase-9, substrates of matrix metalloproteinase-9 (zona occludens-1, laminin), tissue inhibitor of matrix metalloproteinase-1, inflammation (interleukin-1beta), and nuclear factor-kappaB signaling pathways.

MEASUREMENTS AND MAIN RESULTS

Treatment with recombinant osteopontin prevented a significant loss in body weight, neurologic impairment, brain edema, and blood-brain barrier disruption after subarachnoid hemorrhage. These effects were associated with the deactivation of nuclear factor-kappaB activity, inhibition of matrix metalloproteinase-9 induction, the maintenance of tissue inhibitor of matrix metalloproteinase-1, the consequent preservation of the cerebral microvessel basal lamina protein laminin, and the tight junction protein zona occludens-1.

CONCLUSIONS

These results demonstrate that recombinant osteopontin treatment is effective for early brain injury after subarachnoid hemorrhage.

Increased brain edema in aqp4-null mice in an experimental model of subarachnoid hemorrhage

We investigated the role of the glial water channel protein aquaporin-4 in brain edema in a mouse model of subarachnoid hemorrhage in which 30 microl of blood was injected into the basal cisterns. Brain water content, intracranial pressure and neurological score were compared in wildtype and aquaporin-4 null mice. We also measured blood-brain barrier permeability, and the osmotic permeability of the glia limitans, one of the routes of edema elimination. Wildtype and aquaporin-4 null mice had comparable baseline brain water content, intracranial pressure and neurological score. At 6 h after blood injection, aquaporin-4 null mice developed more brain swelling than wildtype mice. Brain water content increased by 1.5+/-0.1% vs. 0.5+/-0.2% (Mean+/-Standard Error, P<0.0005) and intracranial pressure by 36+/-5 vs. 21+/-3 mm Hg (P<0.05) above pre-injection baseline, and neurological score was worse at 18.0 vs. 24.5 (median, P<0.05), respectively. Although subarachnoid hemorrhage produced comparable increases in blood-brain barrier permeability in wildtype and aquaporin-4 null mice, aquaporin-4 null mice had a twofold reduction in glia limitans osmotic permeability. We conclude that aquaporin-4 null mice manifest increased brain edema following subarachnoid hemorrhage as a consequence of reduced elimination of excess brain water.

Brain interstitial fluid TNF-alpha after subarachnoid hemorrhage

OBJECTIVE

TNF-alpha is an inflammatory cytokine that plays a central role in promoting the cascade of events leading to an inflammatory response. Recent studies have suggested that TNF-alpha may play a key role in the formation and rupture of cerebral aneurysms, and that the underlying cerebral inflammatory response is a major determinate of outcome following subrarachnoid hemorrhage (SAH).

METHODS

We studied 14 comatose SAH patients who underwent multimodality neuromonitoring with intracranial pressure (ICP) and cerebral microdialysis as part of their clinical care. Continuous physiological variables were time-locked every 8h and recorded at the same point that brain interstitial fluid TNF-alpha was measured in brain microdialysis samples. Significant associations were determined using generalized estimation equations.

RESULTS

Each patient had a mean of 9 brain tissue TNF-alpha measurements obtained over an average of 72h of monitoring. TNF-alpha levels rose progressively over time. Predictors of elevated brain interstitial TNF-alpha included higher brain interstitial fluid glucose levels (beta=0.066, p<0.02), intraventricular hemorrhage (beta=0.085, p<0.021), and aneurysm size >6mm (beta=0.14, p<0.001). There was no relationship between TNF-alpha levels and the burden of cisternal SAH; concurrent measurements of serum glucose, or lactate-pyruvate ratio.

INTERPRETATION

Brain interstitial TNF-alpha levels are elevated after SAH, and are associated with large aneurysm size, the burden of intraventricular blood, and elevation brain interstitial glucose levels.

