The Use of Continuous Glucose Monitors in Sport: Possible Applications and Considerations.

This review discusses the potential value of tracking interstitial glucose with continuous glucose monitors (CGMs) in athletes, highlighting possible applications and important considerations in the collection and interpretation of interstitial glucose data. CGMs are sensors that provide real time, longitudinal tracking of interstitial glucose with a range of commercial monitors currently available. Recent advancements in CGM technology have led to the development of athlete-specific devices targeting glucose monitoring in sport. Although largely untested, the capacity of CGMs to capture the duration, magnitude, and frequency of interstitial glucose fluctuations every 1-15 min may present a unique opportunity to monitor fueling adequacy around competitive events and training sessions, with applications for applied research and sports nutrition practice. Indeed, manufacturers of athlete-specific devices market these products as a "fueling gauge," enabling athletes to "push their limits longer and get bigger gains." However, as glucose homeostasis is a complex phenomenon, extensive research is required to ascertain whether systemic glucose availability (estimated by CGM-derived interstitial glucose) has any meaning in relation to the intended purposes in sport. Whether CGMs will provide reliable and accurate information and enhance sports nutrition knowledge and practice is currently untested. Caveats around the use of CGMs include technical issues (dislodging of sensors during periods of surveillance, loss of data due to synchronization issues), practical issues (potential bans on their use in some sporting scenarios, expense), and challenges to the underpinning principles of data interpretation, which highlight the role of sports nutrition professionals to provide context and interpretation.

A clinically relevant sheep model of orthotopic heart transplantation 24 h after donor brainstem death.

BACKGROUND: Heart transplantation (HTx) from brainstem dead (BSD) donors is the gold-standard therapy for severe/end-stage cardiac disease, but is limited by a global donor heart shortage. Consequently, innovative solutions to increase donor heart availability and utilisation are rapidly expanding. Clinically relevant preclinical models are essential for evaluating interventions for human translation, yet few exist that accurately mimic all key HTx components, incorporating injuries beginning in the donor, through to the recipient. To enable future assessment of novel perfusion technologies in our research program, we thus aimed to develop a clinically relevant sheep model of HTx following 24 h of donor BSD. METHODS: BSD donors (vs. sham neurological injury, 4/group) were hemodynamically supported and monitored for 24 h, followed by heart preservation with cold static storage. Bicaval orthotopic HTx was performed in matched recipients, who were weaned from cardiopulmonary bypass (CPB), and monitored for 6 h. Donor and recipient blood were assayed for inflammatory and cardiac injury markers, and cardiac function was assessed using echocardiography. Repeated measurements between the two different groups during the study observation period were assessed by mixed ANOVA for repeated measures. RESULTS: Brainstem death caused an immediate catecholaminergic hemodynamic response (mean arterial pressure, p = 0.09), systemic inflammation (IL-6 - p = 0.025, IL-8 - p = 0.002) and cardiac injury (cardiac troponin I, p = 0.048), requiring vasopressor support (vasopressor dependency index, VDI, p = 0.023), with normalisation of biomarkers and physiology over 24 h. All hearts were weaned from CPB and monitored for 6 h post-HTx, except one (sham) recipient that died 2 h post-HTx. Hemodynamic (VDI - p = 0.592, heart rate - p = 0.747) and metabolic (blood lactate, p = 0.546) parameters post-HTx were comparable between groups, despite the observed physiological perturbations that occurred during donor BSD. All p values denote interaction among groups and time in the ANOVA for repeated measures. CONCLUSIONS: We have successfully developed an ovine HTx model following 24 h of donor BSD. After 6 h of critical care management post-HTx, there were no differences between groups, despite evident hemodynamic perturbations, systemic inflammation, and cardiac injury observed during donor BSD. This preclinical model provides a platform for critical assessment of injury development pre- and post-HTx, and novel therapeutic evaluation.

Early and mid-term outcomes following surgical management of infective endocarditis with associated cerebral complications: a single centre experience.

BACKGROUND: Surgical management of patients with infective endocarditis (IE) who have suffered preoperative cerebrovascular complications remains controversial. This study evaluates the impact of timing from stroke to valvular surgery on the early and mid-term neurological sequelae, functional status and quality of life in this high-risk group of patients with IE. METHOD: Data on 13/108 (12%) patients with IE who suffered cerebrovascular complications during the period 1998-2009 was prospectively collected. Mean follow-up was 37.2 months (100% complete). RESULTS: Three of 13 (23%) suffered haemorrhagic stroke, 10/13 (77%) had embolic events (nine, stroke; one, TIA). The clinical diagnosis was made by a neurologist in 6/13 (46%) and confirmed in all by CT scan. Twelve of 13 had motor deficit involving MCA territory. Thirty-day mortality was 2/13 (one, cardiac; one, neurological) with no late deaths. The mean time from embolic stroke to surgery was 2.3 weeks (range 3-60 days). The reason for operating on eight patients in less than two weeks was heart failure in five, uncontrolled sepsis, AMI and TIA (one each). 2/8 (25%) suffered additional postoperative neurological events (one, brain death, one, new MCA stroke). On follow-up of the remaining eight patients with embolic events, five had improved neurology and three had stable neurology. The mean time to surgery from haemorrhagic stroke was 5.8 weeks (range 3-60 days). Deficit improved in two patients (<1 week, 1; >8 weeks, 1). On follow-up the NYHA class was I-II in 6/11 (56%). The EQ-5D questionnaire was used to assess quality of life. Mean index for the group was 0.67 using the US preference-weighted index score (SD 0.27). CONCLUSIONS: Results regarding timing for haemorrhagic stroke cannot be defined from the small numbers. Timely surgical intervention (embolic greater than two weeks and preferably four weeks in absence of heart failure) is associated with acceptable neurological outcome, functional class and quality of life.

