Anemia and Optimal Transfusion Thresholds in Brain-Injured Patients: A Narrative Review of the Literature

Anemia is a highly prevalent condition that may compromise oxygen delivery to vital organs, especially among the critically ill. Although current evidence supports the adoption of a restrictive transfusion strategy and threshold among the nonbleeding critically ill patient, it remains unclear whether this practice should apply to the brain-injured patient, given the predisposition to cerebral ischemia in this patient population, in which even nonprofound anemia may exert a detrimental effect on clinical outcomes. The purpose of this review is to provide an overview of the pathophysiological changes related to impaired cerebral oxygenation in the brain-injured patient and to present the available evidence on the effect of anemia and varying transfusion thresholds on the clinical outcomes of patients with acute brain injury.

Effect of plasma transfusion on in-hospital mortality and morbidities in patients with spontaneous subarachnoid hemorrhage

OBJECTIVE

Spontaneous subarachnoid hemorrhage (SAH) is a critical condition in which patients may require plasma transfusion during hospitalization. However, it remains unknown whether plasma administration has detrimental effects on the prognosis of SAH beyond the correction of coagulopathy or hypovolemia. This study aimed to analyze the association of plasma transfusion with in-hospital mortality and morbidities in patients with SAH.

METHODS

We retrospectively analyzed the data of 1689 adult patients with a primary diagnosis of spontaneous SAH. Differences in the clinical parameters were evaluated between patients who received plasma transfusion and those who did not.

RESULTS

Of 1689 patients, 158 (9.4%) received plasma transfusion. Statistical analysis revealed significant differences in pre-existing comorbidity prevalence between the two study groups. The post-SAH morbidities, including cerebral ischemic events (13.3% vs. 6.4%; p = 0.01), were more common in the plasma transfusion group, whereas the mortality rate was not different between the two study groups (p = 0.166). The mean duration of hospital stay was 19.3 ± 14.4 days and 15.1 ± 15.2 days for patients with and without plasma transfusion, respectively (p = 0.001).

CONCLUSION

Plasma transfusion following spontaneous SAH is not uncommon. Although the in-hospital mortality rate does not increase following plasma transfusion, cerebral ischemic events as well as other morbidities are more frequent in patients receiving plasma transfusion. Therefore, the indication for plasma transfusion following SAH needs careful weighing and should be further defined by well-controlled studies.

Effect of Peri-operative Blood Transfusion on Neurological Outcome Following Aneurysmal Subarachnoid Hemorrhage: A Prospective Observational Study

BACKGROUND

Anemia is a common complication of aneurysmal subarachnoid hemorrhage and is associated with unfavorable outcomes. Whether the physiological benefits of transfusion for anemia surpass the risk of blood transfusion remains to be determined.

OBJECTIVES

The primary outcome was to evaluate the impact of peri-operative blood transfusion on the long-term neurological outcome, assessed by Glasgow Outcome Scale Extended at 3 months. The secondary outcomes included the impact of transfusion on the short-term neurological outcome, assessed by Modified Rankin Score at discharge/7 days, and on the incidence of vasospasm, infarction, re-exploration, tracheostomy, and length of hospital stay.

MATERIAL AND METHODS

This prospective observational study was conducted on 185 patients with aneurysmal subarachnoid hemorrhage undergoing clipping of the aneurysmal neck. In our study, blood transfusion was administered to keep the target Hb around 10 g/dL.

RESULTS

Unfavorable long-term outcome was found in 27/97 (28%) of patients who received a blood transfusion as compared to 13/74 (18%) of patients who did not receive a transfusion (P = 0.116). Patients receiving transfusion had more chances of an unfavorable outcome at discharge/7 days as compared to those not transfused [44/103 (43%) versus 22/80 (27%)], P = 0.025. There were increased chances of vasospasm, infarction, re-exploration, tracheostomy, and increased length of hospital stay in patients receiving transfusion (P < 0.05).

CONCLUSIONS

The use of blood transfusion in patients with aneurysmal subarachnoid hemorrhage was associated with increased neurological complications and hence an unfavorable short-term outcome. However, when used judiciously as per the clinical requirements, blood transfusion did not have a significant effect on long-term neurological outcome.

Differences in Prevalence of Transfusion Protocols between Critically Ill Neurologic and Non-Neurologic Patient Populations

This study describes the prevalence of blood transfusion protocols in ICUs caring for neurologically vs. non-neurologically injured patients across a sample of US ICUs. This prospective, observational multi-center cohort study is a subgroup analysis of the USCIITG-CIOS, comprising 69 ICUs across the US (25 medical, 24 surgical, 20 mixed ICUs). Sixty-four ICUs were in teaching hospitals. A total of 6179 patients were enrolled, with 1266 (20.4%) having central nervous system (CNS) primary diagnoses. We evaluated whether CNS versus non-CNS diagnosis was associated with care in ICUs with restrictive transfusion protocols (RTPs) or massive transfusion protocols (MTPs) and whether CNS versus non-CNS diagnosis was associated with receiving blood products or colloids during the initial 24 h of care. Protocol utilization in CNS vs. non-CNS patients was as follows: RTPs-36.9% vs. 42.9% (p < 0.001); MTPs-48.3% vs. 47.4% (p = 0.57). Blood product transfusions in the first 24 h of ICU care (comparing CNS vs. non-CNS patients) were as follows: packed red blood cells-4.3% vs. 14.6% (p < 0.001); fresh frozen plasma-2.9% vs. 5.1% (p < 0.001); colloid blood products-3.2% vs. 9.2% (p < 0.001). In this cohort, we found differences in ICU utilization of RTPs, but not MTPs, when comparing where critically ill patients with neurologic versus non-neurologic primary diagnoses received ICU care.

