title: Reducing the potential for tourniquet-associated reperfusion injury.
abstract: OBJECTIVE
  Investigate a strategy to minimize tourniquet-associated reperfusion injury.
  
  
  METHODS
  Sixteen healthy patients scheduled for repair of bimalleolar ankle fractures were randomized into two groups. In the standard release group (R, n1=6), the tourniquet was fully deflated at the end of surgery. In the staggered release group (SR, n2=10), the tourniquet was fully deflated for 30 s and subsequently reinflated to 300 mmHg. The procedure was repeated twice at 3 min intervals before complete removal. Haemodynamic and blood biochemistry measurements were obtained from an indwelling arterial catheter immediately before the initial tourniquet deflation and thereafter at 1, 4, 7 and 15 min.
  
  
  RESULTS
  Serum Ca concentrations were less in group R at 4 min (1.027 ± 0.5 vs. 1.084 ± 0.07 mmol/l, P=0.046) and 7 min (1.045 ± 0.04 vs. 1.110 ± 0.06 mmol/l, P=0.013). The serum lactate concentration was higher in group R compared with group SR at 1 min (1.75 ± 0.19 vs. 1.33 ± 0.31 mmol/l, P=0.005) and 4 min (1.98 ± 0.23 vs. 1.48 ± 0.39 mmol/l, P=0.007), respectively. End-tidal CO2 was less in group SR compared with group R at 1 min (4.82 ± 0.45 vs. 5.68 ± 0.26 kPa, P=0.0004) and 4 min (5.01 ± 0.59 vs. 5.68 ± 0.35 kPa, P=0.01), respectively. At 15 min, less hypotension and bradycardia was noted in group SR.
  
  
  CONCLUSIONS
  A staggered tourniquet release was associated with greater haemodynamic stability and reduced the rate of acute systemic metabolic changes associated with limb reperfusion. Reapplication of a tourniquet seemed to halt further reperfusion, providing a window period for patient evaluation and management.
authors.affiliation: Department of Anaesthetics and Intensive Care, Cork University Hospital, Cork, Ireland.
authors.forename: Jason
authors.initials: J
authors.lastname: van der Velde
authors.forename: Leon
authors.initials: L
authors.lastname: Serfontein
authors.forename: Gabriella
authors.initials: G
authors.lastname: Iohom
mesh_terms: D000328:Adult; D000368:Aged; D064386:Ankle Fractures; D001774:Blood Chemical Analysis; D001919:Bradycardia / Q000517:prevention & control; D005260:Female; D005593:Fracture Fixation, Internal / Q000009:adverse effects* / Q000379:methods; D050723:Fractures, Bone / Q000000981:diagnostic imaging / Q000601:surgery; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D007022:Hypotension / Q000517:prevention & control; D015601:Injury Severity Score; D019194:Ischemic Preconditioning / Q000379:methods; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011859:Radiography; D012039:Regional Blood Flow / Q000502:physiology; D015427:Reperfusion Injury / Q000209:etiology / Q000517:prevention & control*; D018570:Risk Assessment; D013997:Time Factors; D014111:Tourniquets / Q000009:adverse effects*; D016896:Treatment Outcome