Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

The original version of this article unfortunately contained a mistake

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Efficient inter prediction for 2D and 3D video coding

In the recent several years, the popularity of High Definition and Three-Dimensional (3D) videos are creating significant challenge for the video compression techniques. There is an increasing demand for video coding tools with higher efficiency and lower complexity. Using advanced inter prediction technique the state-of-the-art video coding standard H.264/ A VC has achieved significant compression gains. However, the complexity of the inter prediction is extremely high, which limits the application of real-time video service. When applying H.264/ A VC to colour plus depth represented 3D videos, the inter prediction designed for Two-Dimensional (2D) videos is not efficient enough for depth map coding, since the depth map is only a 2D signal to aid virtual view rendering. The work described in this thesis speeds up the inter prediction by proposing several fast approaches. A novel inter prediction scheme for 3D video coding is developed to maximise rate distortion performance of rendering image and depth map bit rates. The thesis proposes four methods to reduce complexity of inter prediction. Firstly, the motion estimation searching points are reduced by proposing a novel Adaptive Direction Search algorithm. In this algorithm, the intensive search and coarse search regions are adaptively detected using predicted motion vector direction as an indicator. Secondly, an Adaptive Simulated Annealing Search algorithm is developed to further adjust the search pattern not only in directional regions but also in different distances. Thirdly, the thesis presents a hybrid fast mode decision algorithm, which is mainly based on Coded Block Pattern to infer block's homogeneity characteristic so that the unnecessary inter modes can be eliminated. Fourthly, an improved residual homogeneous based fast mode decision algorithm is proposed. Computational complexity can be further reduced at low Quantisation Parameter conditions. Experimental results indicate that using the proposed algorithms up to 70% of encoding time can be saved with negligible Rate Distortion performance losses. For depth map coding, a novel inter prediction scheme is proposed in this thesis. By employing rendered view distortion in Rate-Distortion Optimisation, the optimal motion vector and inter mode are determined to maximise the quality of the rendered views. An effective Lagrange multiplier is also derived. Finally, fast approaches have been implemented to reduce the complexity. Experimental results illustrate that up to 61 % of bitrate can be saved for depth map coding.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Efficient Inter Prediction for 2D and 3D Video Coding.

In the recent several years, the popularity of High Definition and Three-Dimensional (3D) videos are creating significant challenge for the video compression techniques. There is an increasing demand for video coding tools with higher efficiency and lower complexity. Using advanced inter prediction technique the state-of-the-art video coding standard H.264/AVC has achieved significant compression gains. However, the complexity of the inter prediction is extremely high, which limits the application of real-time video service. When applying H.264/AVC to colour plus depth represented 3D videos, the inter prediction designed for Two-Dimensional (2D) videos is not efficient enough for depth map coding, since the depth map is only a 2D signal to aid virtual view rendering. The work described in this thesis speeds up the inter prediction by proposing several fast approaches. A novel inter prediction scheme for 3D video coding is developed to maximise rate distortion performance of rendering image and depth map bit rates. The thesis proposes four methods to reduce complexity of inter prediction. Firstly, the motion estimation searching points are reduced by proposing a novel Adaptive Direction Search algorithm. In this algorithm, the intensive search and coarse search regions are adaptively detected using predicted motion vector direction as an indicator. Secondly, an Adaptive Simulated Annealing Search algorithm is developed to further adjust the search pattern not only in directional regions but also in different distances. Thirdly, the thesis presents a hybrid fast mode decision algorithm, which is mainly based on Coded Block Pattern to infer block’s homogeneity characteristic so that the unnecessary inter modes can be eliminated Fourthly, an improved residual homogeneous based fast mode decision algorithm is proposed. Computational complexity can be further reduced at low Quantisation Parameter conditions. Experimental results indicate that using the proposed algorithms up to 70% of encoding time can be saved with negligible Rate Distortion performance losses. For depth map coding, a novel inter prediction scheme is proposed in this thesis. By employing rendered view distortion in Rate-Distortion Optimisation, the optimal motion vector and inter mode are determined to maximise the quality of the rendered views. An effective Lagrange multiplier is also derived. Finally, fast approaches have been implemented to reduce the complexity. Experimental results illustrate that up to 61% of bitrate can be saved for depth map coding

Kinematic analysis of a swash-plate controlled variable displacement axial-piston pump with a conical barrel assembly

Variable displacement, swash-plate controlled, axial-piston pumps are widely used in applications that require high pressure and variable flow rates. The pump consists of a rotating barrel assembly that houses several pistons in a circular array. A swash-plate is used to control the displacement of the pistons to adjust the output flow of hydraulic fluid. As the barrel rotates, the pistons slide along the angled swash-plate and draw oil from the supply and then discharge oil into the high pressure circuit. This results in an almost constant output flow rate. This paper analyzes the kinematics of a pump based on its geometry dependent characteristics. The analysis assumes an idealized case in which there is no oil leakage and the fluid is considered to be incompressible. It is revealed through the analysis that the piston displacement and the pump output flow are slightly increased by using a conical barrel. Instantaneous and mean flow rate equations are used to describe the output flow characteristics and flow ripple effect. The output flow rate ripple profile is found to be a function of both swash-plate angle and the conical barrel angle. A term defined as the flow rate uniformity coefficient is used to better quantify the flow ripple phenomenon. A frequency analysis is performed on the output flow rate and an additional order is found to be present when using a conical barrel pump versus one with a cylindrical barrel when the pumps have an odd number of pistons. Conical barrel piston pumps are found to have a slight increase in piston displacement, velocity, and acceleration relative to the rotating barrel frame of reference over a pump with a cylindrical barrel. This translates into an increase in the output flow rate for a conical piston pump under the same operating conditions. The conical barrel is also found to have a reduction in the rotational inertia allowing for faster angular acceleration. The presence of an extra order from a frequency analysis for a conical pump with an odd number of pistons has the potential to cause unwanted noise or vibration to the structure or components attached to the pump

The effects of different dietary crude protein level on faecal crude protein and amino acid flow and digestibility in growing pigs

This study was conducted to evaluate the effects of dietary crude protein (CP) level on faecal CP and amino acid (AA) flow and digestibility, faecal and ileal digesta microbial AA composition. Eighteen Duroc × Landrace × Yorkshire barrows (60 ± 1.43 kg) were randomly divided into 3 groups with 6 barrows in each, and fed a maize–soybean meal diet at the 10% (L-CP), 13% (M-CP) and 16% (H-CP) CP levels. The results indicated the faecal total N, CP, total AA (TAA) flow increased linearly (P < 0.05) whereas dietary CP concentration increased from 10% to 16%. The DM digestibility, CP digestibility, TAA digestibility, essential amino acid and non-essential amino acid digestibility decreased linearly (P < 0.05), whereas dietary CP concentration increased from 10% to 16%. Compared with pigs in M-CP and L-CP groups, pigs in the H-CP group had higher Asp, Cys, His, Arg flow in the faeces (P < 0.05). Compared with pigs in the L-CP group, pigs in M-CP and H-CP groups had less faecal Glu, Ala, Tyr, Pro, Val, Ile, Leu and flow (P < 0.05). Faecal microbial N and AA in the L-CP group was the highest in three groups. Pigs fed a corn–soybean meal-based diet reduced in protein concentration have lower faecal N flow