PURPOSE: It is generally thought that prolonged bed rest and sitting lead to venous stasis and deep venous thrombosis (DVT). Prolonged sitting is particularly important in air travelers who may suffer flight related DVT. In this investigation we tested the hypothesis that ankle exercise while supine and while sitting may increase venous blood velocity.
METHODS: Eighteen healthy volunteers, aged 20- 40 years underwent Doppler measurements of right and left femoral vein blood velocity while supine at rest, and right femoral blood velocity while sitting and during ankle exercise. While supine, the head was elevated 30 degrees. When sitting the angle of the knee was 90 degrees. Volunteers rested for at least 3 minutes before each measurement. Ankle exercise was dorsiflexion and plantar flexion at 80/min (measured with a metronome) when supine and dorsiflexion (80/min) while sitting. Probabilities of differences of average blood velocity were calculated by the students paired t-test and 95% confidence intervals were calculated.
RESULTS: At rest while supine, average blood velocity was the same in the right and left femoral vein (17 cm/sec). During exercise while supine, average blood velocity increased to 30 cm/sec (P=0.001). When sitting at rest, femoral blood velocity decreased from 17 cm/sec to 9 cm/sec (P<0.0001). With exercise, blood velocity increased to 18 cm/sec (P<0.001). Blood velocity during exercise was higher when supine than when sitting (30 cm/sec vs 18 cm/sec) (P<0.0001) (Figure 1).
CONCLUSION: Ankle exercise increased venous blood velocity while supine and sitting.
CLINICAL IMPLICATIONS: Ankle exercise may reduce stasis in bedridden patients. Such exercise may also reduce stasis while sitting, especially during prolonged air travel.
DISCLOSURE: Bakhtiar Mirza, None.