Reconciling chemical flame retardant exposure and fire risk in domestic furniture.

INTRODUCTION: Evidence suggests that standards for resistance of furniture to ignition may lead to an increase in use of chemical flame retardants (CFRs). This is motivating the development of new approaches that maintain high levels of fire safety while facilitating a reduction in use of CFRs. However, reconciling potential fire risk with use of CFRs in relation to specific policy objectives is challenging. OBJECTIVES: To inform the development of a new policy in the UK for the fire safety of furniture, we developed for domestic furniture quantitative models of fire risk and potential for CFR exposure. We then combined the models to determine if any lower fire risk, higher CFR exposure categories of furniture were identifiable. METHODS: We applied a novel mixed-methods approach to modelling furniture fire risk and CFR exposure in a data-poor environment, using literature-based concept mapping, qualitative research, and data visualisation methods to generate fire risk and CFR exposure models and derive furniture product rankings. RESULTS: Our analysis suggests there exists a cluster of furniture types including baby and infant products and pillows that have comparable overall properties in terms of lower fire risk and higher potential for CFR exposure. DISCUSSION: There are multiple obstacles to reconciling fire risk and CFR use in furniture. In particular, these include a lack of empirical data that would allow absolute fire risk and exposure levels to be quantified. Nonetheless, it seems that our modelling method can potentially yield meaningful product clusters, providing a basis for further research.

Defining the safety of early ileostomy closure after ileal pouch anal anastomosis.

PURPOSE: The safety of early ileostomy reversal after ileal pouch anal anastomosis (IPAA) has not been established. Our hypothesis was that ileostomy reversal before 8 weeks is associated with negative outcomes. METHODS: This was a retrospective cohort study from a prospectively maintained institutional database. Patients who underwent primary IPAA with ileostomy reversal between 2000 and 2021 from a Pouch Registry were stratified on the basis of timing of reversal. Those reversed before 8 weeks (early) and those reversed from 8 weeks to 116 days (routine) were compared. The primary outcome was overall complications according to timing and reason for closure. RESULTS: Ileostomy reversal was performed early in 92 patients and routinely in 1908. Median time to closure was 49 days in the early group and 93 days in the routine group. Reasons for early reversal were stoma-related morbidity in 43.3% (n = 39) and scheduled closure in 56.7% (n = 51). The complication rate in the early group was 17.4% versus 11% in the routine group (p = 0.085). When early patients were stratified according to reason for reversal, those reversed early for stoma-related morbidity had an increased complication rate compared to the routine group (25.6% vs. 11%, p = 0.006). Patients undergoing scheduled reversal in the early group did not have increased complications (11.8% vs. 11%, p = 0.9). There was a higher likelihood of pouch anastomotic leak when reversal was performed early for stoma complications compared to routinely (OR 5.13, 95% CI 1.01-16.57, p = 0.049). CONCLUSIONS: Early closure is safe but could be delayed in stoma morbidity as patients may experience increased complications.

Burning behaviour of rainscreen façades.

Four reduced-height (5 m) BS 8414-1 façade flammability tests were conducted, three having mineral-filled aluminium composite material (ACM-A2) with polyisocyanurate (PIR) and phenolic (PF) foam and stone wool (SW) insulation, the fourth having polyethylene-filled ACM (ACM-PE) with PIR insulation. Each façade was constructed from a commercial façade engineer's design, and built by practising façade installers. The ACM-PE/PIR façade burnt so ferociously it was extinguished after 13.5 min, for safety. The three ACM-A2 cladding panels lost their structural integrity, and melted away from the test wall, whereupon around 40% of both the combustible PIR and PF insulation burnt and contributed to the fire spread. This demonstrates why all façade products must be non-combustible, not just the outer panels. For the three ACM-A2 tests, while the temperature in front of the cavity was independent of the insulation, the temperatures within it varied greatly, depending on the insulation. The system using PF/A2 allowed fire to break through to the cavity first, as seen by a sharp increase in temperature after 17 min. For PIR/A2, the temperature increased sharply at 22 minutes, as the panel started to fall away from the wall. For SW/A2, no rapid temperature rise was observed.

