Risk factors associated with day-30 mortality in patients over 60 years old admitted in ICU for severe COVID-19: the Senior-COVID-Rea Multicentre Survey protocol

IntroductionWith the spread of COVID-19 epidemic, health plans must be adapted continuously. There is an urgent need to define the best care courses of patients with COVID-19, especially in intensive care units (ICUs), according to their individualised benefit/risk ratio. Since older age is associated with poorer short-term and long-term outcomes, prediction models are needed, that may assist clinicians in their ICU admission decision. Senior-COVID-Rea was designed to evaluate, in patients over 60 years old admitted in ICU for severe COVID-19 disease, the impact of age and geriatric and paraclinical parameters on their mortality 30 days after ICU admission.Methods and analysisThis is a multicentre survey protocol to be conducted in seven hospitals of the Auvergne-Rhône-Alpes region, France. All patients over 60 years old admitted in ICU for severe COVID-19 infection (or their legally acceptable representative) will be proposed to enter the study and to fill in a questionnaire regarding their functional and nutritional parameters 1 month before COVID-19 infection. Paraclinical parameters at ICU admission will be collected: lymphocytes and neutrophils counts, high-fluorescent lymphoid cells and immature granulocytes percentages (Sysmex data), D-dimers, C-reactive protein, lactate dehydrogenase (LDH), creatinine, CT scan for lung extension rate as well as clinical resuscitation scores, and the delay between the first signs of infection and ICU admission. The primary outcome will be the overall survival at day 30 post-ICU admission. The analysis of factors predicting mortality at day 30 will be carried out using univariate and multivariate logistic regressions. Multivariate logistic regression will consider up to 15 factors.The ambition of this trial, which takes into account the different approaches of geriatric vulnerability, is to define the respective abilities of different operational criteria of frailty to predict patients’ outcomes.Ethics and disseminationThe study protocol was ethically approved. The results of the primary and secondary objectives will be published in peer-reviewed journals.Trial registration numberNCT04422340.

Qualitative analysis of disposition decision making for patients referred for admission from the emergency department without definite medical acuity

ObjectiveTo map the physician approach when determining disposition for a patient who presents without the level of definite medical acuity that would generally warrant hospitalisation.Data sources/study settingSince 2018, our US academic county hospital/trauma centre has maintained a database in which hospitalists (‘triage physicians’) document the rationale and outcomes of requests for admission to the acute care medical ward during each shift.Study designNarrative text from the database was analysed using a grounded theory approach to identify major themes and subthemes, and a conceptual model of the admission decision-making process was constructed.ParticipantsDatabase entries were included (n=300) if the admission call originated from the emergency department and if the triage physician characterised the request as potentially inappropriate because the patient did not have definite medical acuity.ResultsAdmission decision making occurs in three main phases: evaluation of unmet needs, assessment of risk and re-evaluation. Importantly, admission decision making is not solely based on medical acuity or clinical algorithms, and patients without a definite medical need for admission are hospitalised when physicians believe a potential issue exists if discharged. In this way, factors such as homelessness, substance use disorder, frailty, etc, contribute to admission because they raise concern about patient safety and/or barriers to appropriate treatment. Physician decision making can be altered by activities such as care coordination, advocacy by the patient or surrogate, interactions with other physicians or a change in clinical trajectory.ConclusionsThe decision to admit ultimately remains a clinical determination constructed between physician and patient. Physicians use a holistic process that incorporates broad consideration of the patient’s medical and social needs with emphasis on risk assessment; thus, any analysis of hospitalisation trends or efforts to impact such should seek to understand this individual-level decision making.

