https://journal.chestnet.org/article/S0012-3692(16)38415-X/pdf

Definitions for Sepsis and Organ Failure and Guidelines for the Use of Innovative Therapies in Sepsis

The acute respiratory distress syndrome (ARDS) was defined in 1994 by the American-European Consensus Conference (AECC); since then, issues regarding the reliability and validity of this definition have emerged. Using a consensus process, a panel of experts convened in 2011 (an initiative of the European Society of Intensive Care Medicine endorsed by the American Thoracic Society and the Society of Critical Care Medicine) developed the Berlin Definition, focusing on feasibility, reliability, validity, and objective evaluation of its performance. A draft definition proposed 3 mutually exclusive categories of ARDS based on degree of hypoxemia: mild (200 mm Hg < PaO2/FIO2 ≤ 300 mm Hg), moderate (100 mm Hg < PaO2/FIO2 ≤ 200 mm Hg), and severe (PaO2/FIO2 ≤ 100 mm Hg) and 4 ancillary variables for severe ARDS: radiographic severity, respiratory system compliance (≤40 mL/cm H2O), positive end-expiratory pressure (≥10 cm H2O), and corrected expired volume per minute (≥10 L/min). The draft Berlin Definition was empirically evaluated using patient-level meta-analysis of 4188 patients with ARDS from 4 multicenter clinical data sets and 269 patients with ARDS from 3 single-center data sets containing physiologic information. The 4 ancillary variables did not contribute to the predictive validity of severe ARDS for mortality and were removed from the definition. Using the Berlin Definition, stages of mild, moderate, and severe ARDS were associated with increased mortality (27%; 95% CI, 24%-30%; 32%; 95% CI, 29%-34%; and 45%; 95% CI, 42%-48%, respectively; P < .001) and increased median duration of mechanical ventilation in survivors (5 days; interquartile [IQR], 2-11; 7 days; IQR, 4-14; and 9 days; IQR, 5-17, respectively; P < .001). Compared with the AECC definition, the final Berlin Definition had better predictive validity for mortality, with an area under the receiver operating curve of 0.577 (95% CI, 0.561-0.593) vs 0.536 (95% CI, 0.520-0.553; P < .001). This updated and revised Berlin Definition for ARDS addresses a number of the limitations of the AECC definition. The approach of combining consensus discussions with empirical evaluation may serve as a model to create more accurate, evidence-based, critical illness syndrome definitions and to better inform clinical care, research, and health services planning.

Acute respiratory distress syndrome: the Berlin Definition.

Lionel A. Mandell, Richard G. Wunderink, Antonio Anzueto, John G. Bartlett, G. Douglas Campbell, Nathan C. Dean, Scott F. Dowell, Thomas M. File, Jr. Daniel M. Musher, Michael S. Niederman, Antonio Torres, and Cynthia G. Whitney McMaster University Medical School, Hamilton, Ontario, Canada; Northwestern University Feinberg School of Medicine, Chicago, Illinois; University of Texas Health Science Center and South Texas Veterans Health Care System, San Antonio, and Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine, Houston, Texas; Johns Hopkins University School of Medicine, Baltimore, Maryland; Division of Pulmonary, Critical Care, and Sleep Medicine, University of Mississippi School of Medicine, Jackson; Division of Pulmonary and Critical Care Medicine, LDS Hospital, and University of Utah, Salt Lake City, Utah; Centers for Disease Control and Prevention, Atlanta, Georgia; Northeastern Ohio Universities College of Medicine, Rootstown, and Summa Health System, Akron, Ohio; State University of New York at Stony Brook, Stony Brook, and Department of Medicine, Winthrop University Hospital, Mineola, New York; and Cap de Servei de Pneumologia i Allergia Respiratoria, Institut Clinic del Torax, Hospital Clinic de Barcelona, Facultat de Medicina, Universitat de Barcelona, Institut d’Investigacions Biomediques August Pi i Sunyer, CIBER CB06/06/0028, Barcelona, Spain.

