Sedation During Neurocritical Care

Sedation is an essential therapeutic strategy in the care of neurocritical patients. Intravenous sedative agents are the most widely used, with promising alternatives (dexmedetomidine, ketamine, and volatile agents) to propofol and midazolam arising. Studies designed to evaluate superiority and avoid biases are required. A neurological awakening test is safe in most patients. Potential risks and benefits of limiting deep sedation and daily interruption of sedation in these patients remain unclear. The aim of this review was to report recent clinical evidence on sedation in this subgroup of patients, focusing on its effects on clinical prognosis.

Clinical Relevance of Blood Glucose Concentration and Hyperglycemia Management in Neurocritical Care Patients

In patients admitted to a neurocritical care (NCC) unit, management of blood glucose concentration (BGC) is a challenging clinical task. Several studies have shown that episodes of hypo- and hyperglycemia and high BGC variability are associated with poor short- and long-term outcomes. Optimal BGC target-range and BGC management in NCC patients have dramatically evolved in the past decades and new insulin infusion and adequate nutrition protocols are now available. The aim of this narrative review is to report the state-of-the-art on clinical relevance on BGC and hyperglycemia management in NCC patients.

Hemofiltration for neuroprotection in acute ischemic stroke: A prospective, pilot study

BACKGROUND

Hemofiltration reduces blood levels of cytokines, glutamate, and other substances that increase the risk of stroke-associated neurodegeneration. This study aimed to assess the safety and efficacy of hemofiltration in acute ischemic stroke patients.

METHODS

A total of 37 patients (mean age 56 ± 16 years) who had an ischemic stroke within the previous 12 hours were randomized to receive hemofiltration for 36 hours (n = 19) or standard treatment (n = 18). The primary outcome of interest was the occurrence of adverse events during the 28-day period following the stroke symptom onset. The secondary outcome was to assess the efficacy of hemofiltration in acute ischemic stroke.

RESULTS

Eighteen patients who received hemofiltration and 17 patients who received standard care completed the study. There were no cases of sepsis or infection at the hemofiltration cannula site, nor other hemofiltration-related complications. There was one case of fatal hemorrhagic transformation in each of the two groups. We failed to find any favorable effects on NIHSS scores at 7 days. However, we observed 17 patients (94%) with systemic inflammatory response syndrome in the control group and only 13 (68%) in the hemofiltration group.

CONCLUSION

Hemofiltration appears to be safe in acute ischemic stroke patients, but we were unable to demonstrate its efficacy. However, for a definite conclusion on efficacy, a larger study with longer follow-up is required.

Periprocedural management of patients with subarachnoid hemorrhage

PURPOSE OF REVIEW

Anesthesiologists and intensivists may be involved in the management of aneurysmal subarachnoid hemorrhage (aSAH) patients at various stages of care. This article will review the recent advances in the periprocedural management of aSAH patients.

RECENT FINDINGS

New scoring systems to assess gravity and prognosis of aSAH patients have been evaluated and proposed. Rebleeding still remains, with early aneurysmal treatment, a major challenge in the first hours of aSAH management. In the last decades, the treatment of the aSAH has shifted from clipping to coiling and more recently, the use of flow diversion technique has been introduced in selected patients. Although these improvements allow treatment of more complex aneurysms, they have implications for the anesthesiologist, including requiring the management of anticoagulation with its inherent risks. Even though knowledge, monitoring, and management of postprocedural phase of aSAH patients has improved, vasospasm and cerebral-delayed ischemia still remain the major and devastating complications in the postoperative course of aSAH patients.

SUMMARY

Despite recent progress in the scoring, diagnosis, and treatment of aSAH patients, the periprocedural management of these patients is still a major challenge for anesthesiologists and intensivists, who are involved from the first phase of the aneurysm rupture through the postoperative phases and vasospasm period.

Education in neuroanesthesia and neurocritical care: trends, challenges and advancements

PURPOSE OF REVIEW

We summarize the latest evidence in neuroanesthesia and neurocritical care (NCC) training. In addition, we describe the newer advancements that clinical educators face in these subspecialties. Lastly, we highlight educational approaches that may lead to an enhanced learning experience and development of necessary skills for neurosciences trainees.

RECENT FINDINGS

Current neuroanesthesia and NCC training requires acquisition of specific skills for increasing complex surgical cases, specialized neurosurgical practice and new perioperative technologies. Furthermore, there is increasing international interest for standardization and accreditation of neuroanesthesia fellowship programs. Recent evidence has demonstrated that well structured training using high-fidelity simulation improves cognitive and technical skills in acute neurological crises.

