The 50 original articles included in this qualitative , systematic review revealed that the recommendations " Tourniquet " of the DGAI published in 2016 are mostly still up to date despite an inhomogeneous study situation .
INTRODUCTION The effectiveness of a  tourniquet  in the case of life-threatening hemorrhages of the extremities is well recognized and led to the recommendations on " Tourniquet " of the German Society of Anaesthesiology and Intensive Care ( DGAI ) in 2016 .
The aim of this systematic review was to re-evaluate the current medical literature in relation to the published DGAI recommendations .
Tourniquet-induced ischaemia during total knee arthroplasty results in higher proteolytic activities within vastus medialis cells: a randomized clinical trial
Abstract Purpose Recent data suggest diminished post-operative quadriceps muscle strength after tourniquet application  during total knee arthroplasty ( TKA ) . The metabolic effects of the commonly utilized intraoperative tourniquet with consecutive ischaemia on the skeletal muscle cells were unknown . Ubiquitin proteasome system represents one of the main pathways involved in muscle protein breakdown contributing to muscle atrophy . Therefore , the purpose of the present study was to quantify the acute effects of the tourniquet application during TKA on the ( 1 ) concentrations of free/conjugated ubiquitin , ( 2 ) total ubiquitin-protein ligase activity , ( 3 ) proteasome-dependent and ( 4 ) proteasome-independent peptidase activities in the cells of vastus medialis . Methods The r and omized , controlled , monocentric trial included 34 patients scheduled to undergo primary TKA . Each patient was r and omly assigned to the tourniquet ( n = 17 ) or non-tourniquet group ( n = 17 ) after receiving a written consent . Muscle biopsies of ( 5 × 5 × 5 mm ) 125 mm3 were obtained from vastus medialis immediately after performing the surgical approach and exactly 60 min later . After preparation of the muscle tissue specimen , the concentrations of the free/conjugated ubiquitin ( Ub ) were measured by western blot analyses . The ubiquitination was determined as biotinylated Ub incorporated into the sum of the cytosolic proteins and expressed as total ubiquitin-protein ligase activity ( tUbPL ) . The quantification of the proteasome-dependent and proteasome-independent peptidase activities was performed with peptidase assays . Results Tourniquet application did not influence the concentration of the free/conjugated Ub . There were no differences in tUbPL activities between groups and time points . Tourniquet-induced ischaemia result ed in statistically significant higher proteasome-dependent ( caspase-like p = 0.0034 ; chymotryptic-like p = 0.0013 ; tryptic-like p = 0.0036 ) and proteasome-independent ( caspase-like p = 0.03 ; chymotryptic-like p = 0.0001 ; tryptic-like p = 0.0062 ) peptidase activities . Conclusion Tourniquet application did not affect the free/conjugated Ub as well as tUbPL significantly , emphasizing the sophisticated regulation of ubiquitination . The proteasome-dependent peptidase activities were significantly upregulated during tourniquet application , suggesting an increase in protein degradation , which in turn might explain the skeletal muscle atrophy occurring after TKA . These findings add further knowledge and should raise the awareness of surgeons about the effects of tourniquet-induced ischaemia at the molecular level . Additional high- quality research may be warranted to examine the short- and long-term clinical significance of the present data .Level of evidence
The 50 original articles included in this qualitative , systematic review revealed that the recommendations " Tourniquet " of the DGAI published in 2016 are mostly still up to date despite an inhomogeneous study situation .
INTRODUCTION The effectiveness of a  tourniquet  in the case of life-threatening hemorrhages of the extremities is well recognized and led to the recommendations on " Tourniquet " of the German Society of Anaesthesiology and Intensive Care ( DGAI ) in 2016 .
The aim of this systematic review was to re-evaluate the current medical literature in relation to the published DGAI recommendations .