Novedades Bibliográficas

Association Between High Arterial Oxygen Tension and Long-Term Survival After Spontaneous Intracerebral Hemorrhage

Critical Care Medicine - Vie, 01/01/2016 - 08:00
Objective: To determine the relation between high arterial oxygen tension levels (PaO2) and long-term mortality in patients with spontaneous intracerebral hemorrhage treated in the ICU. Design: National observational multicenter cohort study. Setting: Twenty-one ICUs in Finland. Patients: A total of 3,033 adult patients. Interventions: None. Measurements and Main Results: Patients were divided into high (> 150?mm Hg), intermediate (97.5–150?mm Hg), and low (< 97.5?mm Hg) PaO2 groups based on the lowest measured PaO2/FIO2 ratio during the first 24 hours after ICU admission: 63% (n = 1,923) were in the low group, 29% (n = 892) were in the intermediate group, and 7% (n = 218) were in the high group; 80% were mechanically ventilated. The primary outcome was 6-month mortality, which occurred in 49% of patients and was significantly more frequent in the high PaO2 group than in the intermediate and low PaO2 groups (61% vs 52% and 46%, respectively, p < 0.001). In univariate analysis, patients in the high PaO2 group had a significantly increased risk of 6-month mortality compared with the low PaO2 group (odds ratio, 1.82; 95% CIs, 1.36–2.42; p < 0.001), but this statistically significant relation was lost after adjusting for markers of severity of illness in a logistic mixed-effects regression model (odds ratio, 1.10; 95% CI, 0.76–1.60; p = 0.598). Conclusions: No significant relation between PaO2 levels and long-term mortality was found. The clinical role of hyperoxemia in patients with intracerebral hemorrhage treated in the ICU remains controversial and warrants further studies.

Shared Decision Making in ICUs: An American College of Critical Care Medicine and American Thoracic Society Policy Statement

Critical Care Medicine - Vie, 01/01/2016 - 08:00
Objectives: Shared decision making is endorsed by critical care organizations; however, there remains confusion about what shared decision making is, when it should be used, and approaches to promote partnerships in treatment decisions. The purpose of this statement is to define shared decision making, recommend when shared decision making should be used, identify the range of ethically acceptable decision-making models, and present important communication skills. Design: The American College of Critical Care Medicine and American Thoracic Society Ethics Committees reviewed empirical research and normative analyses published in peer-reviewed journals to generate recommendations. Recommendations approved by consensus of the full Ethics Committees of American College of Critical Care Medicine and American Thoracic Society were included in the statement. Main Results: Six recommendations were endorsed: 1) Definition: Shared decision making is a collaborative process that allows patients, or their surrogates, and clinicians to make healthcare decisions together, taking into account the best scientific evidence available, as well as the patient’s values, goals, and preferences. 2) Clinicians should engage in a shared decision making process to define overall goals of care (including decisions regarding limiting or withdrawing life-prolonging interventions) and when making major treatment decisions that may be affected by personal values, goals, and preferences. 3) Clinicians should use as their “default” approach a shared decision making process that includes three main elements: information exchange, deliberation, and making a treatment decision. 4) A wide range of decision-making approaches are ethically supportable, including patient- or surrogate-directed and clinician-directed models. Clinicians should tailor the decision-making process based on the preferences of the patient or surrogate. 5) Clinicians should be trained in communication skills. 6) Research is needed to evaluate decision-making strategies. Conclusions: Patient and surrogate preferences for decision-making roles regarding value-laden choices range from preferring to exercise significant authority to ceding such authority to providers. Clinicians should adapt the decision-making model to the needs and preferences of the patient or surrogate.

Excellence in Intensive Care Medicine

Critical Care Medicine - Vie, 01/01/2016 - 08:00
Objective: Excellence is an important goal for all physicians. Unfortunately, it is hard to define, evaluate, and achieve. To provide a concise interpretive review of excellence in intensive care medicine, with a focus on those key characteristics that excellent physicians possess but are seldom discussed. Data Sources: Electronic search of the PubMed database using the search terms “excellence,” “role models,” “compassion,” “commitment,” “dedication,” and “passion.” Study Selection: Publications or studies of excellence, role models, compassion, commitment, dedication, and passion. Two reviewers evaluated each term. Data Extraction: Publications or studies were abstracted independently and in duplicate. Data Synthesis: Excellence in critical care can be achieved through deliberate practice, feedback, and effective evaluation. Excellence embodies numerous characteristics, which include compassion, commitment, and passion. Conclusions: Awareness of the fundamental characteristics of excellence can help young students and doctors determine what they should strive for to become excellent physicians as well as encourage experienced doctors to rekindle the spark that initially motivated them to become physicians.