Smoke toxicity of rainscreen façades.

The toxic smoke production of four rainscreen façade systems were compared during large-scale fire performance testing on a reduced height BS 8414 test wall. Systems comprising 'non-combustible' aluminium composite material (ACM) with polyisocyanurate (PIR), phenolic foam (PF) and stone wool (SW) insulation, and polyethylene-filled ACM with PIR insulation were tested. Smoke toxicity was measured by sampling gases at two points - the exhaust duct of the main test room and an additional 'kitchen vent', which connects the rainscreen cavity to an occupied area. Although the toxicity of the smoke was similar for the three insulation products with non-combustible ACM, the toxicity of the smoke flowing from the burning cavity through the kitchen vent was greater by factors of 40 and 17 for PIR and PF insulation respectively, when compared to SW. Occupants sheltering in a room connected to the vent are predicted to collapse, and then inhale a lethal concentration of asphyxiant gases. This is the first report quantifying fire conditions within the cavity and assessing smoke toxicity within a rainscreen façade cavity.

Small bowel adenocarcinoma in Crohn's disease: a rare but devastating complication.

BACKGROUND: Small bowel adenocarcinoma (SBA) remains a rare entity but occurs at increased frequency in the setting of chronic Crohn's disease (CD). Our aim was to study the presentation, diagnosis and prognosis of SBA in patients undergoing surgery for CD at a single institution. METHODS: We reviewed the medical records of all patients with CD complicated by adenocarcinoma of the small bowel from 2000 to 2017. Descriptive statistics and Kaplan-Meier overall survival estimates were calculated. RESULTS: In total, 22 patients (14 males) with CD (median duration of Crohn's diagnosis 32 years) were diagnosed with SBA and underwent surgical resection (8 isolated small bowel resections, 12 ileocolic resections, and 2 total proctocolectomies). The median patient age at the time of diagnosis was 54 years (range 22-82 years). A total of 17 patients (77%) underwent cross-sectional CT imaging within 3 months of surgery, a cancer diagnosis was suggested in only one patient. In one other patient, SBA was diagnosed preoperatively on endoscopic biopsy of the terminal ileum. The remaining patients were operated on for obstruction (n = 17), abscess or fistulizing disease (n = 2), and sigmoid cancer (n = 1). For these 20 (90%) patients not suspected to have SBA on preoperative assessment, 5 (25%) were diagnosed intraoperatively on frozen section and 15 (75%) were unexpectedly diagnosed postoperatively on final pathology. T staging was characterized by more advanced tumors (T4: 59%, T3: 27%, T2: 9%, and T1: 5%). Nine patients (41%) had nodal involvement and five patients (23%) had hepatic and/or peritoneal carcinomatosis. The 1-, 3-, and 5-year survival estimates for our cohort were 84%, 30%, and 10%, respectively. Median survival was 30.5 months with median follow-up of 23 months (range 6-84 months). CONCLUSIONS: SBA in the setting of CD is most commonly found incidentally after surgical resection for benign indications. As such, any suspicious finding at the time of surgery in a patient with chronic CD should warrant careful investigation with frozen section and/or resection. Prognosis for CD complicated by SBA remains poor even in the modern era.

Excisional haemorrhoidectomy: is it safe in patients with an ileal pouch-anal anastomosis?

