Design and validation of a virtual reality trainer for ultrasound-guided regional anaesthesia.

Virtual reality is a form of high-fidelity simulation that may be used to enhance the quality of medical education. We created a bespoke virtual reality trainer software using high resolution motion capture and ultrasound imagery to teach cognitive-motor needling skills necessary for the performance of ultrasound-guided regional anaesthesia. The primary objective of this study was to determine the construct validity between novice and experienced regional anaesthetists. Secondary objectives were: to create learning curves for needling performance; compare the virtual environment immersion with other high-fidelity virtual reality software; and compare cognitive task loads imposed by the virtual trainer compared with real-life medical procedures. We recruited 21 novice and 15 experienced participants, each of whom performed 40 needling attempts on four different virtual nerve targets. Performance scores for each attempt were calculated based on measured metrics (needle angulation, withdrawals, time taken) and compared between the groups. The degree of virtual reality immersion was measured using the Presence Questionnaire, and cognitive burden was measured using the NASA-Task Load Index. Scores by experienced participants were significantly higher than novices (p = 0.002) and for each nerve target (84% vs. 77%, p = 0.002; 86% vs. 79%, p = 0.003; 87% vs. 81%, p = 0.002; 87% vs. 80%, p = 0.003). Log-log transformed learning curves demonstrated individual variability in performance over time. The virtual reality trainer was rated as being comparably immersive to other high-fidelity virtual reality software in the realism, possibility to act and quality of interface subscales (all p > 0.06) but not in the possibility to examine and self-performance subscales (all p < 0.009). The virtual reality trainer created workloads similar to those reported in real-life procedural medicine (p = 0.53). This study achieved initial validation of our new virtual reality trainer and allows progression to a planned definitive trial that will compare the effectiveness of virtual reality training on real-life regional anaesthesia performance.

The use of artificial intelligence and robotics in regional anaesthesia.

The current fourth industrial revolution is a distinct technological era characterised by the blurring of physics, computing and biology. The driver of change is data, powered by artificial intelligence. The UK National Health Service Topol Report embraced this digital revolution and emphasised the importance of artificial intelligence to the health service. Application of artificial intelligence within regional anaesthesia, however, remains limited. An example of the use of a convoluted neural network applied to visual detection of nerves on ultrasound images is described. New technologies that may impact on regional anaesthesia include robotics and artificial sensing. Robotics in anaesthesia falls into three categories. The first, used commonly, is pharmaceutical, typified by target-controlled anaesthesia using electroencephalography within a feedback loop. Other types include mechanical robots that provide precision and dexterity better than humans, and cognitive robots that act as decision support systems. It is likely that the latter technology will expand considerably over the next decades and provide an autopilot for anaesthesia. Technical robotics will focus on the development of accurate sensors for training that incorporate visual and motion metrics. These will be incorporated into augmented reality and visual reality environments that will provide training at home or the office on life-like simulators. Real-time feedback will be offered that stimulates and rewards performance. In discussing the scope, applications, limitations and barriers to adoption of these technologies, we aimed to stimulate discussion towards a framework for the optimal application of current and emerging technologies in regional anaesthesia.

The effect of an ultrasound-activated needle tip tracker needle on the performance of sciatic nerve block on a soft embalmed Thiel cadaver.

In this study, we measured the performance of medical students and anaesthetists using a new tracker needle during simulated sciatic nerve block on soft embalmed cadavers. The tracker needle incorporates a piezo element near its tip that generates an electrical signal in response to insonation. A circle, superimposed on the ultrasound image surrounding the needle tip, changes size and colour according to the position of the piezo element within the ultrasound beam. Our primary objective was to compare sciatic block performance with the tracker switched on and off. Our secondary objectives were to record psychometrics, procedure efficiency, participant self-regulation and focused attention using eye-tracking technology. Our primary outcome measures were the number of steps successfully performed and the number of errors committed during each block. Videos were scored by trained experts using validated checklists. Sequential tracker activation and deactivation was randomised equally within subjects. With needle activation, steps improved in 10 (25%) subjects and errors reduced in six (15%) subjects. The most important steps were: needle tip identification before injection, OR (95%CI) 2.12 (1.61-2.80; p < 0.001); and needle tip identification before advance of the needle, 1.80 (1.36-2.39; p < 0.001). The most important errors were: failure to identify the needle tip before injection, 2.40 (1.78-3.24; p < 0.001); and failure to quickly regain needle tip position when tip visibility was lost, 2.03 (1.5-2.75; p < 0.001). In conclusion, needle-tracking technology improved performance in a quarter of subjects.

An initial evaluation of the effect of a novel regional block needle with tip-tracking technology on the novice performance of cadaveric ultrasound-guided sciatic nerve block.

