Delirium in older inpatients with COVID-19: impact on service provision.

Delirium is a common clinical manifestation of SARS-CoV-2 (COVID-19) in older inpatients. We assessed the prevalence of delirium in inpatients aged over 65 years with confirmed COVID-19 infection to identify its clinical correlations and association with in-hospital mortality and admission duration. Data were extracted retrospectively from electronic health records. The prevalence of delirium was found to be 23.9% (158 out of 662 patients). Factors associated with delirium included older age, dementia (including cases of suspected dementia), frailty and concurrent infection. Delirium was not associated with higher mortality. Admission duration was approximately 1.5 times longer in patients who experienced delirium (median 14 days; interquartile range (IQR) 8-30) compared with those who did not (median 9 days; IQR 5-17; p<0.001). We confirmed that delirium is common in older inpatients with COVID-19 and has significant implications for patient care and planning services and rehabilitation.

Anatomically realistic ultrasound phantoms using gel wax with 3D printed moulds.

Here we describe methods for creating tissue-mimicking ultrasound phantoms based on patient anatomy using a soft material called gel wax. To recreate acoustically realistic tissue properties, two additives to gel wax were considered: paraffin wax to increase acoustic attenuation, and solid glass spheres to increase backscattering. The frequency dependence of ultrasound attenuation was well described with a power law over the measured range of 3-10 MHz. With the addition of paraffin wax in concentrations of 0 to 8 w/w%, attenuation varied from 0.72 to 2.91 dB cm-1 at 3 MHz and from 6.84 to 26.63 dB cm-1 at 10 MHz. With solid glass sphere concentrations in the range of 0.025-0.9 w/w%, acoustic backscattering consistent with a wide range of ultrasonic appearances was achieved. Native gel wax maintained its integrity during compressive deformations up to 60%; its Young's modulus was 17.4 ± 1.4 kPa. The gel wax with additives was shaped by melting and pouring it into 3D printed moulds. Three different phantoms were constructed: a nerve and vessel phantom for peripheral nerve blocks, a heart atrium phantom, and a placental phantom for minimally-invasive fetal interventions. In the first, nerves and vessels were represented as hyperechoic and hypoechoic tubular structures, respectively, in a homogeneous background. The second phantom comprised atria derived from an MRI scan of a patient with an intervening septum and adjoining vena cavae. The third comprised the chorionic surface of a placenta with superficial fetal vessels derived from an image of a post-partum human placenta. Gel wax is a material with widely tuneable ultrasound properties and mechanical characteristics that are well suited for creating patient-specific ultrasound phantoms in several clinical disciplines.