Red Blood Cell Transfusions Are Not Associated With Incident Complications or Poor Outcomes in Patients With Intracerebral Hemorrhage

Background Anemia is associated with poor intracerebral hemorrhage (ICH) outcomes, yet the relationship of red blood cell (RBC) transfusions to ICH complications and functional outcomes remains unclear. We investigated the impact of RBC transfusion on hospital thromboembolic and infectious complications and outcomes in patients with ICH. Methods and Results Consecutive patients with spontaneous ICH enrolled in a single-center, prospective cohort study from 2009 to 2018 were assessed. Primary analyses assessed relationships of RBC transfusions on incident thromboembolic and infectious complications occurring after the transfusion. Secondary analyses assessed relationships of RBC transfusions with mortality and poor discharge modified Rankin Scale score 4 to 6. Multivariable logistic regression models adjusted for baseline demographics and medical disease severity (Acute Physiology and Chronic Health Evaluation II), and ICH severity (ICH score).Of 587 patients with ICH analyzed, 88 (15%) received at least one RBC transfusion. Patients receiving RBC transfusions had worse medical and ICH severity. Though patients receiving RBC transfusions had more complications at any point during the hospitalization (64.8% versus 35.9%), we found no association between RBC transfusion and incident complications in our regression models (adjusted odds ratio [aOR], 0.71 [95% CI, 0.42-1.20]). After adjusting for disease severity and other relevant covariates, we found no significant association between RBC transfusion and mortality (aOR, 0.87 [95% CI, 0.45-1.66]) or poor discharge modified Rankin Scale score (aOR, 2.45 [95% CI, 0.80-7.61]). Conclusions In our cohort with ICH, RBC transfusions were expectedly given to patients with higher medical and ICH severity. Taking disease severity and timing of transfusions into account, RBC transfusion was not associated with incident hospital complications or poor clinical ICH outcomes.

Systematic review and meta-analysis of outcome-relevant anemia in patients with subarachnoid hemorrhage

Anemia is a common, treatable condition in patients with aneurysmal subarachnoid hemorrhage (SAH) and has been associated with poor outcome. As there are still no guidelines for anemia management after aneurysm rupture, we aimed to identify outcome-relevant severity of anemia in SAH. We systematically searched PubMed, Embase, Scopus, Web of Science, and Cochrane Library for publications before Oct 23rd, 2022, reporting on anemia in SAH patients. The presence and severity of anemia were assessed according to the reported hemoglobin values and/or institutional thresholds for red blood cells transfusion (RBCT). Out of 1863 original records, 40 full-text articles with a total of 14,701 patients treated between 1996 and 2020 were included in the final analysis (mean 445.48 patients per study). A substantial portion of patients developed anemia during SAH (mean pooled prevalence 40.76%, range 28.3-82.6%). RBCT was administered in a third of the cases (mean 32.07%, range 7.8-88.6%), with institutional threshold varying from 7.00 to 10.00 g/dL (mean 8.5 g/dL). Anemia at the onset of SAH showed no impact on SAH outcome. In contrast, even slight anemia (nadir hemoglobin < 11.0-11.5 g/dL) occurring during SAH was associated with the risk of cerebral infarction and poor outcome at discharge and follow-up. The strongest association with SAH outcome was observed for nadir hemoglobin values ranging between 9.0 and 10.0 g/dL. The effect of anemia on SAH mortality was marginal. The development of anemia during SAH is associated with the risk of cerebral infarction and poor outcome at discharge and follow-up. Outcome-relevant severity of post-SAH anemia begins at hemoglobin levels clearly above the thresholds commonly set for RBCT. Our findings underline the need for further studies to define the optimal management of anemia in SAH patients.

Postoperative Transfusion Guidelines in Aneurysmal Cerebral Subarachnoid Hemorrhage: A Systematic Review and Critical Summary of Available Evidence

OBJECTIVE

Surgical management of aneurysmal subarachnoid hemorrhage (SAH) often involves red blood cell (RBC) transfusion, which increases the risk of postoperative complications. RBC transfusion guidelines report on chronically critically ill patients and may not apply to patients with SAH. Our study aims to synthesize the evidence to recommend RBC transfusion thresholds among adult patients with SAH undergoing surgery.

METHODS

A systematic review was conducted using PubMed, Google Scholar, and Web of Science electronic databases according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines to critically assess primary articles discussing RBC transfusion thresholds and describe complications secondary to RBC transfusion in adult patients with SAH in the perioperative period.

RESULTS

Sixteen articles meeting our search strategy were reviewed. Patients with SAH who received blood transfusion were older, female, had World Federation of Neurosurgical Societies grade IV-V and modified Fisher grade 3-4 scores, and presented with more comorbidities such as hypertension, diabetes, and cardiovascular and pulmonary diseases. In addition, transfusion was associated with multiple postoperative complications, including higher rates of vasospasms, surgical site infections, cardiovascular and respiratory complications, increased postoperative length of stay, and 30-day mortality. Analysis of transfused patients showed that a higher hemoglobin (>10 g/dL) goal after SAH was safe and that patients may benefit from a higher whole hospital stay hemoglobin nadir, as shown by a reduction in risk of cerebral vasospasm and improvement in clinical outcomes (level B class II).

CONCLUSIONS

Among patients with SAH, the benefits of reducing cerebral ischemia and anemia are shown to outweigh the risks of transfusion-related complications.

Association of anemia and transfusions with outcome after subarachnoid hemorrhage

INTRODUCTION

The benefits of correcting anemia using red blood cell transfusion (RBCT) after subarachnoid hemorrhage (SAH) are controversial. We aimed to evaluate the role of anemia and RBCT on neurological outcome after SAH using a restrictive transfusion policy.

OBJECTIVE

We reviewed our institutional database of adult patients admitted to the Department of Intensive Care (ICU) after non-traumatic SAH over a 5-year period. We recorded hemoglobin (Hb) levels daily for a maximum of 20 days, as well as the use of RBCT. Unfavorable neurological outcome (UO) was defined as a Glasgow Outcome Score of 1-3 at 3 months.

RESULTS

Among 270 eligible patients, UO was observed in 40% of them. Patients with UO had lower Hb over time and received RBCT more frequently than others (15/109, 14% vs. 6/161, 4% - p < 0.01). Pre-RBCT median Hb values were similar in UO and FO patients (6.9 [6.6-7.1] vs. 7.3 [6.3-8.1] g/dL - p = 0.21). The optimal discriminative Hb threshold for UO was 9 g/dL. In a multivariable analysis, neither anemia nor RBCT were independently associated with UO.

CONCLUSION

In this retrospective single center study using a restrictive strategy of RBCT in SAH patients was not associated with worse outcome in 3 months.