SUMMARY

High-fidelity simulation in perioperative care of neurosurgical patients can be part of formal neuroanesthesia and NCC curricula, and potentially impact trainees' proficiency. A research agenda is needed to validate the assessment of most effective educational interventions in neurosciences trainees with diverse medical backgrounds. Creative combinations of cost-effective interventions including traditional teaching, specific technical skills workshops, low and high-fidelity simulation deserve to be assessed in future studies.

A multicountry comparative survey about organizational resilience in anaesthesia

RATIONALE, AIMS, AND OBJECTIVES

The application of resilience in health care requires the shift from a cause-effect approach to a systemic approach, yet few tools have been developed to measure resilience potential in this specific context. This study tests a resilience assessment grid (RAG) questionnaire to measure the resilience of anaesthesiologists, with a cross-country survey.

METHOD

A study was conducted with an analytic hierarchy process (AHP) questionnaire containing 57 detailed questions; 16 nations and 172 respondents were involved in the study. The data were statistically analysed to identify insights from the questionnaire, main improvements for further assessment, and confirmation of the design of the questionnaire. The questionnaire reliability was assessed by Cronbach analysis. Weak items were identified by a detailed correlations analysis and through a weight-polarization matrix. Construct validity was confirmed by principal component analysis (PCA) and factor analysis (FA).

RESULTS

The α level of Cronbach analysis is 0.910. PCA and FA confirmed the absence of underlying unexpected factors, with less than 8% from the first factor and a total of just 54% of variability explained by 17 factors. Suggestions for revising the questionnaire ensue from the analysis, with improvements for the questionnaire's significance.

CONCLUSION

The questionnaire shows the potential to assess proxy measures of resilience, even confirming the relevance of a structured weighting approach based on the AHP. The exemplar statistical cross-country analyses encourage the widespread use of a centralized resilience questionnaire to support standardized analyses and the diffusion of best practices among organizations.

Early and late clinical outcomes after decompressive craniectomy for traumatic refractory intracranial hypertension: a systematic review and meta-analysis of current evidence

INTRODUCTION

Decompressive craniectomy (DC) to control refractory intracranial hypertension in patients with traumatic brain injury (TBI), has been listed as possible but controversial therapeutic approach in the latest version of TBI management guidelines. This study aimed to perform a systematic review and meta-analysis on efficacy and safety of DC compared to standard care in TBI patients.

EVIDENCE ACQUISITION

A database search from 2011 to 2017 was conducted to identify studies pertinent to DC compared to standard care after TBI. The primary outcomes were mortality and functional outcome upon hospital discharge and at 6 and 12 months after intervention, whereas secondary outcomes were intracranial pressure (ICP) control, hospitalization data and occurrence of adverse events.

EVIDENCE SYNTHESIS

Three randomized controlled trials and two observational studies enrolling 3451 patients were selected for qualitative analysis, among which four were included in the meta-analysis. DC-treated patients showed a significant reduction of overall mortality (RR, 0.57; 95% CI: 0.5-0.66; P<0.001; I2=17%) with no profound beneficial effect on functional outcome (RR, 0.89; 95% CI: 0.78-1.02; P=0.09; I2=58%) compared to those receiving standard care. A more efficient ICP reduction and a tendency towards shorter duration of hospitalization were recorded in DC versus standard care group. Adverse events are more common in DC-treated patients.

CONCLUSIONS

It seems that, in TBI patients with intracranial hypertension, the use of DC is associated with survival benefit when compared to medical therapy alone, but with no clear improvement of functional outcome. Yet no definite conclusion can be drawn due to limited quantity and considerable heterogeneity of available data.

Xenon anesthesia for awake craniotomy: safety and efficacy

BACKGROUND

The asleep-awake-asleep (AAA) craniotomy is a technique that offers the opportunity of having a patient fully cooperative during the awake phase, and minimizes the possible discomfort, due to the asleep phase. The aim of this prospective observational study was to test the use of xenon in the first asleep phase of an AAA craniotomy, in patients undergoing craniotomy for brain tumor resection.

METHODS

The data have been collected from 40 awake craniotomy procedures, performed in patients with cerebral tumor, treated with the AAA technique. Patients were treated with xenon during the asleep phase, and quality of mapping, complications and qualitative judgment of the experience given by the patients were recorded.