Elucidating novel mechanisms of brain injury following subarachnoid hemorrhage: an emerging role for neuroproteomics

Subarachnoid hemorrhage (SAH) is a devastating neurological injury associated with significant patient morbidity and death. Since the first demonstration of cerebral vasospasm nearly 60 years ago, the preponderance of research has focused on strategies to limit arterial narrowing and delayed cerebral ischemia following SAH. However, recent clinical and preclinical data indicate a functional dissociation between cerebral vasospasm and neurological outcome, signaling the need for a paradigm shift in the study of brain injury following SAH. Early brain injury may contribute to poor outcome and early death following SAH. However, elucidation of the complex cellular mechanisms underlying early brain injury remains a major challenge. The advent of modern neuroproteomics has rapidly advanced scientific discovery by allowing proteome-wide screening in an objective, nonbiased manner, providing novel mechanisms of brain physiology and injury. In the context of neurosurgery, proteomic analysis of patient-derived CSF will permit the identification of biomarkers and/or novel drug targets that may not be intuitively linked with any particular disease. In the present report, the authors discuss the utility of neuroproteomics with a focus on the roles for this technology in understanding SAH. The authors also provide data from our laboratory that identifies high-mobility group box protein-1 as a potential biomarker of neurological outcome following SAH in humans.

Cerebral inflammatory response and predictors of admission clinical grade after aneurysmal subarachnoid hemorrhage

Poor admission clinical grade is the most important determinant of outcome after aneurysmal subarachnoid hemorrhage (aSAH); however, little attention has been focused on independent predictors of poor admission clinical grade. We hypothesized that the cerebral inflammatory response initiated at the time of aneurysm rupture contributes to ultra-early brain injury and poor admission clinical grade. We sought to identify factors known to contribute to cerebral inflammation as well as markers of cerebral dysfunction that were associated with poor admission clinical grade. Between 1997 and 2008, 850 consecutive SAH patients were enrolled in our prospective database. Demographic data, physiological parameters, and location and volume of blood were recorded. After univariate analysis, significant variables were entered into a logistic regression model to identify significant associations with poor admission clinical grade (Hunt-Hess grade 4-5). Independent predictors of poor admission grade included a SAH sum score >15/30 (odds ratio [OR] 2.3, 95% confidence interval [CI] 1.5-3.6), an intraventricular hemorrhage sum score >1/12 (OR 3.1, 95% CI 2.1-4.8), aneurysm size >10mm (OR 1.7, 95% CI 1.1-2.6), body temperature 38.3 degrees C (OR 2.5, 95% CI 1.1-5.4), and hyperglycemia >200mg/dL (OR 2.7, 95% CI 1.6-4.5). In a large, consecutive series of prospectively enrolled patients with SAH, the inflammatory response at the time of aneurysm rupture, as reflected by the volume and location of the hemoglobin burden, hyperthermia, and perturbed glucose metabolism, independently predicts poor admission Hunt-Hess grade. Strategies for mitigating the inflammatory response to aneurysmal rupture in the hyper-acute setting may improve the admission clinical grade, which may in turn improve outcomes.

Brain edema formation and neurological impairment after subarachnoid hemorrhage in rats

Object

Global cerebral edema is an independent risk factor for early death and poor outcome after subarachnoid hemorrhage (SAH). In the present study, the time course of brain edema formation, neurological deficits, and neuronal cell loss were investigated in the rat filament SAH model.

Methods

Brain water content and neurological deficits were determined in rats randomized to sham (1-, 24-, or 48-hour survival), SAH by endovascular perforation (1-, 24-, or 48-hour survival), or no surgery (control). The neuronal cell count (CA1–3) was quantified in a separate set of SAH (6-, 24-, 48-, or 72-hour survival) and shamoperated animals.

Results

Brain water content increased significantly 24 (80.2 ± 0.4% [SAH] vs 79.2 ± 0.1% [sham]) and 48 hours (79.8 ± 0.2% [SAH] vs 79.3 ± 0.1% [sham]) after SAH. The neuroscore was significantly worse after SAH (33 ± 15 [24 hours after SAH] vs 0 ± 0 points [sham]) and correlated with the extent of brain edema formation (r = 0.96, p < 0.001). No hippocampal damage was present up to 72 hours after SAH.

Conclusions

Brain water content and neurological dysfunction reached a maximum at 24 hours after SAH. This time point, therefore, seems to be optimal to test the effects of therapeutic interventions on brain edema formation. Neuronal cell loss was not present in CA1–3 up to 72 hours of SAH. Therefore, morphological damage needs to be evaluated at later time points.

Mild hypothermia (33 degrees C) reduces intracranial hypertension and improves functional outcome after subarachnoid hemorrhage in rats

OBJECTIVE

After a subarachnoid hemorrhage (SAH), the primary cause of mortality is secondary brain injury occurring within the first 48 hours after the initial bleeding. Because of the unknown pathophysiology of these early events, therapeutic approaches are scarce. Because mild hypothermia (33 degrees C) is among the strongest neuroprotectants known so far, the aim of this study was to investigate acute and delayed effects of hypothermia if applied after SAH.

