Shear-Sensing by C-Reactive Protein: Linking Aortic Stenosis and Inflammation.

BACKGROUND: CRP (C-reactive protein) is a prototypical acute phase reactant. Upon dissociation of the pentameric isoform (pCRP [pentameric CRP]) into its monomeric subunits (mCRP [monomeric CRP]), it exhibits prothrombotic and proinflammatory activity. Pathophysiological shear rates as observed in aortic valve stenosis (AS) can influence protein conformation and function as observed with vWF (von Willebrand factor). Given the proinflammatory function of dissociated CRP and the important role of inflammation in the pathogenesis of AS, we investigated whether shear stress can modify CRP conformation and induce inflammatory effects relevant to AS. METHODS: To determine the effects of pathological shear rates on the function of human CRP, pCRP was subjected to pathophysiologically relevant shear rates and analyzed using biophysical and biochemical methods. To investigate the effect of shear on CRP conformation in vivo, we used a mouse model of arterial stenosis. Levels of mCRP and pCRP were measured in patients with severe AS pre- and post-transcatheter aortic valve implantation, and the presence of CRP was investigated on excised valves from patients undergoing aortic valve replacement surgery for severe AS. Microfluidic models of AS were then used to recapitulate the shear rates of patients with AS and to investigate this shear-dependent dissociation of pCRP and its inflammatory function. RESULTS: Exposed to high shear rates, pCRP dissociates into its proinflammatory monomers (mCRP) and aggregates into large particles. Our in vitro findings were further confirmed in a mouse carotid artery stenosis model, where the administration of human pCRP led to the deposition of mCRP poststenosis. Patients undergoing transcatheter aortic valve implantation demonstrated significantly higher mCRP bound to circulating microvesicles pre-transcatheter aortic valve implantation compared with post-transcatheter aortic valve implantation. Excised human stenotic aortic valves display mCRP deposition. pCRP dissociated in a microfluidic model of AS and induces endothelial cell activation as measured by increased ICAM-1 and P-selectin expression. mCRP also induces platelet activation and TGF-ß (transforming growth factor beta) expression on platelets. CONCLUSIONS: We identify a novel mechanism of shear-induced pCRP dissociation, which results in the activation of cells central to the development of AS. This novel mechanosensing mechanism of pCRP dissociation to mCRP is likely also relevant to other pathologies involving increased shear rates, such as in atherosclerotic and injured arteries.

Comparison of Arterial and Venous Interposition Grafting for Arterial Defects in a Rat Model.

BACKGROUND: Interposition microvascular grafting may be required to bridge arterial defects during digital replantation or revascularization and has traditionally been performed utilizing a venous autograft. Arterial interposition grafting has been shown to be superior in maintaining patency in large vessel surgery; there are case reports of its use in microsurgery. METHODS: Six fellowship-trained hand and microsurgeons performed arterial and venous interposition grafts on the femoral arteries of 40 Wistar rats. After sectioning one femoral artery a segment of the contralateral femoral artery or vein was obtained. The time was recorded per graft and patency tested 10 minutes following grafting by an independent assessor. Each surgeon also completed a questionnaire detailing regular microsurgical volume, technical ease, and conceptual preference for either graft. RESULTS: Time for arterial interposition (median time 51.7 minutes) was longer than venous grafting (median time 45.9 minutes, p = 0.075). Arterial grafts were more likely to be patent or questionably patent (odds ratio [OR] = 6.77, p = 0.031). All surgeons found arterial interposition grafting technically easier and preferred it conceptually. Improvements were noted in patency rates (OR = 11.29, p = 0.018) and avoidance of anastomotic leak (OR = 0.19, p = 0.029) when surgeons performed moderate levels or greater of microsurgery within their regular practice. CONCLUSION: Greater immediate patency was noted with arterial interposition grafting in a rodent model when compared to venous grafting, although procedural time was greater. All surgeons found arterial grafting technically easier. Arterial microvascular grafting may be useful in the setting of digital replantation or revascularization with an arterial defect.

Palliative Radiation Therapy for Treatment of Cutaneous T-cell Lymphoma in a Double Yellow-headed Amazon Parrot (Amazona oratrix).

