Neuromuscular fatigability during repeated sprints assessed with an innovative cycle ergometer.

PURPOSE: Repeated sprint ability is an integral component of team sports. This study aimed to evaluate fatigability development and its aetiology during and immediately after a cycle repeated sprint exercise performed until a given fatigability threshold. METHODS: On an innovative cycle ergometer, 16 healthy males completed an RSE (10-s sprint/28-s recovery) until task failure (TF): a 30% decrease in sprint mean power (Pmean). Isometric maximum voluntary contraction of the quadriceps (IMVC), central alterations [voluntary activation (VA)], and peripheral alterations [twitch (Pt)] were evaluated before (pre), immediately after each sprint (post), at TF and 3 min after. Sprints were expressed as a percentage of the total number of sprints to TF (TSTF). Individual data were extrapolated at 20, 40, 60, and 80% TSTF. RESULTS: Participants completed 9.7 ± 4.2 sprints before reaching a 30% decrease in Pmean. Post-sprint IMVCs were decreased from pre to 60% TSTF and then plateaued (pre: 345 ± 56 N, 60% 247 ± 55 N, TF: 233 ± 57 N, p < 0.001). Pt decreased from 20% and plateaued after 40% TSTF (p < 0.001, pre-TF = - 45 ± 13%). VA was not significantly affected by repeated sprints until 60% TSTF (pre-TF = - 6.5 ± 8.2%, p = 0.036). Unlike peripheral parameters, VA recovered within 3 min (p = 0.042). CONCLUSION: During an RSE, Pmean and IMVC decreases were first concomitant to peripheral alterations up to 40% TSTF and central alterations was only observed in the second part of the test, while peripheral alterations plateaued. The distinct recovery kinetics in central versus peripheral components of fatigability further confirm the necessity to reduce traditional delays in neuromuscular fatigue assessment post-exercise.

Haemodialysis before emergency surgery in a patient treated with dabigatran.

Novel oral anticoagulants (NOAs) which directly inhibit thrombin (dabigatran) or factor Xa (rivaroxaban and apixaban) have recently been developed. We report the first case of perioperative management of a patient treated with dabigatran requiring haemodialysis before emergency surgery. A 62-yr-old woman visited the emergency department for a left bi-malleolar ankle fracture; she had a past medical history of severe ischaemic cardiomyopathy, alcoholic cirrhosis Child B, and moderate chronic renal insufficiency. The patient was treated with dabigatran for a left ventricular aneurysm with thrombus. Cutaneous manifestation of a voluminous haematoma required emergency surgery. Blood tests revealed dabigatran anticoagulant activity of 123 ng ml(-1) (therapeutic values: 85-200 ng ml(-1)), activated partial thromboplastin time of 63 s, and a prothrombin ratio of 68%, indicating that dabigatran disturbed coagulation. We decided to perform emergency haemodialysis before surgery. After 2 h, the anticoagulant activity of dabigatran was 11 ng ml(-1), allowing surgery. Surgery proceeded without any problems and the postoperative period was unremarkable. This case highlights the difficulties for the anaesthesiologist regarding emergency perioperative management of patients treated with NOAs and confirms the efficacy of haemodialysis in cases of dabigatran treatment. NOAs should be prescribed with caution, especially for patients with renal or hepatic disease, at least as long as no antagonist is available. In cases of deferred operative urgency in haemodynamically stable patients treated with dabigatran, haemodialysis should be considered to reverse dabigatran's anticoagulant effects.