Circadian Rhythm Disruption in the Critically Ill: An Opportunity for Improving Outcomes*

Critical Care Medicine - Vie, 01/01/2016 - 08:00
Objectives: Circadian rhythms are severely disrupted among the critically ill. These circadian arrhythmias impair mentation, immunity, autonomic function, endocrine activity, hormonal signaling, and ultimately healing. In this review, we present a modern model of circadian disruption among the critically ill, discuss causes of these circadian arrhythmias, review observational and intervention studies of the effects of circadian-rhythm–restoring factors on medical outcomes, and identify needed key trials of circadian interventions in the critically ill. Data Sources: MEDLINE, EMBASE, PsychINFO, Google Scholar through December 2014. Study Selection: Articles relevant to circadian rhythms, melatonin, and light in the critically ill were selected. Data Extraction and Data Synthesis: Articles were synthesized for this review of circadian arrhythmia and the use of circadian-rhythm–restoring interventions among the critically ill. Conclusions: Circadian disruption often demonstrates serial degradation: initially, the amplitude attenuates along with delayed circadian phase. With increasing acuity of illness, circadian rhythmicity may be lost entirely. Causes of chronodisruption may be environmental or internal to the patient. In particular, inadequate daytime illumination and nocturnal light pollution disrupt healthy circadian periodicity. Internal causes of circadian arrhythmia include critical illness itself and subjective experience of distress and pain. Observational studies of windowed rooms and real-time ambient lighting have found that physiologic light-dark patterns may support recovery from critical illness. Studies of early morning bright light or evening melatonin agonists have found improved rates of delirium, enhanced sleep, and lower arrhythmia prevalence. The current evidence base emphasizes that lighting and melatoninergic interventions deserve to be tested in full-scale trials.

Analyzing Neutrophil Morphology, Mechanics, and Motility in Sepsis: Options and Challenges for Novel Bedside Technologies

Critical Care Medicine - Vie, 01/01/2016 - 08:00
Objective: Alterations in neutrophil morphology (size, shape, and composition), mechanics (deformability), and motility (chemotaxis and migration) have been observed during sepsis. We combine summarizing features of neutrophil morphology, mechanics, and motility that change during sepsis with an investigation into their clinical utility as markers for sepsis through measurement with novel technologies. Data Sources: We performed an initial literature search in MEDLINE using search terms “neutrophil,” “morphology,” “mechanics,” “dynamics,” “motility,” “mobility,” “spreading,” “polarization,” “migration,” and “chemotaxis.” We then combined the results with “sepsis” and “septic shock.” We scanned bibliographies of included articles to identify additional articles. Study Selection and Data Extraction: Final selection was done after the authors reviewed recovered articles. We included articles based on their relevance for our review topic. Data Synthesis: When compared with resting conditions, sepsis causes an increase in circulating numbers of larger, more rigid neutrophils that show diminished granularity, migration, and chemotaxis. Combined measurement of these variables could provide a more complete view on neutrophil phenotype manifestation. For that purpose, sophisticated automated hematology analyzers, microscopy, and bedside microfluidic devices provide clinically feasible, high-throughput, and cost-limiting means. Conclusions: We propose that integration of features of neutrophil morphology, mechanics, and motility with these new analytical methods can be useful as markers for diagnosis, prognosis, and monitoring of sepsis and may even contribute to basic understanding of its pathophysiology.

Precision Diagnosis Is a Team Sport

Critical Care Medicine - Vie, 01/01/2016 - 08:00
No abstract available

Should We Embrace the “Open Lung” Approach?*

Critical Care Medicine - Vie, 01/01/2016 - 08:00
No abstract available

Online Editorial Board Acknowledgment

Critical Care Medicine - Vie, 01/01/2016 - 08:00
No abstract available

IV Immunoglobulin for Acute Lung Injury and Bacteremia in Pseudomonas aeruginosa Pneumonia*

