Symptom presentation and evolution in the first 48 hours after injury are associated with return to play after concussion in elite Rugby Union

BACKGROUND

Return to play (RTP) in elite rugby is managed using a 6-stage graduated RTP protocol, which can result in clearance to play within 1 week of injury. We aimed to explore how symptom, cognitive, and balance presentation and evolution during concussion screens 2 h (head injury assessment (HIA) 2) and 48 h (HIA3) after injury were associated with time to RTP) to identify whether a more conservative graduated RTP may be appropriate.

METHODS

A retrospective cohort study was conducted in 380 concussed rugby players from elite men's rugby over 3 consecutive seasons. Players were classified as shorter or longer returns, depending on whether RTP occurred within 7 days (allowing them to be considered to play the match 1 week after injury) or longer than 8 days, respectively. Symptom, cognitive, and balance performance during screens was assessed relative to baseline (normal or abnormal) and to the preceding screen (improving or worsening). Associations between sub-test abnormalities and RTP time were explored using odds ratios (OR, longer vs. shorter). Median day absence was compared between players with abnormal or worsening results and those whose results were normal or improving.

RESULTS

Abnormal symptom results during screens 2 h and 48 h after concussion were associated with longer return time (HIA2: OR = 2.21, 95% confidence interval (95%CI): 1.39-3.50; HIA3: OR = 3.30, 95%CI: 1.89-5.75). Worsening symptom number or severity from the time of injury to 2 h and 48 h post-injury was associated with longer return (HIA2: OR = 2.49, 95%CI: 1.36-4.58; HIA3: OR = 3.34, 95%CI: 1.10-10.15. Median days absence was greater in players with abnormal symptom results at both HIA2 and HIA3. Cognitive and balance performance were not associated with longer return and did not affect median days absence.

CONCLUSION

Symptom presentation and evolution within 48 h of concussion were associated with longer RTP times. This may guide a more conservative approach to RTP, while still adhering to individualized concussion management principles.

Cross-regulation of antibody responses against the SARS-CoV-2 Spike protein and commensal microbiota via molecular mimicry

The commensal microflora provides a repertoire of antigens that illicit mucosal antibodies. In some cases, these antibodies can cross-react with host proteins, inducing autoimmunity, or with other microbial antigens. We demonstrate that the oral microbiota can induce salivary anti-SARS-CoV-2 Spike IgG antibodies via molecular mimicry. Anti-Spike IgG antibodies in the saliva correlated with enhanced abundance of Streptococcus salivarius 1 month after anti-SARS-CoV-2 vaccination. Several human commensal bacteria, including S. salivarius, were recognized by SARS-CoV-2-neutralizing monoclonal antibodies and induced cross-reactive anti-Spike antibodies in mice, facilitating SARS-CoV-2 clearance. A specific S. salivarius protein, RSSL-01370, contains regions with homology to the Spike receptor-binding domain, and immunization of mice with RSSL-01370 elicited anti-Spike IgG antibodies in the serum. Additionally, oral S. salivarius supplementation enhanced salivary anti-Spike antibodies in vaccinated individuals. Altogether, these data show that distinct species of the human microbiota can express molecular mimics of SARS-CoV-2 Spike protein, potentially enhancing protective immunity.

Baseline SCAT Performance in Men and Women: Comparison of Baseline Concussion Screens Between 6288 Elite Men's and 764 Women's Rugby Players

OBJECTIVE

This study compared Sports Concussion Assessment Tool (SCAT) performance in elite male (6288 players) and female (764 players) rugby players, to determine whether reference limits used for the management and diagnosis of concussion should differ between sexes.

DESIGN

Cross-sectional census sample.

SETTING

Data from World Rugby's Head Injury Assessment management system were analyzed. This data set covers global professional rugby.

PARTICIPANTS

All professional players who underwent baseline SCAT testing as part of World Rugby's concussion management requirement formed the study cohort. Ten thousand seven hundred fifty-four SCAT assessments from 6288 elite male rugby players and 1071 assessments from 764 elite female players were analyzed.

INTERVENTION

Elite men and women rugby players are independent variables.

MAIN OUTCOME MEASURES

Sports Concussion Assessment Tool performance, including symptoms endorsed, cognitive submode performance, and balance performance.

RESULTS

Women endorsed significantly more symptoms, with greater symptom severity, than men (relative ratio 1.34, 95% confidence interval, 1.25-1.45 women vs men). Women outperformed men in cognitive submodes with the exception of immediate memory and delayed recall and made fewer balance errors than men during the modified Balance Error Scoring System. Clinical reference limits, defined as submode score achieved by the worst-performing 50% of the cohort, did not differ between men and women.

CONCLUSIONS

Women and men perform differently during SCAT baseline testing, although differences are small and do not affect either the baseline or clinical reference limits that identify abnormal test results for most submodes. The greater endorsement of symptoms by women suggests increased risk of adverse concussion outcomes and highlights the importance of accurate evaluation of any symptom endorsement at baseline.

Expansion of cognitive testing for off-field concussion screening in elite rugby players: A cohort study

OBJECTIVES

Current off-field concussion screening instruments have sub-optimal accuracy and additional testing domains may be necessary to detect the full spectrum of concussion presentations. This study aimed to determine if additional cognitive tests add utility to off-field screening for sport-related concussion.

DESIGN

Reproducibility and diagnostic accuracy cohort studies were performed in the 2017 and 2018 seasons of the Super Rugby competition, conducted in Argentina, Australia, Japan, New Zealand, and South Africa.

METHODS

Abridged versions of Stroop (score, time), Spatial Memory (score, failed trials), and Trail Making Trial-B (time, errors) cognitive tests, modified for off-field use, were examined. Players performed baseline testing prior to each season. Cases undergoing off-field screening as part of the World Rugby Head Injury Assessment Process underwent evaluation with the same cognitive tests during competition matches. Agreement between repeated pre-season baseline measurements, and the diagnostic accuracy of off-field testing against a clinical reference standard of concussion, was evaluated.