RESULTS

The mapping was carried out as planned in 37 out of 40 cases. The doses of xenon administered during the first asleep phase of the anesthesia was 13±2 L. Time for awakening after xenon was switched off was 5±1 minute. A combination of xenon and regional anesthesia (with no need for additional systemic anesthetics) was adequate to accomplish craniotomy in 27/40 patients (67.5%). On the day after the operation, 37 patients recalled the testing procedure for mapping during the awake period, none had recollection of local anesthetic injections for regional anesthesia or sound associated with the neurosurgical drill. Five patients (12.5%) reported mild pain during tumor removal (VAS Score less than three).

CONCLUSIONS

In this case series, xenon anesthesia was successfully used for the sedative phase of an awake craniotomy accomplished with an AAA approach.

Minimizing ICU Neurological Dysfunction with Dexmedetomidine-induced Sleep (MINDDS): protocol for a randomised, double-blind, parallel-arm, placebo-controlled trial

INTRODUCTION

Delirium, which is prevalent in postcardiac surgical patients, is an acute brain dysfunction characterised by disturbances in attention, awareness and cognition not explained by a pre-existing neurocognitive disorder. The pathophysiology of delirium remains poorly understood. However, basic science and clinical studies suggest that sleep disturbance may be a modifiable risk factor for the development of delirium. Dexmedetomidine is a α-2A adrenergic receptor agonist medication that patterns the activity of various arousal nuclei similar to sleep. A single night-time loading dose of dexmedetomidine promotes non-rapid eye movement sleep stages N2 and N3 sleep. This trial hypothesises dexmedetomidine-induced sleep as pre-emptive therapy for postoperative delirium.

METHODS AND ANALYSIS

The MINDDS (Minimizing ICU Neurological Dysfunction with Dexmedetomidine-induced Sleep) trial is a 370-patient block-randomised, placebo-controlled, double-blinded, single-site, parallel-arm superiority trial. Patients over 60 years old, undergoing cardiac surgery with planned cardiopulmonary bypass, will be randomised to receive a sleep-inducing dose of dexmedetomidine or placebo. The primary outcome is the incidence of delirium on postoperative day 1, assessed with the Confusion Assessment Method by staff blinded to the treatment assignment. To ensure that the study is appropriately powered for the primary outcome measure, patients will be recruited and randomised into the study until 370 patients receive the study intervention on postoperative day 0. Secondary outcomes will be evaluated by in-person assessments and medical record review for in-hospital end points, and by telephone interview for 30-day, 90-day and 180-day end points. All trial outcomes will be evaluated using an intention-to-treat analysis plan. Hypothesis testing will be performed using a two-sided significance level (type I error) of α=0.05. Sensitivity analyses using the actual treatment received will be performed and compared with the intention-to-treat analysis results. Additional sensitivity analyses will assess the potential impact of missing data due to loss of follow-up.

ETHICS AND DISSEMINATION

The Partners Human Research Committee approved the MINDDS trial. Recruitment began in March 2017. Dissemination plans include presentations at scientific conferences, scientific publications and popular media.

TRIAL REGISTRATION NUMBER

NCT02856594.

Perioperative hyperglycemia and neurocognitive outcome after surgery: a systematic review

INTRODUCTION

Preliminary evidence suggest a possible relationship between perioperative hyperglycemia, postoperative delirium (POD) or cognitive dysfunction (POCD). We aim to present the available clinical evidence related to chronic (i.e. diabetes mellitus) or acute perioperative hyperglycemia as risk factors for POD/POCD.

EVIDENCE ACQUISITION

A literature search of EMBASE (via Ovid, 1974-present) online medical database and MEDLINE (via PubMed or Ovid, 1946-present) was performed. All types of clinical studies including randomized controlled trials, prospective, as well as retrospective cohort studies were screened. Clinical studies that reported original information on the relationship between diabetes mellitus (DM) and/or acute perioperative abnormal glucose levels and POD or POCD were selected. Reviews and editorials (i.e. articles not presenting original preclinical or clinical research) were excluded and case-reports were not considered for analysis.

EVIDENCE SYNTHESIS

Our search resulted in 2356 papers for screening, from which we selected 29 studies that met our inclusion criteria. DM was investigated in 24 observational papers, acute perioperative hyperglycemia in six observational studies and two randomized controlled trials examined the effect of perioperative glucose lowering on POD/POCD. Diabetes was associated with POD or POCD in 18/24 observational studies and 6/6 of the included observational studies found that perioperative hyperglycemia was associated with POD/POCD, independent of diabetes. The two randomized controlled trials had a different trial design and reported conflicting results.

