Development and internal validation of a model for postoperative morbidity in adults undergoing major elective colorectal surgery: the peri-operative quality improvement programme (PQIP) colorectal risk model.

Over 1.5 million major surgical procedures take place in the UK NHS each year and approximately 25% of patients develop at least one complication. The most widely used risk-adjustment model for postoperative morbidity in the UK is the physiological and operative severity score for the enumeration of mortality and morbidity. However, this model was derived more than 30 years ago and now overestimates the risk of morbidity. In addition, contemporary definitions of some model predictors are markedly different compared with when the tool was developed. A second model used in clinical practice is the American College of Surgeons National Surgical Quality Improvement Programme risk model; this provides a risk estimate for a range of postoperative complications. This model, widely used in North America, is not open source and therefore cannot be applied to patient populations in other settings. Data from a prospective multicentre clinical dataset of 118 NHS hospitals (the peri-operative quality improvement programme) were used to develop a bespoke risk-adjustment model for postoperative morbidity. Patients aged ≥ 18 years who underwent colorectal surgery were eligible for inclusion. Postoperative morbidity was defined using the postoperative morbidity survey at postoperative day 7. Thirty-one candidate variables were considered for inclusion in the model. Death or morbidity occurred by postoperative day 7 in 3098 out of 11,646 patients (26.6%). Twelve variables were incorporated into the final model, including (among others): Rockwood clinical frailty scale; body mass index; and index of multiple deprivation quintile. The C-statistic was 0.672 (95%CI 0.660-0.684), with a bootstrap optimism corrected C-statistic of 0.666 at internal validation. The model demonstrated good calibration across the range of morbidity estimates with a mean slope gradient of predicted risk of 0.959 (95%CI 0.894-1.024) with an index-corrected intercept of -0.038 (95%CI -0.112-0.036) at internal validation. Our model provides parsimonious case-mix adjustment to quantify risk of morbidity on postoperative day 7 for a UK population of patients undergoing major colorectal surgery. Despite the C-statistic of < 0.7, our model outperformed existing risk-models in widespread use. We therefore recommend application in case-mix adjustment, where incorporation into a continuous monitoring tool such as the variable life adjusted display or exponentially-weighted moving average-chart could support high-level monitoring and quality improvement of risk-adjusted outcome at the population level.

Paediatric Psychiatry Admissions to Critical Care.

Aims Children and adolescents may require admission to PICU to manage significant episodes of psychiatric or behavioural disorders. The primary aim was to determine the number of paediatric psychiatry patients requiring PICU admission and the indications for admission. Methods Our patient information system was used to identify patients admitted with a psychiatric presentation. Results Fifteen patients were admitted during the study period. Ten (66%) patients were admitted at a weekend and 12 (80%) were admitted after 5pm. The admitting diagnosis was self-harm in 7 (46%), psychosis in five (33%) and an eating disorder in three (20%) patients. Conclusion The number of patients requiring PICU admission was small but represents a significant challenge to staff and resources. There is a need to establish a governance structure and pathway of care for these patients.

Assessing discards in an illegal small-scale fishery using fisher-led reporting.

About a third of all marine fish in the world are caught in Small-Scale Fisheries (SSF). SSF are increasingly recognised as essential for food security and livelihoods for vulnerable and economically fragile communities globally. Although individual SSF vessels are usually perceived as having little impact on the ecosystem, the cumulative impact of gear type and number of vessels may be substantial. Bottom trawling is a common fishing method that can greatly influence the marine ecosystem by damaging the seafloor and generating high levels of discards. However, appropriate sampling coverage using on-board observer programmes to collect these data from SSF are rare, as they are expensive and pose logistical constraints. A mobile App was used to assess whether self-reporting by fishers could provide reliable fine-scale information on fishing effort and discards over time in an illegal shrimp trawling fishery in northern Peru. Maps depicting the spatial distribution of trawling effort and the proportion of discards from observers and fishers were compared using the Similarity in Means (SIM) Index, which ranges from 0 when spatial patterns differ completely to 1 when spatial patterns are very similar. High levels of agreement between spatio-temporal patterns of effort (SIM Index = 0.81) and discards (0.96) were found between fisher and observer maps. Moreover, far greater spatial coverage was accomplished by fishers, suggesting that self-reporting via an App represents a useful approach to collect reliable fisheries data as an initial step for effective monitoring and management of these fisheries. Supplementary Information: The online version contains supplementary material available at 10.1007/s11160-022-09708-9.