RESULTS

Data were available for repeated preseason baseline testing in 644 players, and 100 cases undergoing off-field concussion screening. There was little individual agreement across pre-season baseline assessments for all tests (Lin's correlation and Gwets AC1 coefficients ranging between 0.2 and 0.3). There was significantly worse performance for the time taken to complete the modified Stroop Test in concussed players undergoing off-field screening, compared to non-concussed players (median time 21.1 v 18.4 s, p < 0.01; area under the receiver operating characteristic curve 0.7 (95% CI 0.5-0.8)). Other cognitive measures did not discriminate between injured and un-injured players, with no-statistically significant differences in distribution medians (p = 0.6-0.9) and AUROC values close to 0.5.

CONCLUSIONS

The time taken to perform a modified Stroop Test may provide additional diagnostic accuracy if added to current off-field concussion screening tools. Abridged Spatial Memory and Trail Making Trial-B tests did not discriminate between concussed and non-concussed players.

Head injury assessment in rugby union: clinical judgement guidelines

Background/aim

Clinical judgement is a recognised component of a complete off-field concussion assessment. This study identifies guidance criteria for team medical staff when using clinical judgement in their decision-making process during the World Rugby off-field concussion-assessment screen (HIA1).

Methods

Retrospective study of examining doctor clinical judgement in 1149 HIA1 assessments after a meaningful head impact event completed on rugby union players participating in elite-level international and national competitions between September 2015 and June 2018. We assessed (1) an abnormal subtest result as worse performance compared with preseason baseline values; (2) the proportion of cases where clinicians overruled abnormal HIA1 assessment subtest results and (3) made recommendations on how clinical judgement decisions may be made more safely based on the accuracy of clinical judgement decisions assessed against the final concussion diagnosis.

Results

One or more subtests were abnormal compared with baseline values in 857 of 1149 HIA1 assessments. Clinical judgement was used to return players to the game despite abnormal subtest results on 424 out of 857 occasions (49%). In a significant majority of cases 356/424 (84%), clinical judgement decisions were correct, with players later cleared of a concussion. An application of guided clinical judgement potentially decreased false negative assessments by 33% (21/63).

Conclusions

Clinical judgement should be applied in the diagnosis of concussion but done so cautiously. We propose doctors should only use clinical judgement to overrule either one of; or a combination of (1) an abnormal tandem gait and (2) one abnormal cognitive test.

SARS-CoV-2 in severe COVID-19 induces a TGF-β-dominated chronic immune response that does not target itself

The pathogenesis of severe COVID-19 reflects an inefficient immune reaction to SARS-CoV-2. Here we analyze, at the single cell level, plasmablasts egressed into the blood to study the dynamics of adaptive immune response in COVID-19 patients requiring intensive care. Before seroconversion in response to SARS-CoV-2 spike protein, peripheral plasmablasts display a type 1 interferon-induced gene expression signature; however, following seroconversion, plasmablasts lose this signature, express instead gene signatures induced by IL-21 and TGF-β, and produce mostly IgG1 and IgA1. In the sustained immune reaction from COVID-19 patients, plasmablasts shift to the expression of IgA2, thereby reflecting an instruction by TGF-β. Despite their continued presence in the blood, plasmablasts are not found in the lungs of deceased COVID-19 patients, nor does patient IgA2 binds to the dominant antigens of SARS-CoV-2. Our results thus suggest that, in severe COVID-19, SARS-CoV-2 triggers a chronic immune reaction that is instructed by TGF-β, and is distracted from itself.

Diagnostic Utility of New SCAT5 Neurological Screen Sub-tests

Background

The Sports Concussion Assessment Tool (SCAT) is recommended to screen for concussion following head impact events in elite sport. The most recent 5th edition (SCAT5) included a ‘rapid neurological screen’ which introduced new subtests examining comprehension, passive neck movement, and diplopia. This study evaluated the additional diagnostic value of these new subtests.

Methods

A prospective cohort study was performed in the Pro14 elite Rugby Union competition between September 2018 and January 2020. The SCAT5 was administered by the team doctor to players undergoing off-field screening for concussion during a medical room assessment. Sensitivity, specificity, false negatives, and positives were examined for SCAT5 comprehension, passive neck movement, and diplopia subtests. The reference standard was a final diagnosis of concussion, established by serial standardised clinical assessments over 48 h.

Results

Ninety-three players undergoing off-field screening for concussion were included. Sensitivity and specificity of the comprehension, passive neck movement, and diplopia subtests were 0, 8, 5% and 0, 91, 97%, respectively (concussion prevalence 63%). No players had any abnormality in comprehension. No players had abnormal passive neck movement or diplopia in the absence of abnormalities in other SCAT5 sub-components.

Conclusions

The new SCAT5 neurological screen subtests are normal in the majority of players undergoing off-field concussion screening and appear to lack diagnostic utility over and above other SCAT5 subtests.

Concussion Guidelines in National and International Professional and Elite Sports

The Berlin statement on sport-related concussion was published in 2017 using evidence-based recommendations. We aimed to examine (1) the implementation of, distribution and education based on the Berlin recommendations, and the development of sport-specific protocols/guidelines among professional and elite sports, (2) the implementation of guidelines at the community level, (3) translation of guidelines into different languages, and (4) research activities. Senior medical advisers and chief medical officers from Australian Football League, All Japan Judo Federation, British Horseracing Authority, Cricket Australia, Fédération Equestre Internationale, Football Association, Gaelic Athletic Association, International Boxing Association, Irish Horseracing Regulatory Board, Major League Baseball, National Football League, National Hockey League, National Rugby League, and World Rugby completed a questionnaire. The results demonstrated that all 14 sporting organizations have published concussion protocols/guidelines based on the Berlin recommendations, including Recognize, Removal from play, Re-evaluation, Rest, Recovery, and Return to play. There is variable inclusion of Prolonged symptoms. Prevention and Risk reduction and Long-term effects are addressed in the guidelines, rules and regulations, and/or sport-specific research. There is variability in education programs, monitoring compliance with guidelines, and publication in other languages. All sporting bodies are actively involved in concussion research. We conclude that the Berlin recommendations have been included in concussion protocols/guidelines by all the sporting bodies, with consistency in the essential components of the recommendations, whilst also allowing for sport- and regional-specific variations. Education at the elite, community, and junior levels remains an ongoing challenge, and future iterations of guidelines may consider multiple language versions, and community- and junior-level guidelines.