Neutrophil to lymphocyte ratio is a prognosis factor for post-operative pneumonia in aneurysmal subarachnoid hemorrhage patients

Background:

Although a variety of risk factors of pneumonia after clipping or coiling of the aneurysm (post-operative pneumonia [POP]) in patients with aneurysmal subarachnoid hemorrhage (aSAH) have been studied, the predictive model of POP after aSAH has still not been well established. Thus, the aim of this study was to assess the feasibility of using admission neutrophil to lymphocyte ratio (NLR) to predict the occurrence of POP in aSAH patients.

Methods:

We evaluated 711 aSAH patients who were enrolled in a prospective observational study and collected admission blood cell counts data. We analyzed available demographics and baseline variables for these patients and analyzed the correlation of these factors with POP using Cox regression. After screening out the prognosis-related factors, the predictive value of these factors for POP was further assessed.

Results:

POP occurred in 219 patients (30.4%) in this cohort. Patients with POP had significantly higher NLR than those without (14.11 ± 8.90 vs. 8.80 ± 5.82, P < 0.001). Multivariate analysis revealed that NLR remained a significant factor independently associated with POP following aSAH after adjusting for possible confounding factors, including the age, World Federation of Neurosurgical Societies (WFNS) grade, endovascular treatment, and ventilator use. And the predictive value of NLR was significantly increased after WFNS grade was combined with NLR (NLR vs. WFNS grade × NLR, P = 0.011).

Conclusions:

Regardless of good or poor WNFS grade, patients having NLR >10 had significantly worse POP survival rate than patients having NLR ≤10. NLR at admission might be helpful as a predictor of POP in aSAH patients.

Multimorbidity and Critical Care Neurosurgery: Minimizing Major Perioperative Cardiopulmonary Complications

With increasing prevalence of chronic diseases, multimorbid patients have become commonplace in the neurosurgical intensive care unit (neuro-ICU), offering unique management challenges. By reducing physiological reserve and interacting with one another, chronic comorbidities pose a greatly enhanced risk of major postoperative medical complications, especially cardiopulmonary complications, which ultimately exert a negative impact on neurosurgical outcomes. These premises underscore the importance of perioperative optimization, in turn requiring a thorough preoperative risk stratification, a basic understanding of a multimorbid patient’s deranged physiology and a proper appreciation of the potential of surgery, anesthesia and neurocritical care interventions to exacerbate comorbid pathophysiologies. This knowledge enables neurosurgeons, neuroanesthesiologists and neurointensivists to function with a heightened level of vigilance in the care of these high-risk patients and can inform the perioperative neuro-ICU management with individualized strategies able to minimize the risk of untoward outcomes. This review highlights potential pitfalls in the intra- and postoperative neuro-ICU period, describes common preoperative risk stratification tools and discusses tailored perioperative ICU management strategies in multimorbid neurosurgical patients, with a special focus on approaches geared toward the minimization of postoperative cardiopulmonary complications and unplanned reintubation.

Red blood cell transfusion in acute brain injury subtypes: An observational cohort study

PURPOSE

Optimal red blood cell (RBC) transfusion thresholds in acute brain injury (ABI) are poorly defined.

MATERIALS AND METHODS

We conducted a retrospective cohort study of adult patients with ABI and moderate anemia (Hb 7-10 g/dL) in a neurological intensive care unit (ICU) at an academic medical center between 2008 and 2015. Transfused and non-transfused patients were matched based on age, ABI subtype, pre-transfusion hemoglobin, and ICU length of stay (LOS) at the time of RBC transfusion. Multivariable regression analyses were performed to assess the relationship between RBC transfusion and hospital LOS, hospital mortality, ICU LOS, ICU mortality, and 24 h change in sequential organ failure assessment (SOFA) scores.

RESULTS

2638 patients met inclusion criteria, with 225 (8.5%) receiving RBC transfusion. Acute ischemic stroke was the most prevalent ABI diagnosis (43.3%) then intracranial hemorrhage (25.6%), subarachnoid hemorrhage (16.5%), and traumatic brain injury (TBI) (14.6%). In multivariable analyses, RBC transfusion was associated with longer hospital and ICU LOS, and higher SOFA scores. Each ABI subtype had similar results, except for TBI which showed no difference in hospital LOS. Mortality was not significantly different.

CONCLUSIONS

In moderately anemic patients with ABI, RBC transfusion was associated with longer hospital and ICU LOS. Prospective investigations are necessary to further assess these relationships.

Neurosurgical applications of viscoelastic hemostatic assays

Patients taking antithrombotic agents are very common in neurosurgical practice. The perioperative management of these patients can be extremely challenging especially as newer agents, with poorly defined laboratory monitoring and reversal strategies, become more prevalent. This is especially true with emergent cases in which rapid reversal of anticoagulation is required and the patient’s exact medical history is not available. With an aging patient population and the associated increase in diseases such as atrial fibrillation, it is expected that the use of these agents will continue to rise in coming years. Furthermore, thromboembolic complications such as deep venous thrombosis, pulmonary embolism, and myocardial infarction are common complications of major surgery. These trends, in conjunction with a growing understanding of the hemostatic process and its contribution to the pathophysiology of disease, stress the importance of the complete evaluation of a patient’s hemostatic profile in guiding management decisions. Viscoelastic hemostatic assays (VHAs), such as thromboelastography and rotational thromboelastometry, are global assessments of coagulation that account for the cellular and plasma components of coagulation. This FDA-approved technology has been available for decades and has been widely used in cardiac surgery and liver transplantation. Although VHAs were cumbersome in the past, advances in software and design have made them more accurate, reliable, and accessible to the neurosurgeon. VHAs have demonstrated utility in guiding intraoperative blood product transfusion, identifying coagulopathy in trauma, and managing postoperative thromboprophylaxis. The first half of this review aims to evaluate and assess VHAs, while the latter half seeks to appraise the evidence supporting their use in neurosurgical populations.