Visibility of the needle tip is difficult to maintain during ultrasound-guided nerve block. A new needle has been developed that incorporates a piezo element 2-2.3 mm from the tip, activated by ultrasound. The electrical signal manifests as a coloured circle surrounding the needle tip, and allows real-time tracking. We hypothesised that novice regional anaesthetists would perform nerve block better with the tracker turned on rather than off. Our primary objective was to evaluate the new needle by measuring the performance of novice anaesthetists conducting simulated sciatic block on the soft embalmed Thiel cadaver. Training consisted of a lecture, scanning in volunteers and practice on cadavers. Testing entailed scanning the sciatic nerve of a cadaver and conducting 20 in-plane sciatic blocks in the mid-to-upper thigh region. Subjects were randomised equally, in groups of five, according to the sequence: tracker on/off/on/off; or tracker off/on/off/on. Video recordings were assessed by six raters for steps performed correctly and errors committed. Eight subjects were recruited and 160 videos were analysed. Using the tracking needle, five correct steps improved and one error reduced. The benefits included: better identification of the needle tip before advancing the needle, OR (95%CI) 3.4 (1.6-7.7; p < 0.001); better alignment of the needle to the transducer, 3.1 (1.3-8.7; p = 0.009); and better visibility of the needle tip 3.0 (1.4-7.3; p = 0.005). In conclusion, use of the tracker needle improved the sciatic block performance of novices on the soft embalmed cadaver.

Investigation into the visual perceptive ability of anaesthetists during ultrasound-guided interscalene and femoral blocks conducted on soft embalmed cadavers: a randomised single-blind study.

BACKGROUND: Errors may occur during regional anaesthesia whilst searching for nerves, needle tips, and test doses. Poor visual search impacts on decision making, clinical intervention, and patient safety. METHODS: We conducted a randomised single-blind study in a single university hospital. Twenty trainees and two consultants examined the paired B-mode and fused B-mode and elastography video recordings of 24 interscalene and 24 femoral blocks conducted on two soft embalmed cadavers. Perineural injection was randomised equally to 0.25, 0.5, and 1.0 ml volumes. Tissue displacement perceived on both imaging modalities was defined as 'target' or 'distractor'. Our primary objective was to test the anaesthetists' perception of the number and proportion of targets and distractors on B-mode and fused elastography videos collected during femoral and sciatic nerve block on soft embalmed cadavers. Our secondary objectives were to determine the differences between novices and experts, and between test-dose volumes, and to measure the area and brightness of spread and strain patterns. RESULTS: All anaesthetists recognised perineural spread using 0.25 ml volumes. Distractor patterns were recognised in 133 (12%) of B-mode and in 403 (38%) of fused B-mode and elastography patterns; P<0.001. With elastography, novice recognition improved from 12 to 37% (P<0.001), and consultant recognition increased from 24 to 53%; P<0.001. Distractor recognition improved from 8 to 31% using 0.25 ml volumes (P<0.001), and from 15 to 45% using 1 ml volumes (P<0.001). CONCLUSIONS: Visual search improved with fusion elastography, increased volume, and consultants. A need exists to investigate image search strategies.

HIV testing: the boundaries. A survey of HIV testing practices and barriers to more widespread testing in a British teaching hospital.

A survey of HIV testing practices among registrars of all admitting specialties within Sheffield Teaching Hospitals National Health Service Trust was performed in 2007. Respondents from most specialties tested patients for HIV infrequently and several barriers were identified, which prevented testing even when the diagnosis was considered.

VZV infection in pregnancy: a retrospective review over 5 years in Sheffield and discussion on the potential utilisation of varicella vaccine in prevention.

OBJECTIVES: To study retrospectively the epidemiology, demography and clinical issues related to varicella in pregnancy in a UK city over a 5-year period and help inform the debate on the potential of varicella immunisation in prevention. METHODS: The hospital records of pregnant women with varicella receiving care at the Regional Department of Infection and Tropical Medicine in Sheffield between 1997 and 2002 were reviewed. Data on pregnant women with varicella not presenting acutely to medical care were obtained. The use of Varicella Zoster Immune Globulin (VZIG) in prevention of varicella during the same 5-year period was determined. The records from the maternity department of Sheffield Hospitals for women undergoing VZV antibody testing between January and December 2004 were reviewed. Data on annual number of deliveries were recorded and the neonatology database used as a source of information regarding effects of chickenpox on the baby. RESULTS: The incidence of varicella infection in pregnancy was at least 6 per 10,000 deliveries. Nineteen pregnant women with varicella were admitted to hospital. Three had pneumonia. Infection occurred in the first pregnancy in a quarter of cases. The minimum cost for all cases admitted to hospital during this period (basic costs per day) was 20,520 pounds sterling. The cost of VZIG use for chickenpox during the same period adjusted for the population size was 10,881 pounds sterling. This was not a comprehensive health economic study and did not attempt to assess additional GP, midwifery, obstetric or social costs nor costs associated with those who did not attend hospital. Two hundred and thirty-three women underwent VZV antibody test during 2004 usually after contact with chickenpox. Sixty percent of women in contact with chickenpox did not present to their GP or hospital immediately. CONCLUSION: Varicella in pregnancy may be associated with significant morbidity and health care cost and prevention by immunisation is desirable. Though targeted vaccination is attractive, screening in pregnancy followed by a post-partum varicella immunisation programme would fail to protect 25% and would be associated with logistical challenges not occurring with rubella immunisation. Varicella is now a preventable disease by immunisation. Exposure in pregnancy with or without infection has financial costs related to antibody testing and prophylaxis. Infection in pregnancy may be associated with additional costs and potential morbidity to mother and baby. Potential immunisation strategies are considered.

