An explanation of workplace-based assessments in postgraduate dental training and a review of the current literature.

Workplace-based assessments (WBAs) are trainee-led formative assessments that measure the highest level of competence of the ability to do a task. So far WBAs are the only available assessment tools to measure performance integrated into practice. Over the years, WBAs have become an integral part of dental foundation and specialty training. The numerous WBAs available can be broadly categorised into three types. The first type involves observation of clinical encounters, for example mini-clinical evaluation exercises; direct observation of procedural skills; and dental evaluation of performance and procedure-based assessments. The second type involves discussion of clinical cases, such as case-based discussions. Finally, the third type includes the mini-peer assessment tool, team assessment of behaviour, 360° assessments and multi-source feedback, and all involve receiving feedback from a combination of colleagues, staff and patients. This article describes the WBAs currently used in postgraduate dental training and explores their strengths, weaknesses, perceived value by trainees and trainers and how these tools can be used in a reliable and valid way.

Access to primary dental care for patients with inherited bleeding disorders.

Patients with inherited bleeding disorders (IBD) can face difficulty in accessing primary dental care either due to disease-specific or patient-related barriers. This can lead to poor oral health and increase the need for more invasive dental treatment. This study aimed to highlight actual and perceived barriers that IBD patients from the East London area were experiencing. It also gives an overview of the experience history of the General Dental Practitioners (GDPs) treating these patients. Information was gathered via pre-designed surveys as part of a service development audit. A total of 105 anonymous patient surveys and 50 GDP surveys were completed between December 2010 and July 2011. The patient survey highlighted more patients to be affected by patient-related than disease-specific barriers to access dental care. The GDP survey identified that just under half of GDPs questioned were not confident in the dental management of patients with bleeding disorders. Identifying misconceptions and barriers to access primary dental care will enable further development of our shared-care approach between General Dental Services, Hospital or Community Dental Services and Haemophilia Centre, optimizing regular preventative advice and follow ups to prevent dental disease and invasive dental treatment requiring haemostatic treatment.

Predicting superficial venous incompetence with strain gauge plethysmography.

BACKGROUND: With currently available effective interventional methods to treat superficial venous insufficiency, it becomes particularly important to have a simple and reliable method to evaluate the location and severity of venous reflux. To date, there are few studies that evaluated plethysmography with and without tourniquet application to differentiate superficial from deep venous incompetence. OBJECTIVES: To determine if strain gauge plethysmography (SGP) with and without tourniquet application can be used to distinguish between the superficial and deep venous components of venous incompetence. METHODS: We conducted a prospective study using SGP with and without tourniquet application and duplex ultrasound (duplex US) to assess the severity and location of venous incompetence in 62 patients (85 limbs, 42 women, with an age range of 32-81 years) referred to our vascular laboratory for haemodynamic evaluation. Based on duplex US results, patients were diagnosed with superficial (SVI), deep and superficial (mixed) and deep vein incompetence (DVI). RESULTS: Mixed incompetence was the most common type. Twenty-three out of 33 limbs in the SVI group normalized their refill rate (RR) with tourniquet application (69.6%). Normalization of the RR with tourniquet application was less common in the mixed (n: 17 out of 40, 42.5%) and DVI (n: 2 out of 6, 33.3%) groups. CONCLUSION: SGP with tourniquet application is a simple and fast technique that can identify patients with SVI, based on RR improvement, who probably would benefit more from ablation procedures. Further studies evaluating impact of SGP with tourniquet test results on clinical outcome of SVI invasive treatment are warranted.

Inspiratory and expiratory aerosol deposition in the upper airway.

Aerosol deposition efficiency (DE) in the extrathoracic airways during mouth breathing is currently documented only for the inspiratory phase of respiration, and there is a need for quantification of expiratory DE. Our aim was to study both inspiratory and expiratory DE in a realistic upper airway geometry. This was done experimentally on a physical upper airway cast by scintigraphy, and numerically by computational fluid dynamic simulations using a Reynolds Averaged Navier?Stokes (RANS) method with a k-? SST turbulence model coupled with a stochastic Lagrangian approach. Experiments and simulations were carried out for particle sizes (3 and 6 µm) and flow rates (30 and 60 L/min) spanning the ranges of Stokes (Stk) and Reynolds (Re) number pertinent to therapeutic and environmental aerosols. We showed that inspiratory total deposition data obtained by scintigraphy fell onto a previously published deposition curve representative of a range of upper airway geometries. We also found that expiratory and inspiratory DE curves were almost identical. Finally, DE in different compartments of the upper airway model showed a very different distribution pattern of aerosol deposition during inspiration and expiration, with preferential deposition in oral and pharyngeal compartments, respectively. These compartmental deposition patterns were very consistent and only slightly dependent on particle size or flow rate. Total deposition for inspiration and expiration was reasonably well-mimicked by the RANS simulation method we employed, and more convincingly so in the upper range of the Stk and Re number. However, compartmental deposition patterns showed discrepancies between experiments and RANS simulations, particularly during expiration.

Energy metabolism of the brain in malnutrition. An experimental study in young rhesus monkeys.

An experimental model of protein-calorie malnutrition (PCM) has been successfully produced in young rhesus monkeys. The model showed close resemblance to the energy kinetics of the brain as observed in human PCM inasmuch as oxygen consumption was decreased while glucose uptake was increased. The cerebral blood flow was also diminished. The observations suggest that a significant part of glucose is perhaps diverted to long-chain fatty acids, etc.

Energy metabolism of brain in human protein-calorie malnutrition.

Cerebral blood flow (CBF) and carbohydrate metabolism were studied in 5 normal children and 25 children, aged 40 months or less, with varying degrees of protein-calorie malnutrition (PCM). CBF in normal children and those suffering from grade I PCM was 90.3 +/- 5.7 ml/100 g/min, a value comparable with that obtained by other investigators, but the proportion of glucose taken up by the brain which combined with oxygen, the oxygen/glucose index (OGI), was 65.8%, indicating significant conversion of glucose into lactic acid. Cerebral lactic acid production was 45.3 micronM/100 g/min, and the respiratory quotient (R.Q.) was 1.00. With increasing severity of PCM, there was increased glucose utilization and a progressive reduction in the OGI. In grade IV PCM, CBF was 68.7 +/- 5.4ml/100g/min, and the OGI was 34.7%. Cerebral lactic acid production was 27.4 micronM/100 g/min, and the R.Q. rose to 1.52. These findings suggest that in severe human PCM the proportion of glucose undergoing aerobic oxidation is reduced, and that in addition to being converted to lactic acid, a significant proportion of glucose is transformed by the brain into long chain fatty acids.

Chloramphenicol metabolism in children with protein-calorie malnutrition.

The plasma levels and urinary excretion of chloramphenicol was studied in ten malnourished children and four normal children after oral administration of a single dose of 25 mg/kg body weight. Plasma peak levels were achieved 2-4 hours later and were 1.5 or 2 times higher in malnourished children compared to the normal. They also took much longer to clear the drug from the plasma, 30 hours or more in malnourished children compared with 12 hours in the normal. These observations point to a slower rate of biotransformation in the liver. The excretion pattern of the drug and its metabolite lends support to this hypothesis. 75-85% of the drug excreted was in the form of conjugated fraction in the normal while only 35-55% was conjugated in malnourished children. In two children the liver biopsy tissue was subjected to assay of bilirubin-UDP transferase and low levels were detected. This observation also points to an alteration in the rate of biosynthesis of chloramphenicol.