Mapping physicians' admission diagnoses to structured concepts towards fully automatic calculation of acute physiology and chronic health evaluation score.

Objective Acute Physiology and Chronic Health Evaluation (APACHE) is most widely used as a mortality prediction score in US intensive care units (ICUs), but its calculation is onerous. The authors aimed to develop and validate automatic mapping of physicians' admission diagnoses to structured concepts for automated APACHE IV calculation. Methods This retrospective study was conducted in medical ICUs of a tertiary healthcare and academic centre. Boolean-logic text searches were used to map admission diagnoses, and these were compared with conventional APACHE database entry by bedside nurses and a gold-standard physician chart review. The primary outcome was APACHE IV predicted hospital mortality. The tool was developed in a larger cohort of ICU patients. Results In a derivation cohort of 192 consecutive critically ill patients, the diagnosis coefficient coded by three different methods had a positive correlation, highest between manual and gold standard (r(2)=0.95; mean square error (MSE)=0.040) and least between manual and automatic tool (r(2)=0.88; MSE=0.066). The automatic tool had an area under the curve (95% CI) value of 0.82 (0.74 to 0.90) which was similar to the physician gold standard, 0.83 (0.75 to 0.91) and standard manual entry, 0.81 (0.73 to 0.89). The Hosmer-Lemeshow goodness-of-fit test demonstrated good calibration of automatically calculated APACHE IV score (χ(2)=6.46; p=0.6). The automatic tool demonstrated excellent discrimination with an area under the curve value of 0.87 (95% CI 0.83 to 0.92) and good calibration (p=0.58) in the validation cohort of 593 patients. Conclusion A Boolean-logic text search is an efficient alternative to manual database entry for mapping of ICU admission diagnosis to structured APACHE IV concepts.

Towards the prevention of acute lung injury: a population based cohort study protocol.

BACKGROUND: Acute lung injury (ALI) is an example of a critical care syndrome with limited treatment options once the condition is fully established. Despite improved understanding of pathophysiology of ALI, the clinical impact has been limited to improvements in supportive treatment. On the other hand, little has been done on the prevention of ALI. Olmsted County, MN, geographically isolated from other urban areas offers the opportunity to study clinical pathogenesis of ALI in a search for potential prevention targets. METHODS/DESIGN: In this population-based observational cohort study, the investigators identify patients at high risk of ALI using the prediction model applied within the first six hours of hospital admission. Using a validated system-wide electronic surveillance, Olmsted County patients at risk are followed until ALI, death or hospital discharge. Detailed in-hospital (second hit) exposures and meaningful short and long term outcomes (quality-adjusted survival) are compared between ALI cases and high risk controls matched by age, gender and probability of developing ALI. Time sensitive biospecimens are collected for collaborative research studies. Nested case control comparison of 500 patients who developed ALI with 500 matched controls will provide an adequate power to determine significant differences in common hospital exposures and outcomes between the two groups. DISCUSSION: This population-based observational cohort study will identify patients at high risk early in the course of disease, the burden of ALI in the community, and the potential targets for future prevention trials.

Diabetes mellitus does not adversely affect outcomes from a critical illness.

OBJECTIVE: Chronic diabetes mellitus (DM) is a known cause of multisystem injury. The effect of DM in acute critical illness may also be detrimental, but is not specifically known. We hypothesized that the preexisting diagnosis of DM is an independent risk factor for mortality in critically ill patients. DESIGN: Parallel retrospective and prospective cohort study. SETTING: Two large patient datasets were used: the retrospective University HealthSystem Consortium database (UHC) and the prospective Mayo Clinic Acute Physiology And Chronic Health Evaluation III critical care database (Mayo). PATIENTS: Inclusion criteria were admission to an intensive care unit and age > or =18 yrs. Patients with diabetic ketoacidosis or hyperosmolar nonketotic coma were excluded. A total of 1,509,890 patients (including 143,078 deaths) in the UHC cohort and 36,414 patients (including 3562 deaths) in the Mayo cohort were included in the study analysis. MEASUREMENTS AND MAIN RESULTS: The primary outcome was in-hospital mortality compared between patients with a history of DM and all other patients. Other outcomes included in-hospital mortality in prespecified subgroups. In the UHC dataset, patients with DM had a lower unadjusted odds ratio (0.90, 95% confidence interval 0.89-0.91, p < .001) and a lower adjusted effect on mortality (odds ratio 0.75, 0.74-0.76, p < .001) compared with that seen in patients without DM. In the Mayo dataset, patients with DM had a comparable unadjusted odds ratio (1.07, 0.97-1.17, p = NS) and a lower adjusted effect on mortality (odds ratio 0.88, 0.79-0.98, p = .022) compared with that seen in patients without DM. A lower mortality in diabetic patients held across multiple demographic subgroups, including patients who underwent coronary-artery bypass grafting (UHC data: unadjusted odds ratio 0.66, 0.62-0.71, p < .001). CONCLUSIONS: Critically ill adults with DM do not have an increased mortality compared with that seen in patients without DM, and may have a decreased mortality. Further investigation needs to be done to determine the mechanism for this effect.

Alcohol consumption and development of acute respiratory distress syndrome: a population-based study.

This retrospective population-based study evaluated the effects of alcohol consumption on the development of acute respiratory distress syndrome (ARDS). Alcohol consumption was quantified based on patient and/or family provided information at the time of hospital admission. ARDS was defined according to American-European consensus conference (AECC). From 1,422 critically ill Olmsted county residents, 1,357 had information about alcohol use in their medical records, 77 (6%) of whom developed ARDS. A history of significant alcohol consumption (more than two drinks per day) was reported in 97 (7%) of patients. When adjusted for underlying ARDS risk factors (aspiration, chemotherapy, high-risk surgery, pancreatitis, sepsis, shock), smoking, cirrhosis and gender, history of significant alcohol consumption was associated with increased risk of ARDS development (odds ratio 2.9, 95% CI 1.3-6.2). This population-based study confirmed that excessive alcohol consumption is associated with higher risk of ARDS.