PreciSSIon: a collaborative initiative to reduce surgical site infections after elective colorectal surgery.

BACKGROUND: Surgical site infections (SSIs) are common after colorectal surgery, but most hospitals do not know their SSI rates. Approximately half of SSIs occur after discharge, and postdischarge surveillance is needed for accurate measurement. Perioperative care bundles are known to reduce SSI rates. PreciSSion is a collaboration between seven hospitals in the West of England. AIMS: To establish reliable SSI measurement after elective colorectal surgery using 30-day patient-reported outcome measures, and to implement an evidence-based four-point care bundle that had already demonstrated a reduction in the SSI rate in a local hospital. The bundle included: 2% chlorhexidine skin preparation, a second dose of antibiotic after 4 h, use of a dual-ring wound protector, and use of antibacterial sutures for abdominal wall closure. METHODS: The 30-day patient-reported SSI rate was determined using the Public Health England questionnaire, and response rates were recorded. The baseline SSI rate was measured from November 2019 to May 2020, and continued after implementation of the care bundle until March 2021. Bundle compliance was also measured. FINDINGS: The average questionnaire response rate was 81%, and average compliance was 92%, 96%, 79% and 85% for each element of the bundle. The baseline SSI rate was 8-30%. Six of seven hospitals reduced their SSI rate, and the regional average SSI rate almost halved from 18% (1447 patients) to 9.5% (1247 patients). CONCLUSION: A care bundle developed in a single hospital can be adopted in other hospitals, and a 50% reduction in SSI rate after elective colorectal surgery can be replicated in other hospitals within 18 months.

Surgical site infection prevention bundle in elective colorectal surgery.

OBJECTIVE: Surgical Site Infections (SSIs) are responsible for a significant economic burden as well as intangible costs suffered by the patient, with up to 60% deemed preventable. Colorectal patients are disproportionally affected by SSI due the risk of wound contamination with bowel content. We aimed to reduce the rate of superficial SSI after elective colorectal surgery using a bundle of evidence-based interventions. METHODS: An SSI prevention bundle was implemented in elective colorectal surgery, comprised of triclosan-coated sutures, 2% chlorhexidine skin preparation and use of warmed carbon dioxide (CO2) during laparoscopic procedures. The SSI reduction strategy was prospectively implemented and compared with historical controls. Our primary outcome measure was the overall rate of superficial SSI. Centres for Disease Control and Prevention criteria, which use microbiological evidence in conjunction with clinical features were used as the definition of SSI. RESULTS: The overall SSI rate was 27.4% in the pre-bundle group (N = 208) and 12.5% in the patients who received the SSI prevention bundle (N = 184) (adjusted odds ratio 0.38; confidence interval 0.21-0.67; P<0.001). The median time to SSI diagnosis was postoperative day 8. Overall patient length of stay (LOS) was unchanged from six days at baseline following implementation of the bundle. CONCLUSIONS: We have shown successful implementation of an SSI prevention bundle which has reduced superficial SSI rate. We recommend this SSI prevention bundle becomes standard practice in elective colorectal surgery and plan to extend the bundle to emergency general surgery.

Impact of surgical complications on the operating surgeon.

AIM: The involvement of surgeons in major adverse outcomes can have a negative impact on their personal and professional lives, as well as on patient outcomes. Healthcare professionals involved in such incidents have been referred to as 'second victims'. We designed an online survey to study the impact of operative complications on surgeons' professional and personal lives. METHOD: An online survey of general, gastrointestinal, hepato-pancreato-biliary and vascular surgeons was conducted using the Twitter feed of the Association of Coloproctology of Great Britain and Ireland, the Association of Surgeons of Great Britain and Ireland and the European Society of Coloproctology over an 8-week period. RESULTS: Questionnaires were completed by 82 participants. Ninety-one per cent of respondents were consultant surgeons, 37% with more than 15 years' experience. Eighty-three per cent were colorectal surgeons. The majority of surgeons (95%) reported that their practice had been affected as a result of serious complications and 54% suggested that it had had a negative impact on their family life. Fifty-five per cent of respondents mentioned lack of support in their institution for healthcare professionals involved in adverse outcomes and an existing blame culture. Suggestions for improvement included mentoring (41%), counselling (38%), openness (66%), peer support groups (52%) and human factors training (32%). CONCLUSION: This survey highlights that the majority of surgeons involved in serious complications are adversely affected. Those involved in the running of surgical services need to improve support for surgeons in the aftermath of such events.