The effect of exercise on baseline SCAT5 performance in male professional Rugby players

Background

Rugby Union requires annual baseline testing using the Sports Concussion Assessment Tool (SCAT5) as part of its head injury assessment protocols. Scores achieved during baseline testing are used to guide return-to-play decisions at the time of head impact events during matches, and concussion diagnosis during subsequent diagnostic screens. Baseline values must be valid, accurate representations of a player’s capability in the various SCAT5 sub-modes, including symptom report, cognitive function and balance. The extent to which prior exercise may affect performance is an important consideration, and the present cross-sectional study aimed to explore how SCAT5 performance differs when assessed at rest (RSCAT) compared to after 30 min of exercise (EXSCAT) in 698 male professional rugby players for whom paired exercise and rest SCAT5 data were available.

Results

Symptom endorsement was greater when assessed after exercise than at rest. Fatigue/Low energy was 1.5 times more likely to be reported when assessed during EXSCAT. Orientation score was improved during SCAT5s performed after exercise, but only when rest and exercise SCAT5s were conducted on the same day, suggesting a learning effect. Concentration score was impaired during EXSCAT. No other cognitive sub-modes were affected by exercise. Total errors during Modified Balance Error Scoring System (MBESS) increased during EXSCAT, as a result of increased errors made during single leg balance, irrespective of testing sequence, with 42% of players making more errors in EXSCAT, compared to 28% making more errors in RSCAT.

Conclusions

Symptoms, cognitive sub-modes and balance sub-modes are all affected by exercise. These may be the result of learning effects that improve cognitive performance, and the direct effects of exercise on sub-mode performance. The clinical implications of these changes may be assessed in the future through a study of diagnostic screens in players after head impact events, to confirm whether an exercise baseline screen is required annually, or whether specific sub-modes of the SCAT5 should be obtained at rest and after exercise.

Effect of a concussion on subsequent baseline SCAT performance in professional rugby players: a retrospective cohort study in global elite Rugby Union

OBJECTIVES

This study assessed whether concussion affects subsequent baseline performance in professional rugby players. Annual baseline screening tests are used to guide return-to-play decisions and concussion diagnosis during subsequent screens. It is important that baseline performances are appropriate and valid for the duration of a season and unaffected by factors unrelated to the current head impact event. One such factor may be a concussion following baseline assessment.

SETTING

The World Rugby concussion management database for global professional Rugby Union.

PARTICIPANTS

501 professional rugby players with two baseline Sports Concussion Assessment Tools (SCATs) and an intervening concussion (CONC) were compared with 1190 control players with successive annual SCAT5s and no diagnosed concussion (CONT).

PRIMARY AND SECONDARY OUTCOME MEASURES

Symptom endorsement, cognitive and balance performance during annual SCAT baseline assessments.

RESULTS

Players with a diagnosed concussion (CONC) endorsed fewer symptoms (change -0.42, 95% CI -0.75 to -0.09), and reported lower symptom severity scores during their second assessment (T2, p<0.001) than non-concussed players (CONT). Concussed players also improved Digits Backward and Final Concentration scores in T2 (p<0.001). Tandem gait time was improved during T2 in CONT. No other sub-mode differences were observed in either group.

CONCLUSIONS

Reduced symptom endorsement and improved cognitive performance after concussion may be the result of differences in the motivation of previously concussed players to avoid exclusion from play, leading to under-reporting of symptoms and greater effort in cognitive tests. Improved cognitive performance may be the result of familiarity with the tests as a result of greater exposure to concussion screening. The changes are small and unlikely to have clinical significance in most cases, though clinicians should be mindful of possible reasons, possibly repeating sub-modes and investigating players whose baseline scores change significantly after concussion. The findings do not necessitate a change in the sport's concussion management policy.

Clinical Experience with Icodextrin in Continuous Ambulatory Peritoneal Dialysis Patients

Objectives

To review the clinical experience in the United Kingdom with icodextrin (Ic).

Design

A retrospective multicenter study.

Patients

(1) the MICAS 1 patients who received Ic and elected to continue using it (called MICAS 2 patients), and (2) patients started on Ic on a named-patient basis (called compassionate use patients). Nearly all this latter group had ultrafiltration (UF) failure and were approaching hemodialysis (HC).

Interventions

The institution of one Ic bag, as the overnight exchange, usually in addition to three glucose bags.

Results

(1) MICAS 2: Of the 67 patients who received Ic and completed MICAS 1, 48 (72%) patients from eight units in the United Kingdom wished to continue Ic. Forty two percent of MICAS 2 patients were well on Ic after approximately 30 months of study (including the 6 months on MICAS 1). The main reasons for withdrawal were transplantation (21 %), death (17%), or transfer to HC for reasons other than UF failure (10%). There were no significant changes in laboratory data, including hematology, simple biochemistry, bone biochemistry, liver function tests, serum osmolality, and maltose levels. The adverse events reported were incidental to Ic. (2) Compassionate use: 30/63 (48%) patients remain well on Ic after 10 months of study. Eight patients (12%) went on to experience UF failure (again) after 13 months on Ic, requiring transfer to HC. The other main outcomes were death (11 %), transplantation (11 %), or transfer to HC for reasons unrelated to Ic (16%), usually intractable peritonitis. The serum sodium concentration decreased from 136.6±3.8 to 134.4±4.2 mmol/L (p < 0.05). There were no other significant changes in hematology or biochemistry measurements.

Conclusion

In MICAS 2 Ic probably maintained its effects, since there were no withdrawals due to UF failure. The compassionate use program has shown that a single Ic exchange is useful in UF failure, being able to prevent or delay transfer to hemodialysis. In both studies the safety and efficacy of Ic has been demonstrated in a large group of patients. A total of 192 patient-years of experience (including MICAS 1) has been accumulated to date. Properly controlled studies are needed to determine whether Ic, in its present form, should remain a “special needs” product (for UF failure) or whether it could replace glucose as the treatment of choice for CAPC patients.