Salmonella Paratyphi A liver abscess--secondary infection of an amoebic liver abscess?

Liver abscess is a rare complication of both enteric fever and non-enteric salmonella infection. We present an unusual case of Salmonella Paratyphi A liver abscess, where secondary bacterial infection of an amoebic liver abscess was suspected.

Ongoing queries: Interpretation of serology in asymptomatic or atypical chronic Q fever.

Chronic Q fever, predominantly associated with endocarditis, can develop insidiously. Although the diagnosis may be straightforward with a typical clinical presentation, incidental discovery of positive Coxiella burnetii serology poses a difficult clinical challenge. We describe the cases of two such patients and review the literature on the serological diagnosis of chronic Q fever.

The European Union of Medical Specialties core training curriculum in infectious diseases: overview of national systems and distribution of specialists.

The European Union of Medical Specialities (UEMS) Section of Infectious Diseases agreed on an infectious disease training programme in 1999, which was updated in 2002. Although the provision of infection services throughout Europe is not uniform, with variation in the roles of infectious disease physicians and microbiologists, there are, nonetheless, physicians with a predominant responsibility for clinical infectious diseases (and tropical medicine) in most countries. However, infectious diseases is formally recognised as a specific discipline by most, but not yet all, European countries. There has been consensus from national representatives to the UEMS on the content of the published curriculum. There are clear areas of overlap in training between different infection disciplines, and exploration of possible areas for closer liaison and collaboration between them has been initiated. The increased movement of medical staff within Europe will place greater demands on those responsible for training, monitoring and quality assurance. The Board and Section of Infectious Diseases have established core training programmes with a generic logbook to assist those countries without a written curriculum or record book and facilitate the development of common standards of training. The duration of training varies across Europe; 4 years is the UEMS standard, or longer if the training is combined with general internal medicine. The numbers of infection specialists (infectious diseases and microbiology) per million population show considerable variation. The UEMS Sections have recognised the importance of working closely with European specialist societies involved with training. The Section for Infectious Diseases has, in partnership with the ESCMID, established a Board for the accreditation of continuing medical education/continuing professional development.

Varicella pneumonia in adults.

Varicella is a common contagious infection in childhood with increasing incidence in adults. Pneumonia, although rare, is the most serious complication that commonly affects adults. Over the last two decades there have been major advances in the understanding of Varicella infections, management and prevention. This review discusses the epidemiology, pathogenesis, pulmonary manifestation, morbidity, long-term clinical consequences and current state of management of Varicella pneumonia in adults. Prevention and other disease-modifying therapy are also discussed.

Prospective study of factors influencing the persistence of symptoms in hospitalised patients with acute infection.

Sequential patients, aged 18-50, admitted to an Infectious Diseases Unit of a large teaching hospital with an acute infection, completed validated psychometric questionnaires on admission and were followed up at three monthly intervals for 12 months. 34% of patients available for follow-up remained symptomatic at 3 months, but by 6 months and for the rest of the study, only about 20% of patients available for follow-up remained symptomatic. Symptoms resembled those of the initial infection at 3 months, but for the remainder of the study, most patients complained of nonspecific symptoms of tiredness and lassitude. Patients symptomatic at 3 and 6 months (S+) had significantly higher depression scores on admission compared with nonsymptomatic group (S-) (P<.05). Stepwise logistic regression revealed that case level depression on admission was predictive of a 13-fold increase in the chance of remaining symptomatic at 6 months. These associations were lost by 12 months. In conclusion, this study has supported the hypothesis that psychopathology occurring at the time of an acute infection can lead to persistent symptoms that at least in the short term resemble those of the acute illness. This relationship breaks down after 6 months, when symptoms become less specific and may be conditioned by exhausting and distressing social situations other than acute illness.