CONCLUSIONS

According to the available evidence, DM and acute perioperative hyperglycemia may be associated with an increased risk for POD/POCD. These conclusions are based mostly on observational studies and deserve more and dedicated research. This systematic review may direct the design of future studies.

Artificial neural networks can be effectively used to model changes of intracranial pressure (ICP) during spinal surgery using different non invasive ICP surrogate estimators

BACKGROUND

Artificial Intelligence (AI) techniques play a major role in anesthesiology, even though their importance is often overlooked. In the extant literature, AI approaches, such as Artificial Neural Networks (ANNs), have been underutilized, mainly being used to model patient's consciousness state, to predict the precise amount of anesthetic gases, the level of analgesia, or the need of anesthesiological blocks, among others. In the field of neurosurgery, ANNs have been effectively applied to the diagnosis and prognosis of cerebral tumors, seizures, low back pain, and also to the monitoring of intracranial pressure (ICP).

METHODS

A MultiLayer Perceptron (MLP), which is a feedforward ANN, with hyperbolic tangent as activation function in the input/hidden layers, softmax as activation function in the output layer, and cross-entropy as error function, was used to model the impact of prone versus supine position and the use of positive end expiratory pressure (PEEP) on ICP in a sample of 30 patients undergoing spinal surgery. Different non invasive surrogate estimations of ICP have been used and compared: namely, mean optic nerve sheath diameter (ONSD), non invasive estimated cerebral perfusion pressure (NCPP), pulsatility index (PI), ICP derived from PI (ICP-PI), and flow velocity diastolic formula (FVDICP).

RESULTS

ONSD proved to be a more robust surrogate estimation of ICP, with a predictive power of 75%, whilst the power of NCPP, ICP-PI, PI, and FVDICP were 60.5%, 54.8%, 53.1%, and 47.7%, respectively.

CONCLUSIONS

Our MLP analysis confirmed our findings previously obtained with regression, correlation, multivariate Receiving Operator Curve (multi-ROC) analyses. ANNs can be successfully used to predict the effects of prone versus supine position and PEEP on ICP in patients undergoing spinal surgery using different non invasive surrogate estimators of ICP.

Cardiac output changes after osmotic therapy in neurosurgical and neurocritical care patients: a systematic review of the clinical literature

AIM

Osmotherapy constitutes a first-line intervention for intracranial hypertension management. However, hyperosmolar solutes exert various systematic effects, among which their impact on systemic haemodynamics is poorly clarified. This review aims to appraise the clinical evidence of the effect of mannitol and hypertonic saline (HTS) on cardiac performance in neurosurgical and neurocritical care patients.

METHOD

A database search was conducted to identify randomized clinical trials and observational studies reporting HTS or mannitol use in acute brain injury setting. The primary end-points were alterations of cardiac output (CO) and other haemodynamic variables, while the impact of osmotic agents on intracranial pressure, brain relaxation, plasma osmolality, electrolyte levels and urinary output constituted secondary outcomes.

RESULTS

Eight studies, enrolling 182 patients in total, were included. HTS exerted a more profound cardiac output augmentation than mannitol, but no distinct difference between groups occurred. Central venous pressure, stroke volume and stroke volume variation were favourably affected by both osmotic agents, whilst the reported changes in blood pressure were inconclusive. HTS infusion yielded a larger intracranial pressure reduction than mannitol but had an equivalent effect on brain relaxation. Mannitol presented a more potent diuretic effect than HTS. Effect on serum osmolality was alike in both osmotic agents, but contrary to HTS-promoted hypernatraemia, mannitol use induced transient hyponatraemia.

CONCLUSIONS

Mannitol or HTS administration seems to induce an enhancement of cardiac performance; being more prominent after HTS infusion. This effect combined with mannitol-induced enhancement of diuresis and HTS-promoted increase of plasma sodium concentration could partially explain the effects of osmotherapy on cerebral haemodynamics.

Acute respiratory distress syndrome in traumatic brain injury: how do we manage it?

Traumatic brain injury (TBI) is an important cause of morbidity and mortality worldwide. TBI patients frequently suffer from lung complications and acute respiratory distress syndrome (ARDS), which is associated with poor clinical outcomes. Moreover, the association between TBI and ARDS in trauma patients is well recognized. Mechanical ventilation of patients with a concomitance of acute brain injury and lung injury can present significant challenges. Frequently, guidelines recommending management strategies for patients with traumatic brain injuries come into conflict with what is now considered best ventilator practice. In this review, we will explore the strategies of the best practice in the ventilatory management of patients with ARDS and TBI, concentrating on those areas in which a conflict exists. We will discuss the use of ventilator strategies such as protective ventilation, high positive end expiratory pressure (PEEP), prone position, recruitment maneuvers (RMs), as well as techniques which at present are used for 'rescue' in ARDS (including extracorporeal membrane oxygenation) in patients with TBI. Furthermore, general principles of fluid, haemodynamic and hemoglobin management will be discussed. Currently, there are inadequate data addressing the safety or efficacy of ventilator strategies used in ARDS in adult patients with TBI. At present, choice of ventilator rescue strategies is best decided on a case-by-case basis in conjunction with local expertise.