A United Kingdom Multicenter Study of Icodextrin in Continuous Ambulatory Peritoneal Dialysis

While glucose remains the only osmotic agent used universally for peritoneal dialysis, its various shortcomings for the long dwell equilibration continuous ambulatory peritoneal dialysis (CAPD) has led to a search for alternative agents. The large molecular weight group has been of interest, because these agents theoretically would lead to greater ultrafiltration and a better metabolic profile. Mostsubstances (dextrans, charged macromolecules) have been found unsuitable for reasons of insolubility, allergenicity, and peritoneal toxicity. Short-chain polypeptides have been studied in humans, but the experience is limited, and there is the potential for allergenicity with long-term use.

The only large molecular weight agent that has been studied in some detail but hitherto in one center only and in a limited number of patients is glucose polymer (generic name, icodextrin). Because of the promise shown by these initial studies, a randomized controlled multicenter investigation of icodextrin in CAPD (MIDAS Study Group) was undertaken to evaluate the long-term safety and efficacy by comparing daily overnight (8 12 hours) use of a slightly hypo-osmolar solution (282 mOsm/ kg) with 1.36% (346 mOsm/kg) and 3.86% (484 mOsm/kg) glucose exchanges. Over a 6-month period 209 patients from 11 centers in the United Kingdom were randomized, with 106 allocated to receive icodextrin (study group) and 103 to remain on glucose (control group). One hundred and thirty-eight patients completed the 6-month study (71 control, 67 study).

The mean net ultrafiltration overnight with icodextrin was 3.5 times greater than 1.36% at 8 hours and 5.5 times greater at 12 hours (p<0.0001), but no different from that of 3.86% glucose at 8 and 12 hours (although for the latter dwell the net mean ultrafiltration volume was greater by about 140 mL). Biochemical profiles were no different except for a small fall in serum sodium and chloride in the icodextrin group. The mean serum maltose rose to a steady-state level of 1.2 g/L within 2 weeks and remained stable. The mean carbohydrate absorbed for icodextrin (29±5 g) was lower than with 3.86% glucose (62±5 g). The use of icodextrin did not increase the incidence of peritonitis, nor did it alter its outcome, affect uptake of icodextrin from the peritoneum, alter serum osmolality or sodium levels. There were no adverse effects associated with the use of icodextrin, and the overall CAPD-related symptom score was significantly better for icodextrin than control subjects.

This study and subsequent extensive use and clinical experience has demonstrated that the daily use of an iso-osmolar icodextrin solution is generally well tolerated, effective, and could replace the overnight use of hyperosmotic glucose solution. Its use was of equal efficacy in peritonitis and in diabetic patients. The elevated levels of maltose did not appear to have any clinical side effects.

Peritonitis Occurrence in a Multicenter Study of Icodextrin and Glucose in Capd

Objective

To compare peritonitis occurrence and outcome in a large U.K. study Multicentre Investigation of Icodextrin in Ambulatory Dialysis (MIDAS).

Design

Prospective, randomized, controlled 6-month comparison of icodextrin with glucose for the long dwell in continuous ambulatory peritoneal dialysis (CAPD) patients.

Setting

Eleven CAPD units in U.K. teaching hospitals.

Patients

A total of 209 patients established on CAPD for at least 3 months (103 control, 106 icodextrin). Twentythree control (C) and 22 icodextrin (I) patients experienced peritonitis during the study.

Intervention

Patients who had peritonitis remained on treatment (unless CAPD was withdrawn, temporarily or permanently).

Main Outcome Measures

The main outcome measures were the rate of peritonitis and duration of CAPD treatment prestudy; the rate of peritonitis episodes and their outcome during study; the effect of peritonitis on laboratory variables, serum icodextrin metabolites, and ultrafiltration efficacy.

Results

Prestudy: Nine (39%) of C but 14 (64%) of I patients had suffered previous peritonitis episode(s), with overall rates of 0.58 and 0.78 episodes per patientyear, respectively.

During study

There were 31 C episodes and 35 I episodes, with overall rates of 0.76 and 0.93 per patientyear, respectively. The increase in the C and I groups was 31% and 19%, respectively. Serum osmolality and sodium levels were unaffected by peritonitis, and there was no increase in serum icodextrin metabolites during peritonitis. Overnight ultrafiltration volume during peritonitis (mean±SD) declined slightly from 218±354 mL to 185±299 mL (NS) in the control group, but increased in the icodextrin group from 570±146 mL to 723±218 mL (p < 0.01).

Conclusions

Using icodextrin for the long dwell in CAPD does not increase the rate of peritonitis, nor does it alter the outcome of peritonitis. Peritonitis does not affect uptake of icodextrin from the peritoneum.

Anti-Inflammatory Effects of 3-Hydroxy-3-Methylglutaryl Coenzyme a Reductase Inhibitors (Statins) in Peritoneal Dialysis Patients

Objective

Elevated C-reactive protein (CRP) level is an independent predictor of all-cause and cardiovascular mortality in peritoneal dialysis (PD) patients. Statins have been demonstrated to have anti-inflammatory properties by virtue of their CRP lowering effects in hemodialysis patients. However, whether statins have an anti-inflammatory effect in PD patients is unknown.

Design

All prevalent PD patients at our center were reviewed. Eligible (257) patients were categorized into 2 groups: those on statin therapy ( n = 137) and those not on statins ( n = 120). Data were abstracted for hemoglobin, albumin, phosphates, cholesterol, CRP, Kt/V, and erythropoietin dose, along with relevant clinical data.

Results

The two groups had similar concentrations of hemoglobin, albumin, and phosphates. They were also matched for dialysis adequacy and duration of dialysis but the statin group patients were older (57 ± 13 vs 52 ± 17 years, p = 0.01). Serum cholesterol was lower in the statin group (4.74 ± 1.05 vs 5.02 ± 1.17 mmol/L, p < 0.05). Single-point (14 ± 13 vs 19 ± 18 mg/L, p < 0.02) and serially measured CRP (9 ± 7.4 vs 12 ± 10 mg/L, p < 0.02) levels were significantly lower in the statin group despite increased comorbidity (0.84 vs 0.54, p < 0.02) and greater incidence of diabetes mellitus (52% vs 25%, p < 0.01).

Conclusion

Statin therapy is associated with low single-point and serially measured CRP levels in PD patients, thereby suggesting that their anti-inflammatory properties persist in PD. These data have implications for considering statin therapy in PD patients as an anti-inflammatory agent in addition to a cholesterol lowering drug.