METHODS

Male Sprague-Dawley rats were subjected to SAH and randomly assigned to the following groups: 1) SAH under normothermia, 2) SAH followed by 2 hours of hypothermia starting 1 hour after the bleeding, and 3) SAH followed by 2 hours of hypothermia starting 3 hours after the bleeding. Cerebral blood flow and intracranial pressure were continuously measured up to 6 hours after SAH. Mortality, neurological deficits, and body weight were assessed from postoperative day 1 to day 7. Brain water content and morphological brain damage were quantified 24 hours and 7 days after SAH, respectively.

RESULTS

Mild hypothermia reduced intracranial pressure (P < 0.001) and posthemorrhagic neurological deficits (P < 0.05) and improved postoperative weight gain significantly (P < 0.05). Mortality, cerebral blood flow, and the formation of cerebral edema were not significantly influenced by mild hypothermia.

CONCLUSION

The current results show that mild hypothermia (33 degrees C) exhibits sustained neuroprotection if applied up to 3 hours after SAH. Overall, mild hypothermia seems to be an effective neuroprotective strategy after SAH and should therefore be evaluated as a treatment option for SAH in patients.

Transient life-threatening cerebral edema in a patient with systemic lupus erythematosus

Central nervous system symptoms occur in a substantial portion of patients with systemic lupus erythematosus. However, coma is a rare presentation and is usually secondary to complications such as subarachnoid hemorrhage, seizure, or ischemia. Here, we present a 49-year-old woman with lupus erythematosus and a history of recurrent aseptic meningitis and mild subarachnoid hemorrhage who presented with altered mental status and lethargy that progressed rapidly over hours to the herniation syndrome of coma, extensor posturing, and unilateral pupillary dilation. Spinal fluid showed massive protein elevation (>1600), and head computed tomography revealed global cerebral edema. The clinical and radiologic findings rapidly reversed with intravenous corticosteroids and mannitol within 24 hours, and her mental status improved to baseline. Her course was complicated by 2 episodes of recurrent encephalopathy when corticosteroids were tapered; these resolved after resuming high dosing. Because of ongoing pancytopenia, chemotherapy immunosuppression was delayed, and instead she received intravenous immunoglobulin with improvement in the pancytopenia. She remained cognitively intact during subsequent corticosteroid tapering. Rapid development of coma in lupus patients may be due to a primary process of the disease impacting blood brain barrier integrity. Although rare, this potentially fatal complication may be reversible with acute corticosteroid administration.

Rehabilitation implications of non-traumatic subarachnoid haemorrhage

OBJECTIVE

Subarachnoid haemorrhage (SAH) remains an important cause of stroke in the rehabilitation population, whose incidence has not been changed by pre-morbid medical treatment. The understanding of the pathophysiological changes that occur after SAH has been more clearly defined, therefore the treatment and outcomes of these patients have undergone drastic changes over the past few years. The purpose of this review is to update and familiarize the rehabilitation professional on the state of the art treatment and common complications associated with this disease and how this may affect the rehabilitation programme. Also, the current literature on the outcomes of these patients will be reviewed to help advise the rehabilitation professional on potential predictors.

DATA SOURCES

Literature review.

STUDY SELECTION

Articles of relevance to the current management of SAH.

DATA EXTRACTION

Information that was deemed significant in the understanding of the pathophysiology, treatment and results of outcomes in patients with SAH.

DATA SYNTHESIS

Subarachnoid haemorrhage (SAH) is the one sub-type of stroke whose incidence has not declined. Due to advances in medical care, mortality rate is on the decline. Outcomes data was analysed to look for common predictors for this patient population.

CONCLUSIONS

While the incidence of SAH has not declined, improving medical treatment has reduced mortality. The rehabilitation professional should be familiar with the latest advances, potential complications and likely outcomes in order to plan the most appropriate therapy course for these patients.

