Abstract
Venous stasis is identified in Virchow’s triad as one of the risk factors leading to deep venous thrombosis (DVT). Preventing or reducing stasis during the peri- and post-operative states should minimise the risk of DVT. We have investigated the efficacy of a new device (Waveform, Amtec Medical Ltd), employing electrical calf stimulation to promote venous return in patients (n=18, mean age 67.2±7.9yrs) presenting for total hip replacement arthroplasty. The device placed over the soleus muscle, offers various levels of stimulation (70–90V) at six second intervals. Duplex ultrasound imaging was used to locate and measure venous flow in the popliteal vein. Velocity measurements were recorded at three time intervals: before (baseline) and after induction of spinal anaesthesia, and finally in response to electrical stimulation. Results showed that immediately following spinal anaesthesia there was an increase in venous flow velocity from the baseline by a factor of 2 (from 9.2cm/s to 17.2cm/s). Furthermore, each activation of the electrical stimulus caused an increase in flow velocity by on average a factor of 4.4 over pre-stimulus flow (8.6cm/s to 39.8cm/s). These data compare favourably with previous observations using the Belfast calf stimulator and demonstrate the effectiveness of electrical calf stimulation as a method of preventing venous stasis in the lower limbs during surgery.
Theses abstracts were prepared by Mr Peter Kay. Correspondence should be address to him at The Hip Centre, Wrightington Hospital, Appley Bridge, Wigan, Lancashire WN6 9EP.