Incidence and risk factors for alopecia in survivors of critical illness: A multi-centre observational study.

PURPOSE: To investigate the incidence, nature and risk factors for patient-reported alopecia in survivors of critical illness. MATERIALS AND METHODS: A multi-centre, mixed methods observational study in the intensive care units (ICU) of ten hospitals in Wales. All patients with an ICU stay of 5 days or more, able to give consent were included. Demographic variables and risk factors were collected. A pre-designed survey was completed at three months post-ICU discharge. Statistical analysis included numbers and percentages (categorical variables) and medians and interquartile ranges (continuous variables). Comparisons between patients with and without alopecia were made using Fisher's Exact test (categorical variables) and Mann Whitney U test (continuous variables). Multivariate logistic regression analysis was used to determine the risk factors for alopecia. RESULTS: The survey was completed by 123 patients with alopecia reported in 44 (36%) patients. The only risk factor for alopecia on analysis was sepsis / septic shock (p < .001; OR: 5.1, 95%CI: 2.1-12.4). CONCLUSIONS: Limited research exists examining the incidence, nature and risk factors for patient-reported alopecia in adult survivors of critical illness. The results of this study highlight the need to discuss the potential for alopecia with survivors of critical illness, who had sepsis / septic shock.

Self-reported sleepwalking in Australian senior secondary school students.

BACKGROUND: Few studies have examined self-reported sleepwalking in older adolescents. The aim of this study was to examine the prevalence rates of sleepwalking in a one-month self-report period in Australian adolescents. METHODS: Participants were 532 Australian adolescents in their final two years of secondary school. RESULTS: The prevalence of sleepwalking in the one-month self-report period was 2.9% (95% confidence interval (CI) 1.47-4.33) in this sample-1% reported sleepwalking at least once a week in the previous month. A significant proportion (17.5%) of the participants was unsure if they had sleepwalked. CONCLUSION: The results provide data on the self-reported prevalence rate of sleepwalking in older adolescents. Compared with the population data, this rate falls within the confidence intervals of child and adult prevalence rates of sleepwalking and is consistent with a decline in sleepwalking from childhood and adulthood. Further research is needed to explore how adolescents know they sleepwalk to understand the reliability of self-report measures.

Spline modelling electron insert factors using routine measurements.

There are many methods available to predict electron output factors; however, many centres still measure the factors for each irregular electron field. Creating an electron output factor prediction model that approaches measurement accuracy--but uses already available data and is simple to implement--would be advantageous in the clinical setting. This work presents an empirical spline model for output factor prediction that requires only the measured factors for arbitrary insert shapes. Equivalent ellipses of the insert shapes are determined and then parameterised by width and ratio of perimeter to area. This takes into account changes in lateral scatter, bremsstrahlung produced in the insert material, and scatter from the edge of the insert. Agreement between prediction and measurement for the 12 MeV validation data had an uncertainty of 0.4% (1SD). The maximum recorded deviation between measurement and prediction over the range of energies was 1.0%. The validation methodology showed that one may expect an approximate uncertainty of 0.5% (1SD) when as little as eight data points are used. The level of accuracy combined with the ease with which this model can be generated demonstrates its suitability for clinical use. Implementation of this method is freely available for download at https://github.com/SimonBiggs/electronfactors.

Psychometric properties of an omnibus sleep problems questionnaire for school-aged children.

OBJECTIVE: There is a paucity of sleep questionnaires that have been psychometrically validated for use in school-aged children. Due to the limitation regarding the psychometric properties and the great variety in question design, there remains a need for a robust omnibus questionnaire that assesses sleep problems in community populations. This study aimed to develop such a questionnaire for school-aged children by assessing the construct validity and reliability of a questionnaire based on a combination of children's sleep domains from two frequently used and validated questionnaires (Habits Questionnaire and Sleep Disorders Scale for Children) and author devised questions. PATIENTS/METHODS: Parents of 1904 children aged 5-10 years (mean 7.7 ± 1.7 years) from 32 elementary schools in Adelaide, South Australia, completed the questionnaire. RESULTS: Principal axis factoring revealed six unique sub-scales--Sleep Routine, Bedtime Anxiety, Morning Tiredness, Night Arousals, Sleep Disordered Breathing, and Restless Sleep--containing a total of 26 items. Internal consistency for sub-scales were moderate to strong (range α = 0.6-0.8) and test-retest reliability was adequate (>0.4). T-score cut-offs were devised for age and sex. CONCLUSION: The new questionnaire provides a robust set of sleep problem sub-scales which can be used for assessment of sleep concerns in a community sample as well as provide for optimal analysis of associations with other measures of childhood daytime functioning such as neurocognition and behaviour.