[General management in intensive care of patient with spontaneous subarachnoid hemorrhage]

Aneurysmal subarachnoid hemorrhage (SAH) is a neurologic emergency and often a neurologic catastrophe. Nontraumatic subarachnoid hemorrhage is characterized by the extravasation of blood into the spaces covering the central nervous system. The leading cause of SAH is rupture of an intracranial aneurysm, which accounts for about 80-85% of cases. Mortality and morbidity can be reduced if SAH is treated urgently. Sudden, explosive headache is a cardinal but nonspecific feature in the diagnosis of SAH; computered tomography (CT) scanning is mandatory in all the patients with symp toms that are suggestive of SAH. Catheter angiography for detecting aneurysms is gradually being replaced by CT angiography. Diagnosing SAH can be challenging and treatment is complex, sophisticated and multidisciplinary. Reble eding is the most imminent danger, which must be prevented by endovascular occlusion with detachable coils (coiling) or by surgical clipping of the aneurysm; the risk of delayed cerebral ischemia is reduced with nimodipine and avoiding hypovolemia; hydrocephalus can be treated by ventricular drainage. Intensive care plays a more important role in the management of SAH than in any other neurological disorder. Excellence in neurologic diagnosis, in operative neurosurgery or neuroradiologic procedures must be accompanied by excellence in Intensive Care. This review emphasizes treatment in the Intensive Care Unit, surgical and endovascular therapeutic options and the current state of treatment of major complications such as rebleeding, cerebral vasospasm and acute hydrocephalus.

Cerebral vasospasm following subarachnoid hemorrhage: time for a new world of thought

OBJECTIVE

Delayed cerebral vasospasm has long been recognized as an important cause of poor outcome after an otherwise successful treatment of a ruptured intracranial aneurysm, but it remains a pathophysiological enigma despite intensive research for more than half a century.

METHOD

Summarized in this review are highlights of research from North America, Europe and Asia reflecting recent advances in the understanding of delayed ischemic deficit.

RESULT

It will focus on current accepted mechanisms and on new frontiers in vasospasm research.

CONCLUSION

A key issue is the recognition of events other than arterial narrowing such as early brain injury and cortical spreading depression and of their contribution to overall mortality and morbidity.

N-acetylcysteine suppresses oxidative stress in experimental rats with subarachnoid hemorrhage

The neuroprotective effect of N-acetylcysteine (NAC), a sulfhydryl-containing antioxidant, on experimentally induced subarachnoid hemorrhage (SAH) in rats was assessed. NAC was administered to rats after the induction of SAH. Neurological deficits and brain edema were investigated. The activity of antioxidant defense enzymes, copper/zinc superoxide dismutase (CuZn-SOD) and glutathione peroxidase (GSH-Px), were measured in the brain cortex by spectrophotometer. The content of the lipid peroxidation product malondialdehyde (MDA) was also analyzed. We found that NAC markedly reversed the SAH-induced neurological deficit and brain edema. We further investigated the mechanism involved in the neuroprotective effects of NAC on rat brain tissue and found that NAC significantly increased CuZn-SOD and GSH-Px activity and decreased MDA content in the SAH brain. NAC has the potential to be a novel therapeutic strategy for the treatment of SAH, and its neuroprotective effect may be partly mediated via enhancing the activity of endogenous antioxidant enzymes and inhibiting free radical generation.

RESUSCITATION AND CRITICAL CARE OF POOR-GRADE SUBARACHNOID HEMORRHAGE

AS OUTCOMES HAVE improved for patients with aneurysmal subarachnoid hemorrhage, most mortality and morbidity that occur today are the result of severe diffuse brain injury in poor-grade patients. The premise of this review is that aggressive emergency cardiopulmonary and neurological resuscitation, coupled with early aneurysm repair and advanced multimodality monitoring in a specialized neurocritical care unit, offers the best approach for achieving further improvements in subarachnoid hemorrhage outcomes. Emergency care should focus on control of elevated intracranial pressure, optimization of cerebral perfusion and oxygenation, and medical and surgical therapy to prevent rebleeding. In the postoperative period, advanced monitoring techniques such as continuous electroencephalography, brain tissue oxygen monitoring, and microdialysis can detect harmful secondary insults, and may eventually be used as end points for goal-directed therapy, with the aim of creating an optimal physiological environment for the comatose injured brain. As part of this paradigm shift, it is essential that aggressive surgical and medical support be linked to compassionate end-of-life care. As neurosurgeons become confident that comfort care can be implemented in a straightforward fashion after a failed trial of early maximal intervention, the usual justification for withholding treatment (survival with neurological devastation) becomes less relevant, and lives may be saved as more patients recover beyond expectations.