/pdf/infectious-diseases-society-of-america-american-thoracic-1cn65eiqga.pdf

Infectious Diseases Society of America/American Thoracic Society Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults

Acute kidney injury (AKI) is a complex disorder for which currently there is no accepted definition. Having a uniform standard for diagnosing and classifying AKI would enhance our ability to manage these patients. Future clinical and translational research in AKI will require collaborative networks of investigators drawn from various disciplines, dissemination of information via multidisciplinary joint conferences and publications, and improved translation of knowledge from pre-clinical research. We describe an initiative to develop uniform standards for defining and classifying AKI and to establish a forum for multidisciplinary interaction to improve care for patients with or at risk for AKI. Members representing key societies in critical care and nephrology along with additional experts in adult and pediatric AKI participated in a two day conference in Amsterdam, The Netherlands, in September 2005 and were assigned to one of three workgroups. Each group's discussions formed the basis for draft recommendations that were later refined and improved during discussion with the larger group. Dissenting opinions were also noted. The final draft recommendations were circulated to all participants and subsequently agreed upon as the consensus recommendations for this report. Participating societies endorsed the recommendations and agreed to help disseminate the results. The term AKI is proposed to represent the entire spectrum of acute renal failure. Diagnostic criteria for AKI are proposed based on acute alterations in serum creatinine or urine output. A staging system for AKI which reflects quantitative changes in serum creatinine and urine output has been developed. We describe the formation of a multidisciplinary collaborative network focused on AKI. We have proposed uniform standards for diagnosing and classifying AKI which will need to be validated in future studies. The Acute Kidney Injury Network offers a mechanism for proceeding with efforts to improve patient outcomes.

Acute Kidney Injury Network: report of an initiative to improve outcomes in acute kidney injury

Objective: In 1991, the American College of Chest Physicians (ACCP) and the Society of Critical Care Medicine (SCCM) convened a "Consensus Conference", the goals of which were to provide a conceptual and a practical framework to define the systemic inflammatory response to infection, which is a progressive inju- rious process that falls under the gen- eralized term 'sepsis' and includes sepsis-associated organ dysfunction as well. The general definitions intro- duced as a result of that conference have been widely used in practice, and have served as the foundation for in- clusion criteria for numerous clinical trials of therapeutic interventions. Nevertheless, there has been an impe- tus from experts in the field to modify these definitions to reflect our current understanding of the pathophysiology of these syndromes. Design: Several North American and European inten- sive care societies agreed to revisit the definitions for sepsis and related con- ditions. This conference was spon- sored by the Society of Critical Care Medicine (SCCM), The European So-

2001 SCCM/ESICM/ACCP/ATS/SIS International Sepsis Definitions Conference

We investigated the influence of head-dependent positions upon functional residual capacity (FRC) and arterial oxygen saturation in 25 patients with clinically stable chronic air-flow obstruction and 25 normal subjects. Lung volume was measured by gas dilution in normal subjects and by plethysmography in patients with chronic obstructive pulmonary disease (COPD). Arterial oxygen saturation was determined by ear oximetry. In normal subjects, sitting FRC declined by 29.9% when a horizontal-supine posture was assumed, but underwent little further change as the supine subject was tilted head-downward to -25 degrees. Lateral decubitus positions caused declines from sitting FRC of 17.1% at 0 degrees, and 27.4% at -25 degrees. In contrast, patients with COPD experienced negligible changes in lung volume as position was varied. The mean falls from sitting FRC were 3.5% and 1.9% in the 0 degree supine and 0 degree lateral decubitus postures, respectively, and little further volume loss occurred in head-dependency. Eight patients actually increased FRC when recumbent. Positional lung volume changes measured by gas dilution exceeded those measured by plethysmography, suggesting that increased air trapping helped to maintain FRC as position was altered. Patients with COPD did not desaturate in any position tested. We conclude that patients with advanced COPD conserve lung volume and do not desaturate when tipped into head-dependent positions. Reduction of FRC is unlikely to contribute to the hypoxemia or dyspnea previously reported to occur in these patients during chest physiotherapy.

