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

Deconvolution of the relaxations associated with local and segmental motions in poly(methacrylate)s containing dichlorinated benzyl moieties in the ester residue

9 pages, 15 figures, 1 scheme.The relaxation behavior of poly(2,3-dichlorobenzyl methacrylate) is studied by broadband dielectric spectroscopy in the frequency range of 10–1–109 Hz and temperature interval of 303–423 K. The isotherms representing the dielectric loss of the glassy polymer in the frequency domain present a single absorption, called B process. At temperatures close to Tg, the dynamical (alfa) relaxation already overlaps with the (beta) process, the degree of overlapping increasing with temperature. The deconvolution of the (alfa) and (beta) relaxations is facilitated using the retardation spectra calculated from the isotherms utilizing linear programming regularization parameter techniques. The temperature dependence of the (beta) relaxation presents a crossover associated with a change in activation energy of the local processes. The distance between the (alfa) and (beta) peaks, expressed as log(fmax;/fmax;) where fmax is the frequency at the peak maximum, follows Arrhenius behavior in the temperature range of 310–384 K. Above 384 K, the distance between the peaks remains nearly constant and, as a result, the (alfa) onset temperature exhibited for many polymers is not reached in this system. The fraction of relaxation carried out through the (alfa) process, without (beta) assistance, is larger than 60% in the temperature range of 310–384 K where the so-called Williams ansatz holds.This work was financially suported by the DGCYT and CAM through Grant Nos. MAT2002-04042-C02 and GR/ MAT/0723/2004. Two of the authors (L.G. and D.R.) thank the FONDECYT for partial financial support through Grant Nos. 21050956 and 1050962, respectively.Peer reviewe

Influence of the fine structure of glass forming materials on the overlapping of the alpha and secondary relaxations

The dielectric behavior of a set of poly benzyl methacrylates with methyl, fluorine, chlorine and difluorine substitutes in the phenyl ring is reported. Attention is paid to the deconvolution of overlapping processes with the aim of obtaining a deeper insight into the influence of the fine chemical structure on the splitting of the α and β relaxations. Deconvolutions are carried out on the retardation time spectra calculated from the dielectric loss in the frequency domain using the linear regularization method. Some difficulties associated with the detection of the β relaxation of this set of polymers were resolved by means of the thermostimulated depolarization currents experiments. © 2007 Elsevier B.V. All rights reserved.Peer Reviewe

Broadband dielectric spectroscopy of polymers with hidden, relaxation

This work reports the relaxation behavior of amorphous polymers the spectra of which do not explicitly present the secondary â relaxation. Poly(2,4-difluorobenzyl methacrylate), a polymer with complex motions in the side groups, was chosen to carry out this study. The apparent distribution of retardation times of the polymer calculated from dielectric loss isotherms in a wide range of temperatures (T > Tg) presents two peaks which do not merge into a single absorption at moderate temperatures. The â absorption appearing as a shoulder of the R relaxation in global thermal stimulated depolarization current experiments is not at first sight detected in the retardation spectra. Separation of the hidden â absorption from the longest time peak in the retardation spectra was carried out by fitting the inverse of the Havriliak-Negami equation to the peak using b ) 1 and b < 1 for the skewness shape parameter of the â and R relaxations, respectively. Moreover, the shortest time peak in the retardation spectra was found to be the result of two overlapping peaks, named in increasing order of time ç and ç¢. Arrhenius plots for the R and â absorptions present a new scenario characterized for displaying both relaxations the same temperature dependence at temperatures not far above Tg. To investigate how small differences in the chemical structure may influence the dielectric response of polymers to perturbation fields, the results obtained for poly(2,4-difluorobenzyl methacrylate) are compared with those previously reported for poly(3-fluorobenzyl methacrylate). The differences in the responses of both polymers are interpreted in terms of molecular motions of the side groups.This research was supported by the DGICYT through Grants MAT2005-05648-C02-01/-02.Peer reviewe

Influence of the fine structure on the response of polymer chains to perturbation fields

The relaxation behavior of poly(3-methylbenzyl methacrylate), poly(3-fluorobenzyl methacrylate), and poly(3-chlorobenzyl methacrylate) was thoroughly studied by broadband dielectric spectroscopy with the aim of investigating the influence of slight differences in chemical structure on the response of polymers to electric perturbation fields. Retardation spectra calculated from dielectric isotherms utilizing linear programming regularization parameter techniques were used to facilitate the deconvolution of strongly overlapped absorptions. Above the glass transition temperature, the spectra of the two halogenated polymers present a secondary ç process well separated from a prominent peak resulting from the overlapping of the R and â relaxations. The spectra of poly(3-methylbenzyl methacrylate) exhibit at long times a well-developed R absorption followed in decreasing order of time by two weak absorptions, named â and ç, whose intensities increase with temperature. The temperature dependence of the distance of the R peak from the â and ç peaks, expressed in terms of log(fmax,â/fmax,R) and log(fmax,ç/fmax,R), respectively, is studied. The Williams ansatz and the extended ansatz give a fairly good account of the relaxation behavior of the polymers. The stretch exponent associated with the R relaxation increases with temperature from ca. 0.2 at low temperatures to the vicinity of 0.5 at high temperatures. At low temperatures, the R relaxation is described by a Vogel-type equation, but at high temperature the â and R processes are roughly described by the same Arrhenius equation. In the whole temperature range, the activation energy o the ç relaxation is significantly lower than that of the â absorption. The mechanisms involved in the development of the secondary relaxations are qualitatively discussed.This work was financially supported by the DGCYT and CAM through Grants MAT2002-04042-C02, MAT2005-05648-C02-02, and GR/MAT/0723/2004. L.G. and D.R. thank the FONDECYT for partial financial support through Grants 21050956 and 1050962, respectively.Peer reviewe

