Tourniquet induced ischemia and changes in metabolism during TKA: a randomized study using microdialysis

Abstract

BackgroundTourniquet use in total knee arthroplasty (TKA) surgery is applied to minimize blood loss thereby creating better overview of the surgical field. This induces ischemia in the skeletal muscle resulting in reperfusion injury. Our aim was to investigate the in vivo metabolic changes in the skeletal muscle during TKA surgery using microdialysis (MD).MethodsSeventy patients were randomly allocated to tourniquet group (n = 35) or non-tourniquet group (n = 35). Prior to surgery, catheters were inserted in the operated leg and non-operated leg. Interstitial dialysate was collected before and after surgery and at 20 min intervals during a 5 h reperfusion period. Main variables were ischemic metabolites: glucose, pyruvate, lactate and glycerol and L/P ratio.ResultsSignificant difference in all metabolites was detected between the two groups, caused by tourniquet application. Tourniquet induced ischemia resulted in decreased levels of glucose and pyruvate to 54 and 60 % respectively, compared to baseline. Simultaneously, accumulation of lactate to 116 % and glycerol to 190 % was observed. L/P ratio was elevated indicating ischemia.In the non-tourniquet group the metabolite changes were less profound and normalized within 60 min.ConclusionsMicrodialysis revealed that performing TKA with tourniquet is associated with increased ischemia. This affects all metabolites but the changes are normalized after 5 h

Microdialysis for the Assessment of Intervertebral Disc and Vertebral Cancellous Bone Metabolism in a Large Porcine Model

“…The cell changes its metabolism from oxidative phosphorylation to anaerobic glycolysis to generate energy and preserve homeostasis. Accordingly, a reduction of oxygen supply will decrease the production of pyruvate with a following increase in lactate, resulting in an increase in the lactate/pyruvate (L/P) ratio (14,19). A L/P ratio above 25 is considered to signify ischemia (20).…”

Tourniquet Use in Total Knee Arthroplasty

“…In animal studies, it has been shown that serum creatinine phosphokinase (CPK), a marker of muscle damage, does not begin to rise until approximately 2 hours. 42 Ejaz et al 43 conducted a prospective RCT that utilized microdialysis to measure metabolic changes within skeletal muscle during TKA. They found that the levels of ischemic byproducts such as lactate and glycerol rose by 116 and 190%, respectively, whereas energy sources such as glucose and pyruvate decreased by 54 and 60%, respectively.…”

The Possible Pathophysiological Outcomes and Mechanisms of Tourniquet‐Induced Ischemia‐Reperfusion Injury during Total Knee Arthroplasty

“…The cellular bioenergetics and mitochondria are preserved during skeletal muscle I/R in the TKA setting [ 11 , 18 , 19 ]. For example, (1) adenosine triphosphate (ATP) concentrations and mitochondrial enzymes were maintained during 60–90 minutes of ischemic time and at 24 hours after reperfusion [ 11 , 18 ], despite significant metabolic changes which suggested ischemic injury to the skeletal muscle cell at approximately 75 minutes of ischemia [ 20 ], and (2) a previous human study [ 19 ] showed mitochondria to have normal appearance when viewed under an electron microscope after 15 minutes of ischemia. However, in cases of myocardial I/R condition, mitochondrial respiratory chain activity was reduced after 30 minutes of ischemia and restored upon reperfusion as a biphasic process [ 21 , 22 ].…”