Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy

Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89.6 per cent) compared with that in countries with a middle (753 of 1242, 60.6 per cent; odds ratio (OR) 0.17, 95 per cent c.i. 0.14 to 0.21, P <0001) or low (363 of 860, 422 per cent; OR 008, 007 to 010, P <0.001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -94 (95 per cent c.i. -11.9 to -6.9) per cent; P <0001), but the relationship was reversed in low-HDI countries (+121 (+7.0 to +173) per cent; P <0001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0.60, 0.50 to 073; P <0.001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Conclusion Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries.Peer reviewe

Global variation in anastomosis and end colostomy formation following left-sided colorectal resection

Background End colostomy rates following colorectal resection vary across institutions in high-income settings, being influenced by patient, disease, surgeon and system factors. This study aimed to assess global variation in end colostomy rates after left-sided colorectal resection. Methods This study comprised an analysis of GlobalSurg-1 and -2 international, prospective, observational cohort studies (2014, 2016), including consecutive adult patients undergoing elective or emergency left-sided colorectal resection within discrete 2-week windows. Countries were grouped into high-, middle- and low-income tertiles according to the United Nations Human Development Index (HDI). Factors associated with colostomy formation versus primary anastomosis were explored using a multilevel, multivariable logistic regression model. Results In total, 1635 patients from 242 hospitals in 57 countries undergoing left-sided colorectal resection were included: 113 (6·9 per cent) from low-HDI, 254 (15·5 per cent) from middle-HDI and 1268 (77·6 per cent) from high-HDI countries. There was a higher proportion of patients with perforated disease (57·5, 40·9 and 35·4 per cent; P < 0·001) and subsequent use of end colostomy (52·2, 24·8 and 18·9 per cent; P < 0·001) in low- compared with middle- and high-HDI settings. The association with colostomy use in low-HDI settings persisted (odds ratio (OR) 3·20, 95 per cent c.i. 1·35 to 7·57; P = 0·008) after risk adjustment for malignant disease (OR 2·34, 1·65 to 3·32; P < 0·001), emergency surgery (OR 4·08, 2·73 to 6·10; P < 0·001), time to operation at least 48 h (OR 1·99, 1·28 to 3·09; P = 0·002) and disease perforation (OR 4·00, 2·81 to 5·69; P < 0·001). Conclusion Global differences existed in the proportion of patients receiving end stomas after left-sided colorectal resection based on income, which went beyond case mix alone

The effect of supplier capacity on the supply chain profit

In this paper, we study the role of capacity on the efficiency of a two-tier supply chain with two suppliers (leaders, first tier) and one retailer (follower, second tier). The suppliers compete via pricing (Bertrand competition) and, as one would expect in practice, are faced with production capacity. We consider a model with differentiated substitutable products where the suppliers are symmetric differing only by their production capacity. We characterize the prices, production amounts and profits in three cases: (1) the suppliers compete in a decentralized Nash equilibrium game, (2) the suppliers “cooperate” to optimize the total suppliers’ profit, and (3) the two tiers of the supply chain are centrally coordinated. We show that in a decentralized setting, the supplier with a lower capacity may benefit from restricting her capacity even when additional capacity is available at no cost. We also show that the loss of total profit due to decentralization cannot exceed 25&nbsp;% of the centralized chain profits. Nevertheless, the loss of total profit is not a monotonic function of the “degree of asymmetry” of the suppliers’ capacities. Furthermore, we provide an upper bound on the supplier profit loss at equilibrium (compared with the cooperation setting) that depends on the “market power” of the suppliers as well as their market size. We show that there is less supplier profit loss as the asymmetry (in terms of their capacities) increases between the two suppliers. The worst case arises when the two suppliers are completely symmetric

The Mantle Section of Neoproterozoic Ophiolites from the Pan-African Belt, Eastern Desert, Egypt: Tectonomagmatic Evolution, Metamorphism, and Mineralization

The Eastern Desert (ED) Neoproterozoic ophiolites are tectonically important elements of the Arabian–Nubian Shield. Although affected by various degrees of dismemberment, metamorphism, and alteration, almost all of the diagnostic Penrose-type ophiolite components can be found, namely, lower units of serpentinized peridotite tectonite and cumulate ultramafics and upper units of layered and isotropic gabbros, plagiogranites, sheeted dykes and pillow lavas. The contacts between the lower unit (mantle section) and the upper unit (crustal section) were originally magmatic, but in all cases are now disrupted by tectonism. The mantle sections of the ED ophiolites are exposed as folded thrust sheets bearing important and distinctive lithologies of serpentinized peridotites of harzburgite and dunite protoliths with occasional podiform chromitites. The ED ophiolites show a spatial and temporal association with suture zones that indicate fossil subduction zone locations. Multiple episodes of regional metamorphism mostly reached greenschist facies with less common amphibolite facies localities. CO₂-metasomatism resulted in the development of talc–carbonate, listvenite, magnesite, and other carbonate-bearing meta-ultramafic rocks. Geochemical data from the ED serpentinites, despite some confounding effects of hydration and alteration, resemble modern oceanic peridotites. The ED serpentinites show high LOI (≤20 wt%); Mg# mostly higher than 0.89; enrichment of Ni, Cr, and Co; depletion of Al₂O₃ and CaO; and nearly flat, depleted, and unfractionated chondrite-normalized REE patterns. The modal abundance of clinopyroxene is very low if it is present at all. Chromian spinel survived metamorphism and is widely used as the most reliable petrogenetic and geotectonic indicator in the ED ophiolite mantle sections. The high-Cr# (mostly ~0.7) and low-TiO₂ (mostly ≤ 0.1 wt%) characters of chromian spinel indicate a high degree of partial melt extraction (≥30%), which is commonly associated with fore-arc settings and equilibration with boninite-like or high-Mg tholeiite melts. Based on the general petrological characteristics, the ED ophiolitic chromitites are largely similar to Phanerozoic examples that have been attributed to melt–peridotite interaction and subsequent melt mixing in fore-arc settings. The comparison between the ED Neoproterozoic mantle peridotites and Phanerozoic equivalents indicates considerable similarity in tectonomagmatic processes and does not support any major changes in the geothermal regime of subduction zones on Earth since the Neoproterozoic era. The mantle sections of ED ophiolites are worthy targets for mining and exploration, hosting a variety of ores (chromite, gold, and iron/nickel laterites) and industrial minerals (talc, asbestos, and serpentine)