Tracking neonatal nosocomial infection: the continuous quality improvement cycle.

Neonatal nosocomial infection (NNI) is a major complication of neonatal care, increasing mortality, morbidity and the costs of healthcare. Management of NNI involves attention to many details of care, creating a culture of change within a neonatal unit and the implementation of a continuous quality improvement cycle. This paper describes the initiation of a quality improvement team (QIT) and the aspects of infection control bundles that have been implemented. The setting was a single large perinatal centre over a seven-year period. Statistical tracking of NNI in exceedingly premature infants was by control charting methodology. A steady and statistically significant decline in NNI rates from 13 to seven episodes per 1000 bed-days (censored to day 35) for infants less than 29 weeks of gestation has been recorded. A multidisciplinary QIT has managed the implementation of measures designed to reduce NNI in the unit. These have included raising awareness of the need for asepsis, improved hand hygiene, increased vigilance in using central lines, monitoring blood culture collection techniques and improving the environment. We believe such measures in conjunction with the positive feedback obtained from charting have been responsible for the steady decline in NNI. This study is one of the first to close the QIT loop and to demonstrate statistical improvement in NNI through the introduction of specific care bundles.

Falls exercise interventions and reduced falls rate: always in the patient's interest?

Falls are a leading cause of mortality and morbidity in older adults. Physical, psychological and social consequences include injury, fall-related fear and loss of self-efficacy. In turn, these may result in decreased physical activity, reduced functional capacity, and increased risk of institutionalisation. Falls prevention exercise programmes (FPEP) are now widespread within the National Health Service, often part of multifactorial interventions, and are designed to minimise impairments that impact physical function, such as strength and balance. Assessment of the clinical efficacy of FPEPs has therefore focused on the measurement of physical function and rate of falls. Whilst important, this approach may be too narrow to capture the highly variable and multidimensional responses that individuals make to a fall and to a FPEP. We argue that the current focus may miss a paradoxical lack of or even deleterious impact on quality of life, despite a reduction in physical performance-related falls risk. We draw upon the Selective Optimisation and Compensation (SOC) model, developed by Paul and Margret Baltes, to explore how this paradox may be a result of the coping strategies adopted by individuals in response to a fall.

Chasing the silver bullet: measuring driver fatigue using simple and complex tasks.

Driver fatigue remains a significant cause of motor-vehicle accidents worldwide. New technologies are increasingly utilised to improve road safety, but there are no effective on-road measures for fatigue. While simulated driving tasks are sensitive, and simple performance tasks have been used in industrial fatigue management systems (FMS) to quantify risk, little is known about the relationship between such measures. Establishing a simple, on-road measure of fatigue, as a fitness-to-drive tool, is an important issue for road safety and accident prevention, particularly as many fatigue related accidents are preventable. This study aimed to measure fatigue-related performance decrements using a simple task (reaction time - RT) and a complex task (driving simulation), and to determine the potential for a link between such measures, thus improving FMS success. Fifteen volunteer participants (7 m, 8 f) aged 22-56 years (mean 33.6 years), underwent 26 h of supervised wakefulness before an 8h recovery sleep opportunity. Participants were tested using a 30-min interactive driving simulation test, bracketed by a 10-min psychomotor vigilance task (PVT) at 4, 8, 18 and 24h of wakefulness, and following recovery sleep. Extended wakefulness caused significant decrements in PVT and driving performance. Although these measures are clearly linked, our analyses suggest that driving simulation cannot be replaced by a simple PVT. Further research is needed to closely examine links between performance measures, and to facilitate accurate management of fitness to drive, which requires more complex assessments of performance than RT alone.

The muscle activation method: an approach to impedance control of brain-machine interfaces through a musculoskeletal model of the arm.

