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.

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.

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.

Efficacy of oral acyclovir treatment of acute herpes zoster.

Oral acyclovir, 800 mg five times per day for seven days, was compared with placebo in a randomized, double-blind trial conducted at three centers in the United Kingdom. The study group consisted of 364 elderly immunocompetent patients with herpes zoster who were entered within 72 hours of the onset of rash. Acyclovir significantly reduced the times to last new lesion formation (p less than 0.01), loss of vesicles (p less than 0.01), and full crusting (p = 0.03). No significant hastening of rash healing was seen in those who started therapy later than 48 hours after the onset of rash. There was also a significant reduction pain during treatment with acyclovir (p = 0.02). Acyclovir produced no effects on the frequency or severity of post-herpetic neuralgia. No clinically important adverse effects of acyclovir were reported.

Assessment of pain in herpes zoster: lessons learned from antiviral trials.

Pain typically accompanies acute herpes zoster and, in a proportion of patients, it persists well beyond rash healing. Pain must therefore be analyzed in trials of antiviral agents in herpes zoster, but different methods have been used to analyze pain in recent published trials. These reports are reviewed and their methodological strengths and weaknesses examined. Based on this review, recommendations for the design and analysis of future trials of antiviral agents in herpes zoster are proposed. The principal recommendation is that antiviral efficacy should be evaluated both by distinguishing post-herpetic neuralgia from acute pain and by considering pain as a continuum. The primary endpoint should address both the prevalence and duration of post-herpetic neuralgia and should be examined in those patients who have post-herpetic neuralgia. Adopting the proposed recommendations in design and analysis of future trials should facilitate comparison across trials of the efficacy of antiviral agents in the treatment of herpes zoster.

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.

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.

Parvovirus B19 causing leucopenia and neutropenia in a healthy adult.

A 27-year-old healthy female presented with a prolonged and intermittent febrile illness. She was found to have leucopenia, neutropenia and thrombocytopenia, but a normal haemoglobin. The patient recovered spontaneously and convalescent serology 1 month later was positive for specific parvovirus B19 IgM and IgG. Parvovirus B19 infection was confirmed by detection of viral DNA by dot blot hybridization in a specimen of blood taken during the acute illness. A review of the previously reported cases of parvovirus B19-induced leucopenia in normal adults is presented. Parvovirus B19 should be considered in the differential diagnosis of leucopenia and neutropenia in healthy adults.

Prolonged cryptosporidiosis during primary HIV infection.

Primary infection with the human immunodeficiency virus causes profound immunosuppression with a decrease in lymphocyte numbers and function. However, this immunosuppression is transient and most individuals regain normal immune function. Infection with opportunist pathogens during the period of immunosuppression is rare. We report a case of severe prolonged cryptosporidiosis complicating primary HIV infection. This has not previously been described. A review of other cases of opportunist infections in primary HIV infection suggests that various pathogens may take advantage of the transient immunosuppression. This has important implications for the diagnosis and management of acute HIV infection, and for the diagnostic criteria currently used for AIDS.

Clinical rubella reinfection--a case of arthropathy.

We describe a case of arthropathy due to rubella reinfection. Clinical rubella reinfection with rash and lymphadenopathy has been reported but as far as we are aware this is the first report of a case with arthropathy as the sole presentation. Rubella IgG subclass and avidity tests confirmed the reinfection.

Coxiella burnetii serology in granulomatous hepatitis.

Granulomatous hepatitis as the sole manifestation of acute Q fever has been reported only rarely, although minimal hepatic dysfunction may be common in the acute disease. In this paper we report two patients with acute Q fever who presented with hepatitis; one of whom had granulomatous hepatitis on liver biopsy. We discuss the serological diagnosis of acute and chronic Q fever particularly in relation to hepatitis.

Recurrent lymphocytic meningitis associated with hereditary isolated IgG subclass 3 deficiency.

We report the case of an otherwise healthy young adult woman who has suffered three episodes of lymphocytic meningitis of possible enteroviral aetiology during a 5 year period. Analysis of immunoglobulin subclasses has revealed a sustained reduction of IgG3 to below the fifth percentile. In addition, the patient's father and brother have a similar degree of IgG3 deficiency. Isolated IgG3 deficiency has previously been described in association with recurrent upper respiratory tract infections, asthma, obstructive lung disease and enteral infections. However, our patient did not have any of these and there was no other identifiable immune defect to account for the recurrent meningitis. Although a mere chance association is possible, the case is interesting as antibody responses involving IgG3 tend to be triggered by protein antigens such as viral envelopes, while humoral immunity is known to be important in the clearance of enteroviral infection.

Is VZV reactivation a common cause of unexplained unilateral pain? Results of a prospective study of 57 patients.

OBJECTIVE: Pain is a common reason for patients to present to a doctor. Many patients with zoster have seen their doctor with pain during the days before the rash and zoster sine herpete is well described. If early varicella zoster virus (VZV) reactivation could be identified confidently, it could provide an opportunity for early antiviral intervention. This prospective study was performed to assess how often patients presenting to their general practitioner with unilateral pain of no obvious clinical cause proved to have evidence of VZV reactivation. METHODS: Fifty-seven patients were recruited and followed for 28 days; laboratory testing included VZV polymerase chain reaction (PCR) from peripheral blood mononuclear cells, VZV IgG, IgA and IgM. The control group consisted of 81 blood donors. RESULTS: Only two study patients developed the rash of zoster. There was no significant difference in PCR or serological responses between the study group and control group. Clinical characteristics did not enable identification of patients presenting to their doctor with unilateral pain who had prodromal zoster. CONCLUSION: There was no evidence on clinical or laboratory tests used in this study to support the view that reactivation of VZV is a common cause of unexplained unilateral pain.