Seminars in respiratory and critical care medicine
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Semin Respir Crit Care Med · Feb 2016
ReviewHow Cool It Is: Targeted Temperature Management for Brain Protection Post-Cardiac Arrest.
Neurological recovery often determines outcome in patients resuscitated after cardiac arrest. Temperature control as a neuroprotective strategy has become standard of care. The first randomized trials showing improved neurological outcomes in patients treated with hypothermia with a target temperature of 33°C over a decade ago led to the inclusion of this intervention in practice guidelines and the broad adoption of hypothermia protocols across the world. ⋯ However, the optimal temperature target, timing of induction, duration of temperature control, and speed of rewarming are unclear. Similarly, the value of targeted temperature management in cases of in-hospital arrest and non-shockable rhythms is unknown. This article reviews the neuroprotective mechanisms of hypothermia, the evidence supporting targeted temperature management after cardiac resuscitation, areas of persistent uncertainty and controversy, and future research directions.
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Semin Respir Crit Care Med · Feb 2016
ReviewToo Little Oxygen: Ventilation, Prone Positioning, and Extracorporeal Membrane Oxygenation for Severe Hypoxemia.
Severe hypoxemia is associated with untoward outcomes in acute respiratory distress syndrome patients. Nevertheless, in and of itself, correction of hypoxemia is not an adequate surrogate outcome for mortality and clear evidence-based targets for correction of hypoxemia remain to be determined. ⋯ Notable progress in care includes further refinements in mechanical ventilation, consideration of salutatory effects of early prone positioning and neuromuscular blockade, and exploration of adjunctive extrapulmonary support with extracorporeal membrane oxygenation. This review focuses on three specific aspects: the evolving trend toward open lung ventilation, tempered by the recent cautionary experience with high-frequency oscillation ventilation; the evolution of prone positioning as a treatment for the most hypoxemic patients; and the continued future promise of extracorporeal support as a true rescue therapy.
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Semin Respir Crit Care Med · Feb 2016
ReviewWhat Is the Evidence for Harm of Neuromuscular Blockade and Corticosteroid Use in the Intensive Care Unit?
Neuromuscular blocking agents and corticosteroids are widely used in medicine and in particular in the intensive care unit (ICU). Neuromuscular blockade is commonly used to ease tracheal intubation, to optimize mechanical ventilation and oxygenation in acute respiratory disorders such as status asthmaticus and acute respiratory distress syndrome (ARDS), to prevent shivering during therapeutic hypothermia, and also in patients with elevated intracranial pressure. In the ICU, patients with sepsis, ARDS, community-acquired pneumonia, exacerbation of chronic obstructive pulmonary disease, severe asthma, or trauma may receive corticosteroids. ⋯ Both superinfections and ICU-acquired paresis are more likely when high doses of fluorinated corticosteroids are combined with prolonged treatment with a long-acting non-depolarizing neuromuscular blocker. Modern ICU practices favor lower dose of corticosteroids and very short course of short-acting curare for the management of sepsis or ARDS. Recent trials provided no evidence for increased risk of secondary infections or critical illness neuromyopathy in patients with sepsis or ARDS with the use of corticosteroids or neuromuscular blockers.
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Survivors of critical illness often experience long-lasting impairments in mental, cognitive, and physical functioning. Acute stress reactions and delusional memories appear to play an important role in psychological morbidity following critical illness, and few interventions exist to address these symptoms. This review elucidates acute psychological stressors experienced by the critically ill. ⋯ Memory may play a role in the genesis of subsequent psychological trauma. Traumatic memories may begin forming even before the patient arrives in the ICU and during their state of unconsciousness in the ICU. Hence, practical interventions for redirecting patients' thoughts, such as positive suggestion techniques and actively involving patients in the treatment process as early as possible, are worthy of further investigation.
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Semin Respir Crit Care Med · Feb 2016
ReviewAdapting the ABCDEF Bundle to Meet the Needs of Patients Requiring Prolonged Mechanical Ventilation in the Long-Term Acute Care Hospital Setting: Historical Perspectives and Practical Implications.
When robust clinical trials are lacking, clinicians are often forced to extrapolate safe and effective evidence-based interventions from one patient care setting to another. This article is about such an extrapolation from the intensive care unit (ICU) to the long-term acute care hospital (LTACH) setting. Chronic critical illness is an emerging, disabling, costly, and yet relatively silent epidemic that is central to both of these settings. ⋯ Recent studies conducted in the traditional ICU setting suggest interprofessional, multicomponent strategies aimed at effectively assessing, preventing, and managing pain, agitation, delirium, and weakness, such as the ABCDEF bundle, may play an important role in the recovery of the chronically critically ill. This article reviews what is known about the chronically critically ill, provide readers with some important historical perspectives on the ABCDEF bundle, and address some controversies and practical implications of adopting the ABCDEF bundle into the everyday care of patients requiring prolonged mechanical ventilation in the LTACH setting. We believe developing new and better ways of addressing both the science and organizational aspects of managing the common and distressing symptoms associated with chronic critical illness and prolonged mechanical ventilation will ultimately improve the quality of life for the many patients and families admitted to LTACHs annually.