Construct and criterion validity testing of the Non-Technical Skills for Surgeons (NOTSS) behaviour assessment tool using videos of simulated operations.

BACKGROUND: Surgeons' non-technical skills are an important part of surgical performance and surgical education. The most widely adopted assessment tool is the Non-Technical Skills for Surgeons (NOTSS) behaviour rating system. Psychometric analysis of this tool to date has focused on inter-rater reliability and feasibility rather than validation. METHODS: NOTSS assessments were collected from two groups of consultant/attending surgeons in the UK and USA, who rated behaviours of the lead surgeon during a video-based simulated crisis scenario after either online or classroom instruction. The process of validation consisted of assessing construct validity, scale reliability and concurrent criterion validity, and undertaking a sensitivity analysis. Central to this was confirmatory factor analysis to evaluate the structure of the NOTSS taxonomy. RESULTS: Some 255 consultant surgeons participated in the study. The four-category NOTSS model was found to have robust construct validity evidence, and a superior fit compared with alternative models. Logistic regression and sensitivity analysis revealed that, after adjusting for technical skills, for every 1-point increase in NOTSS score of the lead surgeon, the odds of having a higher versus lower patient safety score was 2·29 times. The same pattern of results was obtained for a broad mix of surgical specialties (UK) as well as a single discipline (cardiothoracic, USA). CONCLUSION: The NOTSS tool can be applied in research and education settings to measure non-technical skills in a valid and efficient manner.

Evidence-based management of upper tract urolithiasis in the spinal cord-injured patient.

OBJECTIVE: The objective is to review the published literature on the aetiology and evidence-based management of stone disease in the spinal cord-injured patient. METHODS: A PubMed and Medline search was performed using the terms 'spinal cord injury', 'paraplegia', 'stone', 'nephrolithiasis', 'urolithiasis', 'calculus', 'spinal cord injury' or 'paraplegia' with 'SWL', 'ureteroscopy', 'chemolysis' and 'PCNL.' The Cochrane database, the National Institute for Clinical Excellence guidelines and the Scottish Intercollegiate guidelines were searched using the terms 'spinal cord injury' and 'urolithiasis' and 'nephrolithiasis'. RESULTS: A total of 32 papers were identified, mainly case series or case-cohort studies with few contemporary papers. The risk of developing a renal stone after spinal cord injury (SCI) is between 7 and 20% over a period of 8-10 years. Stone formation may be related to early demineralisation of bone or chronic infection. Biochemical abnormalities are not significantly different between stone-forming and non-stone forming patients, though these patients differ from healthy controls. Presentation may be atypical, but is most commonly recurrent urinary tract infection. Treatment may be complicated by lower limb contractures limiting retrograde access. Several case series report success with shock wave lithotripsy varying from 50 to 70%, though comparisons are limited by heterogeneous indications and reporting. Percutaneous nephrolithotomy remains the gold standard for stones measuring 2 cm and above. Stone-free rates of 90% have been reported, though surgery was often complex with higher complication rates. CONCLUSION: Management of upper urinary tract stones in patients with SCI is complex regarding surgical technique, post-operative care and recurrence rates. Further contemporary case series must use standardised reporting tools to allow valid comparisons.

A breast complication of intravenous drug abuse.

Breast infection is now much less common than it used to be. It most commonly occurs in women in the 18 to 50 age group, and can be divided into lactational and non-lactational infection. The most common causative organism is Staphylococcus aureus, although enterococci and Anaerobic streptococci are also seen in non-lactational infection. An unusual case is reported with a new aetiology for breast sepsis.

A comparison of serum and plasma levels of vascular endothelial growth factor during the menstrual cycle in healthy female volunteers.

Angiogenesis is the formation of new blood vessels from the existing vasculature, and is essential for the growth and metastasis of most solid tumours. One of the most important growth factors involved in the angiogenesis process is vascular endothelial growth factor. Vascular endothelial growth factor expression has been shown to be regulated by female hormones in breast cancer cell lines, and two previous authors have reported on cyclical variations in serum vascular endothelial growth factor concentrations with conflicting results. No work has been performed on variations in plasma levels of vascular endothelial growth factor during the menstrual cycle. We therefore conducted the first prospective trial to compare serum and plasma levels of vascular endothelial growth factor in healthy pre-menopausal volunteers. Twenty healthy pre-menopausal women were recruited and had blood samples taken over one menstrual cycle with an average of eight samples taken per patient. Plasma and serum samples were then analysed for sex hormones and vascular endothelial growth factor 165. Serum vascular endothelial growth factor levels were found to be significantly higher than plasma vascular endothelial growth factor levels (P<0.005). We found no significant difference between serum and plasma vascular endothelial growth factor in the luteal and follicular phases of the cycle. The majority of the measurements for plasma levels of vascular endothelial growth factor at all phases of the cycle were under the limit of detection of the vascular endothelial growth factor ELISA kit. We found no significant correlation between plasma or serum levels of vascular endothelial growth factor and either FSH, LH, Oestradiol or Progesterone levels. This study has demonstrated no difference in serum concentrations of vascular endothelial growth factor during the different phases of the menstrual cycle in a group of healthy volunteers. We also demonstrated no obvious difference in plasma concentrations of vascular endothelial growth factor between the phases of the cycle, but most of the measurements were below the level of accuracy reported by the ELISA kit manufacturer. With the sensitivity of this ELISA test, therefore, we must still regard the question of whether there is a variation in plasma concentrations of vascular endothelial growth factor throughout the menstrual cycle as unanswered.