The Frequency of White Blood Cell and Temperature Events During Mechanical Ventilation and Their Association With Ventilator-Associated Events.

BACKGROUND: Changes in white blood cell (WBC) counts and/or temperature could have important implications in patients on ventilators, but the frequency of these events is uncertain. METHODS: We reviewed the medical records from 281 ventilation episodes in our medical intensive care unit to determine patient characteristics and the indications for ventilation. We determined the number of days during each ventilation episode in which the temperature (<96.8°F, >100.4°F) or WBC count (<4000/µL, >12 000/µL) was out of the normal range. RESULTS: This study included 257 patients with a mean Acute Physiology and Chronic Health Evaluation 2 score of 13.5 ± 5.9 and a mean initial Pao2/Fio2 of 210 ± 110. The median number of ventilator days was 4 (interquartile range, 3-9). One hundred ninety-six of 275 eligible ventilator episodes (71.3%) had 1 or more temperature events, and 194 of 253 eligible ventilator episodes (76.7%) had 1 or more WBC events. Nineteen patients met the Center for Disease Control criteria for a ventilator-associated event (VAE). Twelve patients had an increased WBC count during the VAE period, and 11 had an increased temperature during this period. CONCLUSIONS: White blood cell counts and temperature events occur frequently in patients on ventilators and need evaluation but do not reliably identify patients with ventilator-associated complications.

Peak Pressures and PaO2/FiO2 Ratios Are Associated With Adverse Outcomes in Patients on Mechanical Ventilators.

BACKGROUND: Patients requiring mechanical ventilation can have complications related to their underlying diseases and hospital-related events. It is possible that easily obtained information early in the course of mechanical ventilation can provide information about important outcomes. METHODS: Medical records from 281 episodes of mechanical ventilation in the medical intensive care unit were reviewed to collect information on patient demographics, admitting diagnoses, laboratory tests, duration of mechanical ventilation, the development of ventilator-associated events and mortality. Ventilator pressures from day 2 were analyzed for this study. RESULTS: Most patients (72.7%) were ≥50 years, 53.8% were men and 66.3% had a body mass index (BMI) ≥ 25kg/m(2).The mean Acute Physiology and Chronic Healthy Evaluation II score was 13.6 ± 5.9. The median initial PaO2/FiO2 was 240 with interquartile range of 177-414. The median duration of ventilation was 4 days (interquartile range: 2-9 days). A PaO2/FiO2 ratio < 100 was associated with increased mortality compared with PaO2/FiO2 ratio > 500, and a BMI > 30kg/m(2) was associated with decreased mortality compared with normal BMIs. A PaO2/FiO2 ratio < 100 and BMIs <18.5kg/m(2) or >30kg/m(2) were all associated with having a ventilator-associated event. There was a positive correlation between peak pressure (day 2) and the duration of ventilation (r = 0.263, P = 0.007). CONCLUSIONS: Easily available information collected on day 2 of mechanical ventilation can help identify patients at risk for poor outcomes, including the duration of mechanical ventilation, the development of ventilator-associated complications and mortality. Prospective studies measuring peak pressures are needed to evaluate the utility of this simple measurement in the management of patients requiring mechanical ventilation.

Frequency and Etiology of Ventilator-Associated Events in the Medical Intensive Care Unit.

BACKGROUND: The Centers for Disease Control and Prevention (CDC) has developed new criteria based on a significant deterioration in oxygenation to identify ventilator-associated events (conditions). The aim of this study was to determine how frequently this happened and what caused these conditions. METHODS: Electronic medical records and x-rays from 281 ventilator episodes in the medical intensive care unit were reviewed to determine the characteristics of patients requiring ventilation and the number of patients meeting the criteria for ventilator-associated conditions (VACs). RESULTS: This cohort included 257 patients (55.4% men) who required 281 episodes of mechanical ventilation. The mean Acute Physiology and Chronic Healthy Evaluation II score was 13.5 ± 5.9. The initial mean PaO2/FiO2 was 210 ± 110. The median number of ventilator days was 4 (interquartile range: 3-9). The overall mortality was 32.3%. Nineteen patients (11.7% of eligible episodes) met the CDC criteria for a VAC; 6 met FiO2 criteria (31.6%) and 13 met positive end expiratory pressure criteria (68.4%). Twelve patients (63.2%) had an increased white blood cell count (>12k/µL) during the event. Eleven patients had an increase in temperature (>38°C) during this period. The etiology of these conditions included pneumonia (n = 4), atelectasis (n = 4), congestive heart failure (n = 5), acute respiratory distress syndrome (n = 2), and miscellaneous reasons (n = 4). CONCLUSIONS: VACs occurred in 11.7% of patients in our medical intensive care unit. The etiology of these events was diverse and did not usually reflect complications. These new CDC criteria for institutional reporting of complications during mechanical ventilation do not necessarily identify complications or provide a good method for comparing outcomes in hospitals.

Environmental DNA sequencing primers for eutardigrades and bdelloid rotifers.

BACKGROUND: The time it takes to isolate individuals from environmental samples and then extract DNA from each individual is one of the problems with generating molecular data from meiofauna such as eutardigrades and bdelloid rotifers. The lack of consistent morphological information and the extreme abundance of these classes makes morphological identification of rare, or even common cryptic taxa a large and unwieldy task. This limits the ability to perform large-scale surveys of the diversity of these organisms.Here we demonstrate a culture-independent molecular survey approach that enables the generation of large amounts of eutardigrade and bdelloid rotifer sequence data directly from soil. Our PCR primers, specific to the 18s small-subunit rRNA gene, were developed for both eutardigrades and bdelloid rotifers. RESULTS: The developed primers successfully amplified DNA of their target organism from various soil DNA extracts. This was confirmed by both the BLAST similarity searches and phylogenetic analyses. Tardigrades showed much better phylogenetic resolution than bdelloids. Both groups of organisms exhibited varying levels of endemism. CONCLUSION: The development of clade-specific primers for characterizing eutardigrades and bdelloid rotifers from environmental samples should greatly increase our ability to characterize the composition of these taxa in environmental samples. Environmental sequencing as shown here differs from other molecular survey methods in that there is no need to pre-isolate the organisms of interest from soil in order to amplify their DNA. The DNA sequences obtained from methods that do not require culturing can be identified post-hoc and placed phylogenetically as additional closely related sequences are obtained from morphologically identified conspecifics. Our non-cultured environmental sequence based approach will be able to provide a rapid and large-scale screening of the presence, absence and diversity of Bdelloidea and Eutardigrada in a variety of soils.

Inaccessible information is useless information: addressing the knowledge gap.

The burdens of increasing information overload, time constraints, and the high human and financial costs of medical error, mean that doctors cannot practice high quality evidence-based medicine without the aid of decision support systems at the point of care. The physician's role is to formulate a management plan based on clinical judgment, the patient's unique circumstances and preferences, and the best available evidence. Clineguide is a clinical knowledge system that will integrate into the workflow to improve patient outcomes, reduce variability of care, and promote efficiency in the health care process. This article discusses some of the issues surrounding the provision of rapid, accurate, and accessible information to health care professionals.