Determining tolerance levels for quality assurance of 3D printed bolus for modulated arc radiotherapy of the nose.

Given the existing literature on the subject, there is obviously a need for specific advice on quality assurance (QA) tolerances for departments using or implementing 3D printed bolus for radiotherapy treatments. With a view to providing initial suggested QA tolerances for 3D printed bolus, this study evaluated the dosimetric effects of changes in bolus geometry and density, for a particularly common and challenging clinical situation: specifically, volumetric modulated arc therapy (VMAT) treatment of the nose. Film-based dose verification measurements demonstrated that both the AAA and the AXB algorithms used by the Varian Eclipse treatment planning system (Varian Medical Systems, Palo Alto, USA) were capable of providing sufficiently accurate dose calculations to allow this planning system to be used to evaluate the effects of bolus errors on dose distributions from VMAT treatments of the nose. Thereafter, the AAA and AXB algorithms were used to calculate the dosimetric effects of applying a range of simulated errors to the design of a virtual bolus, to identify QA tolerances that could be used to avoid clinically significant effects from common printing errors. Results were generally consistent, whether the treatment target was superficial and treated with counter-rotating coplanar arcs or more-penetrating and treated with noncoplanar arcs, and whether the dose was calculated using the AAA algorithm or the AXB algorithm. The results of this study suggest the following QA tolerances are advisable, when 3D printed bolus is fabricated for use in photon VMAT treatments of the nose: bolus relative electron density variation within [Formula: see text] (although an action level at [Formula: see text] may be permissible); bolus thickness variation within [Formula: see text] mm (or 0.5 mm variation on opposite sides); and air gap between bolus and skin [Formula: see text] mm. These tolerances should be investigated for validity with respect to other treatment modalities and anatomical sites. This study provides a set of baselines for future comparisons and a useful method for identifying additional or alternative 3D printed bolus QA tolerances.

ASSESSMENT OF INTEGRITY AND LEAD-EQUIVALENCE OF SHIELDED GARMENTS USING TWO-DIMENSIONAL X-RAY IMAGES FROM A COMPUTED TOMOGRAPHY SCANNER.

Shielded garments are widely recommended for occupational radiation protection in diagnostic and interventional radiology. This study investigated a novel method for efficiently verifying shielded garment integrity while simultaneously acquiring data for lead-equivalence measurements, using two-dimensional topogram images from computed tomography (CT) scanners. This method was tested against more-conventional measurements with superficial and orthovoltage radiotherapy treatment beams, for 12 shielded garments containing 3 different lead-free shielding materials. Despite some energy-dependent results, all shielded garments approximately achieved their specified lead-equivalence for the energy range expected during clinical use for fluoroscopy procedures, except for three shielded skirts that required two layers of material to be overlapped at the front. All lead-equivalence measurements from CT topograms agreed with or conservatively underestimated the kV narrow-beam results. This method is potentially useful for independently assessing the shielding properties of new shielded garments and performing annual checks for damage or degradation of existing shielded garments.

Clinical implementation of a Monte Carlo based independent TPS dose checking system.

The increase in complexity of treatment plans over time through modalities such as intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) has often not been met with an increase in capability of the secondary dose calculation checking systems typically used to verify the treatment planning system. Monte Carlo (MC) codes such as EGSnrc have become easily available and are capable of performing calculations of highly complex radiotherapy treatments. This educational note demonstrates a method for implementing and using a fully automated system for performing and analysing full MC calculations of conformal, IMRT and VMAT radiotherapy plans. Example calculations were based on BEAMnrc/DOSXYZnrc and are performed automatically after either uploading exported plan DICOM data through a Python-based web interface, or exporting DICOM data to a monitored network location. This note demonstrates how completed MC calculations can then be analysed using an automatically generated dose point comparison report, or easily re-imported back into the treatment planning system. Agreement between the TPS and MC calculation was an improvement on agreement between RadCalc and the TPS, with differences ranging from 1.2 to 5.5% between RadCalc and the treatment planning system (TPS), and 0.1-1.7% between MC and TPS. Comparison of the dose-volume histogram (DVH) parameters [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] for the example VMAT plans showed agreement for the mean planning target volume dose within [Formula: see text], [Formula: see text] and [Formula: see text] generally within [Formula: see text] with the exception of a brain case, and [Formula: see text] within [Formula: see text]. Overall, this note provides a demonstration of a system that has been integrated well into existing clinical workflow, and has been shown to be a valuable additional tool in the secondary checking of treatment plan calculations.