Rugby World Cup 2019 injury surveillance study

Background

Full contact team sports, such as rugby union, have high incidences of injury. Injury surveillance studies underpin player welfare programmes in rugby union.

Objective

To determine the incidence, severity, nature and causes of injuries sustained during the Rugby World Cup 2019.

Methods

A prospective, whole population study following the definitions and procedures recommended in the consensus statement for epidemiologic studies in rugby union. Output measures included players' age (years), stature (cm), body mass (kg), playing position, and group-level incidence (injuries/1000 player-hours), severity (days-absence), injury burden (days absence/1000 player-hours), location (%), type (%) and inciting event (%) of injuries.

Results

Overall incidences of injury were 79.4 match injuries/1000 player-match-hours (95% CI: 67.4 to 93.6) and 1.5 training injuries/1000 player-training-hours (95% CI: 1.0 to 2.3). The overall mean severity of injury was 28.9 (95% CI: 20.0 to 37.8) days absence during matches and 14.8 (95% CI: 4.1 to 25.5) days absence during training. The most common locations and types of match injuries were head/face (22.4%), posterior thigh (12.6%), ligament sprain (21.7%) and muscle strain (20.3%); the ankle (24.0%), posterior thigh (16.0%), muscle strain (44.0%) and ligament sprain (16.0%) were the most common locations and types of injuries during training. Tackling (28.7%), collisions (16.9%) and running (16.9%) were responsible for most match injuries and non-contact (36.0%) and contact (32.0%) rugby skills activities for training injuries.

Conclusion

The incidence, severity, nature and inciting events associated with match and training injuries at Rugby World Cup 2019 were similar to those reported for Rugby World Cups 2007, 2011 and 2015.

Treating Posttransplant Anemia With Erythropoietin Improves Quality of Life but Does Not Affect Progression of Chronic Kidney Disease

OBJECTIVES

Posttransplant anemia affects 30% to 45% of kidney transplant recipients and is associated with increased morbidity. However, there is lack of evidence about safe hemoglobin levels after erythropoietin treatment. Studies are needed to better understand the potential benefits and risks, as well as to define safe target hemoglobin ranges in these patients.

MATERIALS AND METHODS

In this single-center exploratory, open-label randomized controlled trial, kidney trans-plant recipients with anemia 3 months posttransplant were either treated with epoetin beta to a hemoglobin target level of 11.5 to 13.5 g/dL (n = 28) or given no treatment (n = 27). Treatment effects on graft function and health quality of life were assessed.

RESULTS

After 2 years, hemoglobin concentrations were significantly higher in the epoetin beta treatment group than in the no treatment group (12.3 ± 0.18 vs 9.99 ± 0.22 g/dL; P < .0001). Estimated glomerular filtration rate, calculated by Modified Diet in Renal Disease 7, declined by 1.7 mL/min (interquartile range, -6 to 4.24) in the epoetin treatment group and by 4.16 mL/min (interquartile range, -12.42 to 2.78) in the no treatment group (P = .32). Rate of progression, determined by estimated glomerular filtration rate slope, was not significantly different between groups (-0.09 ± 0.1 vs -0.12 ± 0.15 mL/min for treated vs not treated; P = .78). Moreover, we observed no significant differences in proteinuria and blood pressure. Treated patients had greater improvements in the vitality and mental health domains of the Medical Outcomes Short Form Health Survey quality of life scores.

CONCLUSIONS

Treatment of anemia in kidney transplant recipients to a hemoglobin level of 11.5 to 13.5 g/dL with erythropoietin improves some quality of life scores. The treatment was safe and not associated with adverse outcomes. There were no changes in rate of decline of graft function.

International consensus definitions of video signs of concussion in professional sports

BACKGROUND

The use of video to assist professional sporting bodies with the diagnosis of sport-related concussion (SRC) has been well established; however, there has been little consistency across sporting codes with regards to which video signs should be used, and the definitions of each of these signs.

AIM

The aims of this study were to develop a consensus for the video signs considered to be most useful in the identification of a possible SRC and to develop a consensus definition for each of these video signs across the sporting codes.

METHODS

A brief questionnaire was used to assess which video signs were considered to be most useful in the identification of a possible concussion. Consensus was defined as >90% agreement by respondents. Existing definitions of these video signs from individual sports were collated, and individual components of the definitions were assessed and ranked. A modified Delphi approach was then used to create a consensus definition for each of the video signs.

RESULTS

Respondents representing seven sporting bodies (Australian Football League, Cricket Australia, Major League Baseball, NFL, NHL, National Rugby League, World Rugby) reached consensus on eight video signs of concussion. Thirteen representatives from the seven professional sports ranked the definition components. Consolidation and refinement of the video signs and their definitions resulted in consensus definitions for six video signs of possible concussion: lying motionless, motor incoordination, impact seizure, tonic posturing, no protective action-floppy and blank/vacant look.

CONCLUSIONS

These video signs and definitions have reached international consensus, are indicated for use by professional sporting bodies and will form the basis for further collaborative research.

RNAi-based small molecule repositioning reveals clinically approved urea-based kinase inhibitors as broadly active antivirals

Influenza viruses (IVs) tend to rapidly develop resistance to virus-directed vaccines and common antivirals targeting pathogen determinants, but novel host-directed approaches might preclude resistance development. To identify the most promising cellular targets for a host-directed approach against influenza, we performed a comparative small interfering RNA (siRNA) loss-of-function screen of IV replication in A549 cells. Analysis of four different IV strains including a highly pathogenic avian H5N1 strain, an influenza B virus (IBV) and two human influenza A viruses (IAVs) revealed 133 genes required by all four IV strains. According to gene enrichment analyses, these strain-independent host genes were particularly enriched for nucleocytoplasmic trafficking. In addition, 360 strain-specific genes were identified with distinct patterns of usage for IAVs versus IBV and human versus avian IVs. The strain-independent host genes served to define 43 experimental and otherwise clinically approved drugs, targeting reportedly fourteen of the encoded host factors. Amongst the approved drugs, the urea-based kinase inhibitors (UBKIs) regorafenib and sorafenib exhibited a superior therapeutic window of high IV antiviral activity and low cytotoxicity. Both UBKIs appeared to block a cell signaling pathway involved in IV replication after internalization, yet prior to vRNP uncoating. Interestingly, both compounds were active also against unrelated viruses including cowpox virus (CPXV), hantavirus (HTV), herpes simplex virus 1 (HSV1) and vesicular stomatitis virus (VSV) and showed antiviral efficacy in human primary respiratory cells. An in vitro resistance development analysis for regorafenib failed to detect IV resistance development against this drug. Taken together, the otherwise clinically approved UBKIs regorafenib and sorafenib possess high and broad-spectrum antiviral activity along with substantial robustness against resistance development and thus constitute attractive host-directed drug candidates against a range of viral infections including influenza.