A 17-year-old captive female double yellow-headed Amazon parrot (Amazona oratrix) was presented to the Kansas State University Zoological Medicine Service (Manhattan, KS, USA) for a 2-month history of a left sided facial swelling. On examination, a red, raised mass was noted on the left side of the face. A whole-body computed tomography scan of the bird was performed to assess the extent of the mass and evaluate the patient for obvious evidence of disseminated disease. No systemic involvement was detected, and the swelling was localized to the cutaneous and subcutaneous tissues overlying the left rhamphotheca. Two punch biopsies were collected, and histopathology was consistent with cutaneous lymphoma, with strong positive CD3 staining congruous with a T-cell origin. Because of a lack of evidence for disseminated disease, the authors elected to pursue localized radiation therapy, and a single fraction of 8 Gray was administered. The swelling had resolved by the time of the recheck examination 4 weeks post-radiation therapy, and the patient remained clinically normal 52 weeks after radiation therapy.

Adolescent Wrist Pain.

Adolescence is a difficult time, both physically and emotionally. Rapid growth coupled with physical changes in the background of high levels of activity can be overwhelming. Meanwhile, unfamiliar life stressors coupled with undeveloped compensatory mechanisms can lead to overwhelming anxiety and emotional distress. Emotional factors can make injuries and overuse syndromes feel more catastrophic. Occasionally, an adolescent's emotional distress can manifest physically, without antecedent injury or physiologic cause. Understanding the psychological milieu is as important as understanding the disease processes that can affect adolescents if one hopes to manage these patients effectively.

Characterization of the variability in the extent of nonalcoholic fatty liver induced by a high-fat diet in the genetically diverse Collaborative Cross mouse model.

Interindividual variability and sexual dimorphisms in the development of nonalcoholic fatty liver disease (NAFLD) are still poorly understood. In the present study, male and female strains of Collaborative Cross (CC) mice were fed a high-fat and high-sucrose (HF/HS) diet or a control diet for 12 weeks to investigate interindividual- and sex-specific variations in the development of NAFLD. The severity of liver steatosis varied between sexes and individual strains and was accompanied by an elevation of serum markers of insulin resistance, including increases in total cholesterol, low-density lipoproteins, high-density lipoproteins, phospholipids, and glucose. The development of NAFLD was associated with overexpression of the critical fatty acid uptake and de novo lipogenesis genes Pparg, Mogat1, Cd36, Acaab1, Fabp2, and Gdf15 in male and female mice. The expression of Pparg, Mogat1, and Cd36 was positively correlated with liver triglycerides in male mice, and Mogat1 and Cd36 expression were positively correlated with liver triglycerides in female mice. Our results indicate the value of CC mice in combination with HF/HS diet-induced alterations as an approach to study the susceptibility and interindividual variabilities in the pathogenesis of nonalcoholic fatty liver and early nonalcoholic steatohepatitis at the population level, uncovering of susceptible and resistant cohorts, and identifying sex-specific molecular determinants of disease susceptibility.

Targeted deletion of nicotinamide adenine dinucleotide phosphate oxidase 4 from proximal tubules is dispensable for diabetic kidney disease development.

BACKGROUND: The nicotinamide adenine dinucleotide phosphate oxidase isoform 4 (Nox4) mediates reactive oxygen species (ROS) production and renal fibrosis in diabetic kidney disease (DKD) at the level of the podocyte. However, the mitochondrial localization of Nox4 and its role as a mitochondrial bioenergetic sensor has recently been reported. Whether Nox4 drives pathology in DKD within the proximal tubular compartment, which is densely packed with mitochondria, is not yet known. METHODS: We generated a proximal tubular-specific Nox4 knockout mouse model by breeding Nox4flox/flox mice with mice expressing Cre recombinase under the control of the sodium-glucose cotransporter-2 promoter. Subsets of Nox4ptKO mice and their Nox4flox/flox littermates were injected with streptozotocin (STZ) to induce diabetes. Mice were followed for 20 weeks and renal injury was assessed. RESULTS: Genetic ablation of proximal tubular Nox4 (Nox4ptKO) resulted in no change in renal function and histology. Nox4ptKO mice and Nox4flox/flox littermates injected with STZ exhibited the hallmarks of DKD, including hyperfiltration, albuminuria, renal fibrosis and glomerulosclerosis. Surprisingly, diabetes-induced renal injury was not improved in Nox4ptKO STZ mice compared with Nox4flox/flox STZ mice. Although diabetes conferred ROS overproduction and increased the mitochondrial oxygen consumption rate, proximal tubular deletion of Nox4 did not normalize oxidative stress or mitochondrial bioenergetics. CONCLUSIONS: Taken together, these results demonstrate that genetic deletion of Nox4 from the proximal tubules does not influence DKD development, indicating that Nox4 localization within this highly energetic compartment is dispensable for chronic kidney disease pathogenesis in the setting of diabetes.