Blood transfusion indications in neurosurgical patients: A systematic review

Neurosurgical procedures can be complicated by significant blood losses that have the potential to decrease tissue perfusion to critical brain tissue. Red blood cell transfusion is used in a variety of capacities both inside, and outside, of the operating room to prevent untoward neurologic damage. However, evidence-based guidelines concerning thresholds and indications for transfusion in neurosurgery remain limited. Consequently, transfusion practices in neurosurgical patients are highly variable and based on institutional experiences. Recently, a paradigm shift has occurred in neurocritical intensive care units, whereby restrictive transfusion is increasingly favored over liberal transfusion but the ideal strategy remains in clinical equipoise. The authors of this study perform a systematic review of the literature with the objective of capturing the changing landscape of blood transfusion indications in neurosurgical patients.

The Effect of Packed Red Blood Cell Transfusion on Cerebral Oxygenation and Metabolism After Subarachnoid Hemorrhage

BACKGROUND

Anemia adversely affects cerebral oxygenation and metabolism after subarachnoid hemorrhage (SAH) and is also associated with poor outcome. There is limited evidence to support the use of packed red blood cell (PRBC) transfusion to optimize brain homeostasis after SAH. The aim of this study was to investigate the effect of transfusion on cerebral oxygenation and metabolism in patients with SAH.

METHODS

This was a prospective observational study in a neurological intensive care unit of a university hospital. Nineteen transfusions were studied in 15 consecutive patients with SAH that underwent multimodality monitoring (intracranial pressure, brain tissue oxygen, and cerebral microdialysis). Data were collected at baseline and for 12 h after transfusion. The relationship between hemoglobin (Hb) change and lactate/pyruvate ratio (LPR) orbrain tissue oxygen (PbtO2) was tested using univariate and multivariable analyses.

RESULTS

PRBC transfusion was administered on the median post-bleed day 8. The average Hb concentration at baseline was 8.1 g/dL and increased by 2.2 g/dL after transfusion. PbtO2 increased between hours 2 and 4 post-transfusion and this increase was maintained until hour 10. LPR did not change significantly during the 12-h monitoring period. After adjusting for SpO2, cerebral perfusion pressure, and LPR, the change in Hb concentration was independently and positively associated with a change in PbtO2 (adjusted b estimate = 1.39 [95% confidence interval 0.09-2.69]; P = 0.04). No relationship between the change in Hb concentration and LPR was found.

CONCLUSIONS

PRBC transfusion resulted in PbtO2 improvement without a clear effect on cerebral metabolism prior to SAH.

Aneurysmal SubArachnoid Hemorrhage-Red Blood Cell Transfusion And Outcome (SAHaRA): a pilot randomised controlled trial protocol

INTRODUCTION

Anaemia is common in aneurysmal subarachnoid haemorrhage (aSAH) and is a potential critical modifiable factor affecting secondary injury. Despite physiological evidence and management guidelines that support maintaining a higher haemoglobin level in patients with aSAH, current practice is one of a more restrictive approach to transfusion. The goal of this multicentre pilot trial is to determine the feasibility of successfully conducting a red blood cell (RBC) transfusion trial in adult patients with acute aSAH and anaemia (Hb ≤100 g/L), comparing a liberal transfusion strategy (Hb ≤100 g/L) with a restrictive strategy (Hb ≤80 g/L) on the combined rate of death and severe disability at 12 months.

METHODS

Design This is a multicentre open-label randomised controlled pilot trial at 5 academic tertiary care centres. Population We are targeting adult aSAH patients within 14 days of their initial bleed and with anaemia (Hb ≤110 g/L). Randomisation Central computer-generated randomisation, stratified by centre, will be undertaken from the host centre. Randomisation into 1 of the 2 treatment arms will occur when the haemoglobin levels of eligible patients fall to ≤100 g/L. Intervention Patients will be randomly assigned to either a liberal (threshold: Hb ≤100 g/L) or a restrictive transfusion strategy (threshold: Hb ≤80 g/L). Outcome Primary: Centre randomisation rate over the study period. Secondary: (1) transfusion threshold adherence; (2) study RBC transfusion protocol adherence; and (3) outcome assessment including vital status at hospital discharge, modified Rankin Score at 6 and 12 months and Functional Independence Measure and EuroQOL Quality of Life Scale scores at 12 months. Outcome measures will be reported in aggregate.

ETHICS AND DISSEMINATION

The study protocol has been approved by the host centre (OHSN-REB 20150433-01H). This study will determine the feasibility of conducting the large pragmatic RCT comparing 2 RBC transfusion strategies examining the effect of a liberal strategy on 12-month outcome following aSAH.

TRIAL REGISTRATION NUMBER

NCT02483351; Pre-results.

Management of delayed cerebral ischemia after subarachnoid hemorrhage

For patients who survive the initial bleeding event of a ruptured brain aneurysm, delayed cerebral ischemia (DCI) is one of the most important causes of mortality and poor neurological outcome. New insights in the last decade have led to an important paradigm shift in the understanding of DCI pathogenesis. Large-vessel cerebral vasospasm has been challenged as the sole causal mechanism; new hypotheses now focus on the early brain injury, microcirculatory dysfunction, impaired autoregulation, and spreading depolarization. Prevention of DCI primarily relies on nimodipine administration and optimization of blood volume and cardiac performance. Neurological monitoring is essential for early DCI detection and intervention. Serial clinical examination combined with intermittent transcranial Doppler ultrasonography and CT angiography (with or without perfusion) is the most commonly used monitoring paradigm, and usually suffices in good grade patients. By contrast, poor grade patients (WFNS grades 4 and 5) require more advanced monitoring because stupor and coma reduce sensitivity to the effects of ischemia. Greater reliance on CT perfusion imaging, continuous electroencephalography, and invasive brain multimodality monitoring are potential strategies to improve situational awareness as it relates to detecting DCI. Pharmacologically-induced hypertension combined with volume is the established first-line therapy for DCI; a good clinical response with reversal of the presenting deficit occurs in 70 % of patients. Medically refractory DCI, defined as failure to respond adequately to these measures, should trigger step-wise escalation of rescue therapy. Level 1 rescue therapy consists of cardiac output optimization, hemoglobin optimization, and endovascular intervention, including angioplasty and intra-arterial vasodilator infusion. In highly refractory cases, level 2 rescue therapies are also considered, none of which have been validated. This review provides an overview of current state-of-the-art care for DCI management.

