[The impact of different occlusion time on forearm equilibrium pressure and the correlation with systemic hemodynamics].

Objective: To observe the changes of arm equilibrium pressure (P(arm)) in different occlusion time, the reference range of P(arm) in hemodynamic stable patients, and to explore the relationship between P(arm) and systemic hemodynamic parameters. Methods: Mechanically ventilated postoperative abdominal surgery patients who admitted to ICU with stable hemodynamic status were enrolled. After hemodynamic data were recorded, arm stop-flow maneuvers were performed to measure P(arm). At 10, 20, 30, 40, 50, 60 seconds after occlusion, arterial pressure were measured twice within 5 minutes and recorded as the average value. Results: Thirty patients were included. The P(arm) decreased gradually with the prolongation of the occlusion time.The value was not stable within 60 s, but the reducing extent was not obvious after 40s. The 95% reference range of P(arm) 30 s was 23-44 mmHg(1 mmHg=0.133 kPa) and P(arm) 60 s was 19-35 mmHg. P(arm) at 30 s and 60 s were positively correlated with systolic arterial pressure, diastolic arterial pressure, mean arterial pressure, central venous pressure (all P<0.001), but not heart rate and pulse pressure. Linear regression analysis showed that P(arm) at 10 s, 20 s, 30 s only had linear correlation with diastolic arterial pressure (10 s, β=0.504, P=0.001; 20 s, β=0.297, P=0.005; 30 s, β=0.231, P=0.015), and P(arm) at 40 s, 50 s, 60 s were linear correlation with diastolic arterial pressure (40 s, β=0.220, P=0.004; 50 s, β=0.210, P=0.004; 60 s, β=0.213, P=0.004) and central venous pressure (40 s, β=0.516, P=0.018; 50 s, β=0.513, P=0.01; 60 s, β=0.472, P=0.023). Conclusion: In mechanically ventilated postoperative abdominal surgery patients with stable hemodynamic status, P(arm) decreases when occlusion time is prolonged, which is not stable within 60 s occlusion. Arterial blood pressure and central venous pressure are positively correlated with P(arm).