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SERIES “ATS/ERS TASK FORCE: STANDARDISATION OF LUNG FUNCTION TESTING” 

Edited by V. Brusasco, R. Crapo and G. Viegi 

Number 2 in this Series

 [1]: #F13

/pdf/standardisation-of-spirometry-1dkqxgifvl.pdf

Standardisation of spirometry

Background Traditional approaches to mechanical ventilation use tidal volumes of 10 to 15 ml per kilogram of body weight and may cause stretch-induced lung injury in patients with acute lung injury and the acute respiratory distress syndrome. We therefore conducted a trial to determine whether ventilation with lower tidal volumes would improve the clinical outcomes in these patients. Methods Patients with acute lung injury and the acute respiratory distress syndrome were enrolled in a multicenter, randomized trial. The trial compared traditional ventilation treatment, which involved an initial tidal volume of 12 ml per kilogram of predicted body weight and an airway pressure measured after a 0.5-second pause at the end of inspiration (plateau pressure) of 50 cm of water or less, with ventilation with a lower tidal volume, which involved an initial tidal volume of 6 ml per kilogram of predicted body weight and a plateau pressure of 30 cm of water or less. The primary outcomes were death before a patient was discharged home and was breathing without assistance and the number of days without ventilator use from day 1 to day 28. Results The trial was stopped after the enrollment of 861 patients because mortality was lower in the group treated with lower tidal volumes than in the group treated with traditional tidal volumes (31.0 percent vs. 39.8 percent, P=0.007), and the number of days without ventilator use during the first 28 days after randomization was greater in this group (mean [+/-SD], 12+/-11 vs. 10+/-11; P=0.007). The mean tidal volumes on days 1 to 3 were 6.2+/-0.8 and 11.8+/-0.8 ml per kilogram of predicted body weight (P Conclusions In patients with acute lung injury and the acute respiratory distress syndrome, mechanical ventilation with a lower tidal volume than is traditionally used results in decreased mortality and increases the number of days without ventilator use.

Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome.

According to W. Edwards Deming, American companies require nothing less than a transformation of management style and of governmental relations with industry. In Out of the Crisis, originally published in 1982, Deming offers a theory of management based on his famous 14 Points for Management. Management's failure to plan for the future, he claims, brings about loss of market, which brings about loss of jobs. Management must be judged not only by the quarterly dividend, but by innovative plans to stay in business, protect investment, ensure future dividends, and provide more jobs through improved product and service. In simple, direct language, he explains the principles of management transformation and how to apply them.

Out of the Crisis

Objective:To provide an update to the “Surviving Sepsis Campaign Guidelines for Management of Severe Sepsis and Septic Shock,” last published in 2008.Design:A consensus committee of 68 international experts representing 30 international organizations was convened. Nominal groups were assembled at ke

Surviving sepsis campaign: international guidelines for management of severe sepsis and septic shock: 2012.

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.

Rationale: Current guidelines recommend using forced expiratory volume in 1 second (FEV1) % predicted to categorize the severity of airflow obstruction. There are limitations to using FEV1 % predic...

https://www.atsjournals.org/doi/pdf/10.1513/AnnalsATS.201802-104OC

Airflow Obstruction Categorization Methods and Mortality

Long-term radio frequency scar behavior after ablation of atrial fibrillation: lessons learned from LGE-MRI analysis

relate with measures of central cardiovascular function (8, 9). The finding that StO2 varies by location even within the same patient does raise important questions of standardization and generalization of StO2 measurement in the management of shock. Critical aspects of near-infrared spectroscopy measurement include not only the location, but also the measurement probe characteristics and the mathematical algorithm used to calculate the StO2. In the present study, Colin and colleagues used a near-infrared spectroscopy probe with a 25-mm depth. It is not known if other commercially available probes with 15-mm depths will produce the same results. For StO2 measurement to become broadly applied in sepsis management, standardization of equipment and technique must be achieved. A significant potential advantage of tissue StO2 measurement for prognostication and as a therapeutic monitor is that it does not carry the risks, time, and expense of central venous catheter placement. Colin and colleagues have shown that masseter StO2 may rapidly and noninvasively identify sepsis patients with superior vena cava oxygen saturation 70%. These results in combination with previously published results offer the possibility for clinicians to combine both central hemodynamic as well as microcirculatory factors to develop individualized treatment plans. However, before any monitor can be considered truly valuable in the management of shock or sepsis, it must be shown to be consistent over time, characterized in a broad range of patient populations, and responsive to the success or failure of treatment. Interpretation of the test results should be directly related to meaningful, patient-centered outcomes. Finally, because our management of sepsis remains imperfect, the ideal clinical patient monitoring technique should provide additional insight into the pathophysiology of the disease and suggest new avenues for treatment. Masseter muscle StO2 measurement has not yet achieved this status, but it certainly gives us something to chew on. Karl Thomas, MD Kevin Doerschug, MD Division of Pulmonary and Critical Care Medicine University of Iowa Carver College of Medicine Iowa City, IA

Standardizing self-reported surveys in critical care: a good idea.

As applications scale to ever increasing numbers of processors, there is a growing awareness that high-end performance evaluation and tuning requires holistic program analysis. In addition to CPU performance characterization, observation of memory, network, and input/output (I/O) performance can help to understand how all these factors contribute to the overall performance observed. As our performance observation requirements evolve, our performance observation tools and techniques need to keep pace with the new challenges and evolve to answer the key performance questions that developers request. One such question was to provide tools to evaluate and observe I/O in a given code region or phase. This paper describes our experience in extending the modular and extensible tuning and analysis utilities (TAU) performance systemreg to incorporate direct source-level code instrumentation for tracking static and dynamic phases in C, C++, and FORTRAN. We describe the design and implementation of a new wrapper interposition library to track POSIX I/O calls to determine the extent, source, and volume of I/O performed. By coupling these two components, we can now answer questions that correlate application phase performance with I/O performance. We report on results and experiences in applying these new phase and I/O observation capabilities in TAU to the CFDShip-IOWA and STRIPE applications. The information contained in this paper was obtained from open sources.

Alan H. Morris

Papers

Airflow Obstruction Categorization Methods and Mortality

Long-term radio frequency scar behavior after ablation of atrial fibrillation: lessons learned from LGE-MRI analysis

Standardizing self-reported surveys in critical care: a good idea.

Observing Parallel Phase and I/O Performance Using TAU

Guideline adoption: a slow process.