Red Blood Cell Distribution Width is Associated with Poor Clinical Outcome After Subarachnoid Hemorrhage: A Pilot Study

INTRODUCTION

The red cell distribution width (RDW) is a biomarker strongly associated with poor outcome in inflammatory and thrombotic diseases. Subarachnoid hemorrhage (SAH) is both an inflammatory and thrombotic state in which many biomarkers have been studied. In this exploratory pilot study, we sought to determine whether RDW predicts poor outcome in patients with SAH.

METHODS

Patients with moderate-to-severe SAH were prospectively enrolled in an observational study of biomarkers and outcome. CBC, ESR, high sensitivity CRP, D-dimer, and fibrinogen were obtained on post-bleed days (PBD) 1, 3, 5, 7, and 10. Poor outcome was defined as a modified Rankin score of 3-6 at 90-days.

RESULTS

Of 40 patients, 5 (12.5%) died and 19 (47.5%) had a poor outcome. RDW (p = 0.046) when measured serially over the study period, was significantly higher among patients with poor outcome. Maximum RDW (OR 2.3 95% CI 1.2-3.6; p = 0.014) and maximum WBC count (OR 1.29 95% CI 1.04-1.60; p = 0.018) were associated with poor outcome. Stepwise addition of maximum ESR, CRP, D-dimer, and fibrinogen yielded a model with RDW (OR 2.54 95% CI 1.21-5.35; p = 0.014) and fibrinogen (OR 1.01 95% CI 1.002-1.01; p = 0.004) predicting outcome. With addition of age and Hunt and Hess grade, RDW, fibrinogen, and high-grade status remained significantly associated with poor outcome. Use of PBD1 RDW in lieu of maximum RDW, resulted in a similar model.

CONCLUSIONS

An elevated RDW is associated with poor outcome in SAH patients. RDW may be a useful predictor of outcomes after SAH.

Concerns and challenges during anesthetic management of aneurysmal subarachnoid hemorrhage

Anesthetic management of patients with aneurysmal subarachnoid hemorrhage is challenging because of the emergency nature of the presentation, complex pathology, varied intracranial and systemic manifestations and need for special requirements during the course of management. Successful perioperative outcome depends on overcoming these challenges by thorough understanding of pathophysiology of Subarachnoid hemorrhage, knowledge about associated complications, preoperative optimization, choice of definitive therapy, a good anesthetic and surgical technique, vigilant monitoring and optimal postoperative care. Guidelines based on randomized studies and provided by various societies are helpful in the routine management of these patients and wherever there is a lack of high quality evidence, the available data is provided for practical management.

Transfusion Frequency of Red Blood Cells, Fresh Frozen Plasma, and Platelets During Ruptured Cerebral Aneurysm Surgery

BACKGROUND

The use of blood products after subarachnoid hemorrhage (SAH) is common, but not without controversy. The optimal hemoglobin level in patients with SAH is unknown, and data on perioperative need for red blood cell (RBC), fresh frozen plasma (FFP), or platelet transfusions are limited. We studied perioperative administration of RBCs, FFP, and platelets and the impact of red blood cell transfusions (RBCTs) on outcome in patients undergoing surgery for ruptured a cerebral arterial aneurysm.

METHODS

A retrospective analysis was performed of 488 patients with aneurysmal SAH during the years 2006-2009 at Helsinki University Central Hospital. Patients who received RBC, FFP, or platelet concentrates perioperatively were compared with a cohort of patients from the Helsinki database of aneurysmal SAH who did not receive transfusions. A multiple regression model was created to identify factors related to transfusion and outcome.

RESULTS

RBC, FFP, or platelet concentrates were given in 7.6% (37 of 488), 3.1% (15 of 488), and 1.2% (6 of 488) of patients intraoperatively and in 3.5% (17 of 486), 1.6% (8 of 488), and 0.9% (4 of 488) of patients postoperatively. Of 37 intraoperative RBCTs, 26 were related to intraoperative rupture of the aneurysm. Intraoperative RBCTs were associated with lower preoperative hemoglobin concentration, higher World Federation of Neurosurgical Societies classification, and intraoperative rupture of an aneurysm. In multivariate analysis, intraoperative RBCT (odds ratio = 5.13, 95% confidence interval = 1.53-17.15), worse World Federation of Neurosurgical Societies classification and Fisher grade (odds ratio = 1.97, confidence interval = 1.64-2.36 and odds ratio = 1.89, confidence interval = 1.23-2.92, respectively), and increasing age (odds ratio = 1.07, confidence interval = 1.04-1.10) independently increased the risk of poor neurologic outcome at 3 months.

CONCLUSIONS

Transfusion frequencies of RBCs, FFP, and platelets were relatively low. Intraoperative RBCT was strongly related to intraoperative rupture of the aneurysm in patients with poor-grade SAH. The observed association between poor outcome and RBCT in patients with SAH warrants further study.

Mean hemoglobin concentration after acute subarachnoid hemorrhage and the relation to outcome, mortality, vasospasm, and brain infarction

Lower mean hemoglobin (HGB) levels are associated with unfavorable outcome after spontaneous subarachnoid hemorrhage (SAH). Currently, there is no cutoff level for mean HGB levels associated with unfavorable outcome. This study was conducted to evaluate a threshold for mean HGB concentrations after SAH, and to observe the relation to outcome. The medical records of 702 patients with spontaneous SAH were reviewed. Predictors of outcome were proved by univariate analysis. Predictors with p<0.1 were included in a multivariate binary logistic regression model. Cutoff points for mean HGB levels were calculated by receiver operating characteristic curve analysis. Mean HGB was 11.9 g/dl (±standard deviation [SD] 1.7 g/dl) in patients with favorable outcome compared to 10.8 g/dl (±SD 1.1g/dl) in patients with unfavorable outcome (p<0.001). The highest Youden's index value was found for a HGB cutoff at 11.1 g/dl. In a binary logistic regression model, predictors of unfavorable outcome were identified as an initially high Hunt-Hess grade (odds ratio [OR]: 7.7; 95% confidence interval [CI]: 4.4-13.4; p<0.001), cerebral infarction on a CT scan during hospital stay (OR: 3.8; 95% CI: 2.0-7.3; p<0.001), rebleeding during the hospital stay (OR: 3.5; 95% CI: 1.6-8.0; p=0.002), mean HGB concentration <11.1g/dl (OR: 3.3; 95% CI: 2.0-5.3; p<0.001), and hydrocephalus (OR: 2.3; 95% CI: 1.4-3.7; p=0.001). In conclusion, a mean HGB concentration <11.1 g/dl during the hospital stay was associated with unfavorable outcome after acute SAH.

