Hemodynamics and tolerability of lower-limb intermittent pneumatic compression devices and neuromuscular stimulation

Stimulation of venous return is critical for prevention of venous thromboembolism; however, an optimized treatment modality has yet to be defined. Therefore, the main objective of this study was to investigate and compare the hemodynamic effects and the second aim was to assess tolerability of three different intermittent pneumatic compression (IPC) devices, foot-IPC, rapid, and slow calf-IPC, and the recently developed technology of calf neuromuscular electric stimulation (NMES). The blood flow in the right popliteal vein was assessed with Doppler ultrasound in 10 healthy individuals in semirecumbent position without (baseline) and with each of the IPC- and NMES treatment devices. Comfort assessment was completed using visual analogue scale for each treatment modality. All treatments significantly increased peak velocity (PV), mean velocity (MV) volume flow (VF) and ejected volume per individual stimulus (EV) as compared to baseline. Rapid calf-IPC caused the most profound hemodynamic effects with a mean effect size 2.06, taking into account all the above hemodynamic parameters compared to baseline. The weakest response was observed with foot-IPC with a mean effect size 1.50 compared to baseline. All devices compressing the calf produced higher hemodynamic values (mean effect size: 1.89 slow calf-IPC and 1.58 NMES) compared to foot-IPC. Comfort assessment demonstrated unacceptable tolerability for NMES, while the other devices showed an acceptable tolerability. Augmentation of venous return using calf- compared to foot devices is hemodynamically superior. Varying hemodynamic responses are observed between calf blood flow stimulating devices. The low tolerability of NMES, however, may limit its clinical applicability.