Frequency and clinical impact of asymptomatic cerebral infarction due to vasospasm after subarachnoid hemorrhage

OBJECT

The authors sought to determine frequency, risk factors, and impact on outcome of asymptomatic cerebral infarction due to vasospasm after subarachnoid hemorrhage (SAH).

METHODS

The authors prospectively studied 580 patients with SAH admitted to their center between July 1996 and May 2002. Delayed cerebral ischemia (DCI) from vasospasm was defined as 1) a new focal neurological deficit or decrease in level of consciousness, 2) a new infarct revealed by follow-up CT imaging, or both, after excluding causes other than vasospasm. Outcome at 3 months was assessed using the modified Rankin Scale.

RESULTS

Delayed cerebral ischemia occurred in 121 (21%) of 580 patients. Of those with DCI, 36% (44 patients) experienced neurological deterioration without a corresponding infarct, 42% (51 patients) developed an infarct in conjunction with neurological deterioration, and 21% (26 patients) had a new infarct on CT without concurrent neurological deterioration. In a multivariate analysis, risk factors for asymptomatic DCI included coma on admission, placement of an external ventricular drain, and smaller volumes of SAH (all p < or = 0.03). Patients with asymptomatic DCI were less likely to be treated with vasopressor agents than those with symptomatic DCI (64 vs 86%, p = 0.01). After adjusting for clinical grade, age, and aneurysm size, the authors found that there was a higher frequency of death or moderate-to-severe disability at 3 months (modified Rankin Scale Score 4-6) in patients with asymptomatic DCI than in patients with symptomatic DCI (73 vs 40%, adjusted odds ratio 3.9, 95% confidence interval 1.3-12.0, p = 0.017).

CONCLUSIONS

Approximately 20% of episodes of DCI after SAH are characterized by cerebral infarction in the absence of clinical symptoms. Asymptomatic DCI is particularly common in comatose patients and is associated with poor outcome. Strategies directed at diagnosing and preventing asymptomatic infarction from vasospasm in patients with poor-grade SAH are needed.

THERAPEUTIC HYPOTHERMIA IN PATIENTS WITH ANEURYSMAL SUBARACHNOID HEMORRHAGE, REFRACTORY INTRACRANIAL HYPERTENSION, OR CEREBRAL VASOSPASM

OBJECTIVE

To evaluate the feasibility and safety of mild hypothermia treatment in patients with aneurysmal subarachnoid hemorrhage (SAH) who are experiencing intracranial hypertension and/or cerebral vasospasm (CVS).

METHODS

Of 441 consecutive patients with SAH, 100 developed elevated intracranial pressure and/or symptomatic CVS refractory to conventional treatment. Hypothermia (33–34°C) was induced and maintained until intracranial pressure normalized, CVS resolved, or severe side effects occurred.

RESULTS

Thirteen patients were treated with hypothermia alone, and 87 were treated with hypothermia in combination with barbiturate coma. Sixty-six patients experienced poor-grade SAH (Hunt and Hess Grades IV and V) and 92 had Fisher Grade 3 and 4 bleedings. The mean duration of hypothermia was 169 ± 104 hours, with a maximum of 16.4 days. The outcome after 1 year was evaluated in 90 of 100 patients. Thirty-two patients (35.6%) survived with good functional outcome (Glasgow Outcome Scale [GOS] score, 4 and 5), 14 (15.5%) were severely disabled (GOS score, 3), 1 (1.1%) was in a vegetative state (GOS score, 2), and 43 (47.8%) died (GOS score, 1). The most frequent side effects were electrolyte disorders (77%), pneumonia (52%), thrombocytopenia (47%), and septic shock syndrome (40%). Of 93 patients with severe side effects, 6 (6.5%) died as a result of respiratory or multi-organ failure.

CONCLUSION

Prolonged systemic hypothermia may be considered as a last-resort option for a carefully selected group of SAH patients with intracranial hypertension or CVS resistant to conventional treatment. However, complications associated with hypothermia require elaborate protocols in general intensive care unit management.