An Analytic Framework to Assess Organizational Resilience

Background

Resilience engineering is a paradigm for safety management that focuses on coping with complexity to achieve success, even considering several conflicting goals. Modern sociotechnical systems have to be resilient to comply with the variability of everyday activities, the tight-coupled and underspecified nature of work, and the nonlinear interactions among agents. At organizational level, resilience can be described as a combination of four cornerstones: monitoring, responding, learning, and anticipating.

Methods

Starting from these four categories, this article aims at defining a semiquantitative analytic framework to measure organizational resilience in complex sociotechnical systems, combining the resilience analysis grid and the analytic hierarchy process.

Results

This article presents an approach for defining resilience abilities of an organization, creating a structured domain-dependent framework to define a resilience profile at different levels of abstraction, and identifying weaknesses and strengths of the system and potential actions to increase system's adaptive capacity. An illustrative example in an anesthesia department clarifies the outcomes of the approach.

Conclusion

The outcome of the resilience analysis grid, i.e., a weighed set of probing questions, can be used in different domains, as a support tool in a wider Safety-II oriented managerial action to bring safety management into the core business of the organization.

Severe Intraoperative Hyperglycemia Is Independently Associated With Postoperative Composite Infection After Craniotomy: An Observational Study

BACKGROUND

Postoperative infection after craniotomy carries an increased risk of morbidity and mortality. Identification and correction of the risk factors should be prioritized. The association of intraoperative hyperglycemia with postoperative infections in patients undergoing craniotomy is inadequately studied.

METHODS

A total of 224 patients were prospectively enrolled in 2 major medical centers to assess whether severe intraoperative hyperglycemia (SIH, blood glucose ≥180 mg/dL) is associated with an increased risk of postoperative infection in patients undergoing craniotomy. Arterial blood samples were drawn and analyzed immediately after anesthetic induction and again before tracheal extubation. The new onset of any type of infection within 7 days after craniotomy was determined.

RESULTS

The incidence of new postoperative composite infection was 10% (n = 22) within the first week after craniotomy. Weight, sex, American Society of Anesthesiologists score, preoperative and/or intraoperative steroid use, and diabetes mellitus were not associated with postoperative infection. SIH was independently associated with postoperative infection (odds ratio [95% confidence interval], 4.17 [1.50-11.56], P = .006) after fitting a multiple logistic regression model to adjust for emergency surgery, length of surgery, and age ≥65 years.

CONCLUSIONS

SIH is independently associated with postoperative new-onset composite infections in patients undergoing craniotomy. Whether prevention of SIH during craniotomy results in a reduced postoperative risk of infection is unknown and needs to be appraised by further study.

Spine Surgery and Blood Loss: Systematic Review of Clinical Evidence

Spine surgery has been growing rapidly as a neurosurgical operation, with an increase of 220% over a 15-year period. Intraoperative blood transfusion is a major outcome determinant of spine procedures. Various approaches, including pharmacologic and nonpharmacologic therapies, have been tested to decrease both intraoperative and postoperative blood loss. The aim of this systematic review is to report clinical evidence on the relationship between intraoperative blood loss (primary outcome) and on transfusion requirements and postoperative complications (secondary outcomes) in patients undergoing spine surgery. A literature search of PubMed database was performed using 5 key words: spine surgery and transfusion; spine surgery and blood loss; spine surgery and blood complications; spine surgery and deep vein thrombosis; and spine surgery and pulmonary embolism. Clinical reports (randomized controlled trials, prospective and retrospective studies, and case reports) were selected. A total of 473 articles were examined; 450 were excluded, and 24 were selected for this systematic review. Selected articles were categorized into 3 subchapters: (1) drugs active on coagulation (12 studies): tranexamic acid, aminocaproic acid, aprotinin, and recombinant activated factor VII; (2) drugs not active on coagulation (5 studies): ketorolac, epoetin alfa, magnesium sulfate, propofol/sevoflurane, and omega-3 and fish oil; (3) nonpharmacologic approaches (7 studies): surgical tips, patient positioning, and general or spinal anesthesia. Several studies have shown a significant reduction in intraoperative bleeding during spine surgery and in the requirement for blood transfusion.