Current demonstrations of brain-machine interfaces (BMIs) have shown the potential for controlling neuroprostheses under pure motion control. For interaction with objects, however, pure motion control lacks the information required for versatile manipulation. This paper investigates the idea of applying impedance control in a BMI system. An extraction algorithm incorporating a musculoskeletal arm model was developed for this purpose. The new algorithm, called the muscle activation method (MAM), was tested on cortical recordings from a behaving monkey. The MAM was found to predict motion parameters with as much accuracy as a linear filter. Furthermore, it successfully predicted limb interactions with novel force fields, which is a new and significant capability lacking in other algorithms.

Continuous shared control for stabilizing reaching and grasping with brain-machine interfaces.

Research on brain-machine interfaces (BMI's) is directed toward enabling paralyzed individuals to manipulate their environment through slave robots. Even for able-bodied individuals, using a robot to reach and grasp objects in unstructured environments can be a difficult telemanipulation task. Controlling the slave directly with neural signals instead of a hand-master adds further challenges, such as uncertainty about the intended trajectory coupled with a low update rate for the command signal. To address these challenges, a continuous shared control (CSC) paradigm is introduced for BMI where robot sensors produce reflex-like reactions to augment brain-controlled trajectories. To test the merits of this approach, CSC was implemented on a 3-degree-of-freedom robot with a gripper bearing three co-located range sensors. The robot was commanded to follow eighty-three reach-and-grasp trajectories estimated previously from the outputs of a population of neurons recorded from the brain of a monkey. Five different levels of sensor-based reflexes were tested. Weighting brain commands 70% and sensor commands 30% produced the best task performance, better than brain signals alone by more than seven-fold. Such a marked performance improvement in this test case suggests that some level of machine autonomy will be an important component of successful BMI systems in general.

The influence of chain length and electrolyte on the adsorption kinetics of cationic surfactants at the silica-aqueous solution interface.

The equilibrium and kinetic aspects of the adsorption of alkyltrimethylammonium surfactants at the silica-aqueous solution interface have been investigated using optical reflectometry. The effect of added electrolyte, the length of the hydrocarbon chain, and of the counter- and co-ions has been elucidated. Increasing the length of the surfactant hydrocarbon chain results in the adsorption isotherm being displaced to lower concentrations. The adsorption kinetics indicate that above the cmc micelles are adsorbing directly to the surface and that as the chain length increases the hydrophobicity of the surfactant has a greater influence on the adsoption kinetics. While the addition of 10 mM KBr increases the CTAB maximal surface excess, there is no corresponding increase for the addition of 10 mM KCl to the CTAC system. This is attributed to the decreased binding efficiency of the chloride ion relative to the bromide ion. Variations in the co-ion species (Li, Na, K) have little effect on the adsorption rate and surface excess of CTAC up to a bulk electrolyte concentration of 10 mM. However, the rate of adsorption is increased in the presence of electrolyte. Slow secondary adsorption is seen over a range of concentrations for CTAC in the absence of electrolyte and importantly in the presence of LiCl; the origin of this slow adsorption is attributed to a structural barrier to adsorption.

Mechanism of cationic surfactant adsorption at the solid-aqueous interface.

Until recently, the rapid time scales associated with the formation of an adsorbed surfactant layer at the solid-aqueous interface has prevented accurate investigation of adsorption kinetics. This has led to the mechanism of surfactant adsorption being inferred from thermodynamic data. These explanations have been further hampered by a poor knowledge of the equilibrium adsorbed surfactant morphology, with the structure often misinterpreted as simple monolayers or bilayers, rather than the discrete surface aggregates that are present in many surfactant-substrate systems. This review aims to link accepted equilibrium data with more recent kinetic and structural information in order to describe the adsorption process for ionic surfactants. Traditional equilibrium data, such as adsorption isotherms obtained from depletion approaches, and the most popular methods by which these data are interpreted are examined. This is followed by a description of the evidence for discrete aggregation on the substrate, and the morphology of these aggregates. Information gained using techniques such as atomic force microscopy, fluorescence quenching and neutron reflectivity is then reviewed. With this knowledge, the kinetic data obtained from relatively new techniques with high temporal resolution, such as ellipsometry and optical reflectometry, are examined. On this basis the likely mechanisms of adsorption are proposed.

Viscosity effect on the structural compactness of latex flocs formed under weak depletion attractions.

