Cerebral Autoregulation in Non-Brain Injured Patients: A Systematic Review.

Introduction: Cerebral autoregulation (CA) plays a fundamental role in the maintenance of adequate cerebral blood flow (CBF). CA monitoring, through direct and indirect techniques, may guide an appropriate therapeutic approach aimed at improving CBF and reducing neurological complications; so far, the role of CA has been investigated mainly in brain-injured patients. The aim of this study is to investigate the role of CA in non-brain injured patients. Methods: A systematic consultation of literature was carried out. Search terms included: "CA and sepsis," "CA and surgery," and "CA and non-brain injury." Results: Our research individualized 294 studies and after screening, 22 studies were analyzed in this study. Studies were divided in three groups: CA in sepsis and septic shock, CA during surgery, and CA in the pediatric population. Studies in sepsis and intraoperative setting highlighted a relationship between the incidence of sepsis-associated delirium and impaired CA. The most investigated setting in the pediatric population is cardiac surgery, but the role and measurement of CA need to be further elucidated. Conclusion: In non-brain injured patients, impaired CA may result in cognitive dysfunction, neurological damage, worst outcome, and increased mortality. Monitoring CA might be a useful tool for the bedside optimization and individualization of the clinical management in this group of patients.

Development and Validation of a Questionnaire investigating the Knowledge, Attitudes and Practices of Healthcare Workers in the Field of Anesthesiology concerning the Italian Law on Advance Healthcare Directives: a Pilot Study.

Advance healthcare directives are legal documents, in which the patient, foreseeing a potential loss of capacity and autonomy, makes in advance decisions regarding future care and, in particular, end-of-life arrangements. In Italy, advance healthcare directives  are regulated by the Law 219 of 22 December 2017. Objectives of the study were: i) to develop and validate a questionnaire dedicated to evaluate the knowledge of the Law in a sample of 98 anesthesiologists, and ii) to shed light on the process of health-related decision-making and its determinants (age, gender, doctor/training resident, religious beliefs). A second part of the survey  not analyzed  in the present study, aimed to assess, through two simulated clinical scenarios, how patient' directives, relatives and the medical staff could influence physicians' clinical decision. Overall Cronbach's alpha coefficient of the questionnaire resulted 0.83. Three factors explaining up to 38.4% of total variance (communication and relationship with the patient; critical life-threatening situations and binding nature of the advance directive for the physician; and involvement of patients). Most of the doctors (58.7%) did not fully know the recent legislative provision. The lack of knowledge is critical in view of the specificity of the clinical area investigated (anesthesiology and intensive care), which has to cope with ethical issues. An adequate revision and implementation of the traditional curricula could help medical students and trainees develop the aptitudes and skills needed in their future profession.

Mechanical ventilation in neurocritical care setting: A clinical approach.

Neuropatients often require invasive mechanical ventilation (MV). Ideal ventilator settings and respiratory targets in neuro patients are unclear. Current knowledge suggests maintaining protective tidal volumes of 6-8 ml/kg of predicted body weight in neuropatients. This approach may reduce the rate of pulmonary complications, although it cannot be easily applied in a neuro setting due to the need for special care to minimize the risk of secondary brain damage. Additionally, the weaning process from MV is particularly challenging in these patients who cannot control the brain respiratory patterns and protect airways from aspiration. Indeed, extubation failure in neuropatients is very high, while tracheostomy is needed in one-third of the patients. The aim of this manuscript is to review and describe the current management of invasive MV, weaning, and tracheostomy for the main four subpopulations of neuro patients: traumatic brain injury, acute ischemic stroke, subarachnoid hemorrhage, and intracerebral hemorrhage.

Neuromonitoring during general anesthesia in non-neurologic surgery.

Cerebral complications are common in perioperative settings even in non-neurosurgical procedures. These include postoperative cognitive dysfunction or delirium as well as cerebrovascular accidents. During surgery, it is essential to ensure an adequate degree of sedation and analgesia, and at the same time, to provide hemodynamic and respiratory stability in order to minimize neurological complications. In this context, the role of neuromonitoring in the operating room is gaining interest, even in the non-neurolosurgical population. The use of multimodal neuromonitoring can potentially reduce the occurrence of adverse effects during and after surgery, and optimize the administration of anesthetic drugs. In addition to the traditional focus on monitoring hemodynamic and respiratory systems during general anesthesia, the ability to constantly monitor the activity and maintenance of brain homeostasis, creating evidence-based protocols, should also become part of the standard of care: in this challenge, neuromonitoring comes to our aid. In this review, we aim to describe the role of the main types of noninvasive neuromonitoring such as those based on electroencephalography (EEG) waves (EEG, Entropy module, Bispectral Index, Narcotrend Monitor), near-infrared spectroscopy (NIRS) based on noninvasive measurement of cerebral regional oxygenation, and Transcranial Doppler used in the perioperative settings in non-neurosurgical intervention. We also describe the advantages, disadvantage, and limitation of each monitoring technique.