Infectious diseases and the returning traveller--experience from a regional infectious diseases unit over 20 years.

The report from the Chief Medical Officer - Getting Ahead of the Curve (a strategy for combating infectious diseases) included the statement 'Infectious diseases recognize no international boundaries, so that a newly emergent disease in another part of the world must be assessed for a potential threat to this country'. About 50 million journeys abroad are made from the UK every year. Inevitably this brings many into contact with illness they would not otherwise impact. Over the last 20 years there has been a corresponding increase in the number of admissions to the Regional Infectious Diseases Unit in Sheffield that has risen from about 50 in 1985 to over 200 in 2000. Admissions reach their peak in the months of June, July, August and September. This review provides an overview of the infections seen in returning travellers in Sheffield over a 20-year period, including information on the countries where infection has been acquired and comments upon the measures which may be taken to minimize the risk of infection while travelling.

Increased rectal mucosal expression of interleukin 1beta in recently acquired post-infectious irritable bowel syndrome.

BACKGROUND AND AIMS: Chronic bowel disturbances resembling irritable bowel syndrome (IBS) develop in approximately 25% of patients after an episode of infectious diarrhoea. Although we have previously shown that psychosocial factors operating at the time of, or prior to, the acute illness appear to predict the development of post-infectious IBS (PI-IBS), our finding of an increased inflammatory cell number in the rectum persisting for at least three months after the acute infection suggested that there is also an organic component involved in the development of PI-IBS. To evaluate this further, we measured expressions of interleukin 1beta (IL-1beta) and its receptor antagonist (IL-1ra) in these patients to provide additional evidence that the pathogenesis of PI-IBS is underpinned by an inflammatory process. METHODS: Sequential rectal biopsy samples were prospectively obtained during and three months after acute gastroenteritis, from eight patients who developed post-infectious IBS (INF-IBS) and seven patients who returned to normal bowel habits after acute gastroenteritis (infection controls, INF-CON). Eighteen healthy volunteers who had not suffered from gastroenteritis in the preceding two years served as normal controls (NOR-CON). IL-1beta and IL-1ra gene expressions were assayed by reverse transcriptase-polymerase chain reaction, and their levels of expression were quantitated by optical densitometry after electrophoresis on agarose gel. RESULTS: INF-IBS patients exhibited significantly greater expression of IL-1beta mRNA in rectal biopsies than INF-CON patients both during and three months after acute gastroenteritis. Moreover, IL-1beta mRNA expression had increased in biopsies taken from INF-IBS patients at three months after the acute infection but no consistent change was observed in INF-CON patients. IL-1beta mRNA expression of INF-IBS patients at three months post gastroenteritis was significantly greater than NOR-CON whereas that of INF-CON patients was not significantly different from NOR-CON. Despite these differential changes in IL-1beta mRNA expression, no significant changes were observed in IL-1ra mRNA expression among the three groups. CONCLUSIONS: These findings indicate that those patients who develop IBS post infection exhibit greater IL-1beta mRNA expression, both during and after the infection, compared with individuals who do not develop PI-IBS. We conclude that such patients may be susceptible to inflammatory stimuli, and that inflammation may play a role in the pathogenesis of PI-IBS.

Liver abscess in adults: ten years experience in a UK centre.

BACKGROUND: The epidemiology and management of liver abscess (LA) have evolved over time. AIM: To examine our experience over 10 years in a UK teaching centre. DESIGN: Retrospective review of patient records. METHODS: We reviewed the records of all patients aged >16 years discharged from Royal Hallamshire Hospital with a diagnosis of LA between April 1988 and December 1999. RESULTS: There were 69 patients with LA (65 pyogenic, 4 amoebic), giving a crude annual incidence rate of 2.3/100,000/year (18.15/100,000 hospital admissions). Median age was 64 years. Single lesions were found in 41 patients, multiple lesions in 28. Pre-admission, patients were symptomatic for a median 14 days, with the most common symptoms and signs being fever and abdominal pain/tenderness. Pathogens were identified in 74% and predisposing aetiology in 92% of those undergoing investigation. Spread of infection to the liver via the portal venous system was the commonest route of infection (46%), most frequently in patients aged >/=60 years (p=0.019). Abdominal ultrasound (US) was diagnostic for LA in >90% of cases. Treatment with anti-microbial therapy plus interventional radiology was optimal. The case fatality rate was 12.3%, mainly from associated underlying pathology. DISCUSSION: LA is commonly associated with underlying gastrointestinal pathology. Seeking out this underlying aetiology is an integral part of management. We recommend US as the first-line diagnostic tool with guided intervention plus antibiotic(s) as first-line treatment. Prognosis depends chiefly on the underlying pathology.