Admission Control and Bandwidth Allocation for Class A Traffic in RPR Networks

In this thesis, we study the admission control and bandwidth allocation methods for classA traffic in RPR networks. First, we investigate the performance of classA traffic under the current RPR protocol. The simulation results show that RPR networks can support low-delay classA traffic even if the networks are congested with classB and classC traffic. The low-delay performance, however, is subject to the condition that the load of classA traffic must be properly controlled. Consequently, an admission control mechanism must be used for classA traffic. In this thesis, several admission control algorithms are studied. They are the Simple Sum algorithm, the Measured Sum algorithm, and the Equivalent Bandwidth algorithm. The simulation results show that the Equivalent Bandwidth algorithm is the most suitable to use as the admission control mechanism for classA traffic. The admission control mechanism makes admission decision based on the available bandwidth allocated to the classA traffic. The existing RPR standard assumes the bandwidth allocated for classA traffic at each node is fixed. The fixed bandwidth allocation introduces inflexibility and inefficient use of bandwidth for classA traffic. In this thesis, three bandwidth allocation algorithms are proposed to dynamically allocate bandwidth for classA traffic. These algorithms have different levels of complexity and can be applied to different traffic environments. Simulation results show that the proposed algorithms improve the bandwidth efficiency of the RPR networks. The proposed algorithms are also readily integrated with the existing Internet Quality of Services (QoS) paradigms such as Diffserv and RSVP services.

Admission Control and Bandwidth Allocation for Class A Traffic in RPR Networks

In this thesis, we study the admission control and bandwidth allocation methods for classA traffic in RPR networks. First, we investigate the performance of classA traffic under the current RPR protocol. The simulation results show that RPR networks can support low-delay classA traffic even if the networks are congested with classB and classC traffic. The low-delay performance, however, is subject to the condition that the load of classA traffic must be properly controlled. Consequently, an admission control mechanism must be used for classA traffic. In this thesis, several admission control algorithms are studied. They are the Simple Sum algorithm, the Measured Sum algorithm, and the Equivalent Bandwidth algorithm. The simulation results show that the Equivalent Bandwidth algorithm is the most suitable to use as the admission control mechanism for classA traffic. The admission control mechanism makes admission decision based on the available bandwidth allocated to the classA traffic. The existing RPR standard assumes the bandwidth allocated for classA traffic at each node is fixed. The fixed bandwidth allocation introduces inflexibility and inefficient use of bandwidth for classA traffic. In this thesis, three bandwidth allocation algorithms are proposed to dynamically allocate bandwidth for classA traffic. These algorithms have different levels of complexity and can be applied to different traffic environments. Simulation results show that the proposed algorithms improve the bandwidth efficiency of the RPR networks. The proposed algorithms are also readily integrated with the existing Internet Quality of Services (QoS) paradigms such as Diffserv and RSVP services.

Cognitive Work Analysis and Visualization Design for the Graduate Admission Decision Making Process

Graduate admission has always been a complex decision making process. The link between application materials and student success has remained elusive and, as such, there is no validated method for making decisions. To understand the purposes, processes, difficulties and needs of the current graduate admission process, semi-structured interviews were conducted with participants from engineering departments. Cognitive work analysis techniques were used to summarize the findings from the interviews. Visualizations were designed to improve the current online review system. User feedback was collected in an experiment.

Video-Aware Measurement-Based Admission Control

Using instantaneous aggregate arrival rate as an admission control parameter will contribute to either bandwidth under-utilization or over-utilization. Being bursty in nature and variable in rate, video flows might encode any rate between a range of minimum and maximum values. At the time the decision is made, if the measured rate is at the minimum value, the bandwidth might be over-utilized due to accepting more sessions than the link can accommodate. In contrast, it might be under-utilized if the measured rate is at the maximum value due to rejecting more sessions than the link can accommodate. The burstiness can be taken into account by considering the past history of the traffic. This paper investigates the suitability of the average aggregate arrival rate instead of the instantaneous aggregate arrival rate for video admission decisions. It establishes a mathematical model to predict the relationship between the two rates. Simulation results confirm that the average aggregate arrival rate is a more efficient decision factor for a small number of flows. Although it has no additional advantage for moderate and large number of flows, it still can stabilize the admission decision by smoothing the burstiness of a set of the instantaneous rates (within the measurement period) over a period of time.