Consensus summary statement of the International Multidisciplinary Consensus Conference on Multimodality Monitoring in Neurocritical Care: a statement for healthcare professionals from the Neurocritical Care Society and the European Society of Intensive Care Medicine

Neurocritical care depends, in part, on careful patient monitoring but as yet there are little data on what processes are the most important to monitor, how these should be monitored, and whether monitoring these processes is cost-effective and impacts outcome. At the same time, bioinformatics is a rapidly emerging field in critical care but as yet there is little agreement or standardization on what information is important and how it should be displayed and analyzed. The Neurocritical Care Society in collaboration with the European Society of Intensive Care Medicine, the Society for Critical Care Medicine, and the Latin America Brain Injury Consortium organized an international, multidisciplinary consensus conference to begin to address these needs. International experts from neurosurgery, neurocritical care, neurology, critical care, neuroanesthesiology, nursing, pharmacy, and informatics were recruited on the basis of their research, publication record, and expertise. They undertook a systematic literature review to develop recommendations about specific topics on physiologic processes important to the care of patients with disorders that require neurocritical care. This review does not make recommendations about treatment, imaging, and intraoperative monitoring. A multidisciplinary jury, selected for their expertise in clinical investigation and development of practice guidelines, guided this process. The GRADE system was used to develop recommendations based on literature review, discussion, integrating the literature with the participants' collective experience, and critical review by an impartial jury. Emphasis was placed on the principle that recommendations should be based on both data quality and on trade-offs and translation into clinical practice. Strong consideration was given to providing pragmatic guidance and recommendations for bedside neuromonitoring, even in the absence of high quality data.

Consensus summary statement of the International Multidisciplinary Consensus Conference on Multimodality Monitoring in Neurocritical Care : a statement for healthcare professionals from the Neurocritical Care Society and the European Society of Intensive Care Medicine

Neurocritical care depends, in part, on careful patient monitoring but as yet there are little data on what processes are the most important to monitor, how these should be monitored, and whether monitoring these processes is cost-effective and impacts outcome. At the same time, bioinformatics is a rapidly emerging field in critical care but as yet there is little agreement or standardization on what information is important and how it should be displayed and analyzed. The Neurocritical Care Society in collaboration with the European Society of Intensive Care Medicine, the Society for Critical Care Medicine, and the Latin America Brain Injury Consortium organized an international, multidisciplinary consensus conference to begin to address these needs. International experts from neurosurgery, neurocritical care, neurology, critical care, neuroanesthesiology, nursing, pharmacy, and informatics were recruited on the basis of their research, publication record, and expertise. They undertook a systematic literature review to develop recommendations about specific topics on physiologic processes important to the care of patients with disorders that require neurocritical care. This review does not make recommendations about treatment, imaging, and intraoperative monitoring. A multidisciplinary jury, selected for their expertise in clinical investigation and development of practice guidelines, guided this process. The GRADE system was used to develop recommendations based on literature review, discussion, integrating the literature with the participants' collective experience, and critical review by an impartial jury. Emphasis was placed on the principle that recommendations should be based on both data quality and on trade-offs and translation into clinical practice. Strong consideration was given to providing pragmatic guidance and recommendations for bedside neuromonitoring, even in the absence of high quality data.

Haemoglobin management in acute brain injury

PURPOSE OF REVIEW

Anaemia is common among patients in the neurocritical care unit (NCCU) and is thought to exacerbate brain injury. However, the optimal haemoglobin (Hgb) level still remains to be elucidated for traumatic brain injury (TBI), subarachnoid haemorrhage (SAH) and acute ischaemic stroke (AIS). This review outlines recent studies about anaemia and the effects of red blood cell transfusion (RBCT) on outcome in TBI, SAH and AIS patients admitted to the NCCU.

RECENT FINDINGS

Patients with severe SAH, AIS and TBI often develop anaemia and require RBCT. In general critical care, a restrictive RBCT strategy (Hgb ~7 g/dl) is preferable in patients without serious cardiac disease. In severe TBI, AIS and SAH, both anaemia and RBCT may negatively influence clinical outcome. However, the appropriate RBCT trigger remains unclear and there is great variance in how these patients are transfused. There is evidence from PET and microdialysis studies in humans that RBCT can favourably influence brain metabolism and oxygenation. This correction of hypoxia or altered metabolism rather than anaemia may be of greater importance.

SUMMARY

Results from general critical care should not be extrapolated to all patients with acute brain injury. Transfusion is not risk free, but RBCT use needs to be considered also in terms of potential benefit.

Current controversies in the prediction, diagnosis, and management of cerebral vasospasm: where do we stand?

Aneurysmal subarachnoid hemorrhage occurs in approximately 30,000 persons in the United States each year. Around 30 percent of patients with aneurysmal subarachnoid hemorrhage suffer from cerebral ischemia and infarction due to cerebral vasospasm, a leading cause of treatable death and disability following aneurysmal subarachnoid hemorrhage. Methods used to predict, diagnose, and manage vasospasm are the topic of recent active research. This paper utilizes a comprehensive review of the recent literature to address controversies surrounding these topics. Evidence regarding the effect of age, smoking, and cocaine use on the incidence and outcome of vasospasm is reviewed. The abilities of different computed tomography grading schemes to predict vasospasm in the aftermath of subarachnoid hemorrhage are presented. Additionally, the utility of different diagnostic methods for the detection and visualization of vasospasm, including transcranial Doppler ultrasonography, CT angiography, digital subtraction angiography, and CT perfusion imaging is discussed. Finally, the recent literature regarding interventions for the prophylaxis and treatment of vasospasm, including hyperdynamic therapy, albumin, calcium channel agonists, statins, magnesium sulfate, and endothelin antagonists is summarized. Recent studies regarding each topic were reviewed for consensus recommendations from the literature, which were then presented.