Cytosolic Ca2+ oscillations in human cerebrovascular endothelial cells after subarachnoid hemorrhage

Molecular mechanisms of cerebral vasospasm after subarachnoid hemorrhage (SAH) include specific modes of cell signaling like activation of nuclear factor (NF)-kappaB and vascular cell adhesion molecules (VCAM)-1 expression. The study's hypothesis is that cisternal cerebral spinal fluid (CSF) from patients after SAH may cause Ca(2+) oscillations which induce these modes of vascular inflammation in an in vitro model of human cerebral endothelial cells (HCECs). HCECs were incubated with cisternal CSF from 10 SAH patients with confirmed cerebral vasospasm. The CSF was collected on days 5 and 6 after hemorrhage. Cytosolic Ca(2+) concentrations and cell contraction as an indicator of endothelial barrier function were examined by fura-2 microflurometry. Activation of NF-kappaB and VCAM-1 expression were measured by immunocytochemistry. Incubation of HCEC with SAH-CSF provoked cytosolic Ca(2+) oscillations (0.31+/-0.09 per min), cell contraction, NF-kappaB activation, and VCAM-1 expression, whereas exposure to native CSF had no significant effect. When endoplasmic reticulum (ER) Ca(2+)-ATPase and ER inositol trisphosphate (IP3)-sensitive Ca(2+) channels were blocked by thapsigargin or xestospongin, the frequency of the Ca(2+) oscillations was reduced significantly. In analogy to the reduction of Ca(2+) oscillation frequency, the blockers impaired HCEC contraction, NF-kappaB activation, and VCAM-1 expression. Cisternal SAH-CSF induces cytosolic Ca(2+) oscillations in HCEC that results in cellular constriction, NF-kappaB activation, and VCAM-1 expression. The Ca(2+) oscillations depend on the function of ER Ca(2+)-ATPase and IP3-sensitive Ca(2+) channels.

Development of early cerebral swelling in surgically treated ruptured aneurysm of acute stage, its significance, and management

The present study includes 38 patients treated surgically for ruptured aneurysm manifesting subarachnoid hemorrhage without intracerebral hematoma, evaluating clinical grade at admission, secondary development and management of early cerebral swelling, subsequent complications such as cerebral infarction caused by vasospasm, and clinical outcome. Six of 32 patients treated by early surgery within 24 hours developed critical cerebral swelling in the early period after SAH. Five of these 6 patients received barbiturate therapy. Two patients died of advancing cerebral swelling. Three of 5 patients who received barbiturate therapy showed good recovery without any neurologic deficit, 1 suffered intellectual impairment, and the other 1 died. Serial computed tomography (CT), CT angiography, and dynamic CT evaluated elapsing of cerebral swelling, progression of cerebral vasospasm, and change of cerebral blood perfusion (flow) in 2 patients who suffered early cerebral swelling. In these 2 patients, progression or persistence of vasospasm was recorded for a longer period, whereas the cerebral swelling resolved within a short period. Cerebral infarction caused by vasospasm was seen in 8 of these 38 surgical cases, and hydrocephalus was seen in 15 of 38 cases. All 4 survivors after early cerebral swelling developed hydrocephalus and underwent shunting. Development of cerebral swelling in patients with ruptured aneurysm greatly affects outcome. Although barbiturate therapy is useful for the treatment of patients who suffer serious cerebral swelling, improvements in management may be required.

Hypertonic saline solutions for treatment of intracranial hypertension

PURPOSE OF REVIEW

This review aims to provide an update on recent knowledge gained on hypertonic saline solutions for the treatment of intracranial hypertension. Explanatory approaches to the mechanisms underlying the edema-reducing effects of the solutions are outlined, practical aspects of use are presented, and trials that assessed their clinical utility are highlighted.

RECENT FINDINGS

With an established trauma system, hypertonic saline added to conventional fluid resuscitation did not improve long-term outcome in multiple injury with hypotension and brain trauma. In intensive care, hypertonic saline reduced intracranial hypertension after subarachnoid haemorrhage, brain trauma, and a variety of other brain diseases, including cerebral edema in acute liver failure.

SUMMARY

Hypertonic saline solutions have evolved as an alternative to mannitol or may be used in otherwise refractory intracranial hypertension to treat raised intracranial pressure. With high osmolar loads, the efficacy of the solution is enhanced, but no simple relationship between the saline concentration and the clinical effects of a solution is established. Caution is advised with high osmolar loads because they carry increased risks for potentially deleterious consequences of hypernatremia or may induce osmotic blood-brain barrier opening with possibly harmful extravasation of the hypertonic solution into the brain tissue.

Small-volume resuscitation with hyperoncotic albumin: a systematic review of randomized clinical trials

Background

Small-volume resuscitation can rapidly correct hypovolemia. Hyperoncotic albumin solutions, long in clinical use, are suitable for small-volume resuscitation; however, their clinical benefits remain uncertain.