Influence of head-dependent positions on lung volume and oxygen saturation in chronic air-flow obstruction

https://journal.chestnet.org/article/S0012-3692(16)56182-0/pdf

Intermittent Mandatory Ventilation

based inhibitors of influenza virus replication. Nature. 1993;363:418-423. 18. Woods JM, Bethell RC, Coates JAV, et al. 4-Guanido-2,4-dideoxy-2,3-dehydroN-acetylneuraminic acid is a highly effective inhibitor both of sialidase (neuraminidase) and of growth of a wide range of influenza A and B viruses in vitro. Antimicrob Agents Chemother. 1993;37:1473-1479. 19. The MIST (Management of Influenza in the Southern Hemisphere Trialists) Study Group. Randomised trial of efficacy and safety of inhaled zanamivir in treatment of influenza A and B virus infections. Lancet. 1998;352:1877-1881. 20. Hayden FG, Osterhaus ADME, Treanor JJ, et al. Efficacy and safety of the neuraminidase inhibitor zanamivir in the treatment of influenzavirus infections. N Engl J Med. 1997;337:874-880. 21. Gubareva LV, Mastrosovish MN, Brenner MK, Bethell RC, Webster RG. Evidence for zanamivir resistance in an immunocompromised child infected with influenza B virus. J Infect Dis. 1998;178:1257-1262. 22. Kilbourne ED. Influenza: viral determinants of the pathogenicity and epidemicity of an invariant disease of variable occurrence. Philos Trans R Soc Lond. 1980; B228:291-297.

Progress in Understanding Ventilator-Induced Lung Injury

Little is known about the mechanisms through which intensivist physician staffing influences patient outcomes. We aimed to assess the effect of closed-model intensive care on evidence-based ventilatory practice in patients with acute lung injury (ALI). We conducted a secondary analysis of a prospective population-based cohort of 759 patients with ALI who were alive and ventilated on day three of ALI, and were cared for in 23 intensive care units (ICUs) in King County, Washington. We compared day three tidal volume (VT) in open versus closed ICUs adjusting for potential patient and ICU confounders. In 13 closed model ICUs, 429 (63%) patients were cared for. Adjusted mean VT (mL/Kg predicted body weight (PBW) or measured body weight if height not recorded) for patients in closed ICUs was 1.40 mL/Kg PBW (95% confidence interval (CI) = 0.57 to 2.24 mL/Kg PBW) lower than patients in open model ICUs. Patients in closed ICUs were more likely (odds ratio (OR) = 2.23, 95% CI = 1.09 to 4.56) to receive lower VT (≤ 6.5 mL/Kg PBW) and were less likely (OR = 0.30, 95% CI = 0.17 to 0.55) to receive a potentially injurious VT (≥ 12 mL/Kg PBW) compared with patients cared for in open ICUs, independent of other covariates. The effect of closed ICUs on hospital mortality was not changed after accounting for delivered VT. Patients with ALI cared for in closed model ICUs are more likely to receive lower VT and less likely to receive higher VT, but there were no other differences in measured processes of care. Moreover, the difference in delivered VT did not completely account for the improved mortality observed in closed model ICUs.

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The effect of an intensive care unit staffing model on tidal volume in patients with acute lung injury

Steroids have no positive influence upon pulmonary related morbidity and mortality following combined smoke inhalation and thermal cutaneous injury (3, 4). Steroid administration following isolated smoke inhalation without concomitant thermal cutaneous injury has, however, been shown to have beneficial effects in previous animal studies (1). This potential therapeutic approach to treatment has not been examined in the clinical setting. Recent hotel fires in Las Vegas, Nevada, resulted in a large cohort of individuals with similar smoke exposures without associated injuries. Two of four hospitals in the triage system administered steroids following injury. Patients were divided into two groups, a steroid-treated, and a non-treated group. These groups were compared using multivariate and frequency analyses. There were no detectable differences in sex, signs, symptoms, and previous medical history. There were likewise no differences between groups with respect to oxyhemoglobin saturation, arterial oxygen tension, arterial pH, and pulmonary-related morbidity and mortality. These data suggest that steroid coverage has little beneficial effect upon pulmonary-related morbidity and mortality following isolated smoke inhalation injury.

Leonard D. Hudson

Papers

Influence of head-dependent positions on lung volume and oxygen saturation in chronic air-flow obstruction

Intermittent Mandatory Ventilation

Progress in Understanding Ventilator-Induced Lung Injury

The effect of an intensive care unit staffing model on tidal volume in patients with acute lung injury

Steroid therapy following isolated smoke inhalation injury.