Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Burr formation and effects when drilling metallic/composite stack assemblies

Burr formation and poor hole quality can be detrimental to fatigue life as well as hinder the assembly and functionality of drilled components, particularly those made from metallic-composite stacks. Following a detailed literature review, four phases of experimental work were carried out to evaluate the effects of varying cutting parameters, tool geometries/coatings, workpiece configuration and machining strategies on hole quality/integrity, burr formation and subsequent workpiece fatigue performance, following drilling of several 2-layer stack configurations (CFRP/AA2024, AA2024/AA7010 and CFRP/Ti-6A1-4V). This was complemented by the development of numerical models to predict burr formation when drilling metallic alloys. Key contributions of the research were: (i) improved understanding with regard to the influence of cutting speed and feed rate on burr formation and hole quality when drilling individual Ti-6A1-4V, AA2024 and AA7010 alloys together with various stack assemblies; (ii) identification of appropriate tool type and cutting conditions in addition to possible alternative burr suppression methods; (iii) understanding of the significance of burr formation on fatigue life of individual metallic materials and; (iv) derivation of an analytical model for entrance and interlayer burrs as well as formulation of an FE model for enhanced burr formation (entrance and exit) predictions when drilling individual metallic materials

Sustainable Manufacturing: Digital Twinning for a Mechanical Assembly Production Line

There has been a rise in interest in the concept ofthe digital twin (DT) in both academia and industry in smartcities. The DT's implementation architecture generally consistsof physical, virtual, and information-processing layers for asystem. There are several theoretical frameworks presented anddocumented for DT implementation in the context of themanufacturing industry, but there is a lack of actualimplementation studies published in the literature. The primaryobjective of this article is to show that a production unit thatspecialises in making manually assembled mechanical productscan successfully adopt DT in practise. Tecnomatix PlantSimulation (P-sim) software was used to develop a simulationDT model. The DT then used for bottleneck identification toimprove the efficiency of the production line. The DT proved tobe a promising and evolving real-time optimisation tool forsustainable manufacturing

Sustainable Manufacturing: Digital Twinning for a Mechanical Assembly Production Line

There has been a rise in interest in the concept ofthe digital twin (DT) in both academia and industry in smartcities. The DT's implementation architecture generally consistsof physical, virtual, and information-processing layers for asystem. There are several theoretical frameworks presented anddocumented for DT implementation in the context of themanufacturing industry, but there is a lack of actualimplementation studies published in the literature. The primaryobjective of this article is to show that a production unit thatspecialises in making manually assembled mechanical productscan successfully adopt DT in practise. Tecnomatix PlantSimulation (P-sim) software was used to develop a simulationDT model. The DT then used for bottleneck identification toimprove the efficiency of the production line. The DT proved tobe a promising and evolving real-time optimisation tool forsustainable manufacturing

Study on the characterisation of the PTFE transfer film and the dimensional designing of surface texturing in a dry-lubricated bearing system

The ability of polytetrafluoroethylene (PTFE) to form tribo-film in dry sliding condition makes it a popular liner material for self-maintenance bearings, such as those in the helicopter main and tail rotors. Nowadays, hard fillers or reinforcing-fibres are added to form the PTFE composite with enhanced strength and wear resistance; however, this also leads to increasing possibility of wear tracks on counter-surface and therefore more difficulty in observing and characterising the transfer film. In this paper, a surface analysis method based on using SEM analysis, supplemented with a Time-of-flight Secondary-ion mass spectrometry (Tof-SIMS) techniques for calibration was developed to give a comprehensive view of the transfer film formation on bearing steel surfaces. Previous challenges in transfer film identification and characterisation were also pinpointed. A series of laser surface textures (dimples), designed for improving the tribological performance of the bearing were tested, and the effects on transfer film formation have been evaluated by the surface analysis method. It is found that the depth of the dimples should match with the thickness of the transfer film to achieve a benefiting effect of the film formation, while the diameter and the coverage of the textures needs to be relatively small to avoid a high level of abrasion