AIM: Excisional haemorrhoidectomy in patients with ulcerative colitis (UC), especially those undergoing an ileal pouch-anal anastomosis (IPAA), remains controversial. The aim of our study was to determine the safety of excisional haemorrhoidectomy in UC patients with and without an IPAA. METHOD: A retrospective review of all adult UC patients undergoing excisional haemorrhoidectomy between 1 January 1995 and 1 January 2019 at a tertiary inflammatory bowel disease referral centre was performed. Data collected included patient demographics, clinical characteristics of UC, prior surgical intervention for UC (colectomy, IPAA) and complications after haemorrhoidectomy. RESULTS: Forty-one adult patients [50% male; median age 52 (range 25-79) years] with UC underwent excisional haemorrhoidectomy between 1 January 1995 and 1 January 2019. The majority (n = 23) had not previously undergone surgery for UC. However, eight had already undergone construction of an IPAA at the time of haemorrhoidectomy, seven had IPAA at the time of haemorrhoidectomy and three had an IPAA constructed subsequent to haemorrhoidectomy. Two (4.9%) patients need to go back to theatre for postoperative bleeding. There were no further 30-day complications or long-term nonhealing of the surgical site. There were no pouch complications in those who had haemorrhoidectomy at the time of IPAA construction or in the presence of an IPAA. CONCLUSION: Our data suggest that excisional haemorrhoidectomy may be performed safely in carefully selected UC patients with symptomatic haemorrhoids with or without IPAA and even at the time of IPAA construction.

Difference in the frequency of pouchitis between ulcerative colitis and familial adenomatous polyposis: is the explanation in peripouch fat?

AIM: Patients with ulcerative colitis (UC) have an unexplained higher incidence of pouchitis and a greater amount of peripouch fat compared with patients with familial adenomatous polyposis (FAP). The aims of this study were to compare the peripouch fat areas between patients with UC and patients with FAP, and to explore relationship between peripouch fat and pouchitis or chronic antibiotic-refractory pouchitis (CARP). METHOD: Patients with an abdominal CT image from our prospectively maintained Pouch Database were included. Abdominal fat and peripouch fat were measured on CT images at different levels or planes. Comparisons of peripouch fat and CARP were performed before and after propensity score matching. RESULTS: A total of 277 patients with UC and 40 patients with FAP were included. Compared with patients with FAP, patients with UC were found to have a higher incidence of pouchitis (58.5% vs 15.0%, P < 0.001) and CARP (24.5% vs 2.5%, P = 0.002) and a higher total peripouch fat area (P = 0.030) and mesenteric peripouch fat area (P = 0.022) at Level-3. Univariate and multivariate analyses showed that diagnosis (UC vs FAP) and peripouch fat areas at Level-3 and Level-5 were independent risk factors for CARP. With propensity score matching, 38 pairs of patients with UC and FAP were matched successfully. After matching, patients with UC were found to have higher total peripouch fat area and higher mesenteric peripouch fat area at Level-3, and a higher incidence of pouchitis (57.9% vs 13.2%, P < 0.001) and CARP (23.7% vs 2.6%, P = 0.007). CONCLUSION: Our study demonstrates that patients with UC have more peripouch fat than those with FAP, which may explain the difference in the frequency of pouchitis and CARP between these groups of patients.

Fire behaviour of modern façade materials - Understanding the Grenfell Tower fire.

The 2017 Grenfell Tower fire spread rapidly around the combustible façade system on the outside of the building, killing 72 people. We used a range of micro- and bench-scale methods to understand the fire behaviour of different types of façade product, including those used on the Tower, in order to explain the speed, ferocity and lethality of the fire. Compared to the least flammable panels, polyethylene-aluminium composites showed 55x greater peak heat release rates (pHRR) and 70x greater total heat release (THR), while widely-used high-pressure laminate panels showed 25x greater pHRR and 115x greater THR. Compared to the least combustible insulation products, polyisocyanurate foam showed 16x greater pHRR and 35x greater THR, while phenolic foam showed 9x greater pHRR and 48x greater THR. A few burning drips of polyethylene from the panelling are enough to ignite the foam insulation, providing a novel explanation for rapid flame-spread within the facade. Smoke from polyisocyanurates was 15x, and phenolics 5x more toxic than from mineral wool insulation. 1 kg of burning polyisocyanurate insulation is sufficient to fill a 50m3 room with an incapacitating and ultimately lethal effluent. Simple, additive models are proposed, which provide the same rank order as BS8414 large-scale regulatory tests.