Sustainability Challenges and Opportunities in Oligonucleotide Manufacturing.

With a renewed and growing interest in therapeutic oligonucleotides across the pharmaceutical industry, pressure is increasing on drug developers to take more seriously the sustainability ramifications of this modality. With 12 oligonucleotide drugs reaching the market to date and hundreds more in clinical trials and preclinical development, the current state of the art in oligonucleotide production poses a waste and cost burden to manufacturers. Legacy technologies make use of large volumes of hazardous reagents and solvents, as well as energy-intensive processes in synthesis, purification, and isolation. In 2016, the American Chemical Society (ACS) Green Chemistry Institute Pharmaceutical Roundtable (GCIPR) identified the development of greener processes for oligonucleotide Active Pharmaceutical Ingredients (APIs) as a critical unmet need. As a result, the Roundtable formed a focus team with the remit of identifying green chemistry and engineering improvements that would make oligonucleotide production more sustainable. In this Perspective, we summarize the present challenges in oligonucleotide synthesis, purification, and isolation; highlight potential solutions; and encourage synergies between academia; contract research, development and manufacturing organizations; and the pharmaceutical industry. A critical part of our assessment includes Process Mass Intensity (PMI) data from multiple companies to provide preliminary baseline metrics for current oligonucleotide manufacturing processes.

Inhibitors of Advanced Glycation End Product (AGE) Formation and Accumulation.

A range of chemically different compounds are known to inhibit the formation and accumulation of advanced glycation end products (AGEs) or disrupt associated signalling pathways. There is evidence that some of these agents can provide end-organ protection in chronic diseases including diabetes. Whilst this group of therapeutics are structurally and functionally different and have a range of mechanisms of action, they ultimately reduce the deleterious actions and the tissue burden of advanced glycation end products. To date it remains unclear if this is due to the reduction in tissue AGE levels per se or the modulation of downstream signal pathways. Some of these agents either stimulate antioxidant defence or reduce the formation of reactive oxygen species (ROS), modify lipid profiles and inhibit inflammation. A number of existing treatments for glucose lowering, hypertension and hyperlipidaemia are also known to reduce AGE formation as a by-product of their action. Targeted AGE formation inhibitors or AGE cross-link breakers have been developed and have shown beneficial effects in animal models of diabetic complications as well as other chronic conditions. However, only a few of these agents have progressed to clinical development. The failure of clinical translation highlights the importance of further investigation of the advanced glycation pathway, the diverse actions of agents which interfere with AGE formation, cross-linking or AGE receptor activation and their effect on the development and progression of chronic diseases including diabetic complications. Advanced glycation end products (AGEs) are (1) proteins or lipids that become glycated as a result of exposure to sugars or (2) non-proteinaceous oxidised lipids. They are implicated in ageing and the development, or worsening, of many degenerative diseases, such as diabetes, atherosclerosis, chronic kidney and Alzheimer's disease. Several antihypertensive and antidiabetic agents and statins also indirectly lower AGEs. Direct AGE inhibitors currently investigated include pyridoxamine and epalrestat, the inhibition of the formation of reactive dicarbonyls such as methylglyoxal as an important precursor of AGEs via increased activation of the detoxifying enzyme Glo-1 and inhibitors of NOX-derived ROS to reduce the AGE/RAGE signalling.

Empagliflozin modulates renal sympathetic and heart rate baroreflexes in a rabbit model of diabetes.

AIMS/HYPOTHESIS: We determined whether empagliflozin altered renal sympathetic nerve activity (RSNA) and baroreflexes in a diabetes model in conscious rabbits. METHODS: Diabetes was induced by alloxan, and RSNA, mean arterial pressure (MAP) and heart rate were measured before and after 1 week of treatment with empagliflozin, insulin, the diuretic acetazolamide or the ACE inhibitor perindopril, or no treatment, in conscious rabbits. RESULTS: Four weeks after alloxan administration, blood glucose was threefold and MAP 9% higher than non-diabetic controls (p < 0.05). One week of treatment with empagliflozin produced a stable fall in blood glucose (-43%) and increased water intake (+49%) but did not change RSNA, MAP or heart rate compared with untreated diabetic rabbits. The maximum RSNA to hypotension was augmented by 75% (p < 0.01) in diabetic rabbits but the heart rate baroreflex was unaltered. Empagliflozin and acetazolamide reduced the augmentation of the RSNA baroreflex (p < 0.05) to be similar to the non-diabetic group. Noradrenaline (norepinephrine) spillover was similar in untreated diabetic and non-diabetic rabbits but twofold greater in empagliflozin- and acetazolamide-treated rabbits (p < 0.05). CONCLUSIONS/INTERPRETATION: As empagliflozin can restore diabetes-induced augmented sympathetic reflexes, this may be beneficial in diabetic patients. A similar action of the diuretic acetazolamide suggests that the mechanism may involve increased sodium and water excretion. Graphical abstract.