Conventional medications against influenza infections, including vaccination and antiviral drug therapy, are targeted against viral determinants–an approach collectively referred to as pathogen-directed. However, influenza viruses mutate fast and quickly develop resistance to these pathogen-directed treatments. An alternative, yet not well established, is to block host cellular molecules required by the virus to successfully multiply. Such a host-directed approach is anticipated to be more robust against the development of drug resistance. This notion is founded on the different modes of action of the two principal approaches: Virus-directed therapeutics target the virus itself. Thus, just a single mutation could abrogate sensitivity to a virus-directed therapeutic. In contrast, it is unlikely that viruses can easily circumvent a pharmacological blockage of a cellular factor by means of just a few mutations. Instead, the virus needs to either exploit an immediate parallel cellular pathway or adjust its replication cycle to a different cellular factor–the latter being a process likely to require multiple mutations, if possible at all. To identify the most promising targets for a host-directed therapy, we performed a small interfering RNA (siRNA) screen with four different influenza virus strains using a lung epithelial cell line. Subsequently, we tested a series of drugs, specific for the products of the genes that are required for replication of all four influenza virus strains tested. Regorafenib and sorafenib, two chemically related urea-based kinase inhibitors already clinically approved for cancer treatment, turned out to be effective inhibitors of all influenza viruses and displayed low cytotoxicity. These drugs blocked viral replication at an early stage of the life cycle not only in cell lines but also in human primary respiratory cells. Moreover, these drugs exhibited high efficacy even against unrelated viruses. In addition, no development of resistance was observed against regorafenib, which was used in an in vitro assay representatively of urea-based kinase inhibitors. Our results suggest that regorafenib and sorafenib are promising drug candidates for a host-directed therapy of influenza and other viral infections.

International study of video review of concussion in professional sports

Background

Video review has become an important tool in professional sporting codes to help sideline identification and management of players with a potential concussion.

Aim

To assess current practices related to video review of concussion in professional sports internationally, and compare protocols and diagnostic criteria used to identify and manage potential concussions.

Methods

Current concussion management guidelines from professional national and international sporting codes were reviewed. Specific criteria and definitions of video signs associated with concussion were compared between codes. Rules and regulations adopted across the codes for processes around video review were also assessed.

Results

Six sports with specific diagnostic criteria and definitions for signs of concussion identified on video review participated in this study (Australian football, American football, world rugby, cricket, rugby league and ice hockey). Video signs common to all sports include lying motionless/loss of responsiveness and motor incoordination. The video signs considered by the majority of sports as most predictive of a diagnosis of concussion include motor incoordination, impact seizure, tonic posturing and lying motionless. Regulatory requirements, sideline availability of video, medical expertise of video reviewers and use of spotters differ across sports and geographical boundaries. By and large, these differences reflect a pragmatic approach from each sport, with limited underlying research and development of the video review process in some instances.

Conclusions

The use of video analysis in assisting medical staff with the diagnosis or identification of potential concussion is well established across different sports internationally. The diagnostic criteria used and the expertise of the video review personnel are not clearly established, and research efforts would benefit from a collaborative harmonisation across sporting codes.

Implementation of the 2017 Berlin Concussion in Sport Group Consensus Statement in contact and collision sports: a joint position statement from 11 national and international sports organisations

The 2017 Berlin Concussion in Sport Group Consensus Statement provides a global summary of best practice in concussion prevention, diagnosis and management, underpinned by systematic reviews and expert consensus. Due to their different settings and rules, individual sports need to adapt concussion guidelines according to their specific regulatory environment. At the same time, consistent application of the Berlin Consensus Statement's themes across sporting codes is likely to facilitate superior and uniform diagnosis and management, improve concussion education and highlight collaborative research opportunities. This document summarises the approaches discussed by medical representatives from the governing bodies of 10 different contact and collision sports in Dublin, Ireland in July 2017. Those sports are: American football, Australian football, basketball, cricket, equestrian sports, football/soccer, ice hockey, rugby league, rugby union and skiing. This document had been endorsed by 11 sport governing bodies/national federations at the time of being published.

Tackling concussion in professional rugby union: a case–control study of tackle-based risk factors and recommendations for primary prevention

Background/aim

Concussion, the most common injury in professional rugby union, occurs most commonly during the tackle. Thus, we investigated the association between tackle characteristics and concussion.

Methods

182 video clips of tackles leading to clinically diagnosed concussion and 4619 tackles that did not were coded across three professional rugby union competitions. A variable selection process was undertaken to identify the most important variables for interpretation. A multivariate generalised linear model was used to model the association between retained variables and concussion risk. Magnitude-based inferences provided an interpretation of the real-world relevance of the outcomes.

Results

The four retained variables were: accelerating player, tackler speed, head contact type and tackle type. Overall, 70% of concussions occurred to the tackler and 30% to the ball carrier. There was a higher risk of concussion if the tackler accelerated into the tackle (OR: 2.49, 95% CI 1.70 to 3.64) or the tackler was moving at high speed (OR: 2.64, 95% CI 1.92 to 3.63). Head contact with the opposing player’s head (OR: 39.9, 95% CI 22.2 to 71.1) resulted in a substantially greater risk of concussion compared with all other head contact locations.

Conclusions

Interventions that reduce the speed and acceleration of the tackler and reduce exposure to head-to-head contact would likely reduce concussion risk in professional rugby union.

Sport concussion assessment tool-Third edition normative reference values for professional Rugby Union players

OBJECTIVES

To establish normative reference data for the SCAT3 in professional Rugby Union players.

