Statistical primer: using prognostic models to predict the future: what cardiothoracic surgery can learn from Strictly Come Dancing.

OBJECTIVES: Prognostic models are widely used across medicine and within cardiothoracic surgery, where predictive tools such as EuroSCORE are commonplace. Such models are a useful component of clinical assessment but may be misapplied. In this article, we demonstrate some of the major issues with risk scores by using the popular BBC television programme Strictly Come Dancing (known as Dancing with the Stars in many other countries) as an example. METHODS: We generated a multivariable prognostic model using data from the then-completed 19 series of Strictly Come Dancing to predict prospectively the results of the 20th series. RESULTS: The initial model based solely on demographic data was limited in its predictive value (0.25, 0.22; R2 and Spearman's rank correlation, respectively) but was substantially improved following the introduction of early judges' scores deemed representative of whether contestants could actually dance (0.40, 0.30). We then utilize our model to discuss the difficulties and pitfalls in using and interpreting prognostic models in cardiothoracic surgery and beyond, particularly where these do not adequately capture potentially important prognostic information. CONCLUSION: Researchers and clinicians alike should use prognostic models cautiously and not extrapolate conclusions from demographic data alone.

Case Report and Literature Review of Giant Cutaneous Malignant Melanoma: What's Keeping Patients Away?

Background. Giant cutaneous malignant melanoma (MM) is a term that has previously been used to define lesions that are at least 10 cm in diameter or 48 mm in thickness. Such tumours are rare. There is no substantial body of evidence considering why patients may delay presentation with MM until they reach this size. This case report presents one of the largest cases of giant cutaneous MM to date and the first in the literature to show excellent response to adjuvant immunotherapy. The patient was treated successfully and remains alive and well 12 months following initial surgery. A review of the literature discussing giant MM identified a significant need for education on the importance of seeking medical attention in order to prevent advanced disease, especially for vulnerable individuals.

Differential effects of high-altitude exposure on markers of oxidative stress, antioxidant capacity, and iron profiles.

High-altitude (HA) exposure may stimulate significant physiological and molecular changes, resulting in HA-related illnesses. HA may impact oxidative stress, antioxidant capacity, and iron homeostasis, yet it is unclear how both repeated exposure and HA acclimatization may modulate such effects. Therefore, we assessed the effects of weeklong repeated daily HA exposure (2,900-5,050 m) in altitude-naïve individuals (n = 21 individuals, 13 females, mean ± SD, 25.3 ± 3.7 yr) to mirror the working schedule of HA workers (n = 19 individuals, all males, 41.1 ± 9.4 yr) at the Atacama Large Millimeter Array (ALMA) Observatory (San Pedro de Atacama, Chile). Markers of oxidative stress, antioxidant capacity, and iron homeostasis were measured in blood plasma. Levels of protein oxidation (P < 0.001) and catalase activity (P = 0.023) increased and serum iron (P < 0.001), serum ferritin (P < 0.001), and transferrin saturation (P < 0.001) levels decreased with HA exposure in both groups. HA workers had lower levels of oxidative stress, and higher levels of antioxidant capacity, iron supply, and hemoglobin concentration as compared with altitude-naïve individuals. On a second week of daily HA exposure, changes in levels of protein oxidation, glutathione peroxidase, and nitric oxide metabolites were lower as compared with the first week in altitude-naïve individuals. These results indicate that repeated exposure to HA may significantly alter oxidative stress and iron homeostasis, and the degree of such changes may be dependent on if HA is visited naïvely or routinely. Further studies are required to fully elucidate differences in HA-induced changes in oxidative stress and iron homeostasis profiles among visitors of HA.

Does 'Prison Napalm' work? Measuring the cooling temperature of sugar solution burns in a porcine model.

Non-accidental scalds sustained with sugar solution are potentially devastating and often associated with assaults within prisons where they are commonly known as 'Napalm' attacks. However, little is known about the mechanism behind such injuries. Proposed explanations have included a higher initial temperature, increased viscosity compared to water and lower emissivity, although these have yet to be demonstrated in any experimental model. We therefore set out to measure the post-exposure cooling temperature of the dermis after exposure to different concentrations of boiled sugar solution in a dead porcine model. Dead pork belly tissue was pre-heated to human body temperature (36.3-38.4 °C). Five solutions with different concentrations of sugar (0, 250, 500, 1000 and 2000 g/L) were heated to boiling point using standard commercially available kettles and then poured directly onto the tissue. Intradermal temperatures of the dermis were measured at one-minute intervals for a duration of 10 min. At one-minute after exposure, average intradermal porcine temperatures were 46.7 °C, 47.9 °C, 48.9 °C, 50.8 °C and 51.7 °C respectively for increasing concentrations of sugar solution. The rate of cooling was similar in all solutions with an average loss of 1.5 °C per minute. Using a generalised mixed model accounting for concentration and time period, it was identified that increasing sugar concentration resulted in statistically higher temperatures of burn (p = 0.006). Our report finds that higher concentrations of boiled sugar solution caused a higher initial temperature of burn but did not influence cooling rates. This suggests that 'Prison Napalm' attacks will indeed cause more severe burns than those utilising plain water, but not for all the widely believed reasons. We therefore recommend that access to kettles in prison cells should be limited, but where such access is deemed a right, consideration should be given to temperature restricted devices, as is the case in other countries.