Methods

Randomized clinical trials comparing hyperoncotic albumin with a control regimen for volume expansion were sought by multiple methods, including computer searches of bibliographic databases, perusal of reference lists, and manual searching. Major findings were qualitatively summarized. In addition, a quantitative meta-analysis was performed on available survival data.

Results

In all, 25 randomized clinical trials with a total of 1,485 patients were included. In surgery, hyperoncotic albumin preserved renal function and reduced intestinal edema compared with control fluids. In trauma and sepsis, cardiac index and oxygenation were higher after administration of hydroxyethyl starch than hyperoncotic albumin. Improved treatment response and renal function, shorter hospital stay and lower costs of care were reported in patients with liver disease receiving hyperoncotic albumin. Edema and morbidity were decreased in high-risk neonates after hyperoncotic albumin administration. Disability was reduced by therapy with hyperoncotic albumin in brain injury. There was no evidence of deleterious effects attributable to hyperoncotic albumin. Survival was unaffected by hyperoncotic albumin (pooled relative risk, 0.95; 95% confidence interval 0.78 to 1.17).

Conclusion

In some clinical indications, randomized trial evidence has suggested certain benefits of hyperoncotic albumin such as reductions in morbidity, renal impairment and edema. However, further clinical trials are needed, particularly in surgery, trauma and sepsis.

Melatonin decreases mortality following severe subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (SAH) is a devastating disease that is associated with significant morbidity and mortality. There is substantial evidence to suggest that oxidative stress is significant in the development of acute brain injury following SAH. Melatonin is a strong antioxidant that has low toxicity and easily passes through the blood-brain barrier. Previous studies have shown that melatonin provides neuroprotection in animal models of ischemic stroke. This study hypothesizes that melatonin will provide neuroprotection when administered 2 hr after SAH. The filament perforation model of SAH was performed in male Sprague-Dawley rats weighing between 300 and 380 g. Melatonin (15 or 150 mg/kg), or vehicle was given via intraperitoneal injection 2 hr after SAH. Mortality and neurologic deficits were assessed 24 hr after SAH. A significant reduction in 24-hr mortality was seen following treatment with high dose melatonin. There was no improvement in neurologic scores with treatment. Brain water content and lipid peroxidation were measured following the administration of high dose melatonin to identify a mechanism for the increased survival. High dose melatonin tended to reduce brain water content following SAH, but had no effect on the lipid peroxidation of brain samples. Large doses of melatonin significantly reduces mortality and brain water content in rats following SAH through a mechanism unrelated to oxidative stress.

Impact of cardio-pulmonary and intraoperative factors on occurrence of cerebral infarction after early surgical repair of the ruptured cerebral aneurysms

OBJECTIVE

Delayed ischemic deficit or cerebral infarction is the leading cause of morbidity and mortality after aneurysmal subarachnoid hemorrhage (SAH). The purpose of this study is to reassess the prognostic impact of intraoperative elements, including factors related to surgery and anesthesia, on the development of cerebral infarction in patients with ruptured cerebral aneurysms.

METHODS

Variables related to surgery and anesthesia as well as predetermined factors were all evaluated via a retrospective study on 398 consecutive patients who underwent early microsurgery for ruptured cerebral aneurysms in the last 7 years. Patients were dichotomized as following; good clinical grade (Hunt-Hess grade I to III) and poor clinical grade (IV and V). The end-point events were cerebral infarctions and the clinical outcomes were measured at postoperative 6 months.

RESULTS

The occurrence of cerebral infarction was eminent when there was an intraoperative rupture, prolonged temporary clipping and retraction time, intraoperative hypotension, or decreased O(2) saturation, but there was no statistical significance between the two different clinical groups. Besides the Fisher Grade, multiple logistic regression analyses showed that temporary clipping time, hypotension, and low O(2) saturation had odds ratios of 1.574, 3.016, and 1.528, respectively. Cerebral infarction and outcome had a meaningful correlation (gamma=0.147, p=0.038).

CONCLUSION

This study results indicate that early surgery for poor grade SAH patients carries a significant risk of ongoing ischemic complication due to the brain's vulnerability or accompanying cardio-pulmonary dysfunction. Thus, these patients should be approached very cautiously to overcome any anticipated intraoperative threat by concerted efforts with neuro-anesthesiologist in point to point manner.