Italian COnsensus in Neuroradiological Anesthesia (ICONA)

Anesthetic management of patients undergoing endovascular procedures for treating intracranial aneurysms or cerebrovascular malformations must consider a number of specific challenges, in addition to those associated with anesthesia for other specialties. In addition to maintenance of physiological stability, manipulation of systemic and cerebral hemodynamic parameters may be required to treat any sudden unexpected catastrophic neurological events. A multidisciplinary group including neuro- and pediatric anesthesiologists, interventional neuroradiologists, neurosurgeons, and a clinical methodologist contributed to this document. This consensus working group from 21 Italian institutions identified open questions regarding the best practices for management of anesthesia during endovascular neuroradiological procedures for intracranial aneurysms and cerebrovascular malformations, and addressed these by formulating practical consensus statements. At the first meeting in November 2015, nine key areas were identified regarding choice of anesthetic, patient monitoring, hemodynamic targets, postoperative care, and the management of neuromuscular blockade, anticoagulant and/or antiplatelet therapy, and special considerations for pediatric patients. Nine subgroups were established and a medical librarian performed literature searches in the Cochrane and MEDLINE/PubMed databases for each group. Groups drafted literature summaries and provisional responses in the form of candidate consensus statements based on evidence, when possible, and clinical experience, when this was lacking. Final wording was agreed at a meeting in April 2016 and where possible evidence was graded using United States Preventive Services Task Force criteria. Consensus (defined as >90% agreement) was based on evidence, clinical experience, clinician preference, feasibility in the Italian healthcare system, and cost/benefit considerations.

Contrast-Enhanced Ultrasound Imaging in Detection of Changes in Cerebral Perfusion

Contrast-enhanced ultrasonography (CEU) is a non-invasive imaging technique that provides real-time, bedside information on changes in global and segmental organ perfusion. Currently, there is a lack of data concerning changes in the distribution of segmental brain perfusion in acute ischemic stroke treated by decompressive craniectomy. The aim of our case series was to assess the role of CEU after decompressive craniectomy in patients with acute ischemic stroke. CEU was performed in 12 patients at baseline and after any one of the following interventions was performed as dictated by the patient's clinical condition: vasoactive drug administration (in order to achieve cerebral perfusion pressure ≥70 mm Hg and mean arterial pressure <100 mm Hg for management of arterial blood pressure) and mild hyperventilation (carbon dioxide arterial pressure = 30-35 mm Hg). CEU was able to detect a significant variation in cerebral contrast distribution in both normal and pathologic hemispheres after induced hyperventilation (difference in time to peak [dTTP] = -38.4%), vasodilation (dTTP = -6.6%) and vasoconstriction (dTTP = +31.2%) (p < 0.05). CEU can be useful in assessing real-time cerebral perfusion changes in neurocritical care patients.

Clinical prevalence and outcome impact of pituitary dysfunction after aneurysmal subarachnoid hemorrhage: a systematic review with meta-analysis

PURPOSE

Pituitary dysfunction is reported to be a common complication following aneurysmal subarachnoid hemorrhage (aSAH). The aim of this meta-analysis is to analyze the literature on clinical prevalence, risk factors and outcome impact of pituitary dysfunction after aSAH, and to assess the possible need for pituitary screening in aSAH patients.

METHODS

We performed a systematic review with meta-analysis based on a comprehensive search of four databases (PubMed/MEDLINE, ISI/Web of Science, Scopus and Google Scholar).

RESULTS

A total of 20 papers met criteria for inclusion. The prevalence of pituitary dysfunction in the acute phase (within the first 6 months after aSAH) was 49.30 % (95 % CI 41.6-56.9), decreasing in the chronic phase (after 6 months from aSAH) to 25.6 % (95 % CI 18.0-35.1). Abnormalities in basal hormonal levels were more frequent when compared to induction tests, and the prevalence of a single pituitary hormone dysregulation was more frequent than multiple pituitary hormone dysregulation. Increasing age was associated with a lower prevalence of endocrine dysfunction in the acute phase, and surgical treatment of the aneurysm (clipping) was related to a higher prevalence of single hormone dysfunction. The prevalence of pituitary dysfunction did not correlate with the outcome of the patient.