Combined dysfunctions of immune cells predict nosocomial infection in critically ill patients

BACKGROUND

Nosocomial infection occurs commonly in intensive care units (ICUs). Although critical illness is associated with immune activation, the prevalence of nosocomial infections suggests concomitant immune suppression. This study examined the temporal occurrence of immune dysfunction across three immune cell types, and their relationship with the development of nosocomial infection.

METHODS

A prospective observational cohort study was undertaken in a teaching hospital general ICU. Critically ill patients were recruited and underwent serial examination of immune status, namely percentage regulatory T-cells (Tregs), monocyte deactivation (by expression) and neutrophil dysfunction (by CD88 expression). The occurrence of nosocomial infection was determined using pre-defined, objective criteria.

RESULTS

Ninety-six patients were recruited, of whom 95 had data available for analysis. Relative to healthy controls, percentage Tregs were elevated 6-10 days after admission, while monocyte HLA-DR and neutrophil CD88 showed broader depression across time points measured. Thirty-three patients (35%) developed nosocomial infection, and patients developing nosocomial infection showed significantly greater immune dysfunction by the measures used. Tregs and neutrophil dysfunction remained significantly predictive of infection in a Cox hazards model correcting for time effects and clinical confounders {hazard ratio (HR) 2.4 [95% confidence interval (CI) 1.1-5.4] and 6.9 (95% CI 1.6-30), respectively, P=0.001}. Cumulative immune dysfunction resulted in a progressive risk of infection, rising from no cases in patients with no dysfunction to 75% of patients with dysfunction of all three cell types (P=0.0004).

CONCLUSIONS

Dysfunctions of T-cells, monocytes, and neutrophils predict acquisition of nosocomial infection, and combine additively to stratify risk of nosocomial infection in the critically ill.

Hemoglobin levels and transfusions in neurocritically ill patients: a systematic review of comparative studies

Introduction

Accumulating evidence suggests that, in critically ill patients, a lower hemoglobin transfusion threshold is safe. However, the optimal hemoglobin level and associated transfusion threshold remain unknown in neurocritically ill patients.

Methods

We conducted a systematic review of comparative studies (randomized and nonrandomized) to evaluate the effect of hemoglobin levels on mortality, neurologic function, intensive care unit (ICU) and hospital length of stay, duration of mechanical ventilation, and multiple organ failure in adult and pediatric neurocritically ill patients. We searched MEDLINE, The Cochrane Central Register of Controlled Trials, Embase, Web of Knowledge, and Google Scholar. Studies focusing on any neurocritical care conditions were included. Data are presented by using odds ratios for dichotomous outcomes and mean differences for continuous outcomes.

Results

Among 4,310 retrieved records, six studies met inclusion criteria (n = 537). Four studies were conducted in traumatic brain injury (TBI), one in subarachnoid hemorrhage (SAH), and one in a mixed population of neurocritically ill patients. The minimal hemoglobin levels or transfusion thresholds ranged from 7 to 10 g/dl in the lower-Hb groups and from 9.3 to 11.5 g/dl in the higher-Hb groups. Three studies had a low risk of bias, and three had a high risk of bias. No effect was observed on mortality, duration of mechanical ventilation, or multiple organ failure. In studies reporting on length of stay (n = 4), one reported a significant shorter ICU stay (mean, -11.4 days (95% confidence interval, -16.1 to -6.7)), and one, a shorter hospital stay (mean, -5.7 days (-10.3 to -1.1)) in the lower-Hb groups, whereas the other two found no significant association.

Conclusions

We found insufficient evidence to confirm or refute a difference in effect between lower- and higher-Hb groups in neurocritically ill patients. Considering the lack of evidence regarding long-term neurologic functional outcomes and the high risk of bias of half the studies, no recommendation can be made regarding which hemoglobin level to target and which associated transfusion strategy (restrictive or liberal) to favor in neurocritically ill patients.

Controversies in neurosciences critical care

Neurocritical care is an evolving subspecialty with many controversial topics. The focus of this review is (1) transfusion thresholds in patients with acute intracranial bleeding, including packed red blood cell transfusion, platelet transfusion, and reversal of coagulopathy; (2) indications for seizure prophylaxis and choice of antiepileptic agent; and (3) the role of specialized neurocritical care units and specialists in the care of critically ill neurology and neurosurgery patients.

ICU management of aneurysmal subarachnoid hemorrhage

INTRODUCTION

Aneurysmal subarachnoid hemorrhage (SAH) has very high morbidity and mortality rates. Optimal intensive care unit (ICU) management requires knowledge of the potential complications that occur in this patient population.

METHODS

Review of the ICU management of SAH. Level of evidence for specific recommendations is provided.

RESULTS

Grading scales utilizing clinical factors and brain imaging studies can help in determining prognosis and are reviewed. Misdiagnosis of SAH is fairly common so the clinical symptoms and signs of SAH are summarized. The ICU management of SAH is discussed beginning with a focus on avoiding aneurysm re-rupture and securing the aneurysm, followed by a review of the neurologic and medical complications that may occur after the aneurysm is secured. Detailed treatment strategies and areas of current and future research are reviewed.

CONCLUSIONS

The ICU management of the patient with SAH can be particularly challenging and requires an awareness of all potential neurologic and medical complications and their urgent treatments.

Anemia and transfusion after subarachnoid hemorrhage

Delayed cerebral ischemia after subarachnoid hemorrhage (SAH) may be affected by a number of factors, including cerebral blood flow and oxygen delivery. Anemia affects about half of patients with SAH and is associated with worse outcome. Anemia also may contribute to the development of or exacerbate delayed cerebral ischemia. This review was designed to examine the prevalence and impact of anemia in patients with SAH and to evaluate the effects of transfusion. A literature search was made to identify original research on anemia and transfusion in SAH patients. A total of 27 articles were identified that addressed the effects of red blood cell transfusion (RBCT) on brain physiology, anemia in SAH, and clinical management with RBCT or erythropoietin. Most studies provided retrospectively analyzed data of very low-quality according to the GRADE criteria. While RBCT can have beneficial effects on brain physiology, RBCT may be associated with medical complications, infection, vasospasm, and poor outcome after SAH. The effects may vary with disease severity or the presence of vasospasm, but it remains unclear whether RBCTs are a marker of disease severity or a cause of worse outcome. Erythropoietin data are limited. The literature review further suggests that the results of the Transfusion Requirements in Critical Care Trial and subsequent observational studies on RBCT in general critical care do not apply to SAH patients and that randomized trials to address the role of RBCT in SAH are required.