Ileal pouch revision vs excision: short-term (30-day) outcomes from the National Surgical Quality Improvement Program.

AIM: Ileal pouch-anal anastomosis (IPAA) failure occurs in approximately 5%-10% of patients. We aimed to compare short-term (30-day) postoperative outcomes associated with pouch revision and pouch excision using a large international database. Our null hypothesis was that there is no statistically significant difference in overall postoperative complications between patients selected for pouch revision vs pouch excision. METHODS: Using the American College of Surgeons National Surgical Quality Improvement Program Participant User File from 2005 to 2016 we identified patients who underwent either IPAA revision via the combined abdominoperineal approach [Current Procedural Terminology (CPT) 46712] or IPAA excision (CPT 45136). Differences in baseline characteristics and short-term outcomes between groups were assessed with univariate and matched analyses. RESULTS: We identified 593 reoperative IPAA procedures: revision group 78 (13%) and excision group 515 (86%). The groups had similar age and body mass index (kg/m2 ), but the revision group had more women (65.4% vs 51.8%, P = 0.02) and fewer were on chronic steroids (3.9% vs 17.9%, P = 0.0008) relative to the excision group. Revision IPAA patients were more likely to have received a preoperative transfusion (5.1% vs 0.97%, P = 0.02). Revision and excision were associated with similar postoperative length of stay (9.3 vs 8.6 days, 0.44), mortality (nil vs 0.58%, respectively; P = 0.99) and short-term morbidity (34.6% vs 40.2%, respectively; P = 0.88) at 30 days. CONCLUSIONS: Pouch revision and excision have comparable short-term postoperative outcomes, but pouch excision appears to be more commonly utilized. Increased awareness of the indications for pouch revision or referral to specialized centres may improve pouch revision rates.

Flame retardants in UK furniture increase smoke toxicity more than they reduce fire growth rate.

This paper uses fire statistics to show the importance of fire toxicity on fire deaths and injuries, and the importance of upholstered furniture and bedding on fatalities from unwanted fires. The aim was to compare the fire hazards (fire growth and smoke toxicity) using different upholstery materials. Four compositions of sofa-bed were compared: three meeting UK Furniture Flammability Regulations (FFR), and one using materials without flame retardants intended for the mainland European market. Two of the UK sofa-beds relied on chemical flame retardants to meet the FFR, the third used natural materials and a technical weave in order to pass the test. Each composition was tested in the bench-scale cone calorimeter (ISO 5660) and burnt as a whole sofa-bed in a sofa configuration in a 3.4 × 2.25 × 2.4 m3 test room. All of the sofas were ignited with a No. 7 wood crib; the temperatures and yields of toxic products are reported. The sofa-beds containing flame retardants burnt somewhat more slowly than the non-flame retarded EU sofa-bed, but in doing so produced significantly greater quantities of the main fire toxicants, carbon monoxide and hydrogen cyanide. Assessment of the effluents' potential to incapacitate and kill is provided showing the two UK flame retardant sofa-beds to be the most dangerous, followed by the sofa-bed made with European materials. The UK sofa-bed made only from natural materials (Cottonsafe®) burnt very slowly and produced very low concentrations of toxic gases. Including fire toxicity in the FFR would reduce the chemical flame retardants and improve fire safety.

Outcomes of ileal pouch-anal anastomosis without primary diverting loop ileostomy if postoperative sepsis develops.