CONCLUSIONS

Neuroendocrine dysfunction is common after aSAH, but these abnormalities have not been shown to consistently impact outcome in the data available. There is a need for well-designed prospective studies to more precisely assess the incidence, clinical course, and outcome impact of pituitary dysfunction after aSAH.

Anaesthesia Management for Awake Craniotomy: Systematic Review and Meta-Analysis

BACKGROUND

Awake craniotomy (AC) renders an expanded role in functional neurosurgery. Yet, evidence for optimal anaesthesia management remains limited. We aimed to summarise the latest clinical evidence of AC anaesthesia management and explore the relationship of AC failures on the used anaesthesia techniques.

METHODS

Two authors performed independently a systematic search of English articles in PubMed and EMBASE database 1/2007-12/2015. Search included randomised controlled trials (RCTs), observational trials, and case reports (n>4 cases), which reported anaesthetic approach for AC and at least one of our pre-specified outcomes: intraoperative seizures, hypoxia, arterial hypertension, nausea and vomiting, neurological dysfunction, conversion into general anaesthesia and failure of AC. Random effects meta-analysis was used to estimate event rates for four outcomes. Relationship with anaesthesia technique was explored using logistic meta-regression, calculating the odds ratios (OR) and 95% confidence intervals [95%CI].

RESULTS

We have included forty-seven studies. Eighteen reported asleep-awake-asleep technique (SAS), twenty-seven monitored anaesthesia care (MAC), one reported both and one used the awake-awake-awake technique (AAA). Proportions of AC failures, intraoperative seizures, new neurological dysfunction and conversion into general anaesthesia (GA) were 2% [95%CI:1-3], 8% [95%CI:6-11], 17% [95%CI:12-23] and 2% [95%CI:2-3], respectively. Meta-regression of SAS and MAC technique did not reveal any relevant differences between outcomes explained by the technique, except for conversion into GA. Estimated OR comparing SAS to MAC for AC failures was 0.98 [95%CI:0.36-2.69], 1.01 [95%CI:0.52-1.88] for seizures, 1.66 [95%CI:1.35-3.70] for new neurological dysfunction and 2.17 [95%CI:1.22-3.85] for conversion into GA. The latter result has to be interpreted cautiously. It is based on one retrospective high-risk of bias study and significance was abolished in a sensitivity analysis of only prospectively conducted studies.

CONCLUSION

SAS and MAC techniques were feasible and safe, whereas data for AAA technique are limited. Large RCTs are required to prove superiority of one anaesthetic regime for AC.

Neurocritical care for intracranial haemorrhage: a systematic review of recent studies

Intracerebral haemorrhage (ICH) is associated with significant early mortality (up to 50% at 30 days) and long-term morbidity (with permanent neurological deficits in 75-80% of patients) and represents a serious health issue worldwide. The past decade has seen a dramatic increase in clinical research on ICH diagnosis and treatment that has led to revision of the guidelines for the diagnosis and management of ICH from the American Heart Association and American Stroke Association in 2013. This systematic review reports recent clinical evidence (original studies published between September 2013 and July 2015) related to neurocritical care and intensive care unit management of patients with ICH. All but one publication included in this review report original studies related to managment of patients with intracerebral or subarachnoid haemorrhage. These include insights on risk stratification and neurocritical care or intensive care unit treatment, management of haemodynamic variables and mechanical ventilation (goal-directed fluid therapy, advanced haemodynamic monitoring, and avoidance of hyperoxia and hyperventilation), and pharmacological neuroprotection.

A systematic review of methodology applied during preclinical anesthetic neurotoxicity studies: important issues and lessons relevant to the design of future clinical research

Preclinical evidence suggests that anesthetic agents harm the developing brain thereby causing long-term neurocognitive impairments. It is not clear if these findings apply to humans, and retrospective epidemiological studies thus far have failed to show definitive evidence that anesthetic agents are harmful to the developing human brain.

AIM

The aim of this systematic review was to summarize the preclinical studies published over the past decade, with a focus on methodological issues, to facilitate the comparison between different preclinical studies and inform better design of future trials.

METHOD

The literature search identified 941 articles related to the topic of neurotoxicity. As the primary aim of this systematic review was to compare methodologies applied in animal studies to inform future trials, we excluded a priori all articles focused on putative mechanism of neurotoxicity and the neuroprotective agents. Forty-seven preclinical studies were finally included in this review.

RESULTS

Methods used in these studies were highly heterogeneous-animals were exposed to anesthetic agents at different developmental stages, in various doses and in various combinations with other drugs, and overall showed diverse toxicity profiles. Physiological monitoring and maintenance of physiological homeostasis was variable and the use of cognitive tests was generally limited to assessment of specific brain areas, with restricted translational relevance to humans.

