Seminars in respiratory and critical care medicine
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Asthma is a heterogeneous disorder with a complex etiology. Prevalence rates for asthma have been increasing in many countries over the past few decades. ⋯ These include socioeconomic status, environmental exposures, the host microbiome, and genetics. A better understanding of these processes may inform future mechanistic studies and identify modifiable risk factors for targeted health care interventions.
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Semin Respir Crit Care Med · Dec 2017
ReviewAutoimmune Encephalitis in Critical Care: Optimizing Immunosuppression.
Autoimmune diseases affecting the nervous systems are a common cause of admission to the intensive care unit (ICU). Although there exist several well-described clinical syndromes, patients more commonly present with progressive neurologic dysfunction and laboratory and radiographic evidence of central nervous system (CNS) inflammation. In the critical care setting, the urgency to intervene to prevent permanent damage to the nervous system and secondary injury from the systemic manifestations of these syndromes often conflicts with diagnostic uncertainty. ⋯ We approach these disorders not as lists of distinct clinical syndromes or molecular targets of autoimmunity but rather as clusters of syndromes based on these common underlying mechanisms of immune dysfunction. This approach emphasizes early intervention over precise diagnosis. As our understanding of the immune system continues to grow, this framework will allow for a more sophisticated approach to the management of patients with these complex, often devastating but frequently reversible, neurologic illnesses.
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Semin Respir Crit Care Med · Dec 2017
ReviewWho Is Safe to Extubate in the Neuroscience Intensive Care Unit?
Patients admitted to the neuroscience intensive care unit (NICU) may have respiratory compromise from either central or peripheral neurological pathology, and may hence require intubation and mechanical ventilation for very diverse reasons. Liberation from invasive ventilation, that is, extubation, at the earliest possible time is a widely accepted principle in intensive care. For this, classic extubation criteria have been established in the general critical care setting, mainly targeting pulmonary function and cooperativeness of the patient. ⋯ Attempts have been made to identify predictors of EF or success, and to establish extubation scores for the NICU, but results have been partially controversial and the database is still weak. It is very important to have a stepwise protocol to approach extubation in the NICU patient and to be prepared for reintubation (at times in a difficult airway) and alternatives (such as tracheostomy). The particular challenges of safely extubating the NICU patient will be the focus of this review, including a suggestion for a standardized approach.
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Multimodality monitoring provides insights into the critically ill brain-injured patient through the assessment of biochemical, physiological, and electrical data that provides insight into a patient's condition and what strategies may be available to limit further damage and improve the odds for recovery. Modalities utilized include evaluation of intracranial pressure along with cerebral perfusion pressure to determine adequate blood flow; continuous electroencephalography to protect the patient from seizures and to identify early functional manifestations of ischemia and toxicity; transcranial Doppler evaluation for bedside review of circulatory adequacy; tissue oxygen monitoring to establish that brain tissue is receiving adequate oxygen from blood flow; and microdialysis to evaluate the metabolic function of the tissue in areas of concern. These monitors provide insights regarding specific aspects of brain tissue and overall brain function in the critically ill patient. Although recommendations continue to evolve for therapeutic targets for each of these modalities, an effective clinician may use each of these modalities to evaluate patients on an individual basis to improve the outcome of each patient, tailoring management to provide the care needed for any unique clinical presentation.
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Semin Respir Crit Care Med · Dec 2017
ReviewBlood Pressure Management for Acute Ischemic and Hemorrhagic Stroke: The Evidence.
Hypertension is the most common modifiable risk factor for stroke (both ischemic and hemorrhagic types). In the hyperacute phase, a majority of patients shows an elevated blood pressure (BP) at the time of presentation because of sympathetic hyperactivity or a physiological response to tissue ischemia. Therefore, BP may decrease spontaneously in a few hours and may drop further when complete recanalization is achieved. ⋯ However, this recommendation is primarily based on observational studies and requires validation in prospective trials. It has been observed that in patients presenting with an ICH, there is no perihematomal penumbra noted and rapid BP reduction is generally well tolerated without a risk of neurological worsening. Multiple trials describing acute reduction of BP recommend SBP reduction only to 140 mm Hg because while there is no benefit of better functional outcomes below that level, there exists a definite risk of increased renal complications.