Dilute aqueous dispersions of colloidal polystyrene latex spheres were flocculated by adding a nonadsorbing polymer sample, poly(acrylic acid). The structural compactness of the flocs thus formed was characterized in terms of their mass fractal dimension using the small-angle static light scattering technique. It was found that with low poly(acrylic acid) concentrations and thus weak depletion attraction forces, the dispersion medium viscosity had a marked effect on the floc structure. An increase in the viscosity led to formation of denser flocs. This was revealed in three sets of depletion flocculation experiments: (a) adjusting the background electrolyte concentration at a fixed level of poly(acrylic acid), (b) using water and 30% (w/w) glycerol as the respective solvents, and (c) inducing latex flocculation with two poly(acrylic acids) of different molecular weights at the respective critical polyacid concentrations. Direct force measurements were made with atomic force microscopy to isolate the influence of viscosity on floc structure from that of interparticle interaction energies. We conclude that the formation of denser flocs with increasing medium viscosity can be attributed to the reduced diffusivity of particles in the solution. The latter resulted in an enhanced rate of floc restructuring (through relaxation of attached particles) relative to floc growth.

A critical assessment of proximal macrotexturing on cemented femoral components.

We analyzed the cement-metal interface of 3 different types of femoral components that had proximal macrotexturing after in vitro insertion and after fatigue testing designed to produce debonding and micromotion. These components were compared with clinical retrieval specimens. The cement did not flow into the macrotexturing; rather, hollow, brittle volcanoes or calderas were formed. These fragile protrusions of cement become worn down or abraded by debonded components. This abrasion of cement may contribute to the early and aggressive osteolysis seen in some of these early failures with proximal macrotextured components. The formation of these volcanos and calderas can be aborted by placing bone-cement onto the macrotexturing before stem insertion. This simple technique allows the macrotexturing to be filled with cement.

Assessing the health impact of age-specific housing.

It has been claimed that 'retirement communities', defined in this instance as voluntary communities of older people living in shared, purpose-built housing, combine the best attributes of residential and community living. Subjective health status may thereby be improved through a culture in which independence and autonomy are actively promoted. Concern has also been raised that age-segregated communities of this sort might produce 'ghettos' of increasing dependency and service demand. This study, conducted over a 12-month time period, found that when compared to older people living in the local neighbourhood, the retirement community population maintained their physical and mental health (utilising measures including the SF36, Life Satisfaction Index, and 18 semantic differentials). Investigation of these findings indicated that peer support and safety/security, and 'autonomy with inclusion' were key factors in maintaining health status.

A new pin-on-disk wear testing method for simulating wear of polyethylene on cobalt-chrome alloy in total hip arthroplasty.

Hip simulator studies show that the wear of ultra-high molecular weight polyethylene against a cobalt alloy head depends on the wear path, especially the combination of a predominantly linear wear direction on which is superimposed motions in different directions. We postulated that multidirectional motion was necessary to generate realistic wear rates in pin-on-disk testing. To assess this hypothesis, a new pin-on-disk tester was developed, capable of unidirectional and bidirectional motion. Unidirectional motion produced no detectable wear. The rectangular motion produced wear rates, surface morphologies, and wear particles consistent with human acetabular specimens. The results for 1 Hz and 2 Hz were similar.

Microscopic and macroscopic aspects of stick-slip motion in granular shear.

An annular shear cell has been used to investigate a number of factors known to influence stick-slip motion in an assembly of near monosized, spherical glass beads. In this paper, both the sample shear stress and volumetric strain were recorded, allowing new insights into the possible mechanics of stick-slip motion in a granular body. Rather than the commonly presented mechanism of sample dilation and fluidization accompanying the slip events, in the material studied here, sample dilation occurred during the preslip deformations of the granular body, while the slip event was accompanied by assembly contraction. Drive velocity and applied normal pressure were both found to influence the magnitude of the stick-slip spikes in a manner analogous to previous studies of stick-slip in assemblies of confined, near-spherical lubricant systems. Finally, atmospheric relative humidity was found to have a marked effect on the magnitude of the stick-slip motion. To investigate this mechanism more fully, the atomic force microscopy was employed to measure the particle-particle interaction forces as a function of atmospheric relative humidity. A water meniscus was found to form under all humidities, from less than 5% to greater than 95%. However, its influence on the adhesive forces varied by an order of magnitude. While most previous studies of stick-slip phenomena have attempted to remove atmospheric humidity as a variable, here we present a useful link between the role of relative humidity on particle-particle interaction forces and the macroscopic response of the granular assembly.