CONCLUSION

Comparison between studies is thus complicated by this heterogeneous methodology and the relevance of the combined body of literature to humans remains uncertain. Future preclinical studies should use better standardized methodologies to facilitate transferability of findings from preclinical into clinical science.

Aneurysmal Subarachnoid Hemorrhage in Pregnancy-Case Series, Review, and Pooled Data Analysis

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) during pregnancy represents an important cause of maternal and fetal morbidity and mortality. Approaches to diagnostics and treatment are still controversial, and there are only a limited number of cases described in the literature. Our study examines the management of aSAH in pregnant patients, creating a case series by combining patients from our hospital records with those from the limited available literature.

METHODS

Data collected from Addenbrooke's Hospital records and cases published between January 1995 and January 2015 were studied. Chi-square test, exact Fisher's test, and chi-square test for trend were used for analyzing categorical data, while the t-test and Mann-Whitney-Wilcoxon test were used for continuous data.

RESULTS

Fifty-two patients were included. The mean age was 31.47 ± 5.80, and most patients were in their third trimester. A univariate pooled data analysis suggested that the maternal outcome may depend on the mother's age, mother's Hunt and Hess scale score, Glasgow Coma Scale at arrival, treatment modality for the aneurysm, mode, and timing of delivery. However, at the multivariate analysis only the presence of general complications resulted in a significant impact on maternal outcome.

CONCLUSIONS

Ruptured aneurysms in pregnant patients with aSAH may be safely secured in a timely manner. The diagnostic and treatment strategy for each of these patients should consider peculiar maternal and obstetric factors and requires a multidisciplinary assessment involving obstetrics, neurosurgeons, and intensivists. Considering the observed statistical power of our series, our findings should be taken with caution and should be supported by further systematic data collection.

Effects of Anesthetic Management on Early Postoperative Recovery, Hemodynamics and Pain After Supratentorial Craniotomy

Various clinical trials have assessed how intraoperative anesthetics can affect early recovery, hemodynamics and nociception after supratentorial craniotomy. Whether or not the difference in recovery pattern differs in a meaningful way with anesthetic choice is controversial. This review examines and compares different anesthetics with respect to wake-up time, hemodynamics, respiration, cognitive recovery, pain, nausea and vomiting, and shivering. When comparing inhalational anesthetics to intravenous anesthetics, either regimen produces similar recovery results. Newer shorter acting agents accelerate the process of emergence and extubation. A balanced inhalational/intravenous anesthetic could be desirable for patients with normal intracranial pressure, while total intravenous anesthesia could be beneficial for patients with elevated intracranial pressure. Comparison of inhalational anesthetics shows all appropriate for rapid emergence, decreasing time to extubation, and cognitive recovery. Comparison of opioids demonstrates similar awakening and extubation time if the infusion of longer acting opioids was ended at the appropriate time. Administration of local anesthetics into the skin, and addition of corticosteroids, NSAIDs, COX-2 inhibitors, and PCA therapy postoperatively provided superior analgesia. It is also important to emphasize the possibility of long-term effects of anesthetics on cognitive function. More research is warranted to develop best practices strategies for the future that are evidence-based.

Insulin and the Brain: A Sweet Relationship With Intensive Care

BACKGROUND

Insulin receptors (IRs) in the brain have unique molecular features and a characteristic pattern of distribution. Their possible functions extend beyond glucose utilization. In this systematic review, we explore the interactions between insulin and the brain and its implications for anesthesiologists, critical care physicians, and other medical disciplines.

METHODS

A literature search of published preclinical and clinical studies between 1978 and 2014 was conducted, yielding 5996 articles. After applying inclusion and exclusion criteria, 92 studies were selected for this systematic review.

RESULTS

The IRs have unique molecular features, pattern of distribution, and mechanism of action. It has effects on neuronal function, metabolism, and neurotransmission. The IRs are involved in neuronal apoptosis and neurodegenerative processes.

CONCLUSION

In this systematic review, we present a close relationship between insulin and the brain, with discernible effects on memory, learning abilities, and motor functions. The potential therapeutic effects extend from acute brain insults such as traumatic brain injury, brain ischemia, and hemorrhage, to chronic neurodegenerative diseases such as Alzheimer and Parkinson disease. An understanding of the wider effects of insulin conveyed in this review will prompt anaesthesiologists and critical care physicians to consider its therapeutic potential and guide future studies.