Extracranial complications after traumatic brain injury: targeting the brain and the body.

PURPOSE OF REVIEW: The aim of this review is to provide an update on the pathophysiology and treatment of severe traumatic brain injury (TBI)-related complications on extracranial organs. RECENT FINDINGS: Extracranial complications are common and influence the outcome from TBI. Significant improvements in outcome in a sizeable proportion of patients could potentially be accomplished by improving the ability to prevent or reverse nonneurological complications such as pneumonia, cardiac and kidney failure. Prompt recognition and treatment of systemic complications is therefore fundamental to care of this patient cohort. However, the role of extracranial pathology often has been underestimated in outcome assessment since most clinicians focus mainly on intracranial lesions and injury rather than consider the systemic effects of TBI. SUMMARY: Robust evidence about pathophysiology and treatment of extracranial complications in TBI are lacking. Further studies are warranted to precisely understand and manage the multisystem response of the body after TBI.

Mechanical ventilation in patients with acute ischaemic stroke: from pathophysiology to clinical practice.

Most patients with ischaemic stroke are managed on the ward or in specialty stroke units, but a significant number requires higher-acuity care and, consequently, admission to the intensive care unit. Mechanical ventilation is frequently performed in these patients due to swallowing dysfunction and airway or respiratory system compromise. Experimental studies have focused on stroke-induced immunosuppression and brain-lung crosstalk, leading to increased pulmonary damage and inflammation, as well as reduced alveolar macrophage phagocytic capability, which may increase the risk of infection. Pulmonary complications, such as respiratory failure, pneumonia, pleural effusions, acute respiratory distress syndrome, lung oedema, and pulmonary embolism from venous thromboembolism, are common and found to be among the major causes of death in this group of patients. Furthermore, over the past two decades, tracheostomy use has increased among stroke patients, who can have unique indications for this procedure-depending on the location and type of stroke-when compared to the general population. However, the optimal mechanical ventilator strategy remains unclear in this population. Although a high tidal volume (VT) strategy has been used for many years, the latest evidence suggests that a protective ventilatory strategy (VT = 6-8 mL/kg predicted body weight, positive end-expiratory pressure and rescue recruitment manoeuvres) may also have a role in brain-damaged patients, including those with stroke. The aim of this narrative review is to explore the pathophysiology of brain-lung interactions after acute ischaemic stroke and the management of mechanical ventilation in these patients.

Controversies when using mechanical ventilation in obese patients with and without acute distress respiratory syndrome.

INTRODUCTION: As the prevalence of obesity increases, so does the number of obese patients undergoing surgical procedures and being admitted into intensive care units. Obesity per se is associated with reduced lung volume. The combination of general anaesthesia and supine positioning involved in most surgeries causes further reductions in lung volumes, thus resulting in alveolar collapse, decreased lung compliance, increased airway resistance, and hypoxemia. These complications can be amplified by common obesity-related comorbidities. In otherwise healthy obese patients, mechanical ventilation strategies should be optimised to prevent lung damage; in those with acute distress respiratory syndrome (ARDS), strategies should seek to mitigate further lung damage. Areas covered: This review discusses non-invasive and invasive mechanical ventilation strategies for surgical and critically ill adult obese patients with and without ARDS and proposes practical clinical insights to be implemented at bedside both in the operating theatre and in intensive care units. Expert opinion: Large multicentre trials on respiratory management of obese patients are required. Although the indication of lung protective ventilation with low tidal volume is apparently translated to obese patients, optimal PEEP level and recruitment manoeuvres remain controversial. The use of non-invasive respiratory support after extubation must be considered in individual cases.

Mechanical ventilation and respiratory monitoring during extracorporeal membrane oxygenation for respiratory support.

Over the past decade, the use of veno-venous extracorporeal membrane oxygenation (VV-ECMO) for respiratory support has widely expanded as a treatment strategy for patients with acute respiratory distress syndrome (ARDS). Despite considerable attention has been given to the indications, the timing and the management of patients undergoing ECMO for refractory respiratory hypoxemic failure, little is known regarding the management of mechanical ventilation (MV) in this group of patients. ECMO enables to minimize ventilatory induced lung injury (VILI) and it has been successfully used as rescue therapy in patients with ARDS when conventional ventilator strategies have failed. However, literature is lacking regarding the best strategies and MV settings, including positive end expiratory pressure (PEEP), tidal volume (VT), respiratory rate (RR) and plateau pressure (PPLAT). The aim of this review is to summarize current evidence, the rationale and provide recommendations about the best ventilator strategy to adopt in patients with ARDS undergoing VV-ECMO support.