Red blood cell transfusion in the neurological ICU

Red blood cell transfusion (RBCT) is a common therapy used in the intensive care unit to treat anemia. However, due to deleterious side effects and questionable efficacy, the clinical benefit of RBCT in patients who are not actively bleeding is unclear. The results of randomized controlled trials suggest there is no benefit to a liberal transfusion practice in general critical care populations. Whether the results of these trials are applicable to brain injured patients is unknown, as patients with primary neurological injury were excluded. This article reviews the efficacy and complications of RBCT, as well as the relationship between RBCT and its outcome in both the general intensive care unit and neurologically critically ill populations.

Treatment options for cerebral vasospasm in aneurysmal subarachnoid hemorrhage

Cerebral vasospasm occurs frequently after aneurysmal subarachnoid and contributes to delayed cerebral ischemia. In this article we address systematic problems with the literature on vasospasm and then review both established and experimental treatment options.

Iatrogenic cerebral venous sinus occlusion with flowable topical hemostatic matrix

Object

The use of commercially available topical hemostatic adjuncts has increased the safety profile of surgery as a whole. Cranial surgery has also benefited from the development of numerous agents designed to permit more rapid achievement of hemostasis. Flowable topical hemostatic agents applied via syringe injection are now commonly employed in many neurosurgical procedures, including cranial surgery. Intravascular use of these strongly thrombogenic agents is contraindicated, but in certain settings, inadvertent intravascular administration can occur, resulting in vascular occlusion, thrombosis, and potential dissemination. To date, there have no reports detailing the presence and incidence of this complication.

Methods

The authors conducted a retrospective review of all cranial surgeries performed at Presbyterian University Hospital by members of the University of Pittsburgh Medical Center's Department of Neurological Surgery between 2007 and 2009. Cases complicated by vascular occlusion due to inadvertent intravascular administration of flowable topical hemostatic matrix (FTHM) were identified and analyzed.

Results

Iatrogenic vascular occlusion induced by FTHM was identified in 5 (0.1%) of 3969 cranial surgery cases. None of these events occurred in 3318 supratentorial cases, whereas 5 cases of cerebral venous sinus occlusion occurred in 651 infratentorial cases (0.8%). The risk of accidental vessel occlusion was significantly associated with infratentorial surgery, and all events occurred in the transverse and/or sigmoid sinus. No episodes of inadvertent vascular occlusion occurred during endoscopic surgery. No cases of arterial occlusion were identified. Of the 5 patients with FTHM-related cerebral venous sinus occlusion, none developed long-term neurological sequelae referable to the event.

Conclusions

Inadvertent intravascular administration of FTHM is a rare complication associated with cranial surgery that occurs most commonly during infratentorial procedures around the transverse and/or sigmoid sinuses. Modifications in the choice of when to use an FTHM and the method of application may help prevent accidental venous sinus administration.

Transfusion in the critically ill: does it affect outcome?

Anemia and red blood cell (RBC) transfusions are common in critically ill and injured, trauma, and surgical patients. Tolerance of anemia is highly variable, depending on the presence of cardiovascular and other comorbid diseases that may diminish the hemodynamic response to a lower hemoglobin (Hb) level. The quest to define a minimum threshold Hb concentration at which patients achieve significant benefit to improve outcome has not yet been identified. Complications related to RBC transfusion are related to RBC storage and intrinsic properties of donor allogeneic RBCs, including bacterial contamination, transfusion-related acute lung injury, and transfusion-related immunomodulation. The best evidence related to transfusion-related outcome involves titrating transfusion requirements to parameters of severity of illness rather than arbitrarily defined Hb levels.

Red blood cell transfusion in patients with subarachnoid hemorrhage: a multidisciplinary North American survey

INTRODUCTION

Anemia is associated with poor outcomes in patients with aneurysmal subarachnoid hemorrhage (SAH). It remains unclear whether this association can be modified with more aggressive use of red blood cell (RBC) transfusions. The degree to which restrictive thresholds have been adopted in neurocritical care patients remains unknown.

METHODS

We performed a survey of North American academic neurointensivists, vascular neurosurgeons and multidisciplinary intensivists who regularly care for patients with SAH to determine hemoglobin (Hb) concentrations which commonly trigger a decision to initiate transfusion. We also assessed minimum and maximum acceptable Hb goals in the context of a clinical trial and how decision-making is influenced by advanced neurological monitoring, clinician characteristics and patient-specific factors.

RESULTS

The survey was sent to 531 clinicians, of whom 282 (53%) responded. In a hypothetical patient with high-grade SAH (WFNS 4), the mean Hb concentration at which clinicians administered RBCs was 8.19 g/dL (95% CI, 8.07 to 8.30 g/dL). Transfusion practices were comparatively more restrictive in patients with low-grade SAH (mean Hb 7.85 g/dL (95% CI, 7.73 to 7.97 g/dL)) (P < 0.0001) and more liberal in patients with delayed cerebral ischemia (DCI) (mean Hb 8.58 g/dL (95% CI, 8.45 to 8.72 g/dL)) (P < 0.0001). In each setting, there was a broad range of opinions. The majority of respondents expressed a willingness to study a restrictive threshold of ≤8 g/dL (92%) and a liberal goal of ≥10 g/dl (75%); in both cases, the preferred transfusion thresholds were significantly higher for patients with DCI (P < 0.0001). Neurosurgeons expressed higher minimum Hb goals than intensivists, especially for patients with high-grade SAH (β = 0.46, P = 0.003), and were more likely to administer two rather than one unit of RBCs (56% vs. 19%; P < 0.0001). Institutional use of transfusion protocols was associated with more restrictive practices. More senior clinicians preferred higher Hb goals in the context of a clinical trial. Respondents were more likely to transfuse patients with brain tissue oxygen tension values <15 mmHg and lactate-to-pyruvate ratios >40.

CONCLUSIONS

There is widespread variation in the use of RBC transfusions in SAH patients. Practices are heavily influenced by the specific dynamic clinical characteristics of patients and may be further modified by clinician specialty and seniority, the use of protocols and advanced neurological monitoring.