Evaluation of the contribution of theatre attendance to medical undergraduate neuroscience teaching - a pilot study.

Introduction: Medical students often attend the neurosurgical theatre during their clinical neurosciences attachment. However, few studies have been performed to objectively assess the value of this theatre-based learning experience. The main aim of this study was to explore student perceptions on the contribution of neurosurgical theatre attendance to clinical neuroscience teaching.

Materials and Methods: Third-year medical students undergoing their 2-week clinical neurosciences rotation at the Royal Hospitals Belfast were invited to participate in this study. A multi-method strategy was employed using a survey questionnaire comprising of closed and open-ended questions followed by semi-structured interviews to gain a greater 'in-depth' analysis of the potential contribution of neurosurgical theatre attendance to neuroscience teaching.

Results: Based on the completed survey responses of 22 students, the overall experience of neurosurgical theatre-based learning was a positive one. 'In-depth' analysis from semi-structured interviews indicated that students felt that some aspects of their neurosurgical theatre attendance could be improved. Better preparation such as reading up on the case in hand and an introduction to simple theatre etiquette to put the student at ease (in particular, for students who had never attended theatre previously), would improve the learning experience. In addition, having an expectation of what students are expected to learn in theatre making it more learning outcomes-based would probably make it feel a more positive experience by the student.

Conclusions: The vast majority of students acknowledged the positive learning outcomes of neurosurgical theatre attendance and felt that it should be made a mandatory component of the curriculum.

Revascularization versus medical therapy for renal-artery stenosis

Percutaneous revascularization of the renal arteries improves patency in atherosclerotic renovascular disease, yet evidence of a clinical benefit is limited.

Monitoring daily MLC positional errors using trajectory log files and EPID measurements for IMRT and VMAT deliveries

This work investigated the differences between multileaf collimator (MLC) positioning accuracy determined using either log files or electronic portal imaging devices (EPID) and then assessed the possibility of reducing patient specific quality control (QC) via phantom-less methodologies. In-house software was developed, and validated, to track MLC positional accuracy with the rotational and static gantry picket fence tests using an integrated electronic portal image. This software was used to monitor MLC daily performance over a 1 year period for two Varian TrueBeam linear accelerators, with the results directly compared with MLC positions determined using leaf trajectory log files. This software was validated by introducing known shifts and collimator errors. Skewness of the MLCs was found to be 0.03 ± 0.06° (mean ±1 standard deviation (SD)) and was dependent on whether the collimator was rotated manually or automatically. Trajectory log files, analysed using in-house software, showed average MLC positioning errors with a magnitude of 0.004 ± 0.003 mm (rotational) and 0.004 ± 0.011 mm (static) across two TrueBeam units over 1 year (mean ±1 SD). These ranges, as indicated by the SD, were lower than the related average MLC positioning errors of 0.000 ± 0.025 mm (rotational) and 0.000 ± 0.039 mm (static) that were obtained using the in-house EPID based software. The range of EPID measured MLC positional errors was larger due to the inherent uncertainties of the procedure. Over the duration of the study, multiple MLC positional errors were detected using the EPID based software but these same errors were not detected using the trajectory log files. This work shows the importance of increasing linac specific QC when phantom-less methodologies, such as the use of log files, are used to reduce patient specific QC. Tolerances of 0.25 mm have been created for the MLC positional errors using the EPID-based automated picket fence test. The software allows diagnosis of any specific leaf that needs repair and gives an indication as to the course of action that is required.

The In Vitro Susceptibility of Biofilm Forming Medical Device Related Pathogens to Conventional Antibiotics

Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and minimum biofilm eradication concentration (MBEC) and kill kinetics were established for vancomycin, rifampicin, trimethoprim, gentamicin, and ciprofloxacin against the biofilm forming bacteria Staphylococcus epidermidis (ATCC 35984), Staphylococcus aureus (ATCC 29213), Methicillin Resistant Staphylococcus aureus (MRSA) (ATCC 43300), Pseudomonas aeruginosa (PAO1), and Escherichia coli (NCTC 8196). MICs and MBCs were determined via broth microdilution in 96-well plates. MBECs were studied using the Calgary Biofilm Device. Values obtained were used to investigate the kill kinetics of conventional antimicrobials against a range of planktonic and biofilm microorganisms over a period of 24 hours. Planktonic kill kinetics were determined at 4xMIC and biofilm kill kinetics at relative MBECs. Susceptibility of microorganisms varied depending on antibiotic selected and phenotypic form of bacteria. Gram-positive planktonic isolates were extremely susceptible to vancomycin (highest MBC: 7.81 mg L−1: methicillin sensitive and resistant S. aureus) but no MBEC value was obtained against all biofilm pathogens tested (up to 1000 mg L−1). Both gentamicin and ciprofloxacin displayed the broadest spectrum of activity with MIC and MBCs in the mg L−1 range against all planktonic isolates tested and MBEC values obtained against all but S. epidermidis (ATCC 35984) and MRSA (ATCC 43300).