Evaluation of airborne particle exposure for riding elevators.

Social distancing is a key factor for health during the COVID-19 pandemic. In many indoor spaces, such as elevators, it is difficult to maintain social distancing. This investigation used computational-fluid-dynamics (CFD) to study airborne particle exposure in riding an elevator in a typical building with 35 floors. The elevator traveled from the ground floor to the 35th floor with two stops on floor 10 and floor 20, comprising 114 s. The CFD simulated the dispersion of the aerosolized particles exhaled by an index person while breathing in both lobby and elevator areas. The study calculated the accumulated dose of susceptible riders riding in elevators with the index person under different conditions including different ventilation rates, air supply methods, and elevator cab geometries. This investigation also studied a case with a single cough from the index person as the person entered the elevator. The results show that, due to the short duration of the average elevator ride, the number of particles inhaled by a susceptible rider was low. For the reference case with a 72 ACH (air changes per hour) ventilation rate, the highest accumulated particle dose by a susceptible passenger close to the index person was only 1.59. The cough would cause other riders to inhale approximately 8 orders of magnitude higher particle mass than from continuous breathing by the index person for the whole duration of the ride.

Comparing nurse practitioners/physician assistants and physicians in diagnosing pediatric abdominal pain for ESI level 3 patients seen in the emergency department.

BACKGROUND: Accuracy of emergency department (ED) diagnosis affects care management including tests, discharges, and readmissions. PURPOSE: This retrospective study compared nurse practitioners/physician assistants (NPs/PAs) with physicians (MDs/DOs) on accuracy of diagnosing Emergency Severity Index (ESI) level 3 pediatric abdominal pain (AP) in the ED. Abdominal pain unrelated to trauma is a common ED pediatric visit. METHODOLOGY: Data acquired from four hospital sites of a multistate emergency group examined patients younger than 18 years who were initially admitted for AP ESI level 3. RESULTS: The accuracy of AP ESI level 3 diagnoses was 94.9%, 90.9%, and 96.5% by physicians, NPs/PAs, and a collaboration of NP/PA/physician, respectively (χ2 = 13.187, p < .001). Accuracy of AP ESI level 3 diagnoses was greater with general admissions, intensive care unit admissions, transfers, or left against medical advice (100%) than with those who were discharged (χ2 = 11.058, p = .001). Abdominal pain complaints were segmented into five areas (i.e., AP, back pain, chest pain, epigastric pain, and pelvic pain). Irrespective of provider, those with a final diagnosis of AP or epigastric pain were correctly triaged and those with a final diagnosis of chest or back pain were incorrectly triaged as AP ESI level 3. CONCLUSIONS: When comparing providers in this subset (n = 43), there was no significant difference in the accuracy of assigning AP ESI level 3 (χ2 = 0.467, p = .495). IMPLICATIONS: Only cases with a final diagnosis of pelvic/genitourinary pain saw disparity in the accuracy (27 correct, 16 incorrect, χ2 = 1,681.80, p < .001).

Use of noise correlation matrices to interpret ocean ambient noise.

Oceanic ambient noise is a dynamic mixture of biologic, geophysical, and anthropogenic sound sources. A goal of research is to put some order in this cacophony of information, understand the received spectral content and determine the primary contributors to the ambient noise. This paper compares three methods to assist in that process (with emphasis on noise correlation techniques): noise correlation matrices, manual selection of noise spectra, and principal component analysis. Comparison followed a common process: selection of a replica set (best termed a characteristic subset of noise spectra), which are used to recreate the original noise field for comparison and consequent decision as to whether that replica set represented the noise measurements adequately. Conclusions of this study are (1) noise correlation matrices provide the best definition of the spectra that represent a particular source and offer potential in organizing and identifying specific noise source content. (2) Manual sorting of noise spectra, while able to identify specific events easily, is both labor intensive, given the quantity of data available; and suffers from incorrect interpretation of multiple competing sound sources, when present. (3) Principal component analysis provides the best reconstruction of measured noise, but has difficulty linking components to physical source mechanisms.

Comparing nurse practitioners/physician assistants and physicians in diagnosing adult abdominal pain in the emergency department.

BACKGROUND AND PURPOSE: This retrospective study compared nurse practitioners and physician assistants (NPs/PAs) with physicians on their assignment of Emergency Severity Index level 3 (ESI level 3) acute abdominal pain (AAP) in the emergency department (ED). METHODS: Data obtained from a large ED group staffing four hospitals yielded 12,440 de-identified, adult patients diagnosed on ED admission with AAP ESI level 3 for descriptive analysis with logistic regression. CONCLUSIONS: Results revealed that the comparison of ESI level 3 AAP diagnoses was consistent between admission and discharge 95.3% for physicians, 92.9% for NPs/PAs, and 97.1% for NP/PA and physician collaboration (χ = 46.01, p < .001). Logistic regression suggested that NP/PA had significantly reduced odds (31%) of consistent admitting/discharge diagnoses, whereas collaboration of NP/PA with physicians had significantly increased odds of consistent diagnosis (41%) compared with physicians alone. Two hospitals with similar distributions of NPs/PAs and physicians exhibited greater odds of consistent diagnoses over hospitals with disproportionate distributions; a secondary finding worth exploring. Consistent AAP ESI level 3 diagnoses by outcomes were admissions (>99%), discharges (94%), and left against medical advice/transferred (98%; χ = 102.94, p < .001). IMPLICATIONS FOR PRACTICE: The highest percentage of consistent AAP ESI level 3 diagnoses between ED admission and discharge was when NPs/PAs and physicians collaborated.