Assessing the fit of 3D printed bolus from CT, optical scanner and photogrammetry methods.

Bolus plays an important role in the radiation therapy of superficial lesions and the application of 3D printing to its design can improve fit and dosimetry. This study quantitatively compares the fits of boluses designed from different imaging modalities. A head phantom was imaged using three systems: a CT simulator, a 3D optical scanner, and an interchangeable lens camera. Nose boluses were designed and 3D printed from each modality. A 3D printed phantom with air gaps of known thicknesses was used to calibrate mean HU to measure air gaps of unknown thickness and assess the fit of each bolus on the head phantom. The bolus created from the optical scanner data resulted in the best fit, with a mean air gap of 0.16 mm. Smoothing of the CT bolus resulted in a more clinically suitable model, comparable to that from the optical scanner method. The bolus produced from the photogrammetry method resulted in air gaps larger than 1 mm in thickness. The use of optical scanner and photogrammetry models have many advantages over the conventional bolus-from-CT method, however workflow should be refined to ensure accuracy if implemented clinically.

Quasi-simultaneous 3D printing of muscle-, lung- and bone-equivalent media: a proof-of-concept study.

3D printing is a promising solution for the production of bespoke phantoms and phantom components, for radiotherapy dosimetry and quality assurance (QA) purposes. This proof-of-concept study investigated the use of a dual-head printer to deposit two different filaments (polylactic acid (PLA) and StoneFil PLA-concrete (Formfutura BV, Nijmegen, Netherlands)) at several different in-fill densities, to achieve quasi-simultaneous 3D printing of muscle-, lung- and bone-equivalent media. A Raise 3D Pro 3D printer (Raise 3D Technologies Inc, Irvine, USA) was used to print one thoracic and one cranial phantom slab. Analysis using in-house 3D print QA software showed that the two humanoid phantom slabs geometrically matched the stereolithography (STL) files on which they were based, within 0.3 mm, except in one area of the thoracic slab that was affected by thermal warping by up to 3.4 mm. The 3D printed muscle, lung and bone materials in the two humanoid phantom slabs were approximately radiologically-equivalent to human muscle, lung and bone. In particular, the use of StoneFil with a nominally constant in-fill density of 100% resulted in regions that were approximately inner-bone-equivalent, at kV and MV energies. These regions were bounded by walls that were substantially denser than inner bone, although generally not dense enough to be truly cortical-bone-equivalent. This proof-of-concept study demonstrated a method by which multiple tissue-equivalent materials (eg. muscle-, lung- and bone-equivalent media) can be deposited within one 3D print, allowing complex phantom components to be fabricated efficiently in a clinical setting.

Mesophilic microorganisms build terrestrial mats analogous to Precambrian microbial jungles.

Development of Archean paleosols and patterns of Precambrian rock weathering suggest colonization of continents by subaerial microbial mats long before evolution of land plants in the Phanerozoic Eon. Modern analogues for such mats, however, have not been reported, and possible biogeochemical roles of these mats in the past remain largely conceptual. We show that photosynthetic, subaerial microbial mats from Indonesia grow on mafic bedrocks at ambient temperatures and form distinct layers with features similar to Precambrian mats and paleosols. Such subaerial mats could have supported a substantial aerobic biosphere, including nitrification and methanotrophy, and promoted methane emissions and oxidative weathering under ostensibly anoxic Precambrian atmospheres. High C-turnover rates and cell abundances would have made these mats prime locations for early microbial diversification. Growth of landmass in the late Archean to early Proterozoic Eons could have reorganized biogeochemical cycles between land and sea impacting atmospheric chemistry and climate.

A very low diffusion Fricke gel dosimeter with functionalised xylenol orange-PVA (XOPVA).

