Home Return Following Invasive Mechanical Ventilation for the Oldest-Old Patients in Medical Intensive Care Units from Two US Hospitals

Background: The aging of the US population has been associated with an increase in intensive care unit (ICU) utilization and correspondingly, invasive mechanical ventilation (IMV) among the oldest-old (age \u3e/=80 years). While previous studies have examined ICU and IMV outcomes in the elderly, very few have focused on patient-centered outcomes, specifically home return, in the oldest-old. We investigated the rate of immediate home return following IMV in the medical ICU in previously home-dwelling oldest-old patients relative to that of a comparison group of 50-70-year olds. Methods: Data were extracted retrospectively from patient records at Elmhurst Hospital Center in Elmhurst, NY, USA, encompassing the period from January 2009 to May 2014 and Jacobi Medical Center in the Bronx, NY, USA, from January 2010 to March 2014. Medical ICU admissions within those date ranges were screened for possible inclusion into one of two study groups based on age: \u3e/=80 years old and 50-70 years old. The primary end point was hospital discharge: home return versus no home return (death or nonhome discharge). Cox proportional hazards\u27 regression models were used to estimate crude and multivariable-adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) for failure to return home. Results: A total of 375 patients were included in the analysis: 279 (74%) patients aged 50-70 years and 96 (26%) patients aged \u3e/=80 years. Compared to 50-70-year olds, being \u3e/=80 years old was associated with a nearly two-fold greater risk of no home return: adjusted HR: 1.96; 95% CI 1.43-2.67. The oldest-old was at significantly increased risk of both being discharged to a skilled nursing facility or subacute rehabilitation (adjusted HR: 2.19; 95% CI 1.33-3.59) as well as of dying in the hospital (adjusted HR: 1.81; 95% CI 1.21-2.71). Conclusion: Previously home-dwelling oldest-old are at significantly increased risk of failing to return home immediately following medical ICU admission with IMV as compared to patients aged 50-70 years. These results can help medical ICU staff establish appropriate expectations when addressing the families of their oldest patients. Further studies are needed to evaluate the potential for delayed home return among the oldest old and to assess the ability of frailty indices to predict home return within this ICU population

From correlation functions to scattering amplitudes

We study the correlators of half-BPS protected operators in N=4 super-Yang-Mills theory, in the limit where the positions of the adjacent operators become light-like separated. We compute the loop corrections by means of Lagrangian insertions. The divergences resulting from the light-cone limit are regularized by changing the dimension of the integration measure over the insertion points. Switching from coordinates to dual momenta, we show that the logarithm of the correlator is identical with twice the logarithm of the matching MHV gluon scattering amplitude. We present a number of examples of this new relation, at one and two loops.Comment: typos corrected, references adde

Shot noise in mesoscopic systems

This is a review of shot noise, the time-dependent fluctuations in the electrical current due to the discreteness of the electron charge, in small conductors. The shot-noise power can be smaller than that of a Poisson process as a result of correlations in the electron transmission imposed by the Pauli principle. This suppression takes on simple universal values in a symmetric double-barrier junction (suppression factor 1/2), a disordered metal (factor 1/3), and a chaotic cavity (factor 1/4). Loss of phase coherence has no effect on this shot-noise suppression, while thermalization of the electrons due to electron-electron scattering increases the shot noise slightly. Sub-Poissonian shot noise has been observed experimentally. So far unobserved phenomena involve the interplay of shot noise with the Aharonov-Bohm effect, Andreev reflection, and the fractional quantum Hall effect.Comment: 37 pages, Latex, 10 figures (eps). To be published in "Mesoscopic Electron Transport," edited by L. P. Kouwenhoven, G. Schoen, and L. L. Sohn, NATO ASI Series E (Kluwer Academic Publishing, Dordrecht

Observation and analysis of Fano-like lineshapes in the Raman spectra of molecules adsorbed at metal interfaces

Surface enhanced Raman spectra from molecules (bipyridyl ethylene) adsorbed on gold dumbells are observed to become increasingly asymmetric (Fano-like) at higher incident light intensity. The electronic temperature (inferred from the anti-Stokes (AS) electronic Raman signal increases at the same time while no vibrational AS scattering is seen. These observations are analyzed by assuming that the molecule-metal coupling contains an intensity dependent contribution (resulting from light-induced charge transfer transitions as well as renormalization of the molecule metal tunneling barrier). We find that interference between vibrational and electronic inelastic scattering routes is possible in the presence of strong enough electron-vibrational coupling and can in principle lead to the observed Fano-like feature in the Raman scattering profile. However the best fit to the observed results, including the dependence on incident light intensity and the associated thermal response is obtained from a model that disregards this coupling and accounts for the structure of the continuous electronic component of the Raman scattering signal. The temperatures inferred from the Raman signal are argued to be only of qualitative value

Home return following invasive mechanical ventilation for the oldest-old patients in medical intensive care units from two US hospitals

Background: The aging of the US population has been associated with an increase in intensive care unit (ICU) utilization and correspondingly, invasive mechanical ventilation (IMV) among the oldest-old (age ≥80 years). While previous studies have examined ICU and IMV outcomes in the elderly, very few have focused on patient-centered outcomes, specifically home return, in the oldest-old. We investigated the rate of immediate home return following IMV in the medical ICU in previously home-dwelling oldest-old patients relative to that of a comparison group of 50–70-year olds. Methods: Data were extracted retrospectively from patient records at Elmhurst Hospital Center in Elmhurst, NY, USA, encompassing the period from January 2009 to May 2014 and Jacobi Medical Center in the Bronx, NY, USA, from January 2010 to March 2014. Medical ICU admissions within those date ranges were screened for possible inclusion into one of two study groups based on age: ≥80 years old and 50–70 years old. The primary end point was hospital discharge: home return versus no home return (death or nonhome discharge). Cox proportional hazards' regression models were used to estimate crude and multivariable-adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) for failure to return home. Results: A total of 375 patients were included in the analysis: 279 (74%) patients aged 50–70 years and 96 (26%) patients aged ≥80 years. Compared to 50–70-year olds, being ≥80 years old was associated with a nearly two-fold greater risk of no home return: adjusted HR: 1.96; 95% CI 1.43–2.67. The oldest-old was at significantly increased risk of both being discharged to a skilled nursing facility or subacute rehabilitation (adjusted HR: 2.19; 95% CI 1.33–3.59) as well as of dying in the hospital (adjusted HR: 1.81; 95% CI 1.21–2.71). Conclusion: Previously home-dwelling oldest-old are at significantly increased risk of failing to return home immediately following medical ICU admission with IMV as compared to patients aged 50–70 years. These results can help medical ICU staff establish appropriate expectations when addressing the families of their oldest patients. Further studies are needed to evaluate the potential for delayed home return among the oldest old and to assess the ability of frailty indices to predict home return within this ICU population