Frailty assessment to predict short term outcomes after cardiac surgery.

BACKGROUND: Frailty has been used to predict outcome in gerontology but has only recently been applied to measures of perioperative risk stratification. It provides information on physiological reserve not addressed by current scoring systems which are heavily reliant on age. METHODS: We enrolled 123 patients over 70-years old (mean age 77.1 years, 69% male) undergoing open cardiac surgery, and assessed in 11 different frailty measures. These were combined into a cumulative score that was stratified into robust (49%), borderline (37%), and frail (14%) groups. The groups were compared for a short-term composite measure comprising mortality, deep sternal wound infection, inter-facility discharge or prolonged length of stay, as well as 3-month mortality and quality of life and 6-month mortality. RESULTS: Frail patients had a considerably higher incidence of an unfavorable composite outcome (52.9%) compared to their borderline (28.3%) and robust (13.3%) counterparts (p = 0.003). Hospital mortality was 4/123 (3.3%) with a further 3 within 30 days, and 2 late deaths occurred within 6 months postoperatively. This was statistically significant with greater mortality at 6 months in the frail cohort. Quality of life at 3 months showed a trend towards greater improvement in the borderline patients compared to either the robust or frail groups. DISCUSSION: Frailty status impacts on both short- and intermediate-term outcomes, including postoperative quality of life. In an ageing population where nonmaleficence and resource allocation are increasingly important, individual assessment in marginal surgical candidates may provide additional information to both the patient and clinician.

Spontaneous intrahepatic haemorrhage: two cases of segmental arterial mediolysis.

BACKGROUND: Segmental arterial mediolysis (SAM) is an under-recognized degenerative vascular disorder with variable clinical presentations. It affects medium to large calibre arteries, typically those arising from the coeliac axis, and its diagnosis is complicated by overlap with other clinical entities like fibromuscular dysplasia. Diagnosis requires histopathological examination of the affected tissue, although radiographic appearances can be suggestive of SAM. METHODS: We report on two patients presenting with acute rupture of an intrahepatic artery affected by SAM. RESULTS: Both patients ultimately required right hemi-hepatectomy in order to either control ongoing bleeding or for removal of liver rendered ischaemic by intra-arterial embolization. This was achieved safely despite additional SAM lesions present throughout the vasculature. CONCLUSION: In both cases described, presentation followed recent, unrelated abdominal surgery and we propose a link between these two events. Recent research has identified the potential role of noradrenaline in the development of SAM lesions in greyhounds, with levels of endogenous noradrenaline known to rise in the setting of surgery.

Synchronous presentation of cardiac and abdominal paragangliomas.

A 28-year-old male presenting with a hypertensive crisis was found to have synchronous right atrial and retrocaval masses. Serum normetadrenaline was elevated in keeping with functional paragangliomas. After preoperative optimization both masses were successfully excised, including a saphenous vein graft to the right coronary artery. Serum catecholamines returned to the normal range postoperatively and all antihypertensive therapy was ceased.

Surgical pulmonary embolectomy: mid-term outcomes.

BACKGROUND: Despite the widespread use of venous thromboembolism (VTE) prophylaxis in hospitalized patients, pulmonary embolism continues to occur. Massive pulmonary embolism is associated with a high mortality. Surgical embolectomy has traditionally been reserved for cases with haemodynamic collapse or where thrombolysis is contraindicated or has failed. METHODS: Data on 10 patients who underwent surgical embolectomy (40% male, mean age 49 years (range 25-72)) from January 2003 to February 2010 were prospectively collected and retrospectively analysed. RESULTS: Diagnosis was made using computed tomography pulmonary angiography in eight patients and echocardiography in two. Syncope was the most common presenting symptom (7 out of 10, 70%) and relative immobilization was the most common risk factor (7 out of 10, 70%). Four patients (40%) suffered preoperative cardiac arrest, with a further two on induction of anaesthesia. Thirty-day mortality was 4 out of 10 (40%), with one late death. Mean follow-up of five survivors was 39 months and included clinic review or telephone interview, SF-36 questionnaire for quality of life, transthoracic echocardiography for right ventricular (RV) function and respiratory function testing. All survivors received an inferior vena cava filter and 6 months of anticoagulation with no cases of recurrent thromboembolism. RV systolic dysfunction was severe in all cases prior to surgery, but improved to near normal at follow-up. CONCLUSIONS: Survivors had good quality of life, were functionally NYHA class I-II with normal respiratory function.