Retardation time spectra computed from complex compliance functions

This work describes the calculation of retardation time spectra by minimization of the square of the differences between experimental compliance results and those recalculated from the spectra. Spectra were computed taking analytical complex dielectric results as the basis of the minimization process. Comparison of the spectra computed from both the complex dielectric permittivity and the dielectric loss with those calculated analytically shows that minimization methods based on complex dielectric permittivity data are more accurate than those based only on loss dielectric resultsThis work was financially supported by the DGCYT and CAM through the Grant Nos. MAT2005-05648-C02-02 and GR/MAT/0723/2004.Peer reviewe

Secondary and primary relaxations in hyperbranched polyglycerol : A comparative study in the frequency and time domains

The non-Debye relaxation behavior of hyperbranched polyglycerol was investigated by broadband dielectric spectroscopy. A thorough study of the relaxations was carried out paying special attention to truncation effects on deconvolutions of overlapping processes. Hyperbranched polyglycerol exhibits two relaxations in the glassy state named in increasing order of frequency β and γ processes. The study of the evolution of these two fast processes with temperature in the time retardation spectra shows that the β absorption is swallowed by the α in the glass-liquid transition, the γ absorption being the only relaxation that remains operative in the liquid state. In heating, a temperature is reached at which the α absorption vanishes appearing the αγ relaxation. Two characteristics of α absorptions, decrease of the dielectric strength with increasing temperature and rather high activation energy, are displayed by the αγ process. Williams’ ansatz seems to hold for these topologically complex macromolecules.This work was supported by the Dirección General de Investigación Cientifica y Técnica DGICYT through the Grant Nos.MAT2002-04042-C02-01 and MAT2005-05648- C02-02. One of the authors A.G.-B. thanks the Spanish Ministry of Education and Science for a research contract (Ramón y Cajal Program).Peer reviewe

Influence of structural chemical characteristics on polymer chain dynamics

A comparative study of the dielectric relaxation behavior of two structurally close polymers containing aliphatic-aromatic side groups was carried out in order to get a better understanding on how slight differences in chemical structure affect the molecular responses to perturbation fields. Specifically, chain dynamics of poly 2-acryloyloxyethyl-2-naphthalene-2-ylacetate and poly 2-methacryloyloxyethyl-2-naphthalene-2-ylacetate were studied by broadband dielectric spectroscopy in the frequency range of 10−2–108 Hz and temperature window of 298–403 K. Also, the relaxation behavior of 2-acetyloxyethyl-2-naphthalene-2-ylacetate , model compound of the polymer side groups, was analyzed. The isotherms representing the dielectric loss in the frequency domain show important conductive contributions, especially at high temperature, which hide the low frequency side of the relaxation. Conductivity also increases the real component of the complex permittivity in the low frequencies region. Retardation spectra were obtained by minimizing the sum of the squares of the difference between the experimental values of the complex permittivity for each frequency and the analytical ones, predicted by the linear phenomenological theory, using a Tikhonov regularization technique. The spectra present an apparent peak with an excess wing at short time side resulting from the overlapping of the true relaxation and a process. Three absorptions, named in increasing order of time , , and relaxations, are separated by deconvolution methods. The activation energies associated with the process are 70.0 1.8, 68.0 1.4, and 74.8 0.8 kJ mol−1 for 2-acetyloxyethyl-2-naphthalene-2-yl acetate , poly 2-acryloyloxyethyl-2-naphthalene-2-yl acetate and poly 2-methacryloyloxyethyl- 2-naphthalene-2-yl acetate , respectively. The respective activation energies associated with the relaxation are 121.7 2.4, 135.3 1.4, and 141.6 1.3 kJ mol−1. Values of the shape parameters and the strengths of the relaxation processes were obtained as a function of temperature. The dynamic fragility of the polymers and the model compound was studied and compared with that reported for macromolecular and monomeric systems. Also, the evolution of the size of the correlated domains associated with the relaxation was estimated. Finally, the relaxation rather than the absorption obeys the criteria apparently held by the Johari–Goldstein processes.This work was financially supported by the DGCYT and CAM through Grant Nos. MAT2005-05648-C02-02 and GR/ MAT/0723/2004Peer reviewe