Global examination of the wind-dependence of very low frequency underwater ambient noise.

Ocean surface winds play a key role in underwater ambient noise generation. One particular frequency band of interest is the infrasonic or very low frequency (VLF) band from 1 to 20 Hz. In this spectral band, wind generated ocean surface waves interact non-linearly to produce acoustic waves, which couple into the seafloor to generate microseisms, as explained by the theory developed by Longuet-Higgins. This study examines long term data sets in the VLF portion of the ambient noise spectrum, collected by the hydroacoustic systems of the Comprehensive Nuclear-Test Ban Treaty Organization in the Atlantic, Pacific, and Indian Oceans. Three properties of the noise field were examined: (a) the behavior of the acoustic spectrum slope from 1 to 5 Hz, (b) correlation of noise levels and wind speeds, and (c) the autocorrelation behavior of both the noise field and the wind. Analysis results indicate the spectrum slope is site dependent, and for both correlation methods, a high correlation between wind and the noise field in the 1-5 Hz band.

Is low frequency ocean sound increasing globally?

Low frequency sound has increased in the Northeast Pacific Ocean over the past 60 yr [Ross (1993) Acoust. Bull. 18, 5-8; (2005) IEEE J. Ocean. Eng. 30, 257-261; Andrew, Howe, Mercer, and Dzieciuch (2002) J. Acoust. Soc. Am. 129, 642-651; McDonald, Hildebrand, and Wiggins (2006) J. Acoust. Soc. Am. 120, 711-717; Chapman and Price (2011) J. Acoust. Soc. Am. 129, EL161-EL165] and in the Indian Ocean over the past decade, [Miksis-Olds, Bradley, and Niu (2013) J. Acoust. Soc. Am. 134, 3464-3475]. More recently, Andrew, Howe, and Mercer's [(2011) J. Acoust. Soc. Am. 129, 642-651] observations in the Northeast Pacific show a level or slightly decreasing trend in low frequency noise. It remains unclear what the low frequency trends are in other regions of the world. In this work, data from the Comprehensive Nuclear-Test Ban Treaty Organization International Monitoring System was used to examine the rate and magnitude of change in low frequency sound (5-115 Hz) over the past decade in the South Atlantic and Equatorial Pacific Oceans. The dominant source observed in the South Atlantic was seismic air gun signals, while shipping and biologic sources contributed more to the acoustic environment at the Equatorial Pacific location. Sound levels over the past 5-6 yr in the Equatorial Pacific have decreased. Decreases were also observed in the ambient sound floor in the South Atlantic Ocean. Based on these observations, it does not appear that low frequency sound levels are increasing globally.

Diagnostic and treatment challenges in traumatic brain injury patients with severe neuropsychiatric symptoms: insights into psychiatric practice.

Traumatic brain injury (TBI) causes a variety of neuropsychiatric problems that pose diagnostic and treatment challenges for providers. In this report, we share our experience as a referral neuropsychiatry program to assist the general psychiatrist when adult TBI patients with psychiatric symptoms present for evaluation and treatment. We completed a retrospective study of patients with moderate-to-severe TBI and severe neuropsychiatric impairments. We collected information on demographics, nature of injury, symptomatology, diagnoses, and treatments. Data analysis indicates that mood stabilization was a key concern, often requiring aggressive pharmacological management. Cognitive dysfunction was a problem for the majority of patients, but was only medicated in a third, due to poor efficacy or behavioral side effects. The co-occurrence of multiple TBI-related symptoms and diagnoses in this patient cohort emphasizes the need for individualized psychopharmacological approaches and interventions.

Implications for vancomycin-resistant Enterococcus colonization associated with Clostridium difficile infections.

BACKGROUND: Vancomycin-resistant Enterococcus (VRE) colonization of the gastrointestinal tract shares similar risk factors with Clostridium difficile infection. We sought to elucidate the prevalence and risk factors of VRE colonization associated with C difficile infection. METHODS: All adult inpatients with C difficile infection from July 2006 to October 2006 were prospectively evaluated. All C difficile toxin-positive stool samples were screened for detection of VRE. Risk factors for VRE colonization were compared in patients with C difficile infection with and without VRE colonization. RESULTS: Of the 158 cases of C difficile infection evaluated, 88 (55.7%) involved VRE colonization. Independent risk factors for VRE colonization were admission from long-term care facilities (P = .013), dementia (P = .017), and hospitalization in the previous 2 months (P = .014). No statistically significant difference between C difficile infection cases with and without VRE colonization in terms of previous receipt (within 1 month) of antibiotics, including metronidazole and vancomycin, was found on multivariate analysis. C difficile infection cases with VRE colonization had a higher prevalence of coinfection with methicillin-resistant Staphylococcus aureus (P = .002) and Acinetobacter spp (P = .006). CONCLUSION: VRE colonization was associated with >50% of C difficile infection cases and with a higher rate of coinfection with multidrug-resistant pathogens. Given the high rate of C difficile infection associated with VRE colonization, active surveillance of VRE in patients with C difficile infection is reasonable in high-risk settings.