Comparing the accuracy of point-of-care with laboratory (capillary, venous, and arterial) blood glucose levels in critically ill patients with and without shock

OBJECTIVES

To compare the accuracy of point-of-care capillary and venous/arterial samples to laboratory testing of venous/arterial samples in critically sick shocked and non-shocked patients. This is a prospective case-control study including capillary, venous, and arterial blood samples from 268 critically ill patients. The King Fahd Military Medical Complex in Dhahran, Saudi Arabia, was the site of this investigation.

RESULTS

We were able to obtain data on 268 patients for this investigation. POCT and lab findings of venous and central blood did not differ significantly (P = 0.389 and 0.208), while POCT indicated somewhat higher results with venous glucose concentrations of 10.18 and 10.05 (POCT and lab tests respectively) and 9.18 and 9.54 (POCT and lab tests respectively). In addition, the mean differences between POC and laboratory analyses of venous, arterial, and central glucose were 0.13, - 1.75, and - 0.36 mmol/L for venous, arterial, and central glucose, respectively. Except for arterial blood glucose, we did not observe a significant difference between POCT and routine laboratory analysis of glucose concentrations in critically ill patients. Compared to laboratory blood analysis, the use of POCT is marginally accurate, with no difference between shocked and non-shocked patients.

ABO in Correlation to the Requirement of Mechanical Ventilation and Mortality in Critically Ill Patients With COVID-19

Background

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that was first discovered in December 2019 and turned to be pandemic in early March 2020. We aimed to describe the dominant ABO group and outcomes of critically ill patients (respiratory failure requiring mechanical ventilation and mortality) in a Saudi Arabian setting.

Methods

We conducted an observational, analytic cross-sectional, retrospective study in a tertiary care hospital. Around 90 candidates tested positive for COVID-19 were enrolled in this study during admission to critical care unit between May 2020 and September 2020. Blood group was detected in all patients included in the study during admission to critical care unit.

Results

In this study, data of 90 patients with COVID-19 admitted to critical care unit were collected. Some prevalent medical conditions were collected, in which hypertension (64.2%) and diabetes mellitus (58.9%) were the most reported comorbidities among patients and there was no significant difference between groups. Most of the sample had blood group of O (45.6%), while the least group was AB (5.6%). Patients with blood group of A/AB showed the highest mortality vs. group O/B (32% vs. 18.5%) with significant P value of 0.001. Patients of groups A/AB had higher risk for intubation than O/B groups (52.0% and 49.2%, respectively; confidence interval of 0.44 - 2.8 with insignificant P value of 0.055). Length of stay in critical care unit was significantly higher in group A/AB with a mean course of 18.20 days in comparison to group O/B with a mean course of 12.63 days (P = 0.033).

Conclusion

Our data indicate that critically ill patients with COVID-19 with blood group A/AB are at increased risk of mortality and length of stay in critical care unit, with insignificant requirement of mechanical ventilation when compared with patients with blood group O/B. Future larger studies are needed to validate and understand the underlying mechanisms.

How to Observe Users' Movements in Virtual Environments: Viewpoint Control in a Power Wheelchair Simulator

OBJECTIVE

We describe a networked, two-user virtual reality (VR) power wheelchair (PWC) simulator system in which an actor (client) and an observer (clinician) meet. We then present a study with 15 observers (expert clinicians) evaluating the effect of three principal forms of viewpoint control (egocentric-egomotion, egocentric-tethered, and client-centric) on the observer's assessment of driving tasks in a virtual environment (VE).

BACKGROUND

VR allows for the simulation and assessment of real-world tasks in a controlled, safe, and repeatable environment. Observing users' movement behavior in such a VE requires appropriate viewpoint control for the observer. The VR viewpoint user interface should allow an observer to make judgments equivalent or even superior to real-world situations.

METHOD

A purpose-built VR PWC simulator was developed. In a series of PWC driving tasks, we measured the perceived ease of use and sense of presence of the observers and compared the virtual assessment with real-world "gold standard" scores, including confidence levels in judgments.

RESULTS

Findings suggest that with more immersive techniques, such as egomotion and tethered egocentric viewpoints, judgments are both more accurate and more confident. The ability to walk and/or orbit around the view significantly affected the observers' sense of presence.

CONCLUSION

Incorporating the observer into the VE, through egomotion, is an effective method for assessing users' behavior in VR with implications for the transferability of virtual experiences to the real world.

APPLICATION

Our application domain serves as a representative example for tasks where the movement of users through a VE needs to be evaluated.

Immersion factors affecting perception and behaviour in a virtual reality power wheelchair simulator

Virtual Reality based driving simulators are increasingly used to train and assess users' abilities to operate vehicles in a controlled and safe way. For the development of those simulators it is important to identify and evaluate design factors affecting perception, behaviour, and driving performance. In an exemplary power wheelchair simulator setting we identified the three immersion factors display type (head-mounted display v monitor), ability to freely change the field of view (FOV), and the visualisation of the user's avatar as potentially affecting perception and behaviour. In a study with 72 participants we found all three factors affected the participants' sense of presence in the virtual environment. In particular the display type significantly affected both perceptual and behavioural measures whereas FOV only affected behavioural measures. Our findings could guide future Virtual Reality simulator designers to evoke targeted user behaviours and perceptions.