Transient hemodynamic changes following tourniquet release in total knee arthroplasty: a multicenter retrospective
W F Martínez1, A Jaime2, G Grecco3
1Facultad de Medicina, Pontificia Universidad Católica Argentina, Buenos Aires, Argentina; Clínica Privada Hispano Argentina, Tres Arroyos, Argentina; Equipo GRECARO, Argentina.
Background:
The release of a pneumatic tourniquet during total knee arthroplasty (TKA) causes an abrupt increase in blood flow to the lower limb, which may result in transient hemodynamic instability. The aim of this study was to quantify the magnitude and duration of these changes in a real-world clinical setting.
Methods:
A multicenter retrospective observational study was conducted including 149 patients undergoing primary TKA under pneumatic tourniquet ischemia. Systolic (SBP), diastolic (DBP), and mean arterial pressure (MAP), heart rate (HR), respiratory rate (RR), and oxygen saturation (SpO2) were recorded at three time points: baseline (pre-release), 3minutes (T3), and 6minutes (T6) after tourniquet release. Statistical analysis was performed using repeated-measures ANOVA or the Friedman test, according to data distribution, with p<0.05 considered statistically significant.
Results:
Following tourniquet release, a significant immediate decrease in SBP and DBP was observed (p<0.001), with mean reductions of 19.8% and 21.2%, respectively, at T3. HR showed a mild but significant increase (p=0.012). SpO2 decreased slightly (p=0.034) without clinical relevance. Transient arrhythmias were recorded in 8.7% of patients. At 6minutes post-release, all parameters returned to baseline values.
Conclusion:
Tourniquet release during TKA is associated with transient hemodynamic changes and early recovery. These findings support the need for reinforced monitoring in patients classified as ASA III and/or with ischemia times longer than 85minutes, and provide a rationale for future prospective studies incorporating advanced hemodynamic monitoring.
Level Of Evidence:
Level III, retrospective study.