Differential sympathetic response to lesion-induced chronic kidney disease in rabbits.

Chronic kidney disease (CKD) is associated with greater sympathetic nerve activity but it is unclear if this is a kidney-specific response or due to generalized stimulation of sympathetic nervous system activity. To determine this, we used a rabbit model of CKD in which quantitative comparisons with control rabbits could be made of kidney sympathetic nerve activity and whole-body norepinephrine spillover. Rabbits either had surgery to lesion 5/6th of the cortex of one kidney by electro-lesioning and two weeks later removal of the contralateral kidney, or sham lesioning and sham nephrectomy. After three weeks, the blood pressure was statistically significantly 20% higher in conscious rabbits with CKD compared to rabbits with a sham operation, but their heart rate was similar. Strikingly, kidney nerve activity was 37% greater than in controls, with greater burst height and frequency. Total norepinephrine spillover was statistically significantly lower by 34%, and kidney baroreflex curves were shifted to the right in rabbits with CKD. Plasma creatinine and urine output were elevated by 38% and 131%, respectively, and the glomerular filtration rate was 37% lower than in sham-operated animals (all statistically significant). Kidney gene expression of fibronectin, transforming growth factor-ß, monocyte chemotactic protein1, Nox4 and Nox5 was two- to eight-fold greater in rabbits with CKD than in control rabbits. Overall, the glomerular layer lesioning model in conscious rabbits produced a moderate, stable degree of CKD characterized by elevated blood pressure and increased kidney sympathetic nerve activity. Thus, our findings, together with that of a reduction in total norepinephrine spillover, suggest that kidney denervation, rather than generalized sympatholytic treatments, may represent a preferable management for CKD associated hypertension.

The emerging role of NADPH oxidase NOX5 in vascular disease.

Oxidative stress is a consequence of up-regulation of pro-oxidant enzyme-induced reactive oxygen species (ROS) production and concomitant depletion of antioxidants. Elevated levels of ROS act as an intermediate and are the common denominator for various diseases including diabetes-associated macro-/micro-vascular complications and hypertension. A range of enzymes are capable of generating ROS, but the pro-oxidant enzyme family, nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOXs), are the only enzymes known to be solely dedicated to ROS generation in the vascular tissues, kidney, aortas and eyes. While there is convincing evidence for a role of NOX1 in vascular and eye disease and for NOX4 in renal injury, the role of NOX5 in disease is less clear. Although NOX5 is highly up-regulated in humans in disease, it is absent in rodents. Thus, so far it has not been possible to study NOX5 in traditional mouse or rat models of disease. In the present review, we summarize and critically analyse the emerging evidence for a pathophysiological role of NOX5 in disease including the expression, regulation and molecular and cellular mechanisms which have been demonstrated to be involved in NOX5 activation.

Determining Pneumocystis jirovecii Colonisation from Infection Using PCR-Based Diagnostics in HIV-Negative Individuals.

BACKGROUND: Pneumocystis jirovecii pneumonia is increasingly diagnosed with highly sensitive PCR diagnostics in immunocompromised, HIV-negative individuals. We assessed the performance of our in-house quantitative PCR with the aim to optimise interpretation. METHODS: Retrospective audit of all positive P. jirovecii qPCRs on induced sputum or BAL fluid at a single centre from 2012 to 2023. Medical and laboratory records were analysed and people with HIV were excluded. Cases were categorised as colonisation, high-probability PCP or uncertain PCP infection against a clinical gold standard incorporating clinico-radiological data. Quantitative PCR assay targeting the 5s gene was utilised throughout the time period. RESULTS: Of the 82 positive qPCRs, 28 were categorised as high-probability PCP infection, 30 as uncertain PCP and 24 as colonisation. There was a significant difference in qPCR values stratified by clinical category but not respiratory sample type. Current assay performance with a cutoff of 2.5 × 105 copies/mL had a sensitivity of 50% (95% CI, 30.65-69.35%) and specificity of 83.33% (95% CI, 62.62-95.26%). Youden Index calculated at 6.5 × 104 copies/mL had a sensitivity of 75% (56.64-87.32%, 95% CI) and specificity of 66.67% (46.71-82.03%, 95% CI). High and low cutoffs were explored. Significant variables associated with infection were age > 70 years old, the presence of fever, hypoxia or ground glass changes. CONCLUSIONS: A single qPCR cutoff cannot reliably determine P. jirovecii infection from colonisation. Low and high cutoffs are useful, however, a large "possible infection" cohort will remain where interpretation of clinic-radiological factors remains essential. Standardisation of assays with prospective validation in specific immunocompromised groups will allow greater generalisability and allow large-scale prospective assay validation to be performed.

