Gradual versus intermittent release of tourniquet in total knee arthroplasty surgery, effects on hemodynamics and acid base parameters: a prospective randomized controlled study

Abstract

Background: Using of the pneumatic tourniquet is a common practice in many surgeries. While it creates bloodless field, it is not free of complications. Tourniquet deflation is a critical stage, greatly affecting hemodynamics. Till now, no strict guidelines have been developed for managing such a procedure. Methods: Sixty patients, >40 years old, undergoing total knee arthroplasty enrolled in this study. Tourniquet deflation done over 3 min before complete release, either by gradual pressure release 50 mmHg/30 s in gradual deflation (G) group or by three cycles of deflationreinflation (deflation for 10 s and reinflation for 50 s) in intermittent deflation (I) group. Results: No significant difference was found regarding patient demographics and basal data. Mean arterial pressure was significantly lower in G group at times of deflation and post deflation for 5 min (P values 0.011, 0.023, 0.024, 0.001, and 0.013, respectively). Also, heart rate and acid base parameters were more stable and convergent to basal data in I group. Conclusion:Compared to gradual deflation, intermittent deflation of tourniquet in middle and old aged, total knee arthroplasty patients resulted in more stability in hemodynamics and acid base parameters.