Four Weeks Of Cyclic Mechanical Forearm Compressions Do Not Alter Resting Brachial Artery Hemodynamics

Abstract

Intermittent pneumatic compression (IPC) therapy has been successfully employed in the treatment of peripheral arterial disease. Surprisingly, there is a paucity of data describing the effects of IPC on resting hemodynamics in the chronically compressed limb. PURPOSE: To determine the impact of 4 weeks of intermittent pneumatic compressions (IPC) in the forearm on resting hemodynamics in the brachial artery (BA). METHODS: Fourteen healthy male subjects (24±1.3 yrs) were randomly assigned to three compression groups: 50, 100, and 150mmHg of IPC in the non-dominant forearm (1h.day-1, 5d.week-1) for 4 weeks. Cyclic IPC were achieved by inflating/deflating (2s on/3s off) two blood pressure cuffs wrapped around the forearm using a rapid cuff inflator unit. In control and intervention arms, BA diameters and velocities (mean, antegrade, and retrograde) were measured with Doppler ultrasound pre and post (4 weeks) IPC. Shear rate (mean, antegrade, and retrograde) as well as oscillatory shear index (OSI) and blood flow were then calculated. RESULTS: In the compressed arm, IPC did not alter BA diameter in the 50 (4.3 ± 0.3, 4.2 ± 0.3 mm), 100 (4.2 ± 0.2, 4.1 ± 0.2 mm), and 150 (3.9 ± 0.3, 3.9 ± 0.3 mm) groups. There was also no significant effect of intervention on mean blood velocity for 50 (4.5 ± 0.9, 3.3 ± 0.4 cm.sec-1), 100 (4.7 ± 0.8, 4.6 ± 0.9 cm.sec-1), and 150 (5.3 ± 2.8, 5.5 ± 0.7 cm.sec-1) and mean blood flow for 50 (39.0 ± 7.7, 26.6 ± 4.4 ml.min-1), 100 (38.1 ± 6.2, 34.9 ± 6.1 ml.min-1), and 150 (33.7 ± 13.6, 41.2 ± 12.2 ml.min-1) in the compressed arm. Peak antegrade shear rates for 50 (364.2 ± 16.7, 380.2 ± 43.6 sec-1), 100 (377.7 ± 56.5, 387.2 ± 53.1 sec-1) and 150 (382.0 ± 32.2, 430.8 ± 29.8 sec-1) and peak retrograde shear rates for 50 (-71.3 ± 17.0, -101.0 ± 16.6 sec-1), 100 (-59.3 ± 12.2, -63.6 ± 24.7 sec-1), and 150 (-84.0 ± 18.5, -82.4 ± 18.9 sec-1) also were unchanged following the IPC intervention. The OSI was also not affected by the intervention at 50 (0.16 ± 0.02, 0.20 ± 0.01) 100 (0.13 ± 0.01, 0.14 ± 0.02), and 150 (0.19 ± 0.03, 0.17 ± 0.03). CONCLUSION: In conclusion, the present study demonstrates that 4weeks of forearm IPC do not impact resting hemodynamics in the brachial artery.