Mechanical ventilation in aneurysmal subarachnoid hemorrhage: systematic review and recommendations

Objective

Mechanical ventilation (MV) has a complex interplay with the pathophysiology of aneurysmal subarachnoid hemorrhage (aSAH). We aim to provide a review of the physiology of MV in patients with aSAH, give recommendations based on a systematic review of the literature, and highlight areas that still need investigation.

Data sources

PubMed was queried for publications with the Medical Subject Headings (MeSH) terms “mechanical ventilation” and “aneurysmal subarachnoid hemorrhage” published between January 1, 1990, and March 1, 2020. Bibliographies of returned articles were reviewed for additional publications of interest.

Study selection

Study inclusion criteria included English language manuscripts with the study population being aSAH patients and the exposure being MV. Eligible studies included randomized controlled trials, observational trials, retrospective trials, case-control studies, case reports, or physiologic studies. Topics and articles excluded included review articles, pediatric populations, non-aneurysmal etiologies of subarachnoid hemorrhage, mycotic and traumatic subarachnoid hemorrhage, and articles regarding tracheostomies.

Data extraction

Articles were reviewed by one team member, and interpretation was verified by a second team member.

Data synthesis

Thirty-one articles met the inclusion criteria for this review.

Conclusions

We make recommendations on oxygenation, hypercapnia, PEEP, APRV, ARDS, and intracranial pressure monitoring.

Traumatic brain injury in pregnancy

Trauma is the leading cause of nonobstetric maternal mortality and affects up to 8% of all pregnancies. Pregnant patients with traumatic brain injury (TBI) are an especially vulnerable population, and their management is complex, with multiple special considerations that must be taken into account. These include but are not limited to alterations in maternal physiology that occur with pregnancy, potential teratogenicity of pharmacologic therapies and diagnostic studies using ionizing radiation, need for fetal monitoring, Rh immunization status, placental abruption, and preterm labor. Despite these challenges, evidence regarding management of the pregnant patient with a TBI is lacking, limited to only case reports/series and retrospective analyses. Despite this uncertainty, expert opinion on management of these patients seems to be that, overall, the standard therapies for management of TBI are safe and effective in pregnancy, with a few notable exceptions described in this chapter. Significant work is needed to continue to develop best-practice and evidence-based guidelines for the management of TBI pregnancy.

The Extended Treatment Window's Impact on Emergency Systems of Care for Acute Stroke

The window for acute ischemic stroke treatment was previously limited to 4.5 hours for intravenous tissue plasminogen activator and to 6 hours for thrombectomy. Recent studies using advanced imaging selection expand this window for select patients up to 24 hours from last known well. These studies directly affect emergency stroke management, including prehospital triage and emergency department (ED) management of suspected stroke patients. This narrative review summarizes the data expanding the treatment window for ischemic stroke to 24 hours and discusses these implications on stroke systems of care. It analyzes the implications on prehospital protocols to identify and transfer large-vessel occlusion stroke patients, on issues of distributive justice, and on ED management to provide advanced imaging and access to thrombectomy centers. The creation of high-performing systems of care to manage acute ischemic stroke patients requires academic emergency physician leadership attentive to the rapidly changing science of stroke care.

Is There a Neurologist in the House? A Summary of the Current State of Neurovascular Rotations for Emergency Medicine Residents

OBJECTIVES

Neurovascular and neurocritical care emergencies constitute a leading cause of morbidity/mortality. There has been great evolution in this field, including but not limited to extended time-window therapeutic interventions for acute ischemic stroke. The intent of this article is to evaluate the goals and future direction of clinical rotations in neurovascular and neurocritical care for emergency medicine (EM) residents.

METHODS

A panel of 13 board-certified emergency physicians from the Society for Academic Emergency Medicine (SAEM) neurologic emergencies interest group (IG) convened in response to a call for publications-three with fellowship training/board certification in stroke and/or neurocritical care; five with advanced research degrees; three who have been authors on national practice guidelines; and six who have held clinical duties within neurology, neurosurgery, or neurocritical care. A mixed-methods analysis was performed including a review of the literature, a survey of Council of Emergency Medicine Residency Directors (CORD) residency leaders/faculty and SAEM neuro-IG members, and a consensus review by this panel of select neurology rotations provided by IG faculty.

RESULTS

Thirteen articles for residency neurovascular education were identified: three studies on curriculum, three studies evaluating knowledge, and seven studies evaluating knowledge after an educational intervention. Intervention outcomes included the ability to recognize and manage acute strokes, manage intracerebral hemorrhage, calculate National Institutes of Health Stroke Scale (NIHSS), and interpret images. In the survey sent to CORD residency leaders and neuro-IG faculty, response was obtained from 48 programs. A total of 52.1% indicated having a required rotation (6.2% general neurology, 2% stroke service, 18.8% neurologic intensive care unit, 2% neurosurgery, 22.9% on a combination of services). The majority of programs with required rotations have a combination rotation (residents rotate through multiple services) and evaluations were positive.

CONCLUSIONS

Variability exists in the availability of neurovascular/neurocritical care rotations for EM trainees. Dedicated clinical time in neurologic education was beneficial to participants. Given recent advancements in the field, augmentation of EM residency training in this area merits strong consideration.