Virtual Interview, Real Anxiety: Prospective Evaluation of a Focused Teaching Programme on Confidence Levels Among Medical Students Applying for Academic Clinical Posts.

BACKGROUND: In 2020, final year medical students applying for the United Kingdom's competitive academic training posts face an additional challenge because interviews are conducted online rather than in-person. We assessed how this new format influences anxiety and the impact of a targeted course on candidates' confidence levels. METHODS: A mixed-methods national teaching programme including online bespoke mock interviews was delivered to prospective Academic Foundation Programme applicants. Pre- and post-interview questionnaires assessed anxiety levels subjectively and using a Measure of Anxiety in Selection Interviews (MASI) scores. RESULTS: Individuals self-reported greater confidence, experience and preference for interviews delivered in-person as compared to online interviews. Post-course, there was an increase in self-reported confidence specific to online interviews (p = 0.009) and lower MASI scores in three of five domains, indicating reduced anxiety (social anxiety: p = 0.004, performance anxiety: p <0.001, behavioral anxiety: p = 0.003). CONCLUSION: A structured course can increase confidence and reduce anxiety for online academic medicine interviews.

Preparation for the next major incident: are we ready? Comparing major trauma centres and other hospitals.

OBJECTIVES: A major incident is any emergency requiring special arrangements by the emergency services. All hospitals are required by law to keep a major incident plan (MIP) detailing the response to such events. In 2006 and 2019, we assessed the preparedness and knowledge of key individuals in hospitals across England and found a substantial gap in responding to the MIP. In this report, we compare responses from doctors at major trauma centres (MTCs) and other hospitals (non-MTCs). METHODS: We identified trusts in England that received over 30 000 patients through the ED in the fourth quarter of 2016/2017. We contacted the on-call anaesthetic, emergency, general surgery and trauma and orthopaedic registrar at each location and asked three questions assessing their confidence in using their hospital's MIP: (1) Have you read your hospital's MIP? (2) Do you know where you can access your hospital's MIP guidelines? (3) Do you know what role you would play if an MIP came into effect while you are on call?We compared data from MTCs and non-MTCs using multinomial mixed proportional odds models. RESULTS: There was a modest difference between responses from individuals at MTCs and non-MTCs for question 2 (OR=2.43, CI=1.03 to 5.73, p=0.04) but no evidence of a difference between question 1 (OR=1.41, CI=0.55 to 3.63, p=0.47) and question 3 (OR=1.78, CI=0.86 to 3.69, p=0.12). Emergency medicine and anaesthetic registrars showed significantly higher preparedness and knowledge across all domains. No evidence of a systematic difference in specialty response by MTC or otherwise was identified. CONCLUSIONS: Confidence in using MIPs among specialty registrars in England remains low. Doctors at MTCs tended to be better prepared and more knowledgeable, but this effect was only marginally significant. We make several recommendations to improve education on major incidents.

Neurotropism of SARS-CoV-2: COVID-19 presenting with an acute manic episode.

A 41-year-old man with no significant medical history presented with acute behavioural disruption on the background of a 1-day history of severe headache and a 10-day history of dry cough and fever. He was sexually disinhibited with pressured speech and grandiose ideas. His behaviour worsened, necessitating heavy sedation and transfer to intensive care for mechanical ventilation despite no respiratory indication. Investigations confirmed that he was positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Neuroimaging and a lumbar puncture were normal. Initial screening for SARS-CoV-2 in the cerebrospinal fluid was negative although no validated assay was available. The patient's mental state remained abnormal following stepdown from intensive care. Psychiatric assessment found features consistent with acute mania, and he was detained under the Mental Health Act. This case indicates the need to consider COVID-19 in a wider series of clinical presentations and to develop a validated assay for SARS-CoV-2 in the cerebrospinal fluid.

Preparation for the next major incident: are we ready? A 12-year update.

