Patient Blood Management (PBM) has evolved from a transfusion-centered practice to a structured, patient-focused perioperative strategy aimed at improving surgical outcomes while preserving blood resources. In the operating room, where bleeding risk is anticipated and modifiable, PBM requires proactive intervention rather than reactive transfusion. This review synthesizes current evidence on perioperative blood conservation strategies specifically relevant to surgeons and anesthesiologists. Preoperative optimization begins with systematic identification and correction of anemia, most commonly iron deficiency, using appropriately timed oral or intravenous iron therapy and, in selected cases, erythropoiesis-stimulating agents. Careful management of anticoagulant and antiplatelet therapies, early recognition of acquired or inherited coagulopathies, and protocol-driven reversal strategies further reduce perioperative hemorrhagic risk. Intraoperatively, blood conservation depends on meticulous surgical technique, respect for anatomical planes, minimally invasive approaches, and the judicious use of advanced energy devices and topical hemostatic agents. Pharmacologic interventions—particularly tranexamic acid administered with appropriate timing and dosing—have demonstrated consistent reductions in blood loss and transfusion requirements across multiple surgical disciplines. Goal-directed coagulation management guided by viscoelastic testing allows targeted correction of specific hemostatic deficits while minimizing unnecessary blood product exposure. Acute normovolemic hemodilution and intraoperative cell salvage provide additional benefit in selected high-blood-loss procedures. Collectively, these multimodal strategies shift perioperative care from product-driven transfusion toward physiology-based blood conservation. When embedded within institutional protocols and supported by multidisciplinary collaboration, perioperative PBM reduces transfusion exposure, decreases morbidity, shortens hospital stay, and promotes sustainable stewardship of blood resources without compromising patient safety.

Background: Acute appendicitis is one of the most common surgical emergencies worldwide. The presentation of appendicitis and its management can serve as a benchmark for evaluating the efficiency and effectiveness of emergency health systems. This prospective cohort study aims to identify areas for whole systems strengthening in emergency care using pre-defined key performance measures. Methods: This international prospective, multicentre cohort study will include all consecutive patients undergoing appendicectomy for suspected appendicitis. A measurement set comprising eight key outcome measures has been pre-defined to comprehensively evaluate emergency system performance across the world: time from symptom onset to surgical assessment, imaging rate, time from surgical assessment to theatre, laparoscopy rate, perforation rate, negative appendicectomy rate, post-operative length of stay and complication rate. Patients will be followed up at 30 days to collect outcome data. No changes will be made to routine patient care pathways/management or follow-up in this observational study. A mandatory hospital-level survey will explore available resources, infrastructure, surgical expertise, and relevant care protocols of sites participating in the study. It will allow us to account for variations in hospital capabilities and adjust analyses, improving the accuracy of cross-country comparisons and identifying system-level factors that may affect surgical success. Consultant Leads in each participating hospital will ensure appropriate study registration approval as per local regulations and this is mandatory for participation. There will be two optional sub-studies on waste management and sustainability and financing at select sites. Discussion: This study will generate granular data on the global variability in appendicectomy management and outcomes, offering insights into access to emergency care, imaging, and minimally invasive surgery for whole system strengthening. The findings will guide recommendations for both high-income and low- and middle-income countries, informing government policy and improving patient outcomes.

A skeletal model consists of a collection of geometric primitives, such as points, lines, and triangles, that specifies the topology of an object. The skeleton is can be used to define surfaces, resulting in a solid model of the object. Of the various surface models that have been used for skeletal models, the convolution surface has some attractive properties. The convolution surface is an implicit surface that has been formulated for various geometric primitives such as lines, triangles, etc. Modeling with convolution surfaces guarantees a continuous and smoothly blended surface that is relatively easy to deform and intuitive to specify. However, when two skeleton elements are placed close to each other, unwanted blending can occur and the topology of the final shape becomes difficult to control. To be useful in conceptual engineering design, a skeletal modeler must ensure that the topology of surfaces generated agrees with that of the skeleton. Ensuring a match between the topology of the convolution surface and its skeleton is a challenging problem. In this paper, we propose a method based on Morse theory for ensuring topological consistency. By adjusting the parameters of the convolution surfaces, the topology of the final composite surface can be forced to match its root skeleton.

In designing for a system’s lifecycle considerations, long-term energy needs often become an important limiting factor. Shifting from conventional energy sources (e.g. fossil fuels) toward renewable sources (e.g. wind and solar) has become a popular means for focusing on the lifecycle of large-scale systems like automobiles and the national electrical grid. This same shift in small, low-power systems such as sensors has the additional advantage of potentially increasing the operational life of the systems. This paper introduces a methodology for determining the feasibility of in situ energy harvesting as a viable power source for a given low-power system. The method is demonstrated by considering a wireless sensor node and the specific application of monitoring the fatigue life of highway bridges, with a target operational life of ten years for the sensor node. Peak and average power requirements for wireless sensor nodes are calculated and compared to the power density available from solar, wind, and vibration energy. Energy storage is also discussed, including both disposable batteries (as the status quo with which to compare energy harvesting) and rechargeable systems (as a necessary component of the energy harvesting system). Solar, wind, and vibration energy are all found to be feasible sources of power for this particular application. Vibration harvesting has lower power density than solar and wind harvesting, but has the advantage of being less dependent on location, more self-contained, and largely maintenance free. Energy harvesting in general only becomes attractive for projected life cycles exceeding the life of disposable batteries, which for this particular application is estimated at 4–6 years. Thus, energy harvesting is an excellent way to extend the lifespan of low-power systems where power availability is the limiting factor.