Application and use of compression stockings
The function of graduated compression stockings or thromboembolic deterrent (TED) stockings is to increase the main blood flow velocity in the leg veins and reduce venous stasis by applying graduated compression calf pressure of between 14 and 17 mmHg (Class I: light support). Such stockings are available in two lengths, below the knee and thigh length, and are designed to give a pressure gradient from the ankle to the knee or thigh that mimics the pumping action of the deep leg vein calf muscles, with the highest pressure being at the ankle. However, there is much debate about their use in the management of venous thromboembolism (VTE), albeit the National Institute for Health and Care Excellence (NICE) (2015) recommends their use in prophylaxis where there are no contraindications. Figure 71.1 shows the pressures.
In the American College of Chest Physicians (ACCP) guideline, Bates et al. (2008) recommend compression hosiery during pregnancy and in the puerperium for all women with a previous DVT and for women considered to be at high risk of VTE after caesarean section until mobility improves. As the woman becomes more ambulant after the baby’s birth, the stockings may be of less benefit as hydrostatic pressures on standing appear to overcome venous compression from TEDS. In addition, studies comparing thigh-length with knee-length stockings are limited in determining whether or not there is equal effectiveness, albeit a meta-analysis suggested no major difference in efficacy in surgical patients (Sajid et al. 2006). Taking into consideration that in pregnant women most DVTs are iliofemoral, thigh-length TEDS should therefore be worn as a preventative measure.