BACKGROUND: The aim of the present study was to assess the short-term and long-term consequences of diverting loop ileostomy (DLI) omission in ileal pouch-anal anastomosis (IPAA) surgery complicated by postoperative pelvic sepsis. METHODS: This was a retrospective review of a prospectively maintained database. Of 4031 patients who underwent IPAA in 1983-2014, 357 developed IPAA-related pelvic sepsis with or without anastomotic dehiscence. Patients with Crohn's disease or cancer were excluded. The patient cohort was divided into two groups, depending on the presence or absence of DLI. Patient characteristics, short-term and long-term outcomes were compared. Long-term pouch survival was estimated with the Kaplan-Meier method. Quality of life (QOL) in the groups was compared at the latest follow-up. RESULTS: Three hundred and twenty-six patients developing pelvic sepsis had diversion at the time of IPAA (D group) and in 31 who developed pelvic sepsis DLI had been omitted (O group). The length of hospital stay was significantly longer in the O group 11.5 (3-33) days versus 8 (2-59) days in the D group (p = 0.006). Forty-eight percent of patients from the O group with anastomotic leak underwent reoperation and had a DLI formed at this second procedure versus 12% in the D group requiring reoperation (p < 0.0001). In long-term follow-up, there was no difference in pouch survival between the groups: 99 versus 97% after 5 years and 88 versus 87% after 10 years, in the O group and D group, respectively (p = 0.40). There was no difference in QOL observed between the groups. CONCLUSIONS: Omission of DLI in selected patients who had IPAA surgery did not increase pouch failure or adversely affect QOL in the long term, if pelvic sepsis occurred.

The need for unique risk adjustment for surgical site infections at a high-volume, tertiary care center with inherent high-risk colorectal procedures.

BACKGROUND: The aim of the present study was to create a unique risk adjustment model for surgical site infection (SSI) in patients who underwent colorectal surgery (CRS) at the Cleveland Clinic (CC) with inherent high risk factors by using a nationwide database. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was queried to identify patients who underwent CRS between 2005 and 2010. Initially, CC cases were identified from all NSQIP data according to case identifier and separated from the other NSQIP centers. Demographics, comorbidities, and outcomes were compared. Logistic regression analyses were used to assess the association between SSI and center-related factors. RESULTS: A total of 70,536 patients met the inclusion criteria and underwent CRS, 1090 patients (1.5%) at the CC and 69,446 patients (98.5%) at other centers. Male gender, work-relative value unit, diagnosis of inflammatory bowel disease, pouch formation, open surgery, steroid use, and preoperative radiotherapy rates were significantly higher in the CC cases. Overall morbidity and individual postoperative complication rates were found to be similar in the CC and other centers except for the following: organ-space SSI and sepsis rates (higher in the CC cases); and pneumonia and ventilator dependency rates (higher in the other centers). After covariate adjustment, the estimated degree of difference between the CC and other institutions with respect to organ-space SSI was reduced (OR 1.38, 95% CI 1.08-1.77). CONCLUSIONS: The unique risk adjustment strategy may provide center-specific comprehensive analysis, especially for hospitals that perform inherently high-risk procedures. Higher surgical complexity may be the reason for increased SSI rates in the NSQIP at tertiary care centers.

Restorative proctocolectomy: an example of how surgery evolves in response to paradigm shifts in care.

AIM: Surgical technique constantly evolves in response to the pressure of progress. Ileal pouch anal anastomosis (IPAA) is a good example. We analysed the effect of changes in practice on the technique of IPAA and its outcomes. METHOD: Patients undergoing primary IPAA at this institution were divided into three groups by date of the IPAA: those operated from 1983 to 1993, from 1994 to 2004 and from 2005 to 2015. Demographics, patient comorbidity, surgical techniques, postoperative outcomes, pouch function and quality of life were analysed. RESULTS: In all, 4525 patients had a primary IPAA. With each decade, increasing numbers of surgeons were involved (decade I, 8; II, 16; III, 31), patients tended to be sicker (higher American Society of Anesthesiologists score) and three-staged pouches became more common. After an initial popularity of the S pouch, J pouches became dominant and a mucosectomy rate of 12% was standard. The laparoscopic technique blossomed in the last decade. 90-day postoperative morbidity by decade was 38.3% vs 50% vs 48% (P < 0.0001), but late morbidity decreased from 74.2% through 67.1% to 30% (P < 0.0001). Functional results improved, but quality of life scores did not. Pouch survival rate at 10 years was maintained (94% vs 95.2% vs 95.2%; P = 0.06). CONCLUSION: IPAA is still evolving. Despite new generations of surgeons, a more accurate diagnosis, appropriate staging and the laparoscopic technique have made IPAA a safer, more effective and enduring operation.

