Respiratory Microbiome Disruption and Risk for Ventilator-Associated Lower Respiratory Tract Infection.

BACKGROUND: Ventilator-associated lower respiratory tract infection (VA-LRTI) is common among critically ill patients and has been associated with increased morbidity and mortality. In acute critical illness, respiratory microbiome disruption indices (MDIs) have been shown to predict risk for VA-LRTI, but their utility beyond the first days of critical illness is unknown. We sought to characterize how MDIs previously shown to predict VA-LRTI at initiation of mechanical ventilation change with prolonged mechanical ventilation, and if they remain associated with VA-LRTI risk. METHODS: We developed a cohort of 83 subjects admitted to a long-term acute care hospital due to their prolonged dependence on mechanical ventilation; performed dense, longitudinal sampling of the lower respiratory tract, collecting 1066 specimens; and characterized the lower respiratory microbiome by 16S rRNA sequencing as well as total bacterial abundance by 16S rRNA quantitative polymerase chain reaction. RESULTS: Cross-sectional MDIs, including low Shannon diversity and high total bacterial abundance, were associated with risk for VA-LRTI, but associations had wide posterior credible intervals. Persistent lower respiratory microbiome disruption showed a more robust association with VA-LRTI risk, with each day of (base e) Shannon diversity <2.0 associated with a VA-LRTI odds ratio of 1.36 (95% credible interval, 1.10-1.72). The observed association was consistent across multiple clinical definitions of VA-LRTI. CONCLUSIONS: Cross-sectional MDIs have limited ability to discriminate VA-LRTI risk during prolonged mechanical ventilation, but persistent lower respiratory tract microbiome disruption, best characterized by consecutive days with low Shannon diversity, may identify a population at high risk for infection and may help target infection-prevention interventions.

Functional Outcomes, Goals, and Goal Attainment among Chronically Critically Ill Long-Term Acute Care Hospital Patients.

Rationale: Chronically critically ill patients admitted to a long-term acute care hospital (LTACH) setting are a vulnerable population of intensive care unit (ICU) survivors. Little is known of the goals and functional outcomes achieved by patients after rehabilitation in the LTACH setting. Objectives: We sought to examine patient goals and functional outcomes, including swallowing function, among ICU survivors admitted to an LTACH with a tracheostomy. Methods: This was a prospective observational cohort study of chronic critically ill LTACH patients. Results: Fifty older subjects with a median duration of intubation before tracheostomy of 13 days were enrolled. ICU-acquired weakness and cognitive impairment were present in 40 (80%) and 36 (72%) patients, as measured by the Medical Research Council scale and Montreal Cognitive Assessment, respectively. Mental health problems were also common, with 16 (32%) patients experiencing moderate to severe anxiety, 9 (18%) experiencing moderate to severe depression, and 11 (22%) reporting symptoms consistent with post-traumatic stress disorder, according to the Hospital Anxiety and Depression Scale and Post-Traumatic Stress Syndrome 10-Questions Inventory, respectively. Pharyngeal dysfunction, as measured by Fiberoptic Endoscopic Evaluation of Swallow examination, was present in 37 (74%) patients. Patient goals, in decreasing order of frequency, included eating and drinking, speaking, walking, returning home, and toileting. By LTACH discharge, goal attainment was variable, with 97% of those who ranked speaking as important being able to speak and 88% of those who ranked eating and drinking as important being able to eat and drink but with only 21% being able to walk and only 18% being able to self-toilet. Discharge to the home or acute rehabilitation setting, achieved in 52% of the population, was associated with greater strength, as measured by the total Medical Research Council score (P = 0.002) as well as by the European 5-dimension, 5-level health-related quality of life instrument domains of mobility (P = 0.008) and self-care (P = 0.04). Conclusions: Goal attainment during this period of recovery was variable. The ability to speak, eat, and drink, frequently identified as goals by these patients, were achieved, whereas functional goals such as walking were rarely achieved. These findings highlight the importance of identifying patient goals and setting realistic expectations informed by functional assessments when rehabilitating this vulnerable patient population in the LTACH and subsequent post-acute care settings.

Impact of the new ATS/ERS pulmonary function test interpretation guidelines.

RATIONALE: In November 2005, the American Thoracic and European Respiratory Societies jointly published a statement proposing a new interpretation scheme for pulmonary function tests. The practical effect of adoption of these new guidelines has not yet been studied. The purpose of the current study was to address the effects of the new interpretation strategy on the relative distribution of obstructive and restrictive diagnoses in patients evaluated at a single academic medical center laboratory. PATIENTS/METHODS: Pulmonary functions tests from 319 patients were analyzed according to four different interpretation schemes. The number of patients classified according to each as obstructed, restricted, neither, or both were compared, and factors associated with a change in classification using the different approaches were examined. RESULTS: Although similar proportions of patients were identified as restricted using either the "GOLD" scheme (23%) or new approaches (22%), significantly more (P<0.005) were defined as obstructed using the newly proposed scheme (44% versus 33%). Additionally, 36% of subjects defined as obstructed using either the traditional or new schemes were classified differently (i.e., either "gained" or "lost" the diagnosis of obstruction) using the new approach. Women were significantly more likely than men to have a change in classification. CONCLUSIONS: The new interpretation scheme leads to a diagnosis of obstruction in a greater proportion of patients undergoing pulmonary function testing. The clinical significance of this finding has not yet been validated, and its economic impact remains to be assessed.

Medical Subspecialty Textbooks in the 21st Century. Essential or Headed for Extinction?

In recent years, the role of medical subspecialty textbooks as sources of information for students, trainees, and practicing clinicians has been challenged. Although the structure of textbooks continues to evolve from standard, printed versions to digital formats, including e-books and online texts, we maintain that the authoritative compilation of clinical and scientific material by experts in the field (i.e., a modern-day textbook) remains central to the education, training, and practice of subspecialists. Regardless of format, an effective medical subspecialty textbook is authoritative, comprehensive, and integrated in its coverage of the subject. Textbook content represents a unique synthesis of clinical and scientific material of real educational and clinical value. Incorporation of illustrations, including figures, tables, videos, and audios, bolsters the presentation and further solidifies the reader's understanding of the subject. The textbook, both printed and digital, reinforces the many widely available online resources and serves as a platform from which to evaluate other sources of information and to launch additional scientific and clinical inquiry.