The Role of Activator Protein-1 Complex in Diabetes-Associated Atherosclerosis: Insights From Single-Cell RNA Sequencing.

Despite advances in treatment, atherosclerotic cardiovascular disease remains the leading cause of death in patients with diabetes. Even when risk factors are mitigated, the disease progresses, and thus, newer targets need to be identified that directly inhibit the underlying pathobiology of atherosclerosis in diabetes. A single-cell sequencing approach was used to distinguish the proatherogenic transcriptional profile in aortic cells in diabetes using a streptozotocin-induced diabetic Apoe-/- mouse model. Human carotid endarterectomy specimens from individuals with and without diabetes were also evaluated via immunohistochemical analysis. Further mechanistic studies were performed in human aortic endothelial cells (HAECs) and human THP-1-derived macrophages. We then performed a preclinical study using an activator protein-1 (AP-1) inhibitor in a diabetic Apoe-/- mouse model. Single-cell RNA sequencing analysis identified the AP-1 complex as a novel target in diabetes-associated atherosclerosis. AP-1 levels were elevated in carotid endarterectomy specimens from individuals with diabetes compared with those without diabetes. AP-1 was validated as a mechanosensitive transcription factor via immunofluorescence staining for regional heterogeneity of endothelial cells of the aortic region exposed to turbulent blood flow and by performing microfluidics experiments in HAECs. AP-1 inhibition with T-5224 blunted endothelial cell activation as assessed by a monocyte adhesion assay and expression of genes relevant to endothelial function. Furthermore, AP-1 inhibition attenuated foam cell formation. Critically, treatment with T-5224 attenuated atherosclerosis development in diabetic Apoe-/- mice. This study has identified the AP-1 complex as a novel target, the inhibition of which treats the underlying pathobiology of atherosclerosis in diabetes.

Screw and Suspension Fixation for Bennett Fractures.

Bennett fractures are inherently unstable partial articular fractures of the base of the first metacarpal, often resulting from an axial load applied to a partially flexed metacarpal. Multiple options are available for the surgical stabilization of Bennett fractures; each option has associated drawbacks. We present a technique of fixation with headless compression screw(s), combined with suspension fixation, to overcome some of these limitations, with good results.

Cardiovascular characterisation of a novel mouse model that combines hypertension and diabetes co-morbidities.

Epidemiologic data suggest that the prevalence of hypertension in patients with diabetes mellitus is ∼1.5-2.0 times greater than in matched non-diabetic patients. This co-existent disease burden exacerbates cardiac and vascular injury, leading to structural and functional changes to the myocardium, impaired cardiac function and heart failure. Oxidative stress and persistent low-grade inflammation underlie both conditions, and are identified as major contributors to pathological cardiac remodelling. There is an urgent need for effective therapies that specifically target oxidative stress and inflammation to protect against cardiac remodelling. Animal models are a valuable tool for testing emerging therapeutics, however, there is a notable lack of appropriate animal models of co-morbid diabetes and hypertension. In this study, we describe a novel preclinical mouse model combining diabetes and hypertension to investigate cardiac and vascular pathology of co-morbid disease. Type 1 diabetes was induced in spontaneously hypertensive, 8-week old, male Schlager (BPH/2) mice via 5 consecutive, daily injections of streptozotocin (55 mg/kg in citrate buffer; i.p.). Non-diabetic mice received citrate buffer only. After 10 weeks of diabetes induction, cardiac function was assessed by echocardiography prior to post-mortem evaluation of cardiomyocyte hypertrophy, interstitial fibrosis and inflammation by histology, RT-PCR and flow cytometry. We focussed on the oxidative and inflammatory stress pathways that contribute to cardiovascular remodelling. In particular, we demonstrate that markers of inflammation (monocyte chemoattractant protein; MCP-1), oxidative stress (urinary 8-isoprostanes) and fibrosis (connective tissue growth factor; CTGF) are significantly increased, whilst diastolic dysfunction, as indicated by prolonged isovolumic relaxation time (IVRT), is elevated in this diabetic and hypertensive mouse model. In summary, this pre-clinical mouse model provides researchers with a tool to test therapeutic strategies unique to co-morbid diabetes and hypertension, thereby facilitating the emergence of novel therapeutics to combat the cardiovascular consequences of these debilitating co-morbidities.