OBJECTIVES: A major incident is any emergency that requires special arrangements by the emergency services and generally involves a large number of people. Recent such events in England have included the Manchester Arena bombing and the Grenfell Tower disaster. Hospitals are required by law to keep a major incident plan (MIP) outlining the response to such an event. In a survey conducted in 2006 we found a substantial knowledge gap among key individuals that would be expected to respond to the enactment of an MIP. We set out to repeat this survey study and assess any improvement since our original report. METHODS: We identified NHS trusts in England that received more than 30 000 patients through the emergency department in the fourth quarter of the 2016/2017 period. We contacted the on-call anaesthetic, emergency, general surgery, and trauma and orthopaedic registrar at each location and asked each individual to answer a short verbal survey assessing their confidence in using their hospital's MIP. RESULTS: Of those eligible for the study, 62% were able to be contacted and consented to the study. In total 50% of respondents had read all or part of their hospital's MIP, 46.8% were confident that they knew where their plan was stored, and 36% knew the role they would play if a plan came into effect. These results show less confidence among middle-grade doctors compared with 2006. CONCLUSIONS: Confidence in using MIPs among specialty registrars in England is still low. In light of this, we make a number of recommendations designed to improve the education of hospital doctors in reacting to major incidents.

Identifying cardiac surgery operations in hospital episode statistics administrative database, with an OPCS-based classification of procedures, validated against clinical data.

OBJECTIVES: Administrative databases with dedicated coding systems in healthcare systems where providers are funded based on services recorded have been shown to be useful for clinical research, although their reliability is still questioned. We devised a custom classification of procedures and algorithms based on OPCS, enabling us to identify open heart surgeries from the English administrative database, Hospital Episode Statistics, with the objective of comparing the incidence of cardiac procedures in administrative and clinical databases. DESIGN: A comparative study of the incidence of cardiac procedures in administrative and clinical databases. SETTING: Data from all National Health Service Trusts in England, performing cardiac surgery. PARTICIPANTS: Patients classified as having cardiac surgery across England between 2004 and 2015, using a combination of procedure codes, age >18 and consultant specialty, where the classification was validated against internal and external benchmarks. RESULTS: We identified a total of 296 426 cardiac surgery procedures, of which majority of the procedures were coronary artery bypass grafting (CABG), aortic valve replacement (AVR), mitral repair and aortic surgery. The matching at local level was 100% for CABG and transplant, >90% for aortic valve and major aortic procedures and >80% for mitral. At national level, results were similar for CABG (IQR 98.6%-104%), AVR (IQR 105%-118%) and mitral valve replacement (IQR 86.2%-111%). CONCLUSIONS: We set up a process which can identify cardiac surgeries in England from administrative data. This will lead to the development of a risk model to predict early and late postoperative mortality, useful for risk stratification, risk prediction, benchmarking and real-time monitoring. Once appropriately adjusted, the system can be applied to other specialties, proving especially useful in those areas where clinical databases are not fully established.

The potential role of external venous supports in coronary artery bypass graft surgery.

Despite the apparent superiority of arterial conduits for coronary artery bypass grafting (CABG), the long saphenous vein remains the most commonly used graft. The high failure rate of long saphenous vein grafts (SVGs) over time is therefore an important limiting factor for the long-term outcomes of CABG. Various methods to improve SVG patency have been proposed, although few have had a significant impact on clinical practice. External SVG supports have been a focus of research over the past 50 years, with their use intended to minimize well-documented pathophysiological changes that occur in the SVG following implantation into the coronary circulation. These devices have been trialled extensively in animal models to assess their impact on both the morphology and the function of vascular conduits. Recently, a number of studies have been conducted in patients, leading to a substantial development in their design and the accumulation of a large body of evidence attesting to their potential benefit in CABG. In this review, we briefly discuss the proposed mechanism of action of external SVG supports and then evaluate the results from animal studies and more recent research assessing their use in CABG patients. Finally, we conclude that newer models of external stents have the potential to improve long-term outcomes in SVG.

Does Previous Transradial Catheterization Preclude Use of the Radial Artery as a Conduit in Coronary Artery Bypass Surgery?

The radial artery (RA) is a commonly used conduit for coronary artery bypass grafting, and recent studies have demonstrated that it provides superior long-term patency rates to the saphenous vein in most situations. In addition, the RA is also being used with increasing frequency as the access point for coronary angiography and percutaneous coronary interventions. However, there has been concern for many years that these transradial procedures may have a detrimental impact on the function of RA grafts used in coronary artery bypass grafting, and there is now comprehensive evidence that such interventions cause morphologic and functional damage to the artery in situ. Despite this, there remain remarkably few studies investigating the use of previously cannulated RAs as grafts in coronary artery bypass surgery, and there are no clear guidelines on the use of the RA in coronary artery bypass grafting after its catheterization. This article will review concisely the evidence that transradial procedures cause damage to the RA, and discuss the impact this could have on previously cannulated RAs used as coronary artery bypass grafting conduits. On the basis of the evidence assessed, we make a number of recommendations to both surgeons and cardiologists regarding use of the RA in cardiovascular procedures.