Critical Care Medicine - Vie, 01/01/2016 - 08:00
Objectives: Virulent and multidrug-resistant Pseudomonas aeruginosa causes a lethal pneumonia, especially in patients who are artificially ventilated. It has been reported that the virulence mechanism used by P. aeruginosa, which is linked to acute lung injury, is strongly associated with the type III secretion system, and specific antibodies targeting this system have shown a protective effect in both experimental and clinical settings. We investigated the effect of administering IV immunoglobulins on P. aeruginosa pneumonia, including its associated bacteremia and mortality, although focusing especially on type III secretion system–associated P. aeruginosa virulence. Design: Prospective randomized and controlled animal study. Setting: University laboratory. Subjects: Male ICR mice. Interventions: Mice were infected intratracheally with a lethal dose of the virulent P. aeruginosa PA103 strain. IV immunoglobulin administration was examined in three different settings: 1) premixed; 2) pre-IV, prophylactic administration before bacterial infection; and 3) post-IV, therapeutic administration after bacterial infection. The effect of specific antigen titer depletion of IV immunoglobulins was also examined. Measurements and Main Results: Survival and body temperature were monitored for 24 hours. Bacteremia, cytokine concentration, myeloperoxidase activity, WBC counts in the blood, and lung bacterial load were evaluated. Survival improved significantly in mice that received IV immunoglobulins (p < 0.05). Lung edema, lung bacteriologic load, and bacteremia decreased significantly in the IV immunoglobulin–treated mice (p < 0.05). The mechanism of protection was associated with the presence of antibodies against both PcrV and some bacterial surface antigens in the IV immunoglobulins. Conclusions: IV immunoglobulin administration had a significantly protective effect against lethal infection from virulent P. aeruginosa. Prophylactic IV immunoglobulin administration at the highest dose was comparable with that achieved by administrating a specific anti-PcrV polyclonal IgG into the mice. The mechanism of protection is likely to involve the synergic action of anti-PcrV titers and antibodies against some surface antigen(s) that block the type III secretion system–associated virulence of P. aeruginosa.

Hyperbaric Oxygen Therapy Alleviates Carbon Monoxide Poisoning–Induced Delayed Memory Impairment by Preserving Brain-Derived Neurotrophic Factor–Dependent Hippocampal Neurogenesis

Critical Care Medicine - Vie, 01/01/2016 - 08:00
Objective: To test the hypothesis that hyperbaric oxygen therapy ameliorates delayed cognitive impairment after acute carbon monoxide poisoning by promoting neurogenesis through upregulating the brain-derived neurotrophic factor in the hippocampus. Design: Laboratory animal experiments. Setting: University/Medical center research laboratory. Subjects: Adult, male Sprague-Dawley rats. Interventions: Rats were divided into five groups: (1) non–carbon monoxide-treated control, (2) acute carbon monoxide poisoning, (3) acute carbon monoxide poisoning followed by 7-day hyperbaric oxygen treatment, (4) carbon monoxide + hyperbaric oxygen with additional intracerebroventricular infusion of Fc fragment of tyrosine kinase receptor B protein (TrkB-Fc) chimera, and (5) acute carbon monoxide poisoning followed by intracerebroventricular infusion of brain-derived neurotrophic factor. Acute carbon monoxide poisoning was achieved by exposing the rats to carbon monoxide at 2,500 ppm for 40 minutes, followed by 3,000 ppm for 20 minutes. Hyperbaric oxygen therapy (at 2.5 atmospheres absolute with 100% oxygen for 60?min) was conducted during the first 7 days after carbon monoxide poisoning. Recombinant human TrkB-Fc chimera or brain-derived neurotrophic factor was infused into the lateral ventricle via the implanted osmotic minipump. For labeling of mitotic cells in the hippocampus, bromodeoxyuridine was injected into the peritoneal cavity. Distribution of bromodeoxyuridine and two additional adult neurogenesis markers, Ki-67 and doublecortin, in the hippocampus was evaluated by immunohistochemistry or immunofluorescence staining. Tissue level of brain-derived neurotrophic factor was assessed by enzyme-linked immunosorbent assay. Cognitive behavior was evaluated by the use of eight-arm radial maze. Measurements and Main Results: Acute carbon monoxide poisoning significantly suppressed adult hippocampal neurogenesis evident by the reduction in number of bromodeoxyuridine-positive, Ki-67+, and doublecortin+ cells in the subgranular zone of the dentate gyrus. This suppression of adult neurogenesis by the carbon monoxide poisoning was appreciably alleviated by early treatment of hyperbaric oxygen. The hyperbaric oxygen treatment also promoted a sustained increase in hippocampal brain-derived neurotrophic factor level. Blockade of hippocampal brain-derived neurotrophic factor signaling with intracerebroventricular infusion of recombinant human TrkB-Fc chimera significantly blunted the protection by the hyperbaric oxygen on hippocampal neurogenesis; whereas intracerebroventricular infusion of brain-derived neurotrophic factor mimicked the action of hyperbaric oxygen and preserved hippocampal neurogenesis after acute carbon monoxide poisoning. Furthermore, acute carbon monoxide poisoning resulted in a delayed impairment of cognitive function. The hyperbaric oxygen treatment notably restored the cognitive impairment in a brain-derived neurotrophic factor–dependent manner. Conclusions: The early hyperbaric oxygen treatment may alleviate delayed memory impairment after acute carbon monoxide poisoning by preserving adult neurogenesis via an increase in hippocampal brain-derived neurotrophic factor content.
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