Effects of Electrolyte Replacement Protocol Implementation in a Medical Intensive Care Unit.

PURPOSE: To evaluate the effects of electrolyte replacement protocol (ERP) implementation in the medical intensive care unit (MICU) setting. We hypothesized that a protocol would reduce the time of replacement dose administration and increase provider satisfaction with the process of electrolyte replacement. METHODS: This was a retrospective review of electronic medical record data before and after implementation of a standardized ERP in an 18-bed military tertiary care MICU. RESULTS: Median time from abnormal laboratory result to time of documented dose administration for potassium decreased from 180 to 98 minutes ( P < .01), phosphorus decreased from 190 to 135 minutes ( P < .01), calcium decreased from 95 to 61 minutes ( P < .01), and magnesium decreased from 155 to 149 minutes ( P < .01). Overall, there was a significant reduction in time to electrolyte repletion from 146 to 98 minutes ( P < .01) for all electrolytes. Nursing satisfaction for autonomy, timeliness, effectiveness, and the need to seek orders was all improved ( P < .01), and physicians saved 4.4 minutes/patient/day ( P = .04). CONCLUSIONS: Electrolyte replacement protocols can be safely implemented in the MICU and reduce the time from abnormal laboratory result to electrolyte replacement dose administration. They can improve provider satisfaction and reduce physician time with the process of electrolyte replacement.

Diagnostic accuracy of a novel software technology for detecting pneumothorax in a porcine model.

INTRODUCTION: Our objective was to measure the diagnostic accuracy of a novel software technology to detect pneumothorax on Brightness (B) mode and Motion (M) mode ultrasonography. METHODS: Ultrasonography fellowship-trained emergency physicians performed thoracic ultrasonography at baseline and after surgically creating a pneumothorax in eight intubated, spontaneously breathing porcine subjects. Prior to pneumothorax induction, we captured sagittal M-mode still images and B-mode videos of each intercostal space with a linear array transducer at 4cm of depth. After collection of baseline images, we placed a chest tube, injected air into the pleural space in 250mL increments, and repeated the ultrasonography for pneumothorax volumes of 250mL, 500mL, 750mL, and 1000mL. We confirmed pneumothorax with intrapleural digital manometry and ultrasound by expert sonographers. We exported collected images for interpretation by the software. We treated each individual scan as a single test for interpretation by the software. RESULTS: Excluding indeterminate results, we collected 338M-mode images for which the software demonstrated a sensitivity of 98% (95% confidence interval [CI] 92-99%), specificity of 95% (95% CI 86-99), positive likelihood ratio (LR+) of 21.6 (95% CI 7.1-65), and negative likelihood ratio (LR-) of 0.02 (95% CI 0.008-0.046). Among 364 B-mode videos, the software demonstrated a sensitivity of 86% (95% CI 81-90%), specificity of 85% (81-91%), LR+ of 5.7 (95% CI 3.2-10.2), and LR- of 0.17 (95% CI 0.12-0.22). CONCLUSIONS: This novel technology has potential as a useful adjunct to diagnose pneumothorax on thoracic ultrasonography.

The impact of ultraviolet radiation on sunburn-related search activity.

We establish a strong, positive relationship between the Ultraviolet Index and Google search engine activity for sunburn-related terms in the United States. Using the Google Trends utility and data available from the National Weather service, we combine data from a twelve-year period to produce panel data for each state. We fit a time-series regression model of search activity and perform statistical tests on the resulting parameter estimates. This study lays the groundwork for using search-related data to assess the prevalence of, and attitudes about sunburn. By tracking the frequency of searches about preventative measures like "sunscreen" or "protective clothing" versus treatment measures like "sunburn relief," researchers could measure the effectiveness of awareness and prevention programs.

Screening Spirometry in Military Personnel Correlates Poorly with Exercise Tolerance and Asthma History.