DESIGN

A cross sectional study in professional Rugby Union players competing in national and international professional competitions between 2015 and 2016.

METHODS

The SCAT3 was administered pre-season or prior to tournaments. Data was collected electronically using a custom tablet application. SCAT3 subcomponents distributions were described and normative ranges determined using percentile cut-offs for average, unusually low/high, and extremely low/high scores. The association between player characteristics and performance in SCAT3 subcomponents was also investigated in exploratory analyses.

RESULTS

A total of 3611 professional Rugby Union players were included. The most common baseline symptom was fatigue (14%). The symptom score median (md) was 0 (interquartile range (IQR)=0-1). Symptom severity md was 0 (IQR=0-1). The md of the SAC score was 28 (IQR=26-29). The md of the MBESS was 2 (IQR=0-4). The Tandem gait md was 11.1s (IQR=10.0-12.7s). Upper limb coordination was normal in 98.4%. Younger age and lower educational level were associated with worse performance on delayed recall and reverse month sub-components of the SCAT3 (p<0.0001). No statistically significant differences in SCAT3 subcomponents were evident across gender.

CONCLUSIONS

Representative normative reference values for the SCAT3 among professional Rugby Union players are provided. Baseline performance on concentration and delayed recall tests may be lower in younger athletes or in those with lower educational level.

Risk factors for head injury events in professional rugby union: a video analysis of 464 head injury events to inform proposed injury prevention strategies

OBJECTIVES

The tackle is responsible for the majority of head injuries during rugby union. In order to address head injury risk, risk factors during the tackle must first be identified. This study analysed tackle characteristics in the professional game in order to inform potential interventions.

METHODS

464 tackles resulting in a head injury assessment (HIA) were analysed in detail, with tackle type, direction, speed, acceleration, nature of head contact and player body position the characteristics of interest.

RESULTS

Propensity to cause an HIA was significantly greater for active shoulder tackles, front-on tackles, high speeder tackles and an accelerating tackler. Head contact between a tackler's head and ball carrier's head or shoulder was significantly more likely to cause an HIA than contact below the level of the shoulder (incident rate ratio (IRR) 4.25, 95%-CI 3.38 to 5.35). The tackler experiences the majority (78%) of HIAs when head-to-head contact occurs. An upright tackler was 1.5 times more likely to experience an HIA than a bent at the waist tackler (IRR 1.44, 95% CI 1.18 to 1.76).

CONCLUSIONS

This study confirms that energy transfer in the tackle is a risk factor for head injury, since direction, type and speed all influence HIA propensity. The study provides evidence that body position and the height of tackles should be a focus for interventions, since lowering height and adopting a bent at the waist body position is associated with reduced risk for both tacklers and ball carriers. To this end, World Rugby has implemented law change based on the present data.

Should player fatigue be the focus of injury prevention strategies for international rugby sevens tournaments?

OBJECTIVE

To assess the incidence, severity and nature of injuries, to determine risk factors for injury and to identify potential injury prevention strategies in men's international Rugby-7s tournaments.

DESIGN

A prospective cohort study.

PARTICIPANTS

Players from core teams competing in matches at 6 Sevens World Series from 2008/2009 to 2014/2015.

RESULTS

The incidence of injury across all Series was 108.3 injuries/1000 player-match-hours (backs: 121.0; forwards: 91.5) with a mean severity of 44.2 days (backs: 46.1; forwards: 40.9) and a median severity of 28 days (backs: 29; forwards: 26). The proportion of injuries sustained in the second half was significantly higher (60%; p<0.001) than the first half of matches and the proportion increased from match to match and day to day in a tournament. The knee (17.4%), ankle (15.9%) and posterior thigh (13.2%) were the most common injury locations for backs and the knee (18.5%), head/face (17.3%) and shoulder/clavicle (13.0%) for forwards. The four most common injuries across all players were knee ligament (13.0%), ankle ligament (12.8%), concussion (10.4%) and posterior thigh muscle strains (9.8%).

CONCLUSIONS

The incidence of injury in Rugby-7s suggests that teams require squads of around 20 players for a Sevens World Series. The higher incidence of injury in the second half of matches is probably the result of player fatigue; therefore, injury prevention strategies for teams and the Governing Body should address this issue. The results presented support the World Rugby trial allowing 'rolling substitutes' during Sevens World Series matches, as this approach may help to mitigate the effects of player fatigue during the second half of matches.

How much is too much? (Part 2) International Olympic Committee consensus statement on load in sport and risk of illness

The modern-day athlete participating in elite sports is exposed to high training loads and increasingly saturated competition calendar. Emerging evidence indicates that inappropriate load management is a significant risk factor for acute illness and the overtraining syndrome. The IOC convened an expert group to review the scientific evidence for the relationship of load—including rapid changes in training and competition load, competition calendar congestion, psychological load and travel—and health outcomes in sport. This paper summarises the results linking load to risk of illness and overtraining in athletes, and provides athletes, coaches and support staff with practical guidelines for appropriate load management to reduce the risk of illness and overtraining in sport. These include guidelines for prescription of training and competition load, as well as for monitoring of training, competition and psychological load, athlete well-being and illness. In the process, urgent research priorities were identified.

How much is too much? (Part 1) International Olympic Committee consensus statement on load in sport and risk of injury

Athletes participating in elite sports are exposed to high training loads and increasingly saturated competition calendars. Emerging evidence indicates that poor load management is a major risk factor for injury. The International Olympic Committee convened an expert group to review the scientific evidence for the relationship of load (defined broadly to include rapid changes in training and competition load, competition calendar congestion, psychological load and travel) and health outcomes in sport. We summarise the results linking load to risk of injury in athletes, and provide athletes, coaches and support staff with practical guidelines to manage load in sport. This consensus statement includes guidelines for (1) prescription of training and competition load, as well as for (2) monitoring of training, competition and psychological load, athlete well-being and injury. In the process, we identified research priorities.

Rugby World Cup 2015: World Rugby injury surveillance study

OBJECTIVE

To determine the incidence, severity and nature of injuries sustained during the Rugby World Cup (RWC) 2015 together with the inciting events leading to the injuries.