A gel dosimeter has been developed utilising a recently reported system for reducing Fe3+ diffusion in a Fricke gel dosimeter which chelates xylenol orange to the gelling agent poly(vinyl alcohol) (PVA). Formulations were investigated using both gelatin and PVA as the gelling agent, along with the inclusion of glyoxal. The resulting gel had an optical density dose response of 0.0031 Gy-1, an auto-oxidation rate of 0.000 23 h-1, and a diffusion rate of 0.132 mm2 h-1 which is a significant improvement over previously reported gelatin based Fricke gel dosimeters. The gel was also shown to be energy and dose-rate independent and could be reused after irradiation. Thus, this gel dosimeter has the potential to provide a safe and practical solution to three dimensional radiation dosimetry in the medical environment.

Application of retrospective data analysis to clinical protocol design: can the potential benefits of breath-hold techniques for breast radiotherapy be assessed without testing on patients?

The advantages, in terms of heart dose sparing, resulting from using a breath-hold technique when treating supine left breast radiotherapy patients are widely accepted, and increasing numbers of radiotherapy departments are implementing breath-hold techniques. However, due to differences in patient setup and treatment planning protocols between radiotherapy departments, it is important to assess the benefits of using a breath-hold technique within each department, before or during implementation. This study investigated the use of retrospective analysis of past patient treatment plans, as a means to identify the potential for breath-hold techniques to benefit patients. In-house "Treatment and Dose Assessor" code was used to complete a bulk retrospective evaluation of dose-volume metrics for 708 supine and 13 prone breast and chest wall radiotherapy treatments, that were planned using the same clinical protocols, which did not utilise a breath hold technique. For supine patients, results showed statistically significant differences between heart doses from left and right breast treatment plans, in the absence of significant differences between lung doses from left and right breast treatment plans, confirming the potential benefit of using a breath-hold technique for supine left breast radiotherapy patients. Fewer than 1% of the right breast treatment plans showed heart doses high enough to suggest a possible benefit from using a breath-hold technique. Approximately 50% of the prone left breast treatment plans included very low heart doses without intervention, and may therefore have shown no noticeable dosimetric benefit from the use of a breath hold. This study demonstrated the extent of information that can be obtained using retrospective data analysis, before or instead of obtaining multiple CT images of patients and completing a process of dual planning and prospective dose evaluation.

Cannabis Oil in an Irish Children's Critical Care Unit

Aims We present a case of a five-year-old female admitted postoperatively to the Paediatric Critical Care Unit with a history of refractory seizures for which her parents were administering cannabis oil. Methods We discuss the issues surrounding cannabis prescription in Ireland and the role of parental autonomy in medication selection and administration. Results An administration regime was agreed upon following discussion with the child's parents. Conslusion While this case raised ethical and legal issues, we must also consider parental autonomy and their role as advocate for their child during admission to critical care.

Cognitive functioning in systemic lupus erythematosus: a meta-analysis.

Cognitive deficits are common in patients with systemic lupus erythematosus (SLE) regardless of overt neuropsychiatric involvement; however, a clear neuropsychological profile of SLE has not emerged. This study undertook a literature search of the PubMed, Scopus and Ovid (PsychINFO) databases for studies investigating cognitive alterations in SLE, using standardized neuropsychological (NP) measures. The data were analysed using meta-analytical procedures. The results support the observation that relative to healthy controls, SLE (regardless of overt neuropsychiatric involvement) is associated with statistically significant, small effect-sized deficits in visual attention, cognitive fluency, immediate visual memory and visual reasoning. Moreover, the results support a gradient of cognitive disturbance in SLE with significantly greater cognitive impairment in NPSLE patients relative to non-NPSLE patients. Medium-sized deficits were observed in NPSLE patients relative to healthy controls across the domains of: complex attention, delayed verbal memory, language and verbal reasoning (with small or non-significant differences observed in non-NPSLE patients relative to healthy controls). These results are relevant to the understanding, assessment and rehabilitation of patients living with SLE, with or without overt neuropsychiatric involvement.

Accuracy and efficiency of published film dosimetry techniques using a flat-bed scanner and EBT3 film.