The endothelin system and endothelin receptor antagonists.

PURPOSE OF REVIEW: There is increasing evidence that endothelin receptor blockade and, in particular, ET(A) receptor blockade not only confers protection against proteinuric renal disease in diabetes but also confers vasculoprotection. RECENT FINDINGS: Recent clinical trials using ET(A) receptor blockade in treating proteinuria and chronic kidney disease as well as atherosclerosis show great promise; however, adverse effects are still problematic. SUMMARY: Endothelin receptor blockade is associated with a significant attenuation of proteinuria and these effects are mediated in part via inhibition of inflammatory and oxidative stress related pathways as well profibrotic pathways. The addition of ET(A) receptor blockade to currently established therapies such as angiotensin-converting enzyme inhibitors or angiotensin receptor blockers may result in additional or synergistic renoprotection and vasculoprotection in hypertension and, in particular, in the context of diabetes.

Microsporidial myositis, keratitis and hypercalcaemia in a cystic fibrosis lung transplant recipient.

A man in his 50s was admitted with 4 months of myalgia, headaches, hypercalcaemia and declining renal function on a background of lung transplantation for cystic fibrosis 5 years prior. MRI confirmed myositis and a muscle biopsy revealed invasive muscular microsporidial infection. Positron emission tomography(PET)/CT revealed widespread dissemination of the infection. Albendazole was commenced and after a 1 week systemic inflammatory response syndrome, the patient made a significant recovery and was discharged home. PCR testing confirmed the species as Anncaliia algerae, which is known to infect mosquitoes, larvae and contaminate water supplies. This case highlights the need to relentlessly pursue a diagnosis and to consider atypical pathology in immune compromised patients. A tissue sample yielded highly beneficial and unexpected results. A multispecialty approach was essential given the varied infection manifestations, which included myositis, keratitis and possible central nervous system, vocal cord, parapharyngeal and renal involvement.

Hyaluronic Acid-Based Antibacterial Hydrogels for Use as Wound Dressings.

Wound dressings have been shifting toward a more active role in the wound-healing process. Hydrated environments with additives to aid in the healing process are currently being explored through the application of hydrocolloid dressings. However, these moist healing environments are also ideal for bacterial growth, leading to the widespread use of antibiotics with concerns of antibiotic resistance and toxicity. To overcome this concern, we present a hydrogel wound dressing consisting of hyaluronic acid (HA) cross-linked with gentamicin. This hydrogel treats bacterial infection locally, lowering the effective dose and reducing the concerns of antibiotic resistance and systemic exposure. Changing the cross-linking density, by using varied amounts of a cross-linker, created gels that provided a sustained release of gentamicin for up to 9 days with a range of adhesive and cohesive properties. Overall, this HA hydrogel could provide an important solution in treating local infection in burns and other dermal injuries.

An assessment of the accuracy of surgical time estimation by orthopaedic theatre staff.

Objective Optimal utilisation of theatre time increases efficiency and reduces the cost of health care. The accuracy of surgical time estimation between different members of the theatre team has not been well documented, and may aid in more efficient utilisation of available theatre time. This study aims to identify the cohort of theatre staff with greatest accuracy in estimating orthopaedic surgical time. Methods This study was conducted in a prospective fashion using consecutive orthopaedic trauma and elective operative lists over a period of 3 months. Prior to each operating list, a senior member of each of the anaesthetic, orthopaedic and scrub/scout nursing teams predicted the surgical duration for orthopaedic procedures after being provided with information regarding the individual cases. The absolute difference between estimated and actual surgical times was calculated. Results When expressed as a percentage difference from true surgical time, the orthopaedic team provided the most accurate estimates, with a mean difference of 33.0%. This was followed by nursing staff (40.5%) and anaesthetics (50.9%). Similarly, a higher proportion of estimates by the orthopaedic team were within the limits of 20% underestimation and 10% overestimation (deemed clinically significant). Conclusions Surgical times for orthopaedic trauma and elective cases are most accurately estimated by the operating team. These estimates should be implemented when planning theatre utilisation, and may benefit computer algorithms for theatre scheduling.