DESIGN

A prospective, whole population study.

POPULATION

639 international rugby players representing 20 countries.

METHOD

The study protocol followed the definitions and procedures recommended in the consensus statement for epidemiological studies in rugby union; output measures included players' age (years), stature (cm), body mass (kg) and playing position, and the group-level incidence (injuries/1000 player-hours), mean and median severity (days-absence), location (%), type (%) and inciting event (%) for match and training injuries.

RESULTS

Incidence of injury was 90.1 match injuries/1000 player-match-hours (backs: 100.4; forwards: 81.1) and 1.0 training injuries/1000 player-training-hours (backs: 0.9; forwards: 1.2). The mean severity of injuries was 29.8 days-absence (backs: 30.4; forwards: 29.1) during matches and 14.4 days-absence (backs: 6.3; forwards: 19.8) during training. During matches, head/face (22.0%), knee (16.2%), muscle-strain (23.1%) and ligament-sprain (23.1%) and, during training, lower limb (80.0%) and muscle-strain (60.0%) injuries were the most common locations and types of injury. Being-tackled (24.7%) was the most common inciting event for injury during matches and rugby-skills-contact activities (70.0%) the most common during training.

CONCLUSIONS

While the incidence, nature and inciting events associated with match injuries at RWC 2015 were similar to those reported previously for RWCs 2007 and 2011, there were increasing trends in the mean severity and total days-absence through injury.

Injury risk and a tackle ban in youth Rugby Union: reviewing the evidence and searching for targeted, effective interventions. A critical review

It has recently been proposed that the tackle, an integral part of Rugby Union, be banned in school rugby, as a means to reduce the risk of injury. This proposal held that harmful contact should be removed in response to what was termed an unacceptably high-injury risk. Such a ban would represent a significant intervention that could change the nature of Rugby Union. As such, the basis and rationale for such a ban is worthy of critical evaluation. This review aims to describe the research on which such a ban is proposed. It does so through an assessment (identification), estimation (understanding of the magnitude and occurrence) and evaluation (determining acceptability) of the risk before decisions can be made about implementing any risk mitigation strategies. The body of literature describing injury risk, particularly among youths, is indeed thin and fraught with methodological differences that makes definitive conclusions impossible. We describe these, and their implications, arguing that the complete ban on the tackle may be unnecessary in young children, in whom injury risk may not be as high as is often argued, but also that it may have detrimental consequences. Finally, we propose alternative strategies and research questions which must be pursued to effectively reduce risk without creating unintended consequences or changing the nature of the sport.

Does long-distance air travel associated with the Sevens World Series increase players' risk of injury?

OBJECTIVE

To assess whether players who cross ≥6 time zones and/or undertake ≥10 h air travel prior to competition experience a higher risk of injury during the Sevens World Series than players not required to undertake this level of travel.

DESIGN

Five-year, prospective, cohort study.

PARTICIPANTS

All players from nine core teams competing in the Sevens World Series from 2008/2009 to 2013/2014.

RESULTS

A total of 436 match injuries and 3363 player-match-hours of exposure were recorded in the study, which corresponds to an overall incidence of 129.6 injuries/1000 player-match-hours, irrespective of the nature of pretournament travel. The incidence of injury for those players crossing ≥6 time zones and undertaking ≥10 h air travel prior to competition (99.3 injuries/1000 player-match-hours) was significantly lower than that of players undertaking ≥10 h air travel but crossing ≤2 time zones prior to competition (148.8 injuries/1000 player-match-hours; p=0.003) and of those undertaking ≤3 h air travel and crossing ≤2 time zones prior to competition (146.4 injuries/1000 player-match-hours; p=0.004). There was no significant difference in the incidence of injury for players crossing ≤2 time zones in the week prior to competition, irrespective of whether the length of air travel was ≤3 h or ≥10 h (p=0.904). Precompetition air travel had no significant effect (p=0.879) on the performance of teams in terms of their final Tournament ranking positions.

CONCLUSIONS

There was no evidence to suggest that players were exposed to a greater risk of injury following extensive air travel and crossing multiple time zones prior to Tournaments in the Sevens World Series.

The effect of uraemia on the duration of arrhythmias in the context of cardioprotective ischaemic conditioning strategies

BACKGROUND

Sudden cardiac death is a leading cause of death in patients with chronic kidney disease and end stage renal disease. Ischaemic conditioning strategies confer profound myocardial protection and, in the absence of uraemia, have been reported to reduce myocardial dysrhythmias. Recent data confirms that ischaemic conditioning can protect the uraemic heart. However, the effect of uraemia on myocardial arrhythmogenesis in the context of ischaemia-reperfusion injury and whether ischaemic conditioning can modulate this is unknown.

OBJECTIVE

We investigated the effect of underling chronic uraemia on the duration of arrhythmias in the context of cardioprotective ischaemic conditioning strategies.

METHODS

We examined the effect of chronic uraemia on arrhythmias occurring in the context of myocardial ischaemia-reperfusion injury and the ability of ischaemic preconditioning (IPC), remote ischaemic preconditioning (RIPC) and ischaemic postconditioning (iPOST) to suppress arrhythmogenesis in uraemic and non-uraemic animals.

RESULTS

IPC led to a reduction in the frequency and duration of arrhythmias occurring during ischaemia and reperfusion. Neither RIPC nor iPOST affected the duration or frequency of ischaemic or reperfusion arrhythmias. Underlying uraemia did not alter the frequency or duration of ischaemic arrhythmias in any of the experiments however it was associated with a reduction in reperfusion arrhythmia duration in the IPC and iPOST experiments.

CONCLUSIONS

These studies demonstrate that underlying chronic uraemia does not reduce the threshold for arrhythmia timing or duration resulting from myocardial ischaemia-reperfusion and underlying uraemia did not alter the effects of these cardioprotective ischaemic conditioning strategies in the context of arrhythmia duration.

SUMMARY

This novel work in a rodent model of chronic uraemia establishes that underlying uraemia does not increase the susceptibility to myocardial ischaemia-reperfusion induced arrhythmias. When compared with the non-uraemic heart, the uraemic heart has a similar response to the effects of ischaemic conditioning strategies in terms of their effect on arrhythmia timing and duration.