Executive Summary: Diagnosis and Evaluation of Hypersensitivity Pneumonitis: CHEST Guideline and Expert Panel Report.

BACKGROUND: The purpose of this summary is to provide a synopsis of evidence-based and consensus-derived guidance for clinicians to improve individual diagnostic decision-making for hypersensitivity pneumonitis (HP) and decrease diagnostic practice variability. STUDY DESIGN AND METHODS: Approved panelists developed key questions regarding the diagnosis of HP using the PICO (Population, Intervention, Comparator, and Outcome) format. MEDLINE (via PubMed) and the Cochrane Library were systematically searched for relevant literature, which was supplemented by manual searches. References were screened for inclusion and vetted evaluation tools were used to assess the quality of included studies, to extract data, and to grade the level of evidence supporting each recommendation or statement. The quality of the evidence was assessed using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach. Graded recommendations and ungraded consensus-based statements were drafted and voted on using a modified Delphi technique to achieve consensus. RESULTS: The systematic review of the literature based on 14 PICO questions resulted in 14 key action statements: 12 evidence-based, graded recommendations, and 2 ungraded consensus-based statements. All evidence was of very low quality. INTERPRETATION: Diagnosis of HP should employ a patient-centered approach and include a multidisciplinary assessment that incorporates the environmental and occupational exposure history and CT pattern to establish diagnostic confidence prior to considering BAL and/or lung biopsy. Additional research is needed on the performance characteristics and generalizability of exposure assessment tools and traditional and new diagnostic tests in modifying clinical decision-making for HP, particularly among those with a provisional diagnosis.

Diagnosis and Evaluation of Hypersensitivity Pneumonitis: CHEST Guideline and Expert Panel Report.

BACKGROUND: The purpose of this analysis is to provide evidence-based and consensus-derived guidance for clinicians to improve individual diagnostic decision-making for hypersensitivity pneumonitis (HP) and decrease diagnostic practice variability. STUDY DESIGN AND METHODS: Approved panelists developed key questions regarding the diagnosis of HP using the PICO (Population, Intervention, Comparator, Outcome) format. MEDLINE (via PubMed) and the Cochrane Library were systematically searched for relevant literature, which was supplemented by manual searches. References were screened for inclusion, and vetted evaluation tools were used to assess the quality of included studies, to extract data, and to grade the level of evidence supporting each recommendation or statement. The quality of the evidence was assessed using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach. Graded recommendations and ungraded consensus-based statements were drafted and voted on using a modified Delphi technique to achieve consensus. A diagnostic algorithm is provided, using supporting data from the recommendations where possible, along with expert consensus to help physicians gauge the probability of HP. RESULTS: The systematic review of the literature based on 14 PICO questions resulted in 14 key action statements: 12 evidence-based, graded recommendations and 2 ungraded consensus-based statements. All evidence was of very low quality. INTERPRETATION: Diagnosis of HP should employ a patient-centered approach and include a multidisciplinary assessment that incorporates the environmental and occupational exposure history and CT pattern to establish diagnostic confidence prior to considering BAL and/or lung biopsy. Criteria are presented to facilitate diagnosis of HP. Additional research is needed on the performance characteristics and generalizability of exposure assessment tools and traditional and new diagnostic tests in modifying clinical decision-making for HP, particularly among those with a provisional diagnosis.

Making the GRADE: CHEST Updates Its Methodology.

The American College of Chest Physicians (CHEST) has been at the forefront of evidence-based clinical practice guideline development for more than 2 decades. In 2006, CHEST adopted a modified system of Grading of Recommendations Assessment, Development, and Evaluation (GRADE) to support their rigorous guideline development methodology. The evolution of CHEST's Living Guidelines Model, as well as their collaborative efforts with other organizations, has necessitated improvements in their guideline development methodology. CHEST has made the decision to transition to the standard GRADE method for rating the certainty of evidence and grading recommendations in their evidence-based clinical practice guidelines, a deviation from the modified approach that was adopted in 2006. The standard GRADE approach will be used to grade recommendations in all CHEST guidelines, including updates to previously published guidelines. CHEST's adoption of a standard GRADE approach will ensure that its guideline development methodology is more consistent with that used by other organizations, will better align evidence synthesis methods, and will result in more explicit and easy to understand recommendations.

Ventilation of patients with acute lung injury and acute respiratory distress syndrome: has new evidence changed clinical practice?

OBJECTIVES: A recent randomized trial of mechanical ventilation in acute lung injury (ALI)/adult respiratory distress syndrome (ARDS) demonstrated a 22% relative reduction in mortality rate using 6 mL/kg predicted body weight tidal volume vs. 12 mL/kg predicted body weight tidal volume. We determined whether publication of these findings changed clinical practice. DESIGN: Retrospective cohort, 12 months before (Pre) and 12 months after publication (Post) of a randomized trial supporting the use of a 6 mL/kg predicted body weight tidal volume strategy. SETTING: Three tertiary care hospitals in northern New England. PATIENTS: From a sample of 943 patients receiving prolonged mechanical ventilation between 1998 and 1999 (Pre) and between 2000 and 2001 (Post), 300 patients meeting the American-European Consensus Conference definition of ALI or ARDS were selected for analysis. INTERVENTIONS: The tidal volume, tidal volume/kg predicted body weight, and proportion receiving tidal volume/kg > or =6 mL/kg and < or =12 mL/kg predicted body weight were recorded at noon the first day after the diagnosis of ALI or ARDS was established. MEASUREMENTS AND MAIN RESULTS: Pre and Post mean tidal volume (+/- sd) size and tidal volume size/kg predicted body weight were 759 +/- 158 mL (median 750 mL) vs. 639 +/- 138 mL (median 600 mL, p <.001) and 12.3 +/- 2.7 mL/kg (median 11.7 mL/kg) vs. 10.6 +/- 2.4 mL/kg (median 10.7 mL/kg, p <.001) respectively. Pre and Post plateau pressures and peak airway pressures were similar. CONCLUSION: Publication of a trial demonstrating large mortality reductions using small tidal volume was associated with significant reductions in tidal volume delivered to patients with ALI/ARDS. However, wide variation in practice persists, and the proportion of patients receiving tidal volumes within recommended limits (< or =8 mL/kg) remains modest.