An approach for the identification of exemplar sites for scaling up targeted field observations of benthic biogeochemistry in heterogeneous environments.

Continental shelf sediments are globally important for biogeochemical activity. Quantification of shelf-scale stocks and fluxes of carbon and nutrients requires the extrapolation of observations made at limited points in space and time. The procedure for selecting exemplar sites to form the basis of this up-scaling is discussed in relation to a UK-funded research programme investigating biogeochemistry in shelf seas. A three-step selection process is proposed in which (1) a target area representative of UK shelf sediment heterogeneity is selected, (2) the target area is assessed for spatial heterogeneity in sediment and habitat type, bed and water column structure and hydrodynamic forcing, and (3) study sites are selected within this target area encompassing the range of spatial heterogeneity required to address key scientific questions regarding shelf scale biogeochemistry, and minimise confounding variables. This led to the selection of four sites within the Celtic Sea that are significantly different in terms of their sediment, bed structure, and macrofaunal, meiofaunal and microbial community structures and diversity, but have minimal variations in water depth, tidal and wave magnitudes and directions, temperature and salinity. They form the basis of a research cruise programme of observation, sampling and experimentation encompassing the spring bloom cycle. Typical variation in key biogeochemical, sediment, biological and hydrodynamic parameters over a pre to post bloom period are presented, with a discussion of anthropogenic influences in the region. This methodology ensures the best likelihood of site-specific work being useful for up-scaling activities, increasing our understanding of benthic biogeochemistry at the UK-shelf scale.

Comparing benthic biogeochemistry at a sandy and a muddy site in the Celtic Sea using a model and observations.

Results from a 1D setup of the European Regional Seas Ecosystem Model (ERSEM) biogeochemical model were compared with new observations collected under the UK Shelf Seas Biogeochemistry (SSB) programme to assess model performance and clarify elements of shelf-sea benthic biogeochemistry and carbon cycling. Observations from two contrasting sites (muddy and sandy) in the Celtic Sea in otherwise comparable hydrographic conditions were considered, with the focus on the benthic system. A standard model parameterisation with site-specific light and nutrient adjustments was used, along with modifications to the within-seabed diffusivity to accommodate the modelling of permeable (sandy) sediments. Differences between modelled and observed quantities of organic carbon in the bed were interpreted to suggest that a large part (>90%) of the observed benthic organic carbon is biologically relatively inactive. Evidence on the rate at which this inactive fraction is produced will constitute important information to quantify offshore carbon sequestration. Total oxygen uptake and oxic layer depths were within the range of the measured values. Modelled depth average pore water concentrations of ammonium, phosphate and silicate were typically 5-20% of observed values at the muddy site due to an underestimate of concentrations associated with the deeper sediment layers. Model agreement for these nutrients was better at the sandy site, which had lower pore water concentrations, especially deeper in the sediment. Comparison of pore water nitrate with observations had added uncertainty, as the results from process studies at the sites indicated the dominance of the anammox pathway for nitrogen removal; a pathway that is not included in the model. Macrofaunal biomasses were overestimated, although a model run with increased macrofaunal background mortality rates decreased macrofaunal biomass and improved agreement with observations. The decrease in macrofaunal biomass was compensated by an increase in meiofaunal biomass such that total oxygen demand remained within the observed range. The permeable sediment modification reproduced some of the observed behaviour of oxygen penetration depth at the sandy site. It is suggested that future development in ERSEM benthic modelling should focus on: (1) mixing and degradation rates of benthic organic matter, (2) validation of benthic faunal biomass against large scale spatial datasets, (3) incorporation of anammox in the benthic nitrogen cycle, and (4) further developments to represent permeable sediment processes.