Gafchromic EBT3 film is widely used for patient specific quality assurance of complex treatment plans. Film dosimetry techniques commonly involve the use of transmission scanning to produce TIFF files, which are analysed using a non-linear calibration relationship between the dose and red channel net optical density (netOD). Numerous film calibration techniques featured in the literature have not been independently verified or evaluated. A range of previously published film dosimetry techniques were re-evaluated, to identify whether these methods produce better results than the commonly-used non-linear, netOD method. EBT3 film was irradiated at calibration doses between 0 and 4000 cGy and 25 pieces of film were irradiated at 200 cGy to evaluate uniformity. The film was scanned using two different scanners: The Epson Perfection V800 and the Epson Expression 10000XL. Calibration curves, uncertainty in the fit of the curve, overall uncertainty and uniformity were calculated following the methods described by the different calibration techniques. It was found that protocols based on a conventional film dosimetry technique produced results that were accurate and uniform to within 1%, while some of the unconventional techniques produced much higher uncertainties (> 25% for some techniques). Some of the uncommon methods produced reliable results when irradiated to the standard treatment doses (< 400 cGy), however none could be recommended as an efficient or accurate replacement for a common film analysis technique which uses transmission scanning, red colour channel analysis, netOD and a non-linear calibration curve for measuring doses up to 4000 cGy when using EBT3 film.

Organ and Tissue Donation in Irish Paediatric Intensive Care.

Aim Our aim was to present an overview of patterns of paediatric organ donation in the Republic of Ireland from January 2007 to January 2018. Methods We performed a retrospective audit of organ donation practice in paediatric intensive care units (PICU) in Ireland. Results Thirty-six children donated organs or tissue heart valves over the 11-year period. There were 13 paediatric organ donors between 2007 and 2012, this increased to 23 paediatric organ donors between 2013 and 2017. 2017 had the highest number of organ donors at 9 Conclusion Organ donation in Irish PICUs has increased over the last 11 years due to a combination of factors: improved resourcing and organization of Organ Donation Transplantation Ireland (ODTI), the establishment of clinical leads (both medical and nursing) in organ donation, a heightened awareness of organ donation and improved specialist Intensive Care dedicated consultant staffing. Finally organ donation is possible only through the generosity and altruism of bereaved families. Outcomes from donated organs have been excellent throughout the 11 year period audited.

Vaccine-Preventable Admissions to an Irish Paediatric Intensive Care.

In the Republic of Ireland, the schedule of state-funded immunisation for children is comprehensive and includes diphtheria, pertussis, tetanus, pneumococcus, hepatitis B, meningococcus C, haemophilus B, polio, measles, rubella and mumps. Varicella and meningococcal B vaccines are commercially available but are not currently funded by the government. Each of the illnesses preventable by these vaccines can cause substantial morbidity, and rarely mortality, in infants and children. Our PICU continues to see serious illness due to avoidable infection. There were 39 admissions in a 4 year period, with 34 children surviving to discharge. Nine children were infected with pneumococcus, with 4 deaths. There was one case of pertussis, causing death. Most infections occurred in previously healthy children. These preventable conditions represent a significant burden on children, families, and on social and healthcare resources.

Radiological properties of 3D printed materials in kilovoltage and megavoltage photon beams.

PURPOSE: This study evaluates the radiological properties of different 3D printing materials for a range of photon energies, including kV and MV CT imaging and MV radiotherapy beams. METHODS: The CT values of a number of materials were measured on an Aquilion One CT scanner at 80kVp, 120kVp and a Tomotherapy Hi Art MVCT imaging beam. Attenuation of the materials in a 6MV radiotherapy beam was investigated. RESULTS: Plastic filaments printed with various infill densities have CT values of -743±4, -580±1 and -113±3 in 120kVp CT images which approximate the CT values of low-density lung, high-density lung and soft tissue respectively. Metal-infused plastic filaments printed with a 90% infill density have CT values of 658±1 and 739±6 in MVCT images which approximate the attenuation of cortical bone. The effective relative electron density REDeff is used to describe the attenuation of a megavoltage treatment beam, taking into account effects relating to the atomic number and mass density of the material. Plastic filaments printed with a 90% infill density have REDeff values of 1.02±0.03 and 0.94±0.02 which approximate the relative electron density RED of soft tissue. Printed resins have REDeff values of 1.11±0.03 and 1.09±0.03 which approximate the RED of bone mineral. CONCLUSIONS: 3D printers can model a variety of body tissues which can be used to create phantoms useful for both imaging and dosimetric studies.