BACKGROUND: Spirometry is an easy-to-perform test for evaluating pulmonary symptoms but has several limitations to include adequate test performance for valid results. Spirometry is not recommended to screen a general population for evidence of pulmonary disease unless symptoms are present or longitudinal screening is done for potential occupational exposures. METHODS: A single-spirometry examination was performed on 900 active duty Army soldiers, ages 18-35 yr, without documented respiratory disease. Abnormal studies were identified (obstructive, restrictive, mixed, and flow volume loop abnormalities) and compared with reported respiratory symptoms, smoking history, prior diagnosis of asthma, and failure of the Army physical fitness test 2-mile run using generalized linear modeling techniques. RESULTS: The cohort population had spirometry values comparable with published NHANES III reference values. Ninety-eight subjects (10.9%) were identified with abnormal spirometry included 33 obstructive, 44 restrictive, 3 mixed, and 18 isolated flow volume loop abnormalities. Historical features (smoking, exertional dyspnea, cough, asthma, or APFT failure) had no effect on the probability of an abnormal spirometry result (p = 0.56). Although APFT failure probability is strongly affected by exertional dyspnea (p = 0.00) and current smoking (p = 0.01), abnormal spirometry results did not have a statistically significant effect (p = 0.38). DISCUSSION: For potential screening of military personnel with spirometry to detect pulmonary disease, study findings identified a significant percentage with non-specific abnormalities requiring further evaluation. Spirometry may be indicated in those individuals with a history of asthma or active dyspnea symptoms. Spirometry as a screening tool is poorly (and often incorrectly) predictive for respiratory symptoms or decreased exercise tolerance in a military cohort. CONCLUSION: Spirometry should not be used to screen the military force for the presence of respiratory disorders. In those individuals with a history of asthma, in-depth testing should be performed to fully evaluate any non-specific findings identified during spirometry.

Pulmonary Function and Respiratory Health of Military Personnel Before Southwest Asia Deployment.

BACKGROUND: Significant concern exists regarding the respiratory health of military personnel deployed to Southwest Asia, given their exposures to numerous environmental hazards. Although the deployed military force is generally assumed to be fit, the pre-deployment respiratory health of these individuals is largely unknown. METHODS: Soldiers deploying to Southwest Asia were recruited from the pre-deployment processing center at Fort Hood, Texas. Participants completed a general and respiratory health questionnaire and performed baseline spirometry. RESULTS: One thousand six hundred ninety-three pre-deployment evaluations were completed. The average age of the participants was 32.2 y, and 83.1% were male. More than one third of surveyed solders had a smoking history, 73% were overweight or obese, and 6.2% reported a history of asthma. Abnormal spirometry was found in 22.3% of participants. Soldiers with abnormal spirometry reported more asthma (10.1% vs 5.1%, P < .001), failed physical fitness tests (9.0% vs 4.6%, P = .02), and respiratory symptoms (32.8% vs 24.3%, P = .001). DISCUSSION: This is the first prospective pre-deployment evaluation of military personnel that delineates factors potentially associated with the development of pulmonary symptoms and/or disease. This study suggests that deploying soldiers are older, heavier, frequently smoke, and may have undiagnosed pre-deployment lung disease. Abnormal spirometry is common but may not represent underlying disease. Self-reported asthma, wheezing, and slower 2-mile run times were predictive of abnormal spirometry. CONCLUSIONS: Pre-deployment evaluation of military personnel identified numerous soldiers with active pulmonary symptoms and abnormal spirometry. When combined with questions regarding asthma history, wheezing and exercise intolerance, spirometry may identify individuals at risk for deployment-related respiratory complaints.

Assessing and accounting for time heterogeneity in stochastic actor oriented models.

This paper explores time heterogeneity in stochastic actor oriented models (SAOM) proposed by Snijders (Sociological Methodology. Blackwell, Boston, pp 361-395, 2001) which are meant to study the evolution of networks. SAOMs model social networks as directed graphs with nodes representing people, organizations, etc., and dichotomous relations representing underlying relationships of friendship, advice, etc. We illustrate several reasons why heterogeneity should be statistically tested and provide a fast, convenient method for assessment and model correction. SAOMs provide a flexible framework for network dynamics which allow a researcher to test selection, influence, behavioral, and structural properties in network data over time. We show how the forward-selecting, score type test proposed by Schweinberger (Chapter 4: Statistical modeling of network panel data: goodness of fit. PhD thesis, University of Groningen 2007) can be employed to quickly assess heterogeneity at almost no additional computational cost. One step estimates are used to assess the magnitude of the heterogeneity. Simulation studies are conducted to support the validity of this approach. The ASSIST dataset (Campbell et al. Lancet 371(9624):1595-1602, 2008) is reanalyzed with the score type test, one step estimators, and a full estimation for illustration. These tools are implemented in the RSiena package, and a brief walkthrough is provided.