A mechanostatistical approach to cortical bone remodelling: an equine model

In this study, the development of a mechanostatistical model of three-dimensional cortical bone remodelling informed with in vivo equine data is presented. The equine model was chosen as it is highly translational to the human condition due to similar Haversian systems, availability of in vivo bone strain and biomarker data, and furthermore, equine models are recommended by the US Federal Drugs Administration for comparative joint research. The model was derived from micro-computed tomography imaged specimens taken from the equine third metacarpal bone, and the Frost-based 'mechanostat' was informed from both in vivo strain gauges and biomarkers to estimate bone growth rates. The model also described the well-known 'cutting cone' phenomena where Haversian canals tunnel and replace bone. In order to make this model useful in practice, a partial least squares regression (PLSR) surrogate model was derived based on training data from finite element simulations with different loads. The PLSR model was able to predict microstructure and homogenised Young's modulus with errors less than 2.2% and 0.6%, respectively.

A Comparison of Outcomes among Hospital Survivors with and without Severe Comorbidity Admitted to the Intensive Care Unit

Little is known about the experiences of patients with severe comorbidity discharged from Intensive Care Units (ICUs). This project aimed to determine the effects of an ICU stay for patients with severe comorbidity by comparing 1) quality of life (QOL), 2) the symptom profile of hospital survivors and 3) health service use after hospital discharge for patients admitted to ICU with and without severe comorbidity. A case-control study was used. Patients with severe comorbidity were matched to a contemporaneous cohort of ICU patients by age and severity of illness. Assessment tools were the Medical Outcome Study 36-item short-form and European Organisation for Research and Treatment of Cancer QLQ-C15-PAL questionnaires for QOL and the Symptom Assessment Scale for symptom distress. A proportional odds assumption was performed using an ordinal regression model. The difference in QOL outcome was the dependent variable for each pair. Health service use after discharge from ICU was monitored with patient diaries. Patients aged 18+ years admitted to an ICU in a metropolitan teaching hospital between 2011 and 2012 were included. We recruited 30 cases and 30 controls. QOL improved over the six months after hospital discharge for patients with and without severe comorbidity ( P <0.01) within the groups but there was no difference found between the groups ( P >0.3). There was no difference in symptoms or health service use between patients with and without severe comorbidity. ICU admission for people with severe comorbidity can be appropriate to stabilise the patient's condition and is likely to be followed by some overall improvement over the six months after hospital discharge.

Predictive value of abnormally raised serum bilirubin in acute appendicitis: a cohort study

Appendicitis is a common clinical diagnosis aided by biochemical, haematological and radiological investigations. The role of some investigations, such as bilirubin, is controversial but could indicate complicated appendicitis. Accurate diagnosis enables prioritisation of patients on operating lists and a possible reduction in unnecessary investigations.

METHODS

This is a retrospective cohort study of 1347 patients who underwent appendicectomy. Statistical analysis of serum bilirubin levels was performed according to histological classification of appendicitis.

RESULTS

Mean serum bilirubin levels; perforated/gangrenous appendicitis 20.5 mg/L (SD 12.6), inflamed appendicitis mean 17.5 mg/L (SD CI 11.1), normal appendix mean 12.6 mg/L (7.0). Kruskal-Wallis indicated bilirubin levels were significantly different (H=128.87, df=4, p<.001) between histological groups, and a post hoc analysis with Bonferroni adjustment showed perforated/gangrenous to be significantly higher than all other groups (p<.001). Binary logistic regression combining White Cell Count (WCC) level, C-Reactive Protein (CRP) and Bilirubin levels gave a sensitivity and specificity of .69 with AUROC=.766 (std error .015) for gangrenous/perforated. Assessment according to clinical relevance showed only 30.4% of patients with an abnormally raised bilirubin had gangrenous/perforated appendicitis.

CONCLUSIONS

Serum bilirubin does not independently predict perforation/gangrenous appendicitis. Statistical analysis showed differences in mean bilirubin between histological groups however this did not relate to clinical significance as bilirubin levels were still within normal clinical limits. Diagnosis of complicated appendicitis should be made on clinical grounds, with utilization of biochemical/haematological investigations, but there should not be independent reliance on investigations such as bilirubin.

An unusual cause of spinal bone loss detected by DXA scanning

Routine DXA scanning in a 68-year-old asymptomatic man undergoing long-term bisphosphonate treatment for osteogenesis imperfecta showed unexplained loss of bone mineral density in two lumbar vertebrae. Subsequent radiographs revealed a 14-cm abdominal aortic aneurysm eroding the vertebrae. The importance of reviewing all the vertebrae in DXA scans is emphasized, and reasons for the absence of symptoms suggested.

The effectiveness of the South African Triage Score (SATS) in a rural emergency department

BACKGROUND. The Modified Early Warning Score (MEWS) is used to monitor medical inpatients in hospitals in the developed world. The South African Triage Score (SATS) was developed from the MEWS, and its use throughout South Africa has been proposed. OBJECTIVES. We aimed to assess the effectiveness of the SATS in an emergency department (ED) in a rural setting in KwaZulu-Natal (KZN). METHODS. A prospective cross-sectional study undertaken over a 1-month period in June 2009 of patients in the ED of a government hospital in rural KZN, the referral centre for 22 peripheral hospitals. Data capture included physiological parameters, mobility and trauma scores, a list of selected clinical conditions (physician discriminator list), MEWS and SATS scores, final clinical diagnosis, and outcome in the ED (death, hospital admission or discharge). Outcome measures were under- and over-triage rates according to both systems. RESULTS. Over the study period, 589 patients were triaged and their data analysed. The MEWS under-triaged 15.1% (over-triaged 8.3%) of cases that needed admission, compared with an under-triage rate of 4.4% (over-triage rate 4.3%) when the SATS was used. CONCLUSION. Our study supports use of the SATS as a primary triage score in South African urban and rural hospitals. The SATS is superior to the MEWS as a triage scoring system in a rural hospital ED in KZN, its rates of under- and over-triage falling within the limits of the American College of Surgeons Committee on Trauma (ACSCOT) guidelines.

Experience of the introduction of routine antibody testing in primary care and of running a trial for latent autoimmune diabetes in adults (LADA)

This brief report discusses the introduction of routine Glutamic Acid Decarboxylase Antibody (GADA) testing in primary care for newly diagnosed diabetes. GADA testing is well used and the majority of people found to be positive are